Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030252

Authors: Hayato Miyasaka Bungo Ebihara Makoto Takahashi Takashi Fukaya Koichi Iwai Shigeki Kubota Hirotaka Mutsuzaki

Background: Deep squatting is essential for daily activities and sports; however, it is often limited after ankle fracture surgery, and the contributions of posterior ankle soft tissues, including the soleus muscle (SOL), Achilles tendon (AT), flexor hallucis longus muscle (FHL), and Kager’s fat pad (KFP), to this limitation remain unclear. This study aimed to determine the relationship between posterior ankle soft tissue properties (including stiffness and echo intensity [EI]) and deep squatting ability after ankle fracture surgery. Methods: This cross-sectional study included 53 patients (49.5 ± 16.1 years, 26 men) who underwent ankle fracture surgery. We measured the shear modulus of the SOL and AT, and the EI of the FHL and Kager’s fat pad; ankle range of motion and strength were evaluated. Deep squatting ability was also assessed. Multiple regression and receiver operating characteristic (ROC) analyses were performed to identify predictors of squatting limitation and evaluate discriminative performance. Results: Participants with a deep squatting limitation showed a higher shear modulus in the SOL and AT and higher EI in the FHL compared with those without limitations. SOL and AT shear modulus and FHL EI were significant independent predictors of ankle dorsiflexion angle during deep squatting. ROC analysis showed good discriminative ability for SOL shear modulus and AT shear modulus and modest discriminative ability for FHL EI. Conclusions: Increased stiffness and EI of the SOL, AT, and FHL were associated with reduced deep squatting ability after ankle fracture surgery. Targeted assessment and interventions addressing these tissues may improve postoperative function.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030251

Authors: Francesco Liuzza Pierfrancesco Pirri Gianluca Serra Andrea Aureli Fernando De Maio Pasquale Farsetti Giuseppe Rovere

Background: Developmental dysplasia of the hip (DDH) is one of the leading causes of secondary hip osteoarthritis and frequently results in severe anatomical alterations that make total hip arthroplasty (THA) technically demanding. Restoration of hip biomechanics, limb length, and joint stability remains challenging, particularly in patients with moderate-to-severe dysplasia. Objective: To evaluate the clinical and radiographic outcomes of cementless total hip arthroplasty combined with soft-tissue balancing, with or without acetabular reconstruction using autologous femoral head graft, in patients affected by osteoarthritis secondary to DDH. Methods: A retrospective single-center case series was conducted on eight female patients (mean age 53.9 ± 14.6 years; range 33–80 years) who underwent primary cementless THA for DDH-related osteoarthritis between 2019 and 2025. Clinical outcomes were assessed using the Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form-36 (SF-36). Radiographic evaluation included implant positioning, osteolysis, heterotopic ossification, bone graft incorporation, and leg-length discrepancy. Data normality was assessed using the Shapiro–Wilk test. Preoperative and postoperative outcomes were compared using paired Student’s t-test and confirmed with the Wilcoxon signed-rank test. Implant survival and revision-free status were recorded throughout the follow-up period. Results: At a minimum follow-up of 12 months (range 12 months–6 years), significant improvements were observed in all clinical outcome measures. Mean HHS increased from 49.3 ± 2.5 preoperatively to 90.4 ± 2.7 postoperatively (p < 0.001), while mean WOMAC decreased from 53.5 ± 5.6 to 7.4 ± 3.3 (p < 0.001). Mean SF-36 improved from 47.2 ± 3.8 to 89.9 ± 3.2 (p < 0.001). Wilcoxon analysis confirmed the statistical significance of these findings (all p = 0.0078). Radiographic assessment demonstrated satisfactory implant positioning and stable fixation in all patients, with no evidence of osteolysis or implant loosening. Minor complications included one intraoperative periprosthetic femoral fracture treated successfully with cerclage wiring, two cases of Brooker grade I–II heterotopic ossification, and one case of minimal graft resorption without clinical consequences. No revision procedures were recorded during follow-up, and implant survival was 100%. Conclusions: Cementless THA combined with selective soft-tissue balancing provides excellent clinical, functional, and radiographic outcomes in patients with osteoarthritis secondary to DDH. This approach significantly improves hip function and quality of life while ensuring stable implant fixation, low complication rates, and excellent mid-term implant survival.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030250

Authors: Samir Krichen Chirine Aouichaoui Hamada Chaari Liwa Masmoudi Yousri Elghoul Monia Zaouali Wajdi Dardouri Hamdi Chtourou Yassine Trabelsi Mohamed Zouch

Background: Reference values may assist practitioners in interpreting anthropometric and physical performance profiles in youth handball players within comparable sporting contexts. This study aimed to establish sex- and competitive-age-specific anthropometric and physical performance reference values for Tunisian youth handball players aged 9–15 years and to examine differences by sex and competitive age category. Methods: A total of 370 competitive youth handball players participated in this cross-sectional study (182 boys and 188 girls; U11, n = 130; U13, n = 158; U15, n = 82). Participants had at least two years of structured handball training. Assessment included body size, body composition, flexibility, squat jump, countermovement jump, 3 kg medicine ball throw, horizontal jumps, and handgrip strength. Sex, competitive age category, and sex × age category effects were examined using two-way ANOVA, with Bonferroni-adjusted post-hoc comparisons applied when appropriate. Effect sizes were reported as partial eta squared. Percentile values were calculated. Significance was set at p < 0.05. Results: Boys demonstrated higher values than girls in squat jump, (ηp2 = 0.099), countermovement jump (ηp2 = 0.097), medicine ball throw (ηp2 = 0.202), and both dominant (ηp2 = 0.073) and non-dominant handgrip strength (ηp2 = 0.048, p < 0.001). Additionally, older age categories showed higher scores on all these tests (p < 0.001). Sex- and competitive-age-category-specific percentile values were established. Conclusions: The established reference values may support descriptive benchmarking and training/monitoring among comparable Tunisian youth handball players. However, these values should not be interpreted as maturity-adjusted standards or general population norms.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030249

Authors: Christos Kokkotis Ioannis Kansizoglou Dimitrios Pantazis Alexandra Avloniti Dimitrios Balampanos Panagiotis Foteinakis Theodoros Stampoulis Maria Protopapa Alexandros Dendrinos Panagiotis Aggelakis Nikolaos Zaras Paraskevi Malliou Maria Michalopoulou Antonios Gasteratos Athanasios Chatzinikolaou

Objectives: Local positioning systems (LPSs) used in indoor team sports generate a large number of external load variables, often exceeding practical monitoring capacity. The redundancy and overlap among these variables make it difficult to identify the most informative metrics for performance analysis and load management. This study aimed to reduce the dimensionality of external load variables derived from LPS data and to identify data-driven external-load observation profiles using principal component analysis and clustering techniques. Methods: A total of 188 observations from indoor team sports (basketball, handball, and futsal) were analyzed. Continuous external load variables were standardized and subjected to principal component analysis (PCA), with component retention based on a ≥90% cumulative explained variance threshold. K-means clustering was applied in both the full standardized feature space and the PCA-reduced space. The optimal number of clusters was determined using silhouette analysis and the elbow method. Agreement between clustering solutions was assessed using Adjusted Rand Index (ARI) and Normalized Mutual Information (NMI). Cluster characteristics were further examined using descriptive statistics and variable separation analysis. Results: The first two principal components explained 53.7% of the total variance, representing high-intensity external load and neuromuscular load dimensions, while 12 components were required to exceed 90% cumulative explained variance. Clustering analysis consistently identified three moderately separated clusters in both the full and PCA-reduced spaces. The PCA-based solution demonstrated improved separation (silhouette = 0.362) compared to the full-space solution (silhouette = 0.319). Agreement between clustering approaches was high (ARI = 0.981; NMI = 0.971), indicating that dimensionality reduction largely preserved the main clustering structure within the analyzed dataset. The most discriminative variables included jump load, acceleration load, metabolic power, and anaerobic activity distance. Conclusions: A large set of external load variables can be reduced into interpretable latent dimensions that support exploratory external-load profile identification. The combination of PCA and clustering provides an exploratory and structure-preserving framework for summarizing complex external-load datasets and identifying latent load dimensions. These findings may assist future monitoring strategies; however, the practical utility of the identified profiles requires prospective validation before implementation in training-load management.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030248

Authors: Danai Paleta George Gioftsos Stefanos Karanasios Panagiotis Paletas Vasiliki Sakellari

Background and Objectives: Low participation rates in exercise programs among older adults highlight the need for theory-driven, biopsychosocial interventions that enhance adherence, self-efficacy, and functional outcomes. Grounded in principles of motor learning and behavioral reinforcement within physiotherapy practice, this study aimed to examine the effect of periodic assessments combined with verbal feedback on functional and psychological outcomes in community-dwelling older adults. Methods: A pilot RCT was conducted involving 54 individuals aged ≥65 years (53 women and 1 man), recruited from senior community centers. Participants were randomly allocated to an intervention group (periodic assessment and verbal feedback; n = 27) or a control group (n = 27). Both groups participated in an identical 12-week structured exercise program, delivered twice weekly, focusing on balance, gait, and lower-limb functional training. An intention-to-treat approach was applied. Data were analyzed using Linear Mixed Models, with statistical significance set at p < 0.05. Results: Significant group × time interactions were observed in favor of the intervention group for key kinesiology-related functional outcomes, including the Short Physical Performance Battery (SPPB; p < 0.001), Timed Up and Go test (TUG; p = 0.011), and Activities-specific Balance Confidence Scale (ABC; p < 0.001). No statistically significant differences were identified between groups for the Behavioral Regulation in Exercise Questionnaire–2 (BREQ-2; p = 0.164) and the Self-Efficacy for Exercise Scale (ESE; p = 0.108), indicating that the primary psychological outcome (ESE) was not confirmed. However, both ESE and BREQ-2 demonstrated significant baseline differences favoring the intervention group, and, therefore, these findings should be interpreted with caution despite statistical adjustment. Conclusions: Periodic assessments followed by verbal feedback appear to selectively improve the functional effectiveness of structured exercise programs in older women, particularly physical performance, functional mobility, and balance confidence, with no significant differential effect on the primary psychological outcome (ESE; group × time interaction: p = 0.108). These findings support assessment-informed and feedback-driven physiotherapy strategies as a promising adjunct to exercise programs in older adults, with potential implications for optimizing functional outcomes within applied kinesiology and rehabilitation contexts.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030247

Authors: Ciro Ivan De Girolamo Allegra Fullin Ersilia Vallefuoco Annunziata Attena Angela Lucariello Pasquale Arpaia Paolo De Blasiis

Background: The Postural Control System is affected by sensory inputs in stabilizing posture. The impact of postural receptors can be quantitatively evaluated by baropodometry. The lack of a standardized testing environment can decrease the reliability of baropodometric results. Virtual reality (VR) might represent a useful standardization tool. This study aimed to investigate the effects of virtual environment on plantar pressure and postural stability parameters by using a Head-Mounted Display (HMD). Methods: 50 healthy young adults underwent a baropodometric exam in upright standing under four conditions: Open Eyes (OE), Closed Eyes (CE), open (HMD-OE) and closed eyes (HMD-CE) conditions while wearing an HMD. Results: a negligible effect of VR on intrasubject variability of plantar pressure and stabilometric parameters. Moreover, no significant differences in the latter ones were found between OE conditions without and with headset (OE vs. HMD-OE), highlighting no impact of VR; instead, a significant increase in body sway was found in the closed eyes condition compared to OE ones with and without headset (CE vs. OE, CE vs. HMD-OE), underlining the effect of visual deprivation, whereas no significant difference was observed between the HMD-CE and OE conditions and a significant decrease in HMD-CE compared to the CE condition, showing the sensory-proprioceptive effect of the HMD. Eventually, no significant differences in plantar pressure parameters were generally found in different conditions. Conclusions: These findings highlighted the specific effect of visual afferents differently from proprioceptive ones by headset use and the absence of the VR impact on postural stability, suggesting a possible role of virtual reality in standardizing instrumental postural exam.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030246

Authors: Chieh-Ying Chiang Tzu-Han Chan Yi-Cheng Wu Sung-Kai Lin

Objectives: Skeletal muscle architecture (SMA) defines the mechanical limits of force production. However, its associations with force–time strategy under externally loaded conditions have received little research attention. This exploratory study examined associations between vastus lateralis (VL) and lateral gastrocnemius (LG) architecture and force–time strategy, jump-height retention, and stretch–shortening cycle (SSC) transfer-efficiency in collegiate basketball players. Methods: Seventeen collegiate male basketball players completed B-mode ultrasonographic assessment of VL and LG architecture, including muscle thickness, pennation angle (PA), and fascicle length. Athletes performed the squat jump (SJ), loaded squat jump (LSJ), countermovement jump (CMJ), and loaded countermovement jump (LCMJ) on force platforms, with a 20 kg external load applied for loaded conditions. Loaded retention, defined as the percentage of jump height preserved under load, was proposed as a unified construct. Pearson’s correlations were calculated, with Benjamini–Hochberg false discovery rate (FDR) corrections applied within predefined functional groups and pooled across morphology-sensitive correlations. Results: LG PA showed a large negative association with LCMJ rate of force development (r = −0.68 [−0.87, −0.30]) and a large positive association with LCMJ time to peak force (r = 0.68 [0.29, 0.87]), both surviving within-group FDR correction. VL PA was associated with eccentric acceleration time and concentric time across jump conditions (r = 0.52 to 0.61), interpreted as exploratory. Transfer-efficiency indices showed no significant associations with SMA, except for the LCMJ/LSJ concentric time ratio, which showed a moderate negative association with LG PA (r = −0.49 [−0.79, −0.01]). Conclusions: Resting muscle architecture was associated with the temporal and rate characteristics of force expression under load, rather than with the gross preservation of jump height. Integrating architectural assessment with loaded force–time profiling warrants further investigation as a means of characterizing individual force-development strategies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11030245

Authors: Dan Cristian Mănescu Cristina Filip Cristina Ionela Nae Rela Valentina Ciomag

Although athlete monitoring can quantify training exposure and athlete status with increasing detail, conversion into daily training decisions remains inconsistent. This structured narrative review synthesizes evidence on training load, neuromuscular readiness, recovery, fatigue interpretation, measurement reliability, applied decision-making, and proposes the LOAD-R framework: a systems model linking Load, Organism response, Adaptive state, Decision, and Re-evaluation. A transparent non-PRISMA strategy was used because the aim was conceptual integration and framework development rather than effect-size pooling. Evidence was organized around field-applicable monitoring domains and their decision value. LOAD-R builds on existing monitoring approaches by organizing single indicators, fixed thresholds, and dashboard alerts into an explicit interpretation-to-action sequence. It classifies athlete state into adaptive, functional-overload, underloaded, uncertain, or maladaptive zones, each linked to progress, maintain, modify, deload, or recover decisions. The framework also provides implementation levels and testable predictions. By framing monitoring as adaptive decision support rather than passive data collection, LOAD-R may improve decision consistency, reduce maladaptive training responses, and enhance the practical value of athlete monitoring in applied sport settings.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020244

Authors: Sousana Symeonidou Afroditi Lola Georgia Stavropoulou Anastasios Dalkiranis Marios Bismpos Eleni Bassa

Background: Morphological characteristics influence physical performance in youth basketball, but their effects may differ by developmental stage. This study compared the predictive role of morphological variables on motor performance between U13 and U15 male players. Methods: Male youth basketball players (N = 89) were assigned to U13 and U15 groups. Morphological variables included height, body mass, body fat percentage, and fat-free mass (FFM). Motor tests evaluated squat jump (SJ), countermovement jump (CMJ), 10 m and 20 m sprints, T-test, Y-test and Stop-and-Go change-of-direction speed and reactive agility (RA). Pearson correlations and multiple linear regressions assessed relationships and predictive effects. Results: In U13 players, several morphological variables correlated with performance: height and FFM were positively related to jumping and sprinting, while body fat was negatively associated with most measures (p < 0.05). Regression models explained substantial variance in sprint (ranging up to AdjR2 = 0.44) and jump performance (ranging up to AdjR2 = 0.32), though individual predictors were not always significant (p > 0.05). In U15 players, fewer associations emerged as body fat remained a significant negative predictor of jumping and agility, and greater body mass was associated with improved sprint performance (p < 0.05). No significant morphological predictors were found for RA in either group (p > 0.05). Conclusions: Morphological traits exert a stronger, multifactorial influence on performance in younger athletes, whereas body composition and particularly body fat are more influential in older adolescents. These results underscore the need to consider the developmental stage when assessing and training male youth basketball players.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020243

Authors: Milivoj Dopsaj Athanasios A. Dalamitros Klara Šiljeg Andrea Perazzetti Antonio Tessitore Alexandros Nikolopoulos

Background and Objectives: Water polo (WP) is a high-intensity, intermittent aquatic team sport that has been extensively investigated within sports science. While contemporary literature has examined the body composition and morphological characteristics of elite and international WP players, this study aimed to define the general body composition profile of world-class WP players and determine position-specific differences. Methods: The study involved 72 national team players from Serbia, Croatia, Greece, and Italy who participated in the Olympic Games, World Championships, or European Championships. Participants’ body composition was measured using the InBody 720 multichannel bioimpedance method. Ten different variables were examined to assess body structure regarding contractile and ballast components. Results: MANOVA revealed statistically significant differences in body composition across playing positions (Wilks’ lambda = 0.239, p < 0.000, η2p = 0.402). The variables that had the greatest impact on the difference were: body mass, body fat and body mass index with the 47.0, 44.4, and 43.7% of explained total variance of the impact on the differences (p = 0.000), respectively. Conclusions: world-class WP players assigned to different playing positions differ significantly in body composition. These positional profiles should be considered in talent identification, selection procedures, training, and nutritional strategies to optimize performance models, considering the future evolution of the game at the highest competitive level. Coaches could use this information to initially select players for different specific positions based on anthropometric and body composition criteria.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020242

Authors: Diogo Tereso José M. Gamonales Víctor Hernández-Beltrán Rui Paulo

Background: Football is an intermittent sport characterized by high physical and physiological demands, which may be influenced by the competitive level. Understanding differences in match load is fundamental for optimizing training planning, fatigue management, and athlete performance and injury prevention. This study aimed to evaluate and compare external and internal load in senior football players in Portugal across five distinct competitive levels. Methods: Wimu ProTM (Hudl, Lincoln, NE, USA) and Garmin Heart Rate bands (Garmin International Inc., Olathe, KS, USA) were used to quantify and evaluate the external and internal load of the players. A total of 96 athletes were assessed, with ages ranging from 19 to 36 years (mean: 24.28 ± 4.72), who were divided into five competition levels (1st Division (n = 19), 2nd Division (n = 21), 3rd Division (n = 14), 4th Division (n = 20), and Regional Division (n = 22). Results: Significant differences were observed between competitive levels across several external load variables (p > 0.001). The 3rd Division and 4th Division showed higher values in variables associated with reactive and high-intensity actions (p < 0.001; effect size: 0.287), whereas the 2nd Division exhibited a more controlled load profile. Regarding internal load, significant differences were only observed in average heart rate during the second half (p = 0.043; effect size: 0.085), indicating distinct capacities to maintain physiological intensity under fatigue. Conclusions: It can be concluded that competitive level influences load profiles in football, although the differences do not follow a linear pattern. External and internal loads demonstrate greater discriminatory capacity between competitive levels than internal load.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020241

Authors: Giacomo Capece Gerardo Giudice Ruggiero Giliberti Pierluigi Di Cosmo Giuseppe Pizzi Luca Lepore Rosario Junior Sagliocco Francesco Cuozzo Emidio Di Gialleonardo Michele Gison

Lateral femoral neck and peritrochanteric fractures are common and clinically challenging injuries, particularly in the elderly population, with significant implications for morbidity, mortality, and functional recovery. Traditional classification systems are widely used to guide treatment, yet their reproducibility and clinical applicability remain debated. Increasing attention has been directed toward trabecular architecture and its role in fracture behavior and reduction strategies. This review aims to summarize current evidence on classification systems, trabecular-based fracture patterns, pre-operative reduction techniques, and fixation strategies. A narrative review was conducted using PubMed/MEDLINE, Embase, and Scopus databases up to May 2026. Original studies, reviews, and biomechanical investigations focusing on proximal femur fracture classification, reliability, trabecular alignment, reduction techniques, and fixation methods were included. Data were qualitatively analyzed, with emphasis on interobserver reliability, biomechanical implications, and clinical outcomes. Conventional classification systems, including anatomical, Evans–Jensen, and AO/OTA frameworks, demonstrated variable and generally moderate reproducibility, with reported interobserver agreement ranging from approximately κ = 0.30 to 0.60. Emerging evidence highlights the importance of trabecular architecture, distinguishing intradigital fractures—confined within trabecular pathways and relatively stable—from extradigital fractures, which disrupt load-bearing structures and are associated with increased mechanical instability and higher failure rates. Biomechanical and clinical studies indicate that inadequate reduction with trabecular misalignment significantly increases the risk of varus collapse and implant cut-out. Reduction strategies tailored to fracture pattern, such as internal rotation for intradigital fractures and external or combined maneuvers for extradigital patterns, improve alignment and load transfer. In terms of fixation, dynamic hip screws remain effective in stable fractures, whereas cephalomedullary nails demonstrate superior performance in unstable patterns, with lower reoperation rates reported (approximately 5–8% vs. 10–15%). Management of lateral femoral neck and peritrochanteric fractures should extend beyond traditional classification systems to incorporate trabecular biomechanics. Restoration of trabecular alignment, alongside established parameters such as neck–shaft angle and tip–apex distance, is critical for optimizing outcomes. Further prospective studies are needed to validate trabecular-based classifications and standardize reduction strategies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020240

Authors: Joshua J. Aube Peter J. Mendolia Kristi L. Storoschuk Ely Wyman Mason D. Peberdy John J. Wu Nia Simpson-Stairs Paul A. Swinton Brendon J. Gurd

Purpose: The current study tested the hypothesis that a bodyweight training (BWT) protocol with a higher weekly time commitment and training volume would produce greater improvements in cardiorespiratory fitness compared to lower time commitment/volume BWT protocols. Methods: Fifty-eight (n = 21 males; n = 37 females) recreationally active, healthy, young adults were randomized to either a 16 (TAB, n = 20), 27 (5BX, n = 19), or 90 min/week (AMRAP, n = 19) BWT protocol for 6 weeks. Peak work rate (WRpeak) was measured pre- and post-intervention using a cycle ergometer graded exercise test. VO2peak was estimated (eVO2peak) using a simple linear regression of WRpeak and VO2peak generated from a previous study (n = 26; 13M/13F). Results: TAB and 5BX yielded non-inferior improvements in eVO2peak. The 95% confidence intervals of the mean difference in change did not cross our non-inferiority margin of −2.6 mL/kg/min (TAB—AMRAP = 95% CI = −1.16 to 2.07; 5BX—AMRAP 95% CI = −0.29 to 2.89). Conclusions: Our results suggest that 16 and 27 min/week of minimalist BWT yields non-inferior improvements in CRF compared to 90 min/week and provides evidence supporting the efficacy of low-volume BWT protocols compared to higher volume protocols. The study was registered on Open Science Framework on 29 May 2023 (OSF registration).

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020239

Authors: Michele Coviello Luigi Meccariello Giuseppe Rovere Vincenzo Caiaffa Giuseppe Rollo Francesco Liuzza Mario Ronga Francesco Ippolito Amarildo Smakaj Maria Lucia Mancini Antonio Colella Giuseppe Maccagnano

Background: Despite stable fixation, aseptic tibial shaft nonunion represents a severe orthopedic complication. Teriparatide and adipose-derived stem-cell augmentation have been proposed as biological supports, but comparative clinical evidence remains limited. This study explored whether adding adjuvant therapies to reamed intramedullary nailing was associated with faster healing than nailing alone. Methods: We retrospectively reviewed 43 adults with aseptic tibial shaft nonunion treated at three level I trauma centers between 2017 and 2020. Patients underwent reamed intramedullary nailing alone (n = 15), nailing plus teriparatide (n = 15), or nailing plus adipose-derived stem-cell augmentation (n = 13). Group allocation was nonrandom and based on contraindications and patient acceptance; results were therefore interpreted as exploratory. Outcomes included time to tricortical radiographic healing, pain, radiographic healing scores over time, complications, ASAMI classification, and SF-12. Results: Baseline demographic and fracture characteristics were comparable across groups. Time to tricortical radiographic healing was shorter in the teriparatide group (87.46 ± 6.34 days) and the adipose-derived stem-cell group (86.41 ± 5.67 days) than in the nailing-alone group (99.71 ± 4.29 days; p = 0.034). Pain, complication rates, ASAMI outcomes, and quality-of-life recovery did not differ significantly among groups at final follow-up. Conclusions: In this exploratory multicenter retrospective cohort, teriparatide and adipose-derived stem-cell augmentation were associated with shorter radiographic healing time after reamed intramedullary nailing for aseptic tibial shaft nonunion, but not with superior long-term functional outcomes. Because no comparator group treated with standard graft-based biological augmentation was included, the findings should be interpreted cautiously. Larger prospective studies or randomized controlled trials comparing these strategies with established graft-based approaches are needed to validate the present data.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020238

Authors: Juri Taborri Mauro Strippoli Luca Molinaro Stefano Rossi

Objectives: Volleyball playing positions are associated with different functional demands. This study compared postural control, jump performance, and upper-limb mobility across playing roles in competitive male volleyball players. Methods: Fifty male volleyball players competing in the Italian Serie C championship were equally distributed across five roles: middle blockers (MB), liberos (LIB), opposite hitters (OH), setters (SET), and outside hitters (HIT). Using a wearable inertial sensor, athletes performed bipodalic balance tasks with eyes open and closed, dominant- and non-dominant-leg single-leg balance, squat jump (SJ), countermovement jump (CMJ), and bilateral upper-limb flexion and extension tests. Results: Significant role-related differences emerged in balance and jump performance. In bipodalic balance, the eyes-open condition showed a mixed pattern, with HIT displaying the largest ellipse area and SET showing the highest path-related values, whereas in the eyes-closed condition, HIT showed the highest values across all stabilometric parameters. In the single-leg stance, OH showed the largest postural excursions on the dominant side, while LIB stood out on the non-dominant side. In jump tests, MB showed the best vertical performance in both SJ and CMJ, whereas LIB and SET generally showed the lowest outputs. Temporal differences also emerged across roles. Upper-limb mobility was similar across roles in flexion, while extension showed a role-specific pattern, with SET displaying greater ROM than LIB, HIT, and OH. Conclusions: Volleyball roles are associated with distinct functional profiles in balance, jump mechanics, and upper-limb mobility. This integrated assessment may support more specific training, monitoring, and injury-prevention strategies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020237

Authors: Daniela Falat Leütterová Jaroslav Sučka

Background: Isokinetic strength of the knee joint represents a significant determinant of athletic performance and injury prevention; however, its relationship with explosive performance in young female athletes remains insufficiently explored. The aim of the study was to analyze the relationships between isokinetic strength of the knee joint at different angular velocities and explosive jumping performance in young female athletes. Methods: The research sample consisted of 13 young female athletes enrolled in sport-oriented educational programs specializing in athletics. Explosive lower-limb power was assessed using performance tests for countermovement jump (CMJ), countermovement jump free arms (CMJ FAs) and squat jump (SJ) administered with the Chronojump system. Isokinetic strength of the knee flexors and extensors was assessed using the Humac Norm dynamometer in the concentric mode at angular velocities of 60°/s, 180°/s, and 300°/s. Peak torque, the ipsilateral H:Q ratio, and bilateral asymmetries were evaluated. Pearson’s correlation coefficient was used to analyze the relationships between the investigated parameters. Results: The strongest relationships with explosive performance were observed for hamstring strength at an angular velocity of 180°/s, where significant high correlations were identified with performance in the CMJ (r = 0.693), CMJ FA (r = 0.754), and SJ (r = 0.713). In contrast, quadriceps strength demonstrated predominantly low to moderate associations with jumping performance, while no significant correlations were confirmed at an angular velocity of 300°/s. Bilateral asymmetries of the knee extensors and flexors were generally low, ranging approximately between 7 and 10%, whereas the values of the ipsilateral H:Q ratio were within the physiological range of approximately 50–55%. Conclusions: The results suggest that the ability to generate force at higher contraction velocities, particularly in the hamstrings, is significantly associated with explosive performance in young female athletes. At the same time, isokinetic strength assessment appears to be an appropriate tool for evaluating muscular strength, muscle balance, and potential asymmetries in youth sports. However, explosive performance cannot be explained solely by the level of maximal muscular strength, but rather by a complex interaction of neuromuscular and biomechanical factors.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020236

Authors: Federica Moro Irene Cruccolini Mario Mauro Natascia Rinaldo Emanuela Gualdi-Russo Luciana Zaccagni Stefania Toselli

Objectives: To examine disordered eating behaviors, orthorexic tendencies, binge-eating episodes, attitudes toward exercise, perceived hormone-related symptoms and body image perception among competitive bodybuilders across different levels of competitive experience. Methods: In this cross-sectional study, 60 competitive bodybuilders (29 men, 31 women) completed an anonymous online questionnaire. The survey evaluated demographic characteristics, coaching and training management, phase-specific symptoms (such as libido, sleep, eating behaviors, and menstrual alterations), orthorexic tendencies, exercise addiction, and body-image perception. Results: Both sexes reported reduced libido, increased hunger, and sleep disturbances, along with frequent weight monitoring and common binge-eating episodes. Moreover, females frequently reported menstrual irregularities. ORTO-15 scores indicated a potential risk of orthorexia nervosa, while EAI-3 scores suggested a risk of exercise addiction in novice females and advanced males, with differences in mood regulation and guilt across sex and experience. Males showed higher perceived and ideal muscle mass, whereas females reported higher perceived body fat and a preference for leaner physiques. Conclusions: Competitive bodybuilders of both sexes exhibit post-competition binge eating, mood- and appearance-driven exercise behaviors, and pronounced body-image concerns. Screening, education on energy availability, structured post-competition support, and health-focused coaching are recommended to prevent the progression from sport-specific practices to clinical pathology.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020235

Authors: Paulo H. da Silva Steiger Tiago A. F. Almeida Danilo A. Massini Gabriel de Souza Zanini David Michel de Oliveira Víctor Hernández-Beltrán José M. Gamonales Mário C. Espada Dalton M. Pessôa Filho Anderson Geremias Macedo

Objectives: This study aimed to compare the acute effects of high-intensity resistance training (HIRT), low-intensity resistance training (LIRT), and low-intensity resistance training with blood flow restriction (LIRT-BFR) on heart rate variability (HRV), rating of perceived exertion (RPE), total load (kg), and number of repetitions in young trained men. Methods: Thirteen volunteers (21.5 ± 1.6 years; 178.2 ± 8.0 cm; 75.7 ± 8.0 kg) performed three training sessions with six upper- and lower-limb exercises in repetition-to-failure mode. HIRT was performed at 70% 1RM, four sets and 90 s of rest; LIRT at 30% 1RM, four sets and 30 s of rest; and LIRT-BFR at 30% 1RM, four sets, 30 s of rest, and cuff pressure at 80 mmHg. The rest interval between training sessions was 72 h. Results: Total load was higher during LIRT compared with LIRT-BFR (p < 0.05), with no significant difference compared with HIRT (p > 0.05). The number of repetitions was greater in LIRT than in HIRT (p < 0.05), with no significant difference compared with LIRT-BFR (p > 0.05). RPE was lower in LIRT compared with HIRT and LIRT-BFR (p < 0.05). Time-domain parameters SDNN significantly decreased across all protocols (p < 0.001), whereas RMSSD showed no differences. Frequency-domain components (LFnu, HFnu, and LF/HF) showed no significant differences. Conclusions: LIRT elicited lower perceived exertion compared with HIRT and LIRT-BFR and higher repetition performance, whereas LIRT-BFR, despite showing similar autonomic responses, produced greater perceptual stress, resembling that of HIRT.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020234

Authors: Robert Trybulski

Combat sports occupy a distinctive position within sports medicine [...]

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020233

Authors: Félix Menéndez-Vega Sandra Núñez-Rodríguez Jerónimo Javier González-Bernal Jessica Fernández-Solana Pedro Aparicio de Águeda Mirian Santamaría-Peláez

Background: Total knee arthroplasty (TKA) is widely used to treat advanced knee osteoarthritis, yet the optimal timing for initiating postoperative rehabilitation remains unclear, particularly regarding its impact on short- and long-term functional outcomes. Objective: This study aimed to systematically review and compare earlier versus later initiation of structured postoperative rehabilitation following primary TKA according to the timing definitions used in the available literature of structured postoperative rehabilitation after primary TKA and its effects on functional recovery. Methods: Electronic searches were performed in PubMed, Scopus, Web of Science, and ScienceDirect between January and February 2025. Studies were limited to human participants, published in English or Spanish from 2010 onwards. Eligible studies compared early versus delayed rehabilitation following primary TKA and reported at least one predefined outcome related to pain, patient-reported functional measures, range of motion, muscle strength, performance-based functional tests, or hospital length of stay. Study selection was performed independently by two reviewers, and methodological quality was assessed using the Joanna Briggs Institute critical appraisal tools. Results: A total of 662 records were identified, of which five studies (three randomized controlled trials, one prospective observational study, and one retrospective cohort study), including 185 participants, met the inclusion criteria. Early rehabilitation (typically initiated within the first postoperative hours to days) was associated with reductions in hospital length of stay ranging from approximately 1 to 2 days, lower early postoperative pain scores, greater short-term knee flexion gains, and improved early muscle strength compared with delayed rehabilitation protocols. However, no consistent differences were observed in medium- and long-term patient-reported functional outcomes across studies. No increase in postoperative complications was reported. Conclusions: Early initiation of rehabilitation after TKA appears safe and may enhance short-term recovery outcomes. However, no consistent long-term functional differences were observed between earlier and later rehabilitation initiation across the included studies. Further high-quality research with standardized definitions and long-term follow-up is required.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020232

Authors: Atle Hole Saeterbakken Terese Berger Henriksen Benedikte Soeviknes Gideonsen Vidar Andersen Nicolay Stien Goran Paulsen Tom Erik Jorung Solstad

Background: Both unilateral and asymmetric loading have been used to increase training specificity and create over-load in a target limb to reduce inter-limb asymmetries. The aim of the study was to compare the effects of conducting either unilateral- or asymmetric-loaded resistance training with traditional bilateral resistance training on maximal dynamic and isometric strength in untrained women. Methods: Thirty-four women not conducting regular resistance training were randomized into unilateral (UNI), bilateral (BIL) or asymmetric (ASY) upper-body resistance training (2–3·wk−1, 10 wk, 24 sessions in total). UNI conducted all exercises unilaterally (one arm at a time), BIL conducted all exercises bilaterally (both arms), and ASY added 10% of the total load to the non-dominant side. Maximal strength was tested in chest press, seated row (1-RM and MVC in both), and pallof press (only MVC). Results: At post-test, BIL demonstrated greater bilateral 1 RM strength than ASY (p = 0.017, d = 1.25) in chest press, while UNI demonstrated greater 1 RM strength in the dominant side than ASY (p = 0.006, d = 1.45). For the other strength tests, no differences were found between groups in chest press (p = 0.068–0.481), seated row (p = 0.091–0.591) or MVC peak force for both chest press and seated row (p > 0.05). All groups demonstrated pre–post improvements for all measurements in chest press (p < 0.05) and seated row (p < 0.05), but only ASY demonstrated improvements in pallof press on the non-dominant side. Conclusions: Compared to traditional bilateral training, unilateral resistance training did not result in similar effects on dynamic or isometric strength. Asymmetric resistance training demonstrated a lower change in chest press strength on the bilateral and dominant sides compared to the other groups.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020231

Authors: Dimna Zoila Alfaro Quezada Paul César Velásquez Porras Alicia Olinda Neyra Aranda Henri Emmanuel López Gómez Roberto Carlos Dávila-Morán Vilma Luz Aparicio-Salas Zoraida Loaiza-Ortiz Lupe Marilu Huanca Rojas Digmer Pablo Riquez Livia Lindomira Castro Llaja Liliana Inés Romero Núñez

Background: Exercise provides important health benefits for adults with type 1 diabetes; however, it remains associated with substantial glycemic instability that may vary according to exercise modality, intensity, duration, and clinical context. Continuous glucose monitoring (CGM) and wearable sensors offer an opportunity to characterize exercise-related glycemic responses under real-world conditions, yet prospective free-living data remain limited. Objective: This study aimed to evaluate glycemic risk across exercise modalities in adults with type 1 diabetes using CGM and wearable sensors in a real-world prospective cohort. Methods: This prospective cohort study was conducted under free-living conditions in 120 adults with type 1 diabetes. Participants were followed during habitual exercise using CGM, wearable sensor data, and session-level exercise classification. A total of 1568 valid exercise sessions were analyzed and categorized as aerobic, resistance, interval-based, or mixed exercise. The primary outcomes were immediate glucose change and time below range during exercise and within 6 h post-exercise. Secondary outcomes included severe biochemical hypoglycemia, time in range, time above range, glycemic variability, delayed hypoglycemia, nocturnal hypoglycemia, and rescue carbohydrate intake. Results: Glycemic risk differed across exercise modalities. Aerobic exercise was associated with the greatest immediate glucose decline, the highest time below range, the highest frequency of delayed post-exercise hypoglycemia, and the greatest need for rescue carbohydrate intake. Resistance exercise showed the most favorable acute glycemic profile, whereas interval-based and mixed exercise showed intermediate patterns. The associations between exercise modality and glycemic risk were modified by pre-exercise glucose level, time of day, and insulin delivery modality. Sensitivity analyses were consistent with the primary findings. Conclusions: In adults with type 1 diabetes monitored under real-world conditions, glycemic risk varies meaningfully across exercise modalities and is further shaped by clinically relevant contextual factors. These findings support a more individualized interpretation of exercise-related glycemic responses using CGM and wearable-derived data.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020230

Authors: Donalds Steven Guali Victor Manuel Piamba Ome Armando Monterrosa-Quintero Boryi A. Becerra-Patiño Luis Gabriel Rangel Caballero Adrián De la Rosa

Background: Flattening of the medial longitudinal arch is traditionally attributed to excess body weight and Body Mass Index (BMI). However, controversy exists regarding whether adiposity or skeletal structure drives this biomechanical alteration, and which podometric index best detects it. Methods: A cross-sectional study evaluated 99 healthy university students (50 males, 49 females). Body composition was assessed via a four-component model. Plantar footprints were captured using 4K digital podoscopy and analyzed with five morphometric indices. Arch predictors were identified using multivariate regression models (Elastic Net regression) and Generalized Additive Models (GAMs). Results: Only Clarke’s Angle detected significant sexual dimorphism, showing structurally higher arches in females (50.28° ± 7.14) than in males (41.82° ± 11.20; p < 0.001). Multivariate analysis revealed bone mass as the dominant structural predictor, exerting a non-linear negative association with the arch profile, which stabilizes beyond 12 kg. BMI was not a significant predictor, whereas body fat percentage showed a modest positive association. Conclusions: Plantar arch morphology is strongly associated with skeletal load (anthropometrically estimated bone mass) rather than adiposity or BMI. Within this specific cohort, Clarke’s Angle emerged as a highly sensitive instrument for characterizing sexual dimorphism. Clinical assessments diagnosing functional flatfoot should prioritize underlying bone structure over BMI, particularly when evaluating a healthy and physically active university population. Future studies incorporating DXA or radiographic validation are needed to confirm these anthropometric findings.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020229

Authors: Georges Dumas Pierre Denise Art Mallinson Enrico Armato Hannes Petersen Philippe Perrin

Motorist’s disorientation syndrome (MDS) is seen in 1 to 5% of patients in a tertiary neurotology clinic and remains an underdiagnosed pathology. It was first described in 1985 by Page & Gresty, using the term “visual vertigo”. Patients described sensations of veering or turning over while driving an automobile when visual input was restricted. This was exacerbated at high speeds, on winding roads, going down hills, or when overtaken by a vehicle. All patients in this initial study had peripheral or central neurotological abnormalities and showed exaggerated responses during optokinetic stimulation. Some sufferers considered giving up driving. The first aims of this narrative review were to delineate the symptoms of MDS as detailed in the literature, to outline precipitating situations and to discuss associated pathologies such as anxiety. The second aim was to differentiate MDS from similar syndromes, such as persistent postural-perceptual dizziness (PPPD) and motion sickness (MS). In addition, we looked at the role of vestibular assessments and discussed the involvement of the otolith organs and semicircular canals. In this review, eight publications were analyzed. MDS is related to a visual-vestibular or a visio-visual conflict and occurs in drivers (both males and females). It is associated with anxiety in 17–39% of cases. Mild vestibular-test abnormalities or exaggerated response to opto-kinetic stimulations are seen in 60–100% of cases. Between 50 and 62% of patients have a migraine history. Convergence and strabismic problems are also often seen. Symptoms usually settle after 6 ± 4 years but can persist for longer in females. MDS is multifactorial, and similar to certain forms of PPPD but different than MS. Its pathophysiology is still in question, and we support the role of the velocity storage integrator as a recent hypothesis. Treatment includes vestibular rehabilitation, virtual reality, cognitive behavioral therapies and orthoptic sessions, and the results are promising. The authors also strongly feel that future research on clarifying MDS pathology should study a wider scope of vestibular assessments to evaluate semicircular canal/otolithic function, as well as the vestibulo-ocular reflex, analyze optokinetic nystagmus time constant, and perform a systematic orthoptic examination.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020228

Authors: Miloslav Gajdoš Jakub Čuj Katarína Hnatová Wioletta Mikuľáková Lucia Demjanovič Kendrová

Objectives: The Arch Index (AI) is commonly used to assess medial longitudinal arch morphology; however, values obtained using different measurement technologies may not be interchangeable. This study aimed to compare AI values derived from optical pedography and a barometric platform during bilateral static stance assessment in children and to evaluate their agreement. Methods: Thirty-eight healthy children aged 5–10 years underwent standardized bilateral static foot assessment. AI was calculated using identical segmentation and formula for both systems. Paired t-tests, Pearson correlation, intraclass correlation coefficient, and Bland–Altman analysis were used to assess agreement between methods. Results: Optical pedography produced significantly higher AI values than barometric assessment for both the left (0.284 ± 0.055 vs. 0.188 ± 0.092) and right foot (0.286 ± 0.048 vs. 0.169 ± 0.072; p < 0.001). Agreement between methods was moderate (ICC = 0.494–0.581), with wide limits of agreement. Inter-method differences increased with age. Conclusions: AI values obtained from optical pedography and barometric platforms are not interchangeable in children. Consistent use of a single measurement technology is recommended in pediatric assessment to avoid misinterpretation of developmental changes.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020227

Authors: Alessandro de Sire Andrea Parente Andrea Demeco Emanuele Prestifilippo Martina Cocco Stefano Fasano Klemen Grabljevec Umile Giuseppe Longo Nicola Marotta Antonio Ammendolia

Objectives: This study aimed to evaluate the effects of a combined treatment consisting of O2O3 injections and McKenzie-based physiotherapy exercises, compared to a Control group treated with O2O3 injections and a Back School physiotherapy program, in reducing pain and disability in individuals with chronic non-specific neck pain. Methods: In this prospective double-arm pilot study, patients with chronic non-specific neck pain and a Numerical Rating Scale (NRS) > 4 were enrolled. All patients received eight weekly sessions of O2O3 injections (10 μg/mL, 10 mL total, and 2 mL bilaterally into the cervical paravertebral muscles). Patients were then randomly assigned (1:1 ratio) to either an experimental group receiving McKenzie physiotherapy or a Control group undergoing Back School techniques, with five sessions per week over two weeks. Outcome measures included the Neck Disability Index (NDI), NRS, EuroQol-5D-3L (EQ5D3L), and EuroQol Visual Analog Scale (EQ-VAS). Results: A total of 41 patients were included and divided into two groups: Back School (n = 21; mean age: 63.9 ± 13.4 years) and McKenzie (n = 20; mean age: of 57.3 ± 12.9 years). Both groups showed significant improvement in NDI, NRS, EQ5D3L, and EQ-VAS following the O2O3 injection cycle (∆T0–T1 p < 0.001). The subsequent addition of physical therapy led to further improvements across all outcomes in both groups (∆T1–T2 p < 0.001), with the McKenzie group showing slightly greater benefits, despite the lack of significant differences. Conclusions: This study demonstrated the effects of combining O2O3 injections with either McKenzie or Back School therapy in improving pain, disability, and quality of life in patients with chronic non-specific neck pain.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020226

Authors: Yanqing Zhou Qianyun Cheng Zuoqing Yan Chao Lu Bingxuan Hua

Objectives: Circadian rhythms regulate key physiological processes, including metabolism and energy balance. Emerging evidence suggests that the timing of physical activity may influence metabolic outcomes. However, how the timing of endurance exercise impacts long-term metabolic health and the role of the circadian clock in this process remain unclear. This study aimed to investigate whether time-dependent endurance exercise improves metabolic health via circadian rhythm regulation. Methods: A 12-week endurance exercise protocol was established using wild-type (WT) and circadian-disrupted ClockΔ19 mice. Mice were assigned to exercise at Zeitgeber time 0 (ZT0) or Zeitgeber time 0 (ZT12), or to sedentary controls. Assessments included rotarod fatigue test, body weight, epididymal fat ratio, fasting blood glucose, serum triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-esterified fatty acids (NEFA), intraperitoneal glucose tolerance test (IPGTT), and insulin tolerance test (ITT). Results: ClockΔ19 mice exhibited circadian phase-dependent fatigue susceptibility on the rotarod, particularly at ZT0. Both exercised ClockΔ19 groups (ZT0 and ZT12) showed significant weight reduction compared to sedentary controls, indicating that endurance exercise may counteracts circadian disruption-induced weight gain independent of timing. In WT mice, evening exercise (ZT12) led to enhanced lipid regulation and better glucose tolerance. These time-dependent benefits were absent in ClockΔ19 mutants, demonstrating that the full metabolic advantages of exercise require a functional circadian clock. Notably, endurance training also partially restored serum HDL-C levels in ClockΔ19 mice, suggesting compensatory metabolic responses. Conclusions: Aligning endurance exercise with the body’s internal clock provides greater metabolic benefits than untimed exercise. The circadian clock is essential for time-dependent improvements in glucose and lipid metabolism, although some beneficial effects occur independently of a functional clock.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020225

Authors: Raphael Augusto Gir de Carvalho Bianca Benelli Pizzolato Guilherme Pasqualin Afonso de Souza Evanil Minussi Filho Gustavo Fonseca Lemos Calixto Ewerton Alexandre Galdeano Mariana Mattar Sampaio Madureira Waldinei Merces Rodrigues Marcelo Rodrigues da Cunha Eduardo Gomes Machado Fernando Bento Cunha Rogerio Leone Buchaim Marcelo de Azevedo Souza Munhoz

Background: Proximal lower-extremity muscle strengthening is an important conservative intervention for patellofemoral pain syndrome (PFPS), as these muscle groups play critical roles in femoral stabilization and knee valgus control. However, evidence remains limited regarding the effectiveness of muscle strengthening in improving lower-extremity axial alignment through modulation of femoral neck anteversion, femoral internal rotation, and tibial external rotation. Therefore, the present study aimed to determine whether a strengthening protocol targeting the quadriceps and hip external rotator and hip abductor muscles could improve knee alignment and reduce bone torsion in young adults with patellofemoral pain syndrome. Methods: This prospective interventional cohort study implemented a muscle strengthening protocol in ten university students with PFPS. Outcomes included femoral neck anteversion angle (FNA), tibial tubercle–trochlear groove distance (TT–TG), tibial external torsion angle (TET), and the knee Q-angle, assessed via 3D reconstruction of computed tomography (3D-CT) images. Pre- and post-intervention data were analyzed using the Shapiro-Wilk test for normality and repeated-measures ANOVA (p < 0.05; 95% confidence interval). Results: Muscle strengthening improved lower-limb axial alignment, with reductions observed across all measures post-intervention. Mean changes were 0.68 ± 1.26° for FNA (p = 0.0626); 1.51 ± 0.97 mm for TT–TG (p = 0.0001); 1.38 ± 3.36° for TET (p = 0.2231); and 1.14 ± 1.52° for the Q-angle. Statistically significant improvements were observed for TT–TG and the Q-angle. Conclusions: Proximal muscle strengthening improved knee valgus and axial lower-limb alignment, as evidenced by significant reductions in Q angle and TT–TG distance. Reductions in femoral neck anteversion (FNA) and tibial external torsion angle (TET) were observed. However, these differences were not statistically significant. These findings support muscle strengthening as a noninvasive strategy for improving lower-limb alignment in individuals with patellofemoral pain syndrome.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020224

Authors: Alessandro de Sire Andrea Demeco Emanuele Prestifilippo Rita Ilaria De Socio Marco Mazzei Annunziata Filippo Stefano Fasano Kristian Efremov Nicola Marotta Antonio Ammendolia

Background: Chronic shoulder pain associated with subacromial bursitis is a common clinical condition characterized by pain and functional limitation, factors that contribute significantly to chronic morbidity for the patient. The combination of ultrasound-guided corticosteroid injections and physical therapy may improve clinical outcomes. This study compared the effectiveness of Proprioceptive Neuromuscular Facilitation and standardized exercise-based physiotherapy after a common protocol of ultrasound-guided corticosteroid injections in patients with chronic shoulder pain associated with subacromial bursitis. Methods: A randomized controlled pilot study was conducted on adult patients with chronic shoulder pain (NRS ≥ 4), who received 3 weekly intra-bursal ultrasound-guided injections of corticosteroids and local anesthetic, followed by either 10 sessions of PNF or standardized exercise-based physiotherapy. The primary outcome was pain intensity assessed by NRS. Secondary outcomes included DASH, EQ-5D, EQ-VAS, and ROM, assessed at baseline, 2 weeks, 4 weeks, 12 weeks, and 24 weeks. Results: The PNF group showed greater improvements in selected outcomes and at some follow-up time points, particularly for functional measures and shoulder ROM. However, between-group differences were not consistent across all predefined outcomes. Conclusions: Both PNF-based rehabilitation and standardized exercise-based physiotherapy may improve clinical outcomes after ultrasound-guided corticosteroid injection in patients with subacromial bursitis. However, the added value of PNF appears limited to selected outcomes and time points, and its superiority over standardized physiotherapy cannot be definitively established.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020223

Authors: Raffaele Vitiello Antonio Bove Guglielmo Miele Andrea De Fazio Luca Magrini Marianna Citro Matteo Turchetta Fabrizio Forconi

Background: Functional testing after an ankle sprain may help identify patients who later develop mechanical instability and require surgery. This study aimed to identify early clinical and functional predictors of surgical stabilization for chronic ankle instability (CAI) after acute sprains and to develop a simple composite predictive score (TALAR). Methods: This prospective observational study included 197 patients with acute lateral ankle sprains. Comprehensive clinical and functional assessments, including range of motion (ROM), strength, and pain, were performed two weeks post-injury. The primary outcome was subsequent surgical management for instability within a 24-month follow-up period. Results: Eight patients (4%) ultimately underwent surgical stabilization. Univariable analysis identified three significant predictors of surgical outcome: eversion mobility ≥ 20°, plantar flexor strength ≤ 17 kg, and the presence of pain during dorsiflexion (VAS > 0). These variables were integrated into the 0–3 TALAR (Triage Assessment of Lateral Ankle sprain Surgical Risk) score, which demonstrated promising exploratory discrimination with an AUC of 0.889 (95% CI: 0.799–0.954). An optimal cut-off of ≥2 yielded a sensitivity of 0.875 and a specificity of 0.822. While the baseline surgical risk was 4%, patients with a TALAR score ≥2 had a 17.5% conversion rate to surgery, representing a significantly higher risk (OR: 32.24; p < 0.001). Conclusion: The TALAR score represents a promising exploratory tool for early risk stratification after an acute ankle sprain. As an exploratory study, it highlights that early functional red flags, though formal internal and external validation, along with robust calibration on longer follow-up cohorts, are required before clinical implementation.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020222

Authors: Beibei Luo Ruoxi Fan Rui Li Rongda Wang Xiaomiao Zheng Rui Huang Shuxin Zhang Yiwei Sun Zhibei Zhou Yunya Zhang

Background: Wushu, a traditional Chinese exercise, has been demonstrated to be effective in promoting lower-limb strength in children. However, studies comparing the effects of different intervention durations on preschool children remain limited. Objectives: The present study examined the short- and long-term effects of Wushu exercise programs on lower-limb explosive power in preschool children aged 5–6 years. Methods: This study was conducted across two experiments, with separate cohorts of children. The children were randomly assigned to either an intervention (INT) or a control (CON) group based on their Kindergarten classes. In Experiment 1, the INT-1 group (n = 55) completed a 4-week ‘Twelve Zodiac’ Wushu exercise program, which comprised three 30-minute sessions per week, while the CON-1 group (n = 49) participated in construction and carrying-based unstructured free play, which was designed to provide a comparable amount of moderate-to-vigorous physical activity. In Experiment 2, the INT-2 group (n = 57) undertook a 10-week Wushu program, and the CON-2 group (n = 38) engaged in similar activities as CON-1 for a 10-week period. The standing long jump (SLJ) was the primary outcome measure in both experiments. Secondary outcomes included the double-leg continuous jump, 15 m zigzag run, grip strength, sit-and-reach, and anthropometric measurements. In Experiment 2, countermovement jump (CMJ) and squat jump (SJ) heights were also measured using a force plate as additional secondary outcomes. A linear mixed-effects model (LMM) was used to analyze the data. Results: At baseline, no significant outcome measures were observed between CON-1 and INT-1, nor between CON-2 and INT-2. In Experiment 1, SLJ exhibited a significant enhancement in INT-1 in comparison to CON-1 (p = 0.007). The INT-2 in Experiment 2 showed significant improvements compared with CON-2 in the SLJ (p = 0.048), double-leg continuous jump (p = 0.005), and 15 m zigzag run (p = 0.043). A strong correlation was observed between SLJ and 15 m zigzag run time (r = −0.53, p < 0.001), and between double-leg continuous jump time and 15 m zigzag run time (r = 0.56, p < 0.001). Conclusions: The findings of this study indicate that 4-week and 10-week Wushu exercise programs enhance explosive power in the lower limbs of children aged 5–6 years. The 10-week Wushu program improves lower limb coordination and jumping agility. These task-specific adaptations support the value of Wushu interventions for fostering comprehensive lower-limb motor competence in preschoolers.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020221

Authors: Danny Lum Paul Comfort Dustin J. Oranchuk

Background: Maximal isometric co-contraction (MICC) of upper-limb muscles enhances strength and size, but its effects on lower-limb function are unknown. The aim of this study was to examine whether MICC training targeting the lower limbs can improve muscular strength and functional performance in sedentary adults. Methods: Twenty sedentary individuals (10 men, 10 women; 48.5 ± 7.5 years; BMI = 24.8 ± 4.2 kg/m2) were randomly assigned to either an experimental (EXP) or control (CON) group. The EXP group performed MICC of the knee flexors and extensors three times per week for four weeks, completing three sets of 5–10 maximal effort 3 s contractions per session. Assessments conducted pre- and post-intervention included the isometric mid-thigh pull (IMTP), 3-m timed up and go (TUG), and 30 s chair stand (CS) tests. Results: Significant time (p < 0.001) and time × group (p < 0.001) effects were found for all outcomes. Compared with CON, the EXP group showed greater improvements in IMTP peak force (p < 0.001, g = 1.80), faster TUG times (p < 0.001, g = 2.73), and more CS repetitions (p < 0.001, g = 3.90). Conclusions: Twelve sessions of MICC training improved maximal strength and functional performance in sedentary adults. This simple, equipment-free method may be particularly useful for individuals with limited access to conventional exercise facilities or supervision.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020220

Authors: Sauvik Das Gupta Kanako Kamishita Megumi Kondo Yoshiyuki Kobayashi

Objectives: Treadmill walking is often employed for tightly controlled gait and energetics research, but growing evidence suggests that treadmill-based metabolic and biomechanical measurements may not directly reflect the ecologically valid mode of overground walking. While many previous studies focused on older adults, much less is known about how treadmill walking influences gait energetics and spatiotemporal parameters in young healthy adults across matched speeds. We investigated energy expenditure, metabolic cost of walking and spatiotemporal gait parameters in healthy young adults walking overground and on a treadmill at three speeds (slow—1.0, comfortable—1.3, fast—1.5 m/s). Our hypothesis was that at the comfortable speed, treadmill and overground energetics and gait parameters would be comparable. However, at slow and fast speeds, there would be a significant energetic penalty, accompanied by significant differences in spatiotemporal parameters. Methods: Twenty young participants (10 males and 10 females) completed a randomized cross-over walking protocol with a minimum of ten minutes treadmill familiarization at 1.3 m/s. Breath-by-breath oxygen consumption (V˙O2) and Respiratory Exchange Ratio were measured using a portable indirect calorimetry system and gait parameters were calculated from Inertial Measurement Units. Gross and net energy expenditures, costs of walking, cadence, average step and stride lengths, and walk ratio were calculated. A three-way mixed ANOVA was used for primary statistical analyses. Results: Treadmill walking was characterized by higher gross and net energy expenditures and metabolic costs (p < 0.001, ηp2 = 0.6) across all speeds compared to overground. It was also characterized by faster cadence and shorter average step and stride lengths (p < 0.001, ηp2 = 0.9). Additionally, there was an effect of sex (p = 0.01, ηp2 = 0.3) on the gait parameters, with females exhibiting a faster cadence and shorter average step and stride lengths than males. Conclusions: Our findings show that treadmill walking imposes a medium-to-large metabolic penalty even in healthy young adults, with compensatory gait adaptations, possibly reflecting increased stabilization demands and altered neuromuscular control strategies. These results underscore the limits of generalizing treadmill derived gait data to overground walking and we caution against the uncritical use of treadmills, especially while trying to understand ecologically relevant human walking mechanics and energetics.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020219

Authors: Gema Santamaría Elena Jiménez-Callejo Noelia Rodríguez López Luis M. Cacharro Eduardo Gutiérrez-Abejón Leticia Sánchez-Valdeón Diego Fernández-Lázaro

Background: Aquatic therapy has emerged as a promising rehabilitation strategy for people with multiple sclerosis (MS), potentially improving physical and psychological outcomes through the unique properties of water. The aim of the study was to systematically evaluate the effects of aquatic therapy on fatigue, mobility, physical function, and quality of life (QoL) in people with MS. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. Electronic databases (PubMed, Scopus, Web of Science, PEDro, CINAHL, and Cochrane) were searched from inception to February 2026. Eligible studies included adults with MS undergoing aquatic therapy interventions. Risk of bias and methodological quality was assessed using the Cochrane tool and the PEDro scale, respectively. Effect sizes were calculated as standardized mean differences (SMD) using a random-effects model. Results: Seven randomized controlled trials (RCTs) were included in the review. Meta-analysis demonstrated a large reduction in fatigue (SMD ≈ −1.20), moderate improvements in mobility and physical function (SMD ≈ 0.7), and small-to-moderate improvements in QoL (SMD ≈ 0.45) in favour of aquatic therapy. Heterogeneity ranged from moderate to high depending on the outcome. Qualitative synthesis supported these findings and indicated additional benefits in strength, balance, psychological well-being, and disease-related symptoms. No adverse events were reported. Conclusions: Aquatic therapy may represent a generally well-tolerated and potentially beneficial rehabilitation strategy for improving fatigue, mobility, and QoL in people with MS. However, these findings should be interpreted with caution due to the limited number of included RCTs, relatively small sample sizes, and substantial heterogeneity across interventions and outcome measures.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020218

Authors: Isaac Ignacio-Rodríguez Silvia Aranda-García Marcos Sanmartín-Montes Oscar Morales-Rejas Martín Otero-Agra Myriam Santos-Folgar Fernando Zarzosa-Alonso Roberto Barcala-Furelos

Objectives: In lifeguarding, when prevention fails, rapid and safe rescue is essential to prevent submersion and enable appropriate care. These operations demand high physical fitness. High-Intensity Functional Training (HIFT), such as CrossFit®, has become a widely used training model. This study examined the integration of HIFT into lifeguard training to enhance preparedness for aquatic rescues. The aim was to analyse the external and internal load generated by a lifeguard-specific HIFT protocol and to assess its utility both as a training method and as a fitness evaluation tool. Methods: Twenty-seven lifeguards completed a 15 min HIFT protocol in an AMRAP (As Many Rounds As Possible) format with four stations: running, swimming with a tow, victim extraction, and cardiopulmonary resuscitation (CPR). Variables measured included time per round (TRound), number of completed rounds, maximum and average heart rate (MaxHR, AvgHR), post-exercise blood lactate, rating of perceived exertion (RPE) per round and overall, and CPR quality (Q-CPR). Results: TRound ranged from 238 to 268 s, with significant differences between consecutive rounds, though remaining at submaximal levels. Most participants (74%) completed three rounds, and none completed four. AvgHR was 164 bpm (82% of MaxHR). RPE increased significantly across rounds (p < 0.001), reaching 9 post-AMRAP (p < 0.001). Post-AMRAP blood lactate was 15.50 mmol/L (p < 0.001), indicating high physiological stress. Despite accumulated fatigue, Q-CPR remained consistently high, ranging from 86% to 94%, with no significant differences across rounds. Conclusions: The results of this pilot study suggest that physically active lifeguards can sustain a controlled, high-intensity effort at submaximal heart rates and high perceived exertion without compromising CPR quality. These preliminary findings support the feasibility and potential utility of a lifeguard-specific HIFT programme structured as an AMRAP for high-intensity training and ecological fitness assessment in rescue-specific conditions; formal validation studies are needed before broader recommendations can be made.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020217

Authors: Mariasole Antonietta Guerriero Vittoria Lettieri Fiorenzo Moscatelli Giovanni Messina Marcellino Monda Antonieta Messina Nicola Mancini Maria Ruberto Rita Polito

Background: Physical inactivity and sedentary behaviour are major public health concerns associated with an increased risk of non-communicable diseases, reduced quality of life, and substantial healthcare burden. In recent years, technology-based interventions, including wearable devices, mobile health applications, artificial intelligence-driven systems, and adaptive digital platforms, have been increasingly adopted to promote physical activity and reduce sedentary time in adult populations. However, the evidence remains fragmented across intervention types, behavioural targets, and population groups. The aim of this scoping review was to map the recent literature on digital interventions designed to promote active lifestyles in adults, with a specific focus on their reported impact on physical activity promotion and sedentary behaviour reduction. Methods: This scoping review was conducted in accordance with the PRISMA-ScR guidelines. A literature search was performed in PubMed and Scopus using a predefined search strategy combining terms related to digital technologies, physical activity, sedentary behaviour, and adult populations. Studies published in English between 2022 and 2026 were considered. After removal of duplicates and screening of titles and abstracts, full texts were assessed according to predefined eligibility criteria. Data were charted descriptively and synthesised narratively to identify the main intervention models and emerging research trends. Results: The search identified 887 records, of which 35 studies were included in the final synthesis. The literature included was grouped into four broad categories: wearable devices and mHealth tools for monitoring and goal-setting; adaptive interventions based on Just-In-Time Adaptive Interventions, artificial intelligence, and gamification; advanced technologies such as Internet of Things systems and exoskeleton-based approaches; and hybrid interventions combining digital tools with human support or environmental modifications. Overall, technology-based interventions were generally associated with increases in step count, moderate-to-vigorous physical activity, and adherence to movement-related behaviours. In contrast, their effectiveness in reducing sedentary behaviour was less consistent and appeared to depend more strongly on context-sensitive prompting, posture-focused strategies, and multicomponent or hybrid intervention models. Conclusions: Digital health interventions represent a promising strategy for promoting physical activity in adults, but their impact on sedentary behaviour reduction remains more limited and heterogeneous. The findings suggest that simply increasing exercise is not sufficient to address prolonged sitting and that more tailored, adaptive, and context-aware approaches are needed. Future research should prioritise methodological standardisation, longer follow-up periods, and interventions specifically designed to interrupt sedentary time across different adult populations.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020216

Authors: Anna Pisz Dusan Blazek Petr Stastny

Objectives: This study investigated bilateral strength asymmetry, the bilateral asymmetry index, and the bilateral deficit ratio during one-repetition maximum leg press testing performed under bilateral, unilateral, and split-load conditions and examined their associations with isokinetic knee and hip strength asymmetries. Methods: 31 resistance-trained males completed 1RM leg press tests in all loading modes, followed by isokinetic knee flexion/extension and hip extension assessments at 60°·s−1. Results: The repeated measure ANOVA showed that split-load leg press had a significantly greater bilateral deficit ratio (14.29 ± 7.71%) compared to the bilateral condition (5.16 ± 9.60%, p < 0.001). Isokinetic testing showed significant inter-limb differences for knee flexion and extension but not hip extension. The bilateral strength asymmetry varied across tasks (5.17 ± 4.44% in leg press to 17.84 ± 12.40% in eccentric hip extension), while bilateral asymmetry index remained consistently lower. Bilateral strength asymmetry differed significantly across leg press conditions, whereas the bilateral asymmetry index did not. Knee flexion bilateral asymmetry index correlated with dominant and non-dominant hamstring to quadriceps ratios (respectively, r = 0.61; r = 0.37) and cross-limb flexor–extensor ratios (r = 0.42). No significant relationships were found for hip extension asymmetry. Conclusions: Split-load leg press might be used to test lower limb bilateral deficit, because it provides easily detectable deficit values. Unilateral leg press might be used to detect lateral strength differences, since it provides relation to isokinetic strength of knee flexors and extensors.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020215

Authors: Petra Švábová (nee Uhrová) Iveta Cihová Michal Soták Darina Falbová Lenka Vorobeľová Radoslav Beňuš Lucia Bundová

Background: Biological maturity assessment is increasingly discussed in youth sport because chronological age alone does not reflect inter-individual variation in growth and pubertal timing. Ultrasound-based systems such as BAUSport™ provide a radiation-free alternative to radiographic skeletal age assessment. This exploratory cross-sectional study examined skeletal age (SA) in Slovak female volleyball players, track-and-field athletes, and non-athletes using BAUSport™, while acknowledging substantial age differences between groups. Methods: Eighty girls (55 non-athletes, 13 volleyball players, 12 track-and-field athletes; aged 6.85–14.41 years) underwent anthropometric measurement and skeletal age (SA) assessment with BAUSport™. Chronological age (CA) was calculated as decimal age from birth date to measurement date. Groups were not age-matched; volleyball players were on average markedly older than the other groups. Skeletal maturity was categorized as early, on-time, or late using a ±1.0-year SA–CA threshold. Menarche status was recorded as an indicator of pubertal development. Group differences were evaluated using chi-square or Fisher’s exact tests as appropriate, while differences in SA and SA–CA according to menarche status were assessed using Welch’s t-test. Results: Volleyball players were older (12.90 ± 0.95 years) than non-athletes (10.22 ± 2.40 years) and track-and-field athletes (8.47 ± 1.51 years). They also demonstrated the largest mean SA–CA difference (+1.98 ± 0.73 years). The distribution of maturity categories differed across groups (χ2(4) = 14.32, p = 0.006, Cramer’s V = 0.30). Post-menarcheal girls exhibited significantly higher skeletal age and SA–CA values compared to pre-menarcheal girls. However, the substantial age disparity between groups represents a primary confounding factor and limits interpretation of sport-specific effects. Conclusions: This study demonstrates the practical application of BAUSport™ for rapid, radiation-free skeletal age assessment in youth. Differences according to menarche status support the biological relevance of skeletal maturity assessment. However, no valid between-group sport-specific inferences can be made because the groups were not age-matched and puberty is the dominant driver of skeletal maturation. Larger, age-matched studies are required before drawing conclusions regarding sport-specific selection patterns.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020214

Authors: Joshua P. M. Mattock Julie R. Steele Karen J. Mickle

Objectives: The aim of this paper is to determine whether leg kinematics and the normal force generated during the stance phase of running differed between (i) long-distance runners with medial tibial stress syndrome (MTSS) or (ii) long-distance runners who were asymptomatic at baseline testing but developed MTSS compared to asymptomatic control participants. Methods: Lower-limb kinematics, normalised stance-phase forces and spatiotemporal outcome variables were compared between the limbs of MTSS symptomatic long-distance runners (n = 11) and matched asymptomatic controls (n = 11). Outcome variables were also compared between the limbs of long-distance runners who were asymptomatic at baseline but developed MTSS (n = 4) compared to asymptomatic control limbs. Results: In the case-control comparison, MTSS symptomatic participants demonstrated slower running speeds but no differences in stance-phase normal forces or kinematics compared to asymptomatic controls. In the case study, participants who developed MTSS during the study displayed substantially lower normal forces, less plantar flexion and a more vertical tibia than the asymptomatic controls. Conclusions: The slower running speeds observed among the MTSS symptomatic participants may be pain-related or reflect reduced plantar flexor propulsive capacity. The development of MTSS by Participants 1 and 2, despite lower normal forces and plantar flexion compared with asymptomatic controls, suggests that the tibial load tolerance may vary among individuals. Furthermore, the peak stance-phase force appears to have limited utility as a standalone screening tool for MTSS injury risk. Finally, further prospective research is required to investigate plantar flexor function, propulsive force capacity and the risk of MTSS development to substantiate these findings.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020213

Authors: Gabriella D’Orsi Paride Vasco Raffaella R. R. Marzovillo Natalia Forte Giulia Scioscia Giuseppe Cartagena Luigi A. Marinaccio Maria L. Torquato Giuseppe Cibelli Anna A. Valenzano

Background: Breath-hold training (BHT) has emerged as a novel strategy to enhance metabolic efficiency and autonomic resilience in national-level athletes. This signal-generating single-case study examined physiological and neuroendocrine adaptations to an eight-week BHT program in a nationally ranked competitive swimmer. Methods: A national-level 23-year-old female freestyle sprinter (50 m best time = 26.59 s; 100 m = 60.40 s) completed three weekly BHT sessions integrated into her regular training. Pre- and post-intervention assessments included an incremental Mader cycling test with measurements of blood lactate ([La−]), heart rate (HR), salivary cortisol (sCort), and salivary alpha-amylase (sAA). Blood chemistry and pulmonary function, including diffusing capacity of the lung for carbon monoxide (DLCO), were also evaluated. Results: Post intervention, the athlete demonstrated reduced [La−] and HR at all workloads, a 20 W increase in power at 4 mmol·L−1 [La−], and an elevated final workload achieved during the Mader test. Salivary stress biomarkers showed blunted responses with significant reductions in area under the curve and large effect sizes. These changes were observed under standardized pre-analytical conditions and individualized training adjustments. Conclusions: This study highlights coordinated improvements in metabolic, cardiovascular, and stress regulation mechanisms following BHT in a swimmer with verified national-level performance benchmarks. BHT, when applied in sport-specific contexts, may serve as an effective adjunct to high-performance training.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020212

Authors: Christoph Anders Beatrice Steiniger Florian Saenger Martin Marks Lena Mader Evgenij Dukvin Anna Schneider

Background: In this study, trunk extension strength was compared between healthy female and male participants. Methods: Overall, 115 women and 124 men underwent isometric maximal voluntary contraction (MVC) testing in an upright standing position. Upper body weight was additionally assessed. The primary outcome variables were maximal torque, upper body weight expressed as torque, and the MVC-to-upper-body-weight ratio. In view of the large sample size, interpretation of the results was based not only on statistical significance but also on clinical/practical relevance, as reflected by effect size (ES) and the relationship between the difference in mean values (DMV) and the minimal important difference (MID). Results were classified as relevant only when all three predefined criteria were met (p < 0.05, ES > 0.5, and DMV > MID). Results: Men showed significantly higher MVC values than women (241 Nm vs. 162 Nm; p < 0.0001; ES = 1.974; DMV > MID). Likewise, upper body torque was significantly greater in men than in women (115 Nm vs. 80 Nm; p < 0.0001; ES = 2.119; DMV > MID). However, after normalization for upper body torque, the between-sex difference in relative strength was no longer considered relevant (2.16 vs. 2.00; p = 0.0055; ES = 0.364; DMV < MID). Conclusions: These findings indicate that although absolute trunk extension strength differs markedly between sexes, relative strength adjusted for upper body weight is broadly comparable. Both women and men demonstrated a physiological strength reserve of approximately 100% relative to upper body weight.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020211

Authors: Kyriakos-Marios Oikonomou Apostolia Ntovoli Nikolaos Koutlianos Maria Anifanti Christos Mantzios Sotiria Iliopoulou Anastasia Mata Ilias Marios Oikonomou Kostas Alexandris Evangelia Kouidi

Background: Recreational half-marathon participation is increasing, particularly among middle-aged amateur runners, yet the interpretation of early post-race cardiac findings remains challenging in exercise-based cardiovascular health evaluation. This exploratory study assessed early post-race changes in left ventricular diastolic indices and circulating biomarkers in 20 healthy amateur runners (80% male; mean age 50.7 ± 12.3 years) after the 11th PELLA HALF MARATHON (21.1 km). Methods: Participants underwent transthoracic echocardiography and venous blood sampling within 30 days before the race and within 30 min after finishing. Diastolic assessment included the E/A ratio, tissue Doppler early diastolic myocardial velocity (e′), the E/e′ ratio, isovolumic relaxation time (IVRT), and left atrial area. Biomarkers included C-reactive protein (CRP), creatine phosphokinase (CPK), creatine kinase-MB (CK-MB), and high-sensitivity cardiac troponin I (hs-cTnI). Results: Post-race assessment showed a consistent pattern of lower early diastolic filling/relaxation indices, higher IVRT and left atrial area, and significant increases in all measured biomarkers. hs-cTnI exceeded the sex-specific 99th percentile upper reference limit in 7/20 participants (35%). Conclusions: Half-marathon completion was associated with early echocardiographic and biomarker changes in this cohort of amateur runners. These findings are consistent with acute physiological cardiac stress and may help clinicians contextualise early post-race abnormalities when advising on vigorous endurance exercise participation. However, subclinical myocardial injury cannot be excluded without serial biomarker assessment and advanced imaging, and the findings should be interpreted as exploratory because of the small convenience sample, absence of a control group, lack of hydration assessment, and single early post-race timepoint.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020210

Authors: Andreja Baljozovic Uros Andjelic Marko Vujacic Marko Dimitrijevic Danijela Djonic Zoran Bascarevic Jelena Jadzic

Background: Reports on subchondral bone mechano-structure in individuals with various stages of knee osteoarthritis (KOA) are limited and often conflicting in contemporary literature. Our study aimed to assess differences in subchondral trabecular bone mechano-structure across late KOA stages in a homogenous group of patients with varus malalignment (confirmed by negative hip-knee-ankle-angle values). Methods: This retrospective cross-sectional study included micro-computed tomography scanning and Vickers micro-hardness testing of 90 bone samples (30 femoral and 60 tibial) collected from 15 adult patients with primary KOA undergoing total knee arthroplasty (TKA). The Kellgren–Lawrence grading system was used to assess the severity of KOA lesions in the included individuals, and bone samples were divided into the following groups: moderate KOA (42 samples from seven patients, age: 70 ± 7 years, females: 3/7) and end-stage KOA (48 samples from eight patients, age: 70 ± 6 years, females: 5/8). Results: Our data revealed site-specific sclerotic alterations in subchondral trabecular bone mechano-structure (thicker trabeculae, coupled with higher bone mineral content and increased bone micro-hardness) in individuals with end-stage KOA compared to moderate KOA, supporting its role in KOA pathogenesis beyond the exclusive cartilage degeneration effect. Our data also revealed that most heterogeneous subchondral trabecular mechano-structure was present in bone samples obtained from the medial part of the tibial and femoral condyle, revealing the substantial effect of mechanical loading during varus knee malalignment. Conclusions: Observed site-specific alterations in subchondral bone mechano-structure in individuals with end-stage KOA supported the role of subchondral sclerosis in primary KOA pathogenesis beyond its exclusive effect on cartilage degeneration.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020209

Authors: Emilio González-Arnay Artimes García-Parra Isabel Pérez-Santos Marye Merce Méndez-Ojeda Elena Bañón-Boulet Pablo Díaz-Rojas Lidia Real-Yanes Noé Liria-Martín Marta Rodríguez-Padrón Mario Fajardo-Pérez

Background: The glenohumeral ligaments are key stabilizers of the glenohumeral joint. Three distinct fascicles are usually described from the anterior surface of the shoulder joint: a superior glenohumeral ligament (SGHL); a middle glenohumeral ligament (MGHL); and an anteroinferior glenohumeral ligament (AIGHL). A remarkable interindividual variation has been reported, and there are few data about the patterns of insertion of these ligaments. A recent study provided a much-needed insight into the quantitative details of the glenohumeral ligament insertions. However, there is a lack of studies describing linear measurements (closer to real-life surgical anatomy) of glenohumeral ligamentous insertions according to their pattern. Methods: Hereby, we present a Thiel-based anatomical study describing proximal (glenoid) insertions of glenohumeral ligaments in 39 specimens from volunteer body donors to the Applied Anatomy Laboratory at the Autonomous University of Madrid. Results: Only 30.8% of cases showed a canonical pattern of SGHL, MGHL, and AIGHL, with scapular insertions ranging from 0.28 to 1.58 cm for SGHL, 0.1–3.6 cm for MGHL, and 0.45–2.05 cm for AIGHL, frequently mixed between the labrum and the osseous edge of the glenoid surface. Most cases show a single glenohumeral ligament inserted, usually in the labrum. A wide range of patterns regarding the number of insertions and their labral or osseous nature is present in our sample. Conclusions: Overall, there are three different patterns of glenohumeral ligaments in the anterior aspect of the shoulder joint, with the canonical pattern (three ligaments) represented in less than half of the cases. The morphometric study of the glenohumeral ligaments should consider their pattern of distribution. Also, insertions vary between the labrum and the scapular osseous articular surface.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020208

Authors: Miki Oka Shozo Tobimatsu Akira Yokote Ayako Sakoda Saeko Inamizu Yuri Nakamura Keiko Haro Yuki Yanagihara Yasutaka Iwanaga Ken-Ichiro Yamashita Jun-Ichi Kira

Background: We investigated whether combining a sural nerve sensory conduction study (s-SCS) and tibial nerve SEPs (t-SEPs) improves diagnostic accuracy for peripheral sensory neuropathy. Methods: We retrospectively reviewed 74 consecutive cases (114 lower limbs) of patients suspected of having neuropathy or radiculopathy who underwent s-SCSs and t-SEPs between July 2021 and December 2024. Abnormal S-SCSs were defined as a reduction in amplitude or a slowing of conduction velocity. Abnormal t-SEPs were defined as failure to evoke N20 or P37, or prolonged latency of either. Results: No cases showed s-SCS abnormalities with normal t-SEPs. Then, we classified the groups based on the combination of abnormality of s-SCSs and t-SEPs. Group 1 (G1) had normal s-SCSs and normal t-SEPs, which were observed in 31 limbs (27.2%). Group 2 (G2) had normal s-SCSs and abnormal t-SEPs, which were found in 45 limbs (39.5%). Subgroups of G2 included normal N20 with abnormal P37, abnormal N20 with normal P37, and N20/P37 abnormalities. Group 3 (G3) had abnormal s-SCSs with abnormal t-SEPs, which were seen in 38 limbs (33.3%). Conclusions: Electrophysiological testing reveals normal distal and proximal sensory nerves in G1, suggesting preserved sensory nerve function. The distal sensory nerves are normal in G2. However, abnormal N20/P37 and abnormal N20 with normal P37 indicate proximal sensory nerve involvement. Normal N20 with abnormal P37 indicates posterior column dysfunction. In G3, both the distal and proximal sensory nerve segments are abnormal. Therefore, adding t-SEPs to s-SCSs allows us to evaluate the full length of the peripheral nerves, which is useful for diagnosis and assessing treatment efficacy.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020207

Authors: Steff Norbert Ioan Sabin Sopa Dionisie-Vladimir Turcu Iulian Stoian Ioan Teodor Hășmășan Hășmășan Denisa Elena Sonia Gabriela Neagu Radu Antonia

Background: Smartphones are an integral part of young people’s everyday lives and offer an interactive digital environment that can be incorporated into sport training to support engagement and skill development. Methods: A total of 40 male basketball players aged 12–14 years participated in this quasi-experimental study. Participants were allocated by existing school teams, with one team assigned to the experimental group (n = 20) and the other to the control group (n = 20). Both groups completed a six-month training period consisting of three sessions per week. Hand–eye coordination and dribbling-related performance were evaluated using two standardized mobile-application-based field tests with both hands during initial and final assessments. The data were analyzed using mixed-design repeated-measures ANOVA, with time as the within-subject factor and group as the between-subject factor. Results: The mixed-design repeated-measures ANOVA showed significant time × group interactions for all assessed outcomes, indicating greater improvements in coordination performance and bilateral upper-limb performance in the experimental group compared with the control group. Conclusions: These results indicate that mobile-application-based training can be a practical and effective approach for developing coordination and supporting bilateral upper-limb performance in youth basketball players.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020206

Authors: Sacha Beca Bonnange-Michael Fundu Ngoie Zola Kalenga Gracia Bundo Arnaud Delafontaine Virginie Cordemans

Background: Acute compartment syndrome (ACS) is a limb-threatening surgical emergency most commonly associated with fractures or high-energy trauma. Non-fracture-related ACS in athletes is uncommon and may lead to delayed diagnosis. Repetitive blunt trauma during combat sports has rarely been described as a potential mechanism. Case Methods: The case concerns a 21-year-old elite-level kickboxing athlete who developed acute compartment syndrome of the left lower leg following repeated calf kicks sustained during sparring. The patient presented with rapidly progressive calf pain, swelling, compartment firmness, paresthesias and weight bearing difficulties. CT angiography demonstrated diffuse edema of the posterior compartments associated with a large intramuscular soleus hematoma without active arterial bleeding. Results: In view of the severity of the symptoms and the characteristic clinical presentation, an emergency fasciotomy was performed in operating room. Progressive closure was achieved using the vessel loop shoelace technique, allowing gradual tension-free closure. Wound healing progressed without infection, and physiotherapy was introduced with joint mobilization. The patient achieved full functional recovery after 6 months. Conclusions: This case illustrates an atypical etiology of ACS—repetitive targeted calf strikes—and underscores the importance of early recognition even in the absence of fracture or major trauma. Clinical vigilance remains paramount, and prompt surgical intervention is critical to prevent irreversible muscle and nerve damage. Awareness of such mechanisms is particularly relevant for clinicians managing athletes in combat sports. To our knowledge, this is the first documented case of ACS secondary to repeated calf kicks in kickboxing.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020205

Authors: Anna Chalkia Georgios Tsigaras Alexandra Kallistratou Paris Iakovidis Dimitrios Lytras Christoforos Pando Ilias Kallistratos

Background: Vision is a key sensory system for postural regulation; however, the effects of degraded visual input and complete visual occlusion on static balance are not fully understood. The aim of the present study was to compare postural control during single-leg stance under two reduced-vision conditions (eyes open in darkness vs. complete visual occlusion) in healthy young adults and examine the potential influence of sex and mild visual deficits. Materials and Methods: This within-subject laboratory study included 42 healthy young adults (21 males, 21 females; mean age 20.67 ± 0.48 years). Participants performed three valid 20 s single-leg stance trials on a force platform under two visual conditions: eyes open in darkness and complete visual occlusion using an opaque mask. The order of conditions was randomized and counterbalanced, and the mean value of the three valid trials under each condition was used for analysis. Postural sway outcome variables included CoP Area, Oscillation Width, Oscillation Height, Total Displacement, and Mean Velocity. A two-way mixed-design ANOVA examined the effects of visual condition and sex. Additional mixed ANCOVA analyses were performed using body weight as a covariate to verify whether the sex-related findings remained after adjustment for body weight. Exploratory subgroup analyses based on mild visual deficits were performed using independent-samples t-tests. Results: No significant overall main effect of visual condition was observed for any postural sway variable (all p > 0.05). However, a significant condition × sex interaction was found for CoP Area (F(1,40) = 9.910, p = 0.003, η2p = 0.199), indicating different response patterns between males and females across conditions. Significant main effects of sex were also found for Total Displacement (F(1,40) = 9.212, p = 0.004, η2p = 0.187) and Mean Velocity (F(1,40) = 9.090, p = 0.004, η2p = 0.185), with males showing higher values overall. The sex-related findings for CoP Area, Total Displacement, and Mean Velocity remained significant after adjustment for body weight. No significant sex effects were found for Oscillation Width or Oscillation Height, and no significant differences were observed between participants with and without mild visual deficits in either condition (all p > 0.05). Conclusions: Altered visual input did not produce a uniform overall effect on postural sway during single-leg stance in healthy young adults. Instead, the findings indicate a more differentiated pattern, with a sex-specific response for CoP Area and overall sex-related differences in Total Displacement and Mean Velocity that were not explained by body weight. Mild visual deficits were not associated with significant balance alterations under the present experimental conditions. These findings support a more nuanced interpretation of postural regulation under reduced visual input and highlight the importance of considering individual characteristics, particularly sex, in balance assessment.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020204

Authors: Michail Tsenos Christos Kokkotis Dimitrios Draganidis Nikos Alibertis Dimitrios Pantazis Panagiotis Tsimeas Athanasios Poulios Nikolaos Zaras Paraskevi Malliou Ilias Tsaousidis Maria Michalopoulou Dimitris Tsakalidis Alexandra Avloniti Ioannis G. Fatouros Athanasios Chatzinikolaou

Sports-related injuries remain a major challenge in team sports, with important consequences for athlete health, performance, and team success. Recent advances in artificial intelligence (AI) and sensor-based monitoring technologies have enabled the integration of large volumes of training, competition, and physiological data to support injury prediction and risk modelling. However, the literature is characterised by substantial methodological diversity, limiting the ability to draw consistent conclusions. Hence, this scoping review aimed to map the existing evidence on the use of AI and sensor-based monitoring technologies for injury prediction and risk modelling in team sports, and to identify key methodological trends and research gaps. The scoping review was conducted in accordance with the PRISMA-ScR guidelines. Systematic searches were performed in PubMed and Scopus. Eligible studies included team-sport athletes and applied AI or machine learning approaches to predict injury occurrence, injury risk, or related outcomes using data derived from wearable or monitoring systems. Data were charted on study characteristics, sports and competition level, data sources, modelling techniques, validation strategies, and performance metrics. The database search yielded 123 records (PubMed: n = 37; Scopus: n = 86). After screening and eligibility assessment, 11 studies met the inclusion criteria. Most studies focused on football and rugby and relied primarily on wearable-derived data, particularly GPS and inertial sensor outputs. Common predictors included external workload variables, training exposure, previous injury history, and, in some studies, wellness or physiological markers. A wide range of models was reported, including logistic regression, decision trees, random forests, support vector machines, and neural networks. Validation strategies and reported performance varied markedly, and external validation was rarely undertaken. Across the included studies, injury risk was most consistently associated with external workload metrics, previous injury history, and internal or physiological indicators of recovery and readiness. However, current models remain limited by heterogeneous methodologies, single-team datasets, and the lack of external validation. Future research should emphasise multimodal data integration and multi-centre validation to develop reliable, interpretable, and practically applicable AI-based injury prediction systems.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020203

Authors: Kohei Katsumi Hitoshi Koda Noriyuki Kida

Background: In tennis, the volley is an important shot; however, studies describing its movement characteristics have been limited to the forehand volley (FV). In this study, we analyzed the characteristics of upper-limb movement during FV and backhand volley (BV) in skilled and less-skilled tennis players. Methods: Twelve tennis players with experience (skilled group) and eight with little experience (less-skilled group) were included. The participants stood in front of a simulated net and volleyed balls were fed toward the target. Movements were recorded using three video cameras, and three-dimensional coordinates were obtained using the direct linear transformation method. The measured variables were bilateral shoulder rotation angle, pelvic rotation angle, shoulder–pelvis twist angle, and the racket–forearm angle. A two-way analysis of variance (ANOVA) was conducted with player level (skilled vs. less skilled) and time point (backswing event vs. impact event) as factors. Results: In the FV, a significant main effect of time point was observed for the bilateral shoulder rotation angle (F1,18 = 7.471, p = 0.014, η2 = 0.293). In the BV, significant main effects at both player level and time point were observed for the pelvic rotation (player level; F1,18 = 8.759, p = 0.008, η2 = 0.327, time point; F1,18 = 13.351, p = 0.002, η2 = 0.426). Also, significant main effects at both player level and time point were observed for racket–forearm angles (player level; F1,18 = 6.752, p = 0.018, η2 = 0.273, time point; F1,18 = 10.213, p = 0.005, η2 = 0.362). However, a significant main effect of the player level was observed for the shoulder–pelvis twist angle (F1,18 = 12.124, p = 0.003, η2 = 0.402). Conclusions: In contrast to FV, BV prioritizes ball control by maintaining the shoulder–pelvis angular relationship without releasing the twist. These results suggest that skill-related differences in volleying are more pronounced in the BV than in the FV.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020202

Authors: Mattia D’Alleva Luca Innella Nicola Giovanelli Lara Mari Jacopo Stafuzza Simone Zaccaron Francesco Graniero Véronique Billat Enrico Rejc Stefano Lazzer

Background: The aim of this study was to investigate the preliminary evidence supporting the validity of the Running Advisor Billat Training test (RABIT®) in determining the three intensity domains in male adults with obesity. Methods: Thirteen male adults with obesity completed a graded (GRAD) and a RABIT® test. The RABIT® test consisted of three fixed levels of perceived exertion (RPE): (1) 10 min at RPE 13, (2) 5 min at RPE 16, and (3) 3 min at RPE 18. GRAD was composed of 1 min step, increasing speed by 0.5 km/h every minute until volitional exhaustion. Results: At RPE 18, maximal oxygen consumption (V.O2max), minute ventilation (V.E), maximal heart rate (HRmax), and running speed were not significantly different from the values measured during the GRAD. As well, oxygen consumption (V.O2), V.E, and HR measured during RPE 16 and RPE 13 of the RABIT® test were not significantly different from the anaerobic threshold (AnT) and aerobic Threshold (AerT) values measured during GRAD. However, running speed at RPE 16 and RPE 13 of the RABIT® test was lower by −5.03% (p = 0.041) and −7.00% (p < 0.001), compared to GRAD. Conclusions: The data obtained in our study provide preliminary evidence supporting the ability of the RABIT® test to estimate maximal exercise parameters, as well as most parameters associated with AerT and AnT. Consequently, the test may be useful for identifying the three training intensity domains and for planning training sessions for adults with obesity.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020201

Authors: Alessandro Garofolini William Anthony Sparrow Rezaul Begg

Background: Human locomotion requires coordinated torque production across multiple joints, yet conventional gait analysis typically evaluates joint behavior independently, limiting insight into inter-joint coordination. This study aimed to quantify task-dependent reorganization of ankle–knee mechanical coordination using a moment–moment phase space framework. Methods: A normative dataset of healthy adults (N = 50) performing natural-speed walking, toe walking, heel walking, stair ascent, and stair descent was analyzed. Sagittal-plane external ankle and knee moments were extracted from time-normalized stride cycles and z-score normalized within each stride to emphasize coordination topology. Ankle–knee trajectories were represented in moment–moment space and characterized using three geometric metrics: loop magnitude (|Area|), principal axis orientation, and anisotropy. Metrics were aggregated within subject and analyzed using linear mixed-effects models with planned contrasts against walking. Results: Loop magnitude differed significantly across tasks (p < 0.001), with the largest increases observed during toe walking (+3.45 relative to walking) and stair descent (+2.41). Principal axis orientation also showed a significant task effect (p = 0.026), with stair descent producing the largest rotation of the coordination axis (−29.8°). Anisotropy varied significantly across tasks (p < 0.001), indicating systematic changes in the dimensionality and strength of inter-joint torque coupling. Conclusions: Locomotor tasks induce structured, task-dependent reorganization of ankle–knee coordination topology. Moment–moment phase space analysis provides a compact and interpretable framework for quantifying inter-joint torque coupling, with potential applications in biomechanics research and the development of activity-aware assistive technologies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020200

Authors: Matt S. Stock Heather N. Fowler Ashleigh L. Ditmyer Charles E. Nyberg Debbie L. Hahs-Vaughn Randi M. Richardson

Background: Echo intensity (EI) has emerged as a promising and accessible tool for tracking changes in skeletal muscle quality; however, its utility during early-phase rehabilitation has not been studied. Using an observational cohort design, we examined changes in quadriceps muscle strength, size, and quality, along with self-reported knee function, 2, 6, and/or 10 weeks following anterior cruciate ligament reconstruction (ACLR). Methods: Thirteen participants (4 males, 9 females; mean age = 23 years) were assessed for bilateral isometric peak torque and cross-sectional area (CSA) and corrected EI of the vastus lateralis and rectus femoris. Self-reported knee function was measured using the International Knee Documentation Committee (IKDC) questionnaire. Results: Quadriceps peak torque was significantly lower in the surgical limb at 2 weeks following surgery but increased from weeks 2 to 10, while the nonsurgical limb remained stable. IKDC scores improved significantly over time. Vastus lateralis CSA decreased in the surgical limb between weeks 2 and 6, while rectus femoris CSA increased between weeks 6 and 10 in both limbs. Corrected EI values did not change over time. No significant correlations were observed among changes in muscle strength, size, quality, or self-reported knee function. Conclusions: We conclude that quadriceps strength, size, quality, and self-reported knee function change independently and do not follow a shared recovery trajectory.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020199

Authors: Kousuke Shiwaku Carmelo Pirri Hidenori Otsubo Andrea Porzionato Rikiya Itagaki Daiki Nishikawa Tomoaki Kamiya Daisuke Suzuki Hiroyuki Takashima Makoto Emori Atsushi Teramoto Carla Stecco

Background: Definitive quantification of fluid spread within the paraneural sheath (PNS) but external to the epineurium during hydrorelease (HR)-like procedures is lacking. We aimed to investigate the spread of low-volume HR within the intra-PNS surrounding the sciatic, tibial, and common peroneal nerves using human cadaveric specimens. Methods: HR with 2.5 mL of dye-mixed saline was performed under ultrasound guidance into the intra-PNS of seven lower limbs from four fresh-frozen cadavers. Dye spread was quantified by measuring longitudinal distance and circumferential dispersion, followed by anatomical dissection within 1 min of injection. Results: All injections demonstrated consistent longitudinal spread along the intra-PNS layer without intraneural infiltration. The mean spread distances were 10.63 ± 3.66, 9.97 ± 3.60, and 8.36 ± 3.04 cm in the sciatic, tibial, and common peroneal nerves, respectively, indicating no significant differences. An opposite-side circumferential spread was observed in all cases, with mean scores indicating mild-to-moderate extension. Conclusions: Low-volume HR selectively spreads within the intra-PNS layer, suggesting that this anatomical layer is a structurally valid and reproducible target for perineural injection techniques.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020198

Authors: Noel Marcen-Cinca Pablo Jesús Bascuas Juan Rabal-Pelay

Background: Bicycle Motocross (BMX) performance is strongly influenced by the start phase, which requires rapid force and power production to achieve optimal race posi-tioning; however, the relationship between lower-body power and sport-specific start performance remains insufficiently investigated. Objectives: The aim of this cross-sectional study was to assess lower-body muscular performance and analyze its relationship with start performance in international BMX riders. Methods: Ten international-level BMX riders (n = 10) completed a testing battery including squat jump and countermovement jump, force–velocity profile assessment, and a Wingate test preceded by 5 s maximal sprints to determine peak power (PP1, PP2), peak power during the 30 s Wingate test, and mean power. A sport-specific start test was performed on a BMX ramp, with time over the first 15 m recorded using photocell timing gates. Results: StartGate 15 m time showed a large negative correlation with PP2 (r = −0.800, 95% CI: −0.95 to −0.33, p = 0.05), whereas no significant correlations were observed with vertical jump performance or Power Mean Wingate. Strong correlations were observed among laboratory-based power variables. Conclusions: These findings suggest that short-duration peak cycling power may be associated with BMX start performance. However, given the small sample size and the borderline p-value, this relationship should be interpreted with caution. Sport-specific start testing may provide relevant information for performance assessment and training monitoring in international BMX riders.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020197

Authors: Tommaso Grossi Lorenzo Micheli Matteo Magnoni Vahid Shoaei Piero Benelli Carlo Ferri Marini Francesco Lucertini

Background: The primary aim of this study is to evaluate the concurrent validity and practical applicability of the MetricVBT smartphone application compared with the Vitruve linear position transducer (VitruveLPT) for measuring mean velocity (MV) and peak velocity (PV) at one-repetition maximum (1-RM) during the Smith machine bench press (SMBP). A secondary aim is to assess the range of motion (ROM). Methods: Eighteen resistance-trained men completed a single 1-RM SMBP exercise test, with barbell kinematics simultaneously recorded using VitruveLPT and MetricVBT. Between-device differences were assessed using Wilcoxon signed-rank and paired-sample t-tests with Bonferroni correction (α ≤ 0.05). Associations were examined using Spearman’s (ρ) and Pearson’s (r) correlations, and absolute agreement was evaluated via intraclass correlation coefficients (ICC) and Bland-Altman analyses. Results: Significant differences were observed for MV (p = 0.026), but not for PV (p = 0.143) or ROM (p = 0.130). PV showed a very high correlation (r = 0.91, p < 0.001), whereas MV (ρ = 0.65, p = 0.002) and ROM (ρ = 0.55, p = 0.018) demonstrated moderate correlations. Agreement was good for PV (ICC = 0.888), moderate for MV (ICC = 0.612), and poor for ROM (ICC = 0.236). Mean bias was small for MV (−0.02 m·s−1) and PV (0.02 m·s−1), whereas ROM showed a larger bias (1.64 cm) and wide limits-of-agreement (LoA) for all variables (MV: −0.07 to 0.04 m·s−1; PV: −0.08 to 0.11 m·s−1; ROM: −13.82 to 17.10 cm). Conclusions: Although no statistically significant differences were observed, MetricVBT did not meet the reliability criteria for velocity monitoring. Despite small mean bias, the wide LoA for MV, PV, and ROM indicates that MetricVBT and VitruveLPT are not interchangeable for assessing performance parameters.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020196

Authors: Asaf Shalom Roni Gottlieb Julio Calleja-Gonzalez

This narrative review explores the potential role of cognitive–motor dual-task training (CMDT) approaches within training methods used in sports clubs, with particular emphasis on soccer clubs, to support performance enhancement, recovery, and injury prevention; improve agility, decision making, and functional readiness; and enhance training quality and specificity. The review discusses how CMDT may be integrated as part of the broader and more comprehensive planning of the club’s full training program, including during the preseason period, as part of preparation for training and competition, within recovery sessions, during periods of high load, and throughout the rehabilitation process and the transition back to team training and contact exposure, while also potentially contributing to variety, mental stimulation, enjoyment, and player engagement. The review also emphasizes the importance of implementing CMDT within a coordinated professional framework, through collaboration and synchronization within the professional and medical staff of the club, and in broad alignment with club goals, player characteristics, and sport-specific demands. The key insight is that CMDT has the potential to serve as a practical, complementary approach that helps bridge the gap between controlled training and rehabilitation settings and the dynamic demands of soccer participation. Based on this review, practical recommendations and future research directions are presented, while emphasizing that CMDT should be applied with caution, through gradual and context-specific progression, and in line with established training, recovery, and rehabilitation principles.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020195

Authors: Alan J. Pearce Samuel Hardy Kane Middleton Doug King

Background: Sports-related concussion (SRC) is associated with elevated subsequent musculoskeletal (MSK) injury risk, yet no study has examined whether a mandatory post-concussion rest period mitigates this risk in professional Australian rules football. The aim of this study was to compare subsequent injury risk following SRC in Australian Football League (AFL) male athletes across two periods: a discretionary return-to-play period (2016 to 2019) and a mandatory 12-day non-competition period (2021 to 2024). Methods: Injury data were extracted from publicly available AFL injury reports across eight seasons (n = 4351 players). Risk ratios (RRs) with 95% confidence intervals were calculated using log-binomial methods, with pooled estimates derived via the Mantel–Haenszel approach. Results: Across both periods, SRC significantly increased overall MSK injury risk compared to MSK-first injury risk (2016 to 2019: RR:1.59 [95%CI:1.31 to 1.92]; p < 0.001; 2021 to 2024: RR:1.56 [95%CI:1.28 to 1.91]; p < 0.001). Upper and lower limb injury risks were similarly elevated across both eras. Notably, the risk of subsequent concussion was significantly elevated during 2016 to 2019 (RR:3.14, p < 0.001), whereas no statistically significant elevation was demonstrated during 2021 to 2024 (RR:1.30, p = 0.324). Conclusions: During the 12-day rest period, subsequent concussion risk was no longer significantly elevated, while MSK injury risk remained increased, suggesting longer recovery periods may be warranted for full neuromuscular recovery following SRC.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020194

Authors: Prokopios Chatzakis Giorgos Paradisis Kostas Patas Stylianos Chatzipanagiotou Chrysoula Nikolaou Elias Zacharogiannis

Objectives: The purpose of the present study was to examine the acute effects on hematological, inflammatory, cellular, muscular, myocardial, liver, biliary, and humoral immunity biomarkers during and after a 12-h track ultra-marathon event. Methods: Twelve healthy male ultra-marathon runners completed the race and all measurements, including venous blood sampling performed before the race (PRE), at 6 h during the race (MID), and immediately after finishing (POST). Results: White blood cells, neutrophils, monocytes, basophils, and platelets increased at 6 h (MID) and remained elevated after the finish (POST), while eosinophils and lymphocytes decreased at mid-race and remained suppressed until post-race. The immunoglobulin G and C-reactive protein increased post-race compared to pre- and mid-race values, while lactate dehydrogenase and interleukin-6 increased at mid-race, with no further change until post-race. Creatine kinase, creatine kinase-MB, high-sensitivity cardiac troponin I, aspartate aminotransferase, and alanine aminotransferase significantly increased mid-race and showed a further significant increase post-race. Significant correlations were found between total distance covered and the percentage of PRE-MID difference of interleukin-6 and the percentage of PRE-POST difference of interleukin-6 and lactate dehydrogenase. Conclusions: The results of the present study indicate that participation in a 12-h track ultra-marathon is associated with marked exercise-induced alterations in multiple hematological and biochemical biomarkers, with several responses already evident at mid-race (6 h).

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020193

Authors: Nuria Pérez-Romero Annais Rubilar-Barrera Constanza Carolina Salinas-Parada Karen Navarrete-Valenzuela Valentina Paz Vera-Espinoza Oscar Núñez Enrique Cerda-Vega

Background: Fibromyalgia is a chronic nociplastic pain condition often accompanied by mental health comorbidities, with anxiety and depression being the most prevalent. The objective of this umbrella review is to analyze the effects of physical exercise on anxiety and depression symptoms in individuals with fibromyalgia. Methods: Following Cochrane and PRIOR guidelines, a systematic search was conducted in PubMed, Web of Science, Scopus, and CINAHL Complete up to 28 August 2025. Systematic reviews with or without meta-analyses that evaluated physical exercise interventions in adults with fibromyalgia and reported anxiety or depressive symptom outcomes were included. Risk of bias was assessed with AMSTAR-2; overlap was evaluated using MOoR and CCA. Results: Fourteen reviews (eight meta-analyses, three systematic reviews, two meta-analyses treated as descriptive, and one network meta-analysis) were included, synthesizing 98 randomized controlled trials (RCTs) with 4325 participants (in the 12 reviews that provided data). The majority of the patients were women and people aged between 10 and 65. Regarding anxiety, five of seven reviews reported significant improvements. Aquatic exercise showed the greatest effect (SMD = −1.14). Regarding depression, eight of 11 reviews reported significant benefits. Aquatic exercise again stood out with the highest effect (SMD = −1.18). Adherence varied between 64% and 97%. Methodological quality according to AMSTAR-2 showed considerable heterogeneity. Conclusions: Physical exercise, especially aerobic and aquatic modalities, may support the reduction of symptoms of anxiety and depression in people with fibromyalgia. These findings support its inclusion in rehabilitation programs, although methodological and prescription variability suggests caution in interpreting optimal parameters. PROSPERO-ID: CRD42024590799.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020192

Authors: Dimitra P. Sklavou George S. Metsios Antonios Stavropoulos-Kalinoglou Claire Chrysanthi Karpodini Apostolos Vantarakis Yiannis Koutedakis

Objectives: Although many governments and scientific organisations have developed strategies to combat the epidemic of childhood obesity, the unsatisfactory results thus far warrant further studies. The aim of this systematic review is to investigate the effects of active video games (AVGs) on physical activity (PA) levels and BMI (body mass index)/body composition in overweight and obese children 6–12 years of age. Methods: Articles were retrieved from the databases of Scopus, PubMed (MEDLINE), SPORTDiscus, and CINAHL. Thirteen articles met the inclusion criteria and were categorised according to the AVG intervention length. Results: AVG intervention periods of 4–12 weeks seem to moderately improve PA levels and refine BMI/body composition levels. In contrast, interventions lasting 13–24 weeks revealed encouraging results for improving PA, but had little effect on BMI/body composition levels. Conclusions: AVGs can generally help overweight and obese children 6–12 years of age to improve their PA levels and reduce BMI and/or improve body composition.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020191

Authors: Stelios Hadjisavvas Irene-Chrysovalanto Themistocleous Michalis A. Efstathiou Elena Papamichael Christina Michailidou Manos Stefanakis

Background: Acute fatigue is frequently experienced during handball training and match play and may impair throwing performance; however, findings across studies are inconsistent. This systematic review and meta-analysis examined the acute effects of fatigue on throwing velocity and accuracy in handball. Methods: PubMed, MEDLINE Complete, CINAHL, and Scopus were searched from inception to 24 January 2026, supplemented by Google Scholar and citation tracking. Eligible studies included handball players exposed to an acute fatigue protocol with throwing-performance outcomes. Random-effects meta-analyses were conducted using standardized mean differences (Hedges’ g), oriented so that negative values indicated worse performance under fatigue. Results: Τen studies met the inclusion criteria for qualitative synthesis. For quantitative synthesis, 10 comparisons contributed to the throwing-velocity meta-analysis and 6 comparisons contributed to the throwing-accuracy meta-analysis. Fatigue showed a small-to-moderate tendency to reduce throwing velocity (g = −0.31, 95% CI −0.65 to 0.03; I2 = 77.8%). For throwing accuracy, the pooled estimate suggested a possible decline under fatigue (g = −0.82, 95% CI −1.95 to 0.31), but heterogeneity was very high (I2 = 95.8%) and findings were sensitive to influential effects. Conclusions: Acute fatigue showed a small-to-moderate tendency to reduce throwing velocity in handball players, with more consistent impairments observed during jump-shot tasks and after localized upper-limb fatigue protocols. In contrast, no robust conclusion can be drawn for throwing accuracy/precision because heterogeneity was extremely high and studies used substantially different outcome definitions, including hit counts, success percentages, points-based scores, and spatial error. Therefore, accuracy findings should be interpreted with considerable caution.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020190

Authors: Moeketsi Robert Mohlakoana Gerrit Jan Breukelman Lourens Millard

Background: Visio-spatial skills (VSS) are essential perceptual-cognitive skills that enable athletes to process visual information, interpret spatial relationships, and execute appropriate motor responses in dynamic sporting environments. In combat sports, athletes must rapidly anticipate and react to an opponent’s actions, making well-developed VSS crucial for optimal performance. Although boxing, karate, and taekwondo share similar competitive characteristics, each discipline presents distinct technical and perceptual demands that may influence the development of specific VSS profiles. This study aimed to investigate whether significant differences exist in VSS profiles among boxing, karate, and taekwondo athletes. Methods: A comparative cross-sectional design was used involving 150 amateur combat sport athletes, 50 boxers, 50 karate athletes, and 50 taekwondo athletes. Participants were assessed using a VSS test battery measuring six variables: accommodation facility (AF), saccadic eye movement (SEM), speed of recognition (SR), (HEC), peripheral awareness (PA), and visual memory (VM). Data was analyzed using one-way ANOVA with η2, ω2, and Cohen’s f effect sizes, and principal component analysis (PCA). Results: One-way ANOVA revealed statistically significant differences in five of six VSS (all p < 0.001). PA produced the largest sport-specific differentiation (η2 = 0.457, Cohen’s f = 0.918), followed by HEC (η2 = 0.273, f = 0.612), SR (η2 = 0.224, f = 0.537), and SEM (η2 = 0.180, f = 0.468). AF yielded a significant moderate effect (η2 = 0.108, f = 0.347). VM was the sole non-significant variable (F (2.147) = 0.74, p = 0.479, ω2 = 0.000), suggesting domain-general encoding processes insensitive to discipline-specific training at this developmental level. Boxing athletes achieved the highest scores in SEM, SR, and PA, while karate athletes led in AF and HEC. PCA revealed a single dominant component (PC1 = 93.91% of variance), confirming that VSS function as a highly integrated perceptual-motor construct rather than independent sub-skills. Conclusions: Visio-spatial skills in combat sports are governed by a dominant integrated factor, with discipline-specific variations reflecting unique performance requirements. Visio-spatial skills in combat sport athletes are highly interdependent and largely governed by a single perceptual-motor construct, with discipline-specific profiles observed across boxing, karate, and taekwondo. The findings support the integration of sport-specific, ecologically valid visual training programs targeting key perceptual-cognitive skills, alongside routine assessment to inform athlete development and performance optimization.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020189

Authors: Fernando Martin-Rivera Darío Rodrigo-Mallorca Alvaro Juesas Angel Saez-Berlanga Iván Chulvi-Medrano

Background: Velocity loss (VL) is widely used in velocity-based training (VBT) to index mechanical fatigue, yet attentional focus cues may alter velocity profiles and their relationship with internal load. This study tested whether internal focus, external focus, or control modifies repetition-level velocity, lactate kinetics, and lactate–VL% coupling during bench press (BP) at 60% one-repetition maximum (1RM). Methods: Thirty-six trained men were randomized into three groups. Thirty-four participants completed the study and were included in the final analyses according to outcome-specific data availability. Participants completed two counterbalanced sessions on a Smith machine BP: (i) a single set to technical failure, and (ii) a conventional 3 sets × 10 repetitions at 60% 1RM. Concentric velocity was recorded via a linear position transducer and analyzed at the repetition level using linear mixed-effects models. Lactate was analyzed via Gaussian generalized estimating equations (GEEs). Results: Repetitions to failure and terminal velocity at failure did not differ between groups (Welch p = 0.328; ω2 = 0.045). During 3 sets × 10 repetitions, velocity decreased across sets and repetitions (both p < 0.001); adding group terms improved fit (LR χ2(12) = 42.26, p < 0.001), with additional improvement for group-dependent fatigue patterns (LR χ2(6) = 14.90, p = 0.021). Lactate increased over time (Wald χ2(4) = 244.56, p < 0.001) with convergence by post-lactate set 3 and post-lactate 30 s. Lactate–VL% coupling was strongly moderated by group (post-lactate × group: χ2(2) = 80.42, p < 0.001), with slopes (ΔVL% per 1 mmol·L−1) of 5.27 (internal focus), 13.60 (external focus), and 0.04 (control). After Holm correction across prespecified primary outcomes, only the post-session rating of perceived exertion differed (pHolm = 0.004; ω2 = 0.045), with higher values in the external focus group. Pairwise effects were calculated as comparator minus external focus; therefore, negative g values indicate a higher rate of perceived exertion (RPE) in the external focus group (gHedges ≈ −1.50 vs. control; −1.37 vs. internal focus). Conclusions: Attentional cueing did not consistently alter averaged VL% outcomes after multiplicity correction, but it was associated with differences in early lactate kinetics and modified the observed association between post-set lactate and VL% in the interaction-based coupling model. Cueing scripts should therefore be reported verbatim and standardized in VBT studies, particularly when VL-derived indices are interpreted alongside internal load markers.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020188

Authors: Philip Gallardo Antonios Papageorgiou Vasileios Tsagkogiannis Panagiotis V. Tsaklis

Background: Strength-Duration (S-D) assessment is commonly used in clinics to examine the excitability of peripheral nerves and muscles. Yet, how changes in neuromuscular excitability relate to improved athletic and muscular performance in healthy subjects remains poorly understood. Therefore, the aim of the study was to evaluate the electrophysiological changes in neuromuscular excitability in the vastus medialis (VM) muscle using the S-D assessment, following a back squat conditioning activity (BS-CA) protocol designed to elicit a post-activation potentiation (PAP)/post-activation performance enhancement (PAPE) effect in healthy athletic males. Methods: Eleven male physical education students were included in this study. All subjects performed two trials: one examining their BS one-repetition maximum (1-RM), and a main experiment. During the main experiment, baseline levels of rectangular rheobase (R-RIC), triangular rheobase (R-DIC), and chronaxie were collected from the VM muscle following a standard warmup. Subsequently, the subjects performed four warmup BS sets and executed a top set of five repetitions (reps) at 80% of 1-RM. Afterwards, R-RIC, R-DIC, and chronaxie were reassessed for pre and post analysis. Based on these S-D curve (SDC) parameters, the muscle adjustability quotient (MAQ) and threshold charge (Q) were also computed and compared. Results: The R-RIC, R-DIC and Q were all significantly higher following the BS-CA, compared to pre-intervention (p < 0.001). No significant differences were observed for the chronaxie and MAQ (p > 0.05), although an increasing trend was noted for the chronaxie (p = 0.054). Conclusions: Based on the findings from this study, the neuromuscular excitability in the VM muscle can be acutely altered following a BS-CA protocol. However, these changes seem to be more related to muscle fatigue than PAP/PAPE. Nevertheless, S-D assessment may broaden our understanding of the fatigue process during exercise.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020187

Authors: Elric Pretorius Mark Kramer Adele Broodryk

Background: Sleep hygiene protocols (SHPs) have been shown to improve sleep and stress regulation; however, the role of cortisol in shaping downstream physiological and performance adaptations remains unclear. This study primarily examined the effects of a short-term SHP on sleep duration and salivary cortisol responses across resting, pre-exercise, and post-exercise states in female collegiate soccer players and, secondarily, whether cortisol statistically mediated selected aerobic and anaerobic performance outcomes. Methods: Fourteen players (22.1 ± 3.3 y; 157.8 ± 6.0 cm; 53.5 ± 3.9 kg) completed a randomised, counterbalanced crossover study comparing habitual sleep (no sleep hygiene protocol; nSHP) with a comprehensive SHP incorporating environmental, behavioural, and educational strategies. Salivary cortisol was sampled one hour post-waking and 30 min pre- and 15 min post-exercise during standardised testing sessions. Performance outcomes included vertical jump, sprint performance (40 m and repeated sprints [RAST]), and the Yo-Yo Intermittent Recovery Test Level 1. Linear mixed-effects models assessed cortisol responses, and mediation analyses explored cortisol–performance relationships. Results: After SHP, perceived (7.87 h vs. 6.5 h; p = 0.002, ESg = 1.0) and calculated sleep duration (8.5 h vs. 6.9 h; p = 0.004, ESg = 0.95) increased significantly. Cortisol was markedly lower following SHP at selected timepoints, including before RAST (−43.05%, p = 0.006, ESg = 0.84), with additional timepoint-specific, condition-dependent differences post-anaerobic and post-aerobic exercise (Δ = 7.37 and 5.98 nmol·L−1, respectively; p < 0.001). Vertical jump height demonstrated significant total (9.92 cm, p = 0.002) and direct effects (7.72 cm, p = 0.034), and peak repeated-sprint performance showed a significant direct effect (p = 0.026). Cortisol did not significantly mediate any performance outcomes (ACME p > 0.05). Conclusions: Short-term sleep hygiene is associated with increased sleep duration, timepoint-specific modulation of cortisol responses, and selected anaerobic performance benefits; however, these effects were not explained by measured cortisol responses and are unlikely to be sustained without ongoing reinforcement or support, particularly in athletic populations.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020186

Authors: Froukje Sliedrecht Kilian Stoker Inge K. Stoter Stein G. P. Menting Marije T. Elferink-Gemser

Background: Long conjugate sequence (LCS) resistance training aims to maintain and increase strength and power to enhance sport-specific performance. This study examined (1) how strength and power change during alternating periods of an LCS program, and (2) the relationship between strength, power, and performance in long-track (LT) and short-track (ST) speed skating. Methods: Twenty-three speed skaters (sixteen men, seven women; age = 18.0 [17.0, 19.0], sub-elite to elite performance level) followed a 39-week LCS program alternating strength and power periods. Strength (Isometric Mid-Thigh Pull) and power (Squat Jump) were assessed after each period. Linear mixed-effects models were used to examine the effects of time (baseline and four follow-up assessments), sport (long-track vs. short-track), and sex (male vs. female) on absolute and relative measures of strength and power. Models included fixed effects for time, sport, and sex with all two-way interactions, a random intercept for participants, and a first-order autoregressive covariance structure to account for repeated measures. Model selection followed backward elimination guided primarily by the corrected Akaike Information Criterion (AICc). Kendall’s tau correlations tested associations between strength, power, and competition performances closest to assessments. Results: Change in absolute and relative strength across the season differed by sex (F(4, 33.57) = 2.72, p = 0.046; F(4, 31.86) = 3.50, p = 0.02), with an increase only in male skaters (baseline to Test 4: +406 N ± 115, p = 0.01; +4.37 N/kg ± 1.41, p = 0.03). Absolute power changed (F(4, 33.74) = 3.81, p = 0.01) specifically in the early season (baseline to Test 1: +151 N ± 40, p < 0.01), while relative power remained stable (F(4, 53.05) = 1.94, p = 0.12). Higher absolute strength and power correlated with better LT (n = 12, τ = −0.58–0.67) and ST (n = 9, τ = −0.56–0.89) performance. Yet, relative strength related only to ST performance (n = 9, τ = −0.78–0.89), and relative power chiefly to the first 100 m of a LT performance (n = 12, τ = −0.49). Conclusions: The LCS method is associated with strength development without compromising power. The findings highlight the relationship between resistance training-induced outcomes and speed skating performance.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020185

Authors: Phillip Hartog Lee J. Hinkle Ulrike H. Mitchell Aaron Wayne Johnson

Background: Collegiate gymnastics imposes high repetitive loads on the lower extremities, particularly the Achilles and patellar tendons, yet longitudinal data describing tendon adaptation across a competitive season remain limited. Objectives: To examine seasonal changes in Achilles and patellar tendon morphology (thickness, cross-sectional area [CSA], echogenicity, vascularity, and symmetry) across a twelve-month competitive cycle in Division I female gymnasts and to explore relationships with pain. Methods: This longitudinal observational study included twenty-five Division I female gymnasts (age: 20.0 ± 1.6 years; height: 159.5 ± 6.2 cm; weight: 57.8 ± 5.7 kg). Bilateral ultrasound assessments of the Achilles and patellar tendons were performed at three time points (post-summer, preseason, and postseason). Tendon thickness, CSA, echogenicity, and vascularity were evaluated using standardized imaging protocols. Symmetry indices were calculated, and pain was assessed using validated scales. Normality was assessed using appropriate statistical tests. Parametric data were expressed as mean ± standard deviation (SD), and non-parametric data as median and interquartile range. Paired comparisons were conducted using paired t-tests or Wilcoxon signed-rank tests, with Holm correction applied for multiple comparisons. Results: Achilles tendon thickness increased from summer to postseason (p < 0.05), with no significant changes in CSA after adjustment. Echogenicity and vascularity remained unchanged. Patellar tendon morphology was largely stable; however, left proximal thickness decreased from summer to preseason and remained reduced at postseason (p < 0.01), with no other consistent regional changes. Pain prevalence increased modestly across the season without a clear lateralized pattern or association with symmetry indices. Conclusions: Achilles tendon thickness appears to be a sensitive marker of seasonal adaptation in female collegiate gymnasts, whereas patellar tendon morphology remains stable. These findings support the use of longitudinal ultrasound monitoring for athlete screening and load management.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020184

Authors: Francisco Javier Nuñez Marco Carletta Gloria Picco Reyes Adorna Juan Luis Nuñez-González Luis Suarez-Arrones

Objective: The primary aim of this study was to compare eccentric knee flexion isokinetic performance at two commonly used angular velocities (60°·s−1 and 180°·s−1) between dominant and non-dominant limbs in healthy professional soccer players through the analysis of peak torque, mean peak torque, angle of peak torque, total work, and rate-of-torque-development-related variables. The secondary aim was to describe concentric knee extension and knee flexion strength variables assessed at 60°·s−1. Methods: Forty male professional soccer players performed concentric knee flexion–extension testing at 60°·s−1 and eccentric knee flexion testing at 60°·s−1 and 180°·s−1 using an isokinetic dynamometer. Peak torque (PT), mean peak torque (MPT), angle of peak torque (APT), total work (TW), and hamstrings: quadriceps ratios (H:Q ratios) were analyzed for dominant and non-dominant limbs. Inter-limb differences, repetition effects, and reliability indices were calculated. Results: No significant inter-limb differences were observed for most variables (trivial–small effect sizes), except for higher eccentric TW at 180°·s−1 in the dominant limb (p = 0.009). Eccentric PT and MPT decreased at higher velocities in both dominant (p = 0.002 and p < 0.001, respectively) and non-dominant (p = 0.008 and p < 0.001, respectively) limbs, while APT shifted toward more flexed knee angles (p < 0.001). Reliability was good to excellent (ICC = 0.81–0.87), with low measurement error. Conclusion: Eccentric knee flexion assessment at 60°·s−1 and 180°·s−1 angular velocities provided different results in PT, MPT, and APT for the same group of players, supporting the use of more than one eccentric test for obtaining information about these variables in elite soccer.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020183

Authors: Kristína Němá Peter Kačúr Tomáš Kozák Ján Pohlod Pavel Ružbarský

Background: Operational performance in security-force settings depends on maintaining accurate motor–cognitive and shooting performance under acute physical strain. This descriptive pilot study examined pre–post performance patterns during a fixed-order acute-load protocol and explored whether trial-level and spatial analyses identified changes beyond aggregate scores. Methods: Nineteen applicants (10 men, 9 women; 21.6 ± 1.0 years) completed two testing sequences separated by one week. All participants completed Sequence 1 first and Sequence 2 second; therefore, sequence-related observations were interpreted descriptively rather than causally. In both sequences, participants performed Hawk Eye testing, IPSC-based shooting, and the Jaciak Motor Coordination Test, with the order of Hawk Eye and shooting reversed between sequences. Primary outcomes were first-shot hit rate and Hawk Eye error count. Secondary and exploratory outcomes included shooting miss rate and time, Hawk Eye stimulus time, minimum and maximum response times, trial-level timing, spatial distributions, and cross-task coupling. Results: Heart rate increased markedly after the Jaciak test in both sequences, with end-of-test values corresponding to approximately 86–88% of age-predicted HRmax. Model-based analysis indicated lower post-load odds of a first-shot hit compared with pre-load performance. In contrast, no detectable pre–post change was observed for Hawk Eye error probability. Descriptively, first-shot hit rate decreased in Sequence 1 (62.1 ± 19.9% vs. 42.1 ± 28.2%; p = 0.029), while the decrease in Sequence 2 was smaller and not statistically significant (61.1 ± 24.5% vs. 52.6 ± 28.4%; p = 0.267). Hawk Eye error count showed no statistically detectable pre–post change in either sequence, although maximum response time decreased in Sequence 1 (p = 0.008). Trial-level and spatial analyses indicated additional temporal and location-specific patterns, but exploratory cross-task spatial associations were inconsistent. Conclusions: In this fixed-order descriptive pilot study, post-load testing was associated with lower first-shot shooting performance in this sample, whereas no statistically detectable deterioration was observed for Hawk Eye error probability. However, because the design lacked a no-load control condition and all participants completed the same sequence order, the observed pre-to-post differences cannot be attributed specifically to acute physical load. They should be interpreted as descriptive performance patterns within the implemented protocol.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020182

Authors: Chiara Tuccella Lorenzo Nespoli Sofia Potenziani Gabriele Maisto Pierfrancesco Zito Alina Schiavone Monica Cialone Lorenzo Pugliese Maria Giulia Vinciguerra Valerio Bonavolontà

Background: Fibromyalgia is a chronic condition characterized by a complex array of symptoms that impact multiple domains, including physical, psychological, and social aspects of an individual’s well-being. Although home-based adapted physical activity (HAP) interventions represent a promising strategy to improve health-related physical fitness (PF), studies on the topic are still lacking and further research is required. The objective of the present study was to evaluate the impact of participation in a 12-week HAP intervention on health-related PF in adult women with fibromyalgia syndrome (FS). Methods: Participants were women with fibromyalgia (n = 29; 47.1 ± 9.5 yrs) assigned to the 12-week HAP program (n = 17) or wait-list control group (n = 12). Participants completed two weekly circuit-training sessions delivered through an online platform. PF components were assessed through a standardized test battery: 30-s chair stand (lower-body strength), arm curl (upper-body strength), 2-min step (cardiorespiratory fitness), back scratch (flexibility) and 8-foot up-and-go test (agility and balance). Three time-point evaluations were planned: at baseline (T0), after 6 weeks (T1), and after 12 weeks (T2). Linear mixed models were used, and partial eta-squared (η2p) effect sizes were calculated. Results: A significant time × group interaction emerged for upper body strength (p = 0.001; η2p = 0.404), agility (p < 0.001; η2p = 0.569) and cardiorespiratory fitness (p = 0.009, η2p = 0.292). Specifically, from baseline to 12 weeks, the experimental group improved in the arm-curl test (from 15.8 ± 4.5 to 18.9 ± 5.0 repetitions), agility (from 6.6 ± 1.5 to 5.2 ± 1.1 s), and cardiorespiratory fitness (from 69.1 ± 18.8 to 77.2 ± 21.1 repetitions), while the control group showed no meaningful changes. Conclusions: The participation in a 12-week HAP intervention had a positive impact on different components of PF in women with FS, which may have implications for greater physical autonomy and well-being.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020181

Authors: Tomás T. Freitas Elena Marín-Cascales Cristian Marín-Pagán Linda H. Chung Antonio Martínez-Serrano Nicola A. Maffiuletti Anthony J. Blazevich Pedro E. Alcaraz

Background: This study aimed to investigate the extent and time course of peripheral neuromuscular fatigue of the knee extensors following different concurrent training protocols in recreationally active men. Methods: In a randomized, counterbalanced, crossover design, ten participants completed one exercise session of three concurrent exercise protocols in consecutive weeks and in similar resting conditions: traditional concurrent training (TCT), sprint interval training (SIT), and high-intensity resistance circuit training (HRC). Maximal voluntary isometric contraction (MVIC) and electrically evoked tetanic force of the knee extensors were assessed before, immediately after, and at 24 and 48 h following each exercise session. Linear mixed models were used to examine the differences among exercise modalities and time points. Results: No significant changes were found in MVIC force following HRC and TCT at any time point (p > 0.05), while significant declines were observed post-exercise (p = 0.015), 24 h (p = 0.001) and at 48 h (p = 0.003) after SIT. Moreover, MVIC force was significantly lower for SIT than HRC at 48 h (p = 0.001). Tetanic force significantly declined in SIT from pre-exercise to post-exercise (p = 0.034), with significant differences when compared to HRC (p = 0.003) and TCT (p = 0.003). HRC and TCT induced no knee extensor fatigue, contrary to a single session of SIT. Conclusions: Peripheral fatigue seemed to prevail following SIT in comparison with HRC and TCT, as seen by the decreased tetanic force in the former only. From an applied perspective, practitioners should carefully plan training activities to be performed the days following a SIT session, as force-generating capacity may be impaired for up to 48 h.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020180

Authors: John Nyland Maggie Head Essa H. Gul Brandon Pyle Jarod Richards

Background: Anterior cruciate ligament (ACL) injuries are increasing in young athletes and many are related to non-contact, spontaneous mechanical fatigue-related ruptures. The objective of this narrative review is to identify and synthesize the anatomical, histological, physiological, and biomechanical basis of extracellular matrix (ECM) factors that contribute to ACL injuries and suggest ways to decrease their occurrence. Methods: The primary investigator searched PubMed, Web of Science, and Google Scholar database titles and abstracts using search phrases with Boolean operators: “anterior cruciate ligament” OR “ACL”, OR “cranial cruciate ligament” AND “disease”; “anterior cruciate ligament” OR “ACL”, OR “cranial cruciate ligament” AND “spontaneous rupture” OR “non-contact injury”; and “anterior cruciate ligament” OR ACL, OR cranial cruciate ligament” AND “crosslink”, “collagen” OR “extracellular matrix”; and “anterior cruciate ligament” OR “ACL”, OR “cranial cruciate ligament” AND “microtrauma”, OR “sudden” OR “fatigue failure”. The primary investigator and a sports orthopedic surgeon reviewed titles and abstracts of diverse evidence sources. From these identified sources, the study team performed full text reviews, selected contributing articles, performed Strength of Recommendation Taxonomy (SORT) grading, and synthesized the following themes: A Hostile Environment, ACL Strain, and Poor Nutrient Delivery; Accumulative ACL Microtrauma and Mechanical Failure; The ACL Differs From Other Ligaments; Collagen, the ECM, and ACL Mechanobiology; Crimps and ACL ECM Stretch; Crosslinks Improve ECM Mechanical Properties; The Delicate Collagen Synthesis and Degradation Balance; Exercise Training and the ACL; Can Nutraceuticals Help Restore the Balance?; Training Induced ACL Hypoxia; Estrogen and the Female Athlete; Counting Pitches or Counting Collagen Fiber Ruptures; and Restoring A Positive Anabolic–Catabolic Collagen Balance. Results: Regular exercise training within a physiologically safe loading range is vital to ACL ECM health. However, low or moderate evidence suggested that poor blood supply, slow metabolism, and a hypoxic environment may unbalance anabolic and catabolic homeostasis. Active rest and recovery concepts that prevent youth baseball shoulder and elbow injuries may help prevent non-contact ACL injuries. Conclusions: More prescriptive active rest and recovery intervals and neuromuscular control training may restore the anabolic–catabolic balance that increases mature crosslink density and improves ACL ECM strength. Confirmatory studies are needed to better establish therapeutic intervention mode(s), timing, dosage, and frequency optimization.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020179

Authors: Rafał Szafraniec Sebastian Klich Dawid Koźlenia

Objectives: The primary aim of this study was to compare the acute effects of two stretching techniques—static stretching (SST) and proprioceptive neuromuscular facilitation (PNF)—on functional outcomes related to postural balance (stabilographic parameters) and ankle range of motion (ROM; active and passive measures). Furthermore, the study aimed to assess the association between changes in balance- and ROM-related parameters. Methods: The study sample consisted of 24 young adults in the age range of 21–24. The SS group (n = 12) mean body height was 174.3 ± 7.8 [cm], body weight 68.0 ± 13.1 [kg], and BMI 22.2 ± 2.8 [kg/m2]. The PNF group’s (n = 12) mean body height was 173.7 ± 7.3 [cm], body weight 68.6 ± 13.5 [kg], and BMI 22.5 ± 3.0 [kg/m2]. The subjects performed static stretching or proprioceptive neuromuscular facilitation stretching involving the tibialis anterior, gastrocnemius, and soleus muscles. Before and immediately after the intervention, the active and passive range of plantar and dorsal flexion of the foot and the stability of the body posture in the anterior–posterior plane were measured based on the analysis of the center of pressure (COP) sway. Results: The results of the mixed model ANOVA (intervention × time) showed no statistically significant effect of the intervention or interaction between intervention and time for ROM and COP measurements. In both cases, a statistically significant time effect was found. After intervention, significant differences were found in COP variability (p = 0.02), COP range (p = 0.03), fractal dimension (p = 0.04), and sample entropy (p = 0.01). Similarly, for range of motion, differences were observed in passive dorsiflexion (p < 0.01), active plantarflexion (p < 0.01), and passive plantarflexion (p = 0.01). Pearson’s correlation analysis did not reveal significant associations between changes in ankle range of motion and COP variables. Conclusions: The results of this study indicate that both static and PNF stretching acutely increase the range of motion in the ankle joint; however, they also lead to a decrease in postural stability under more challenging conditions involving visual or vestibular deprivation. The magnitude of the range of motion changes was not associated with alterations in stabilographic parameters.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020178

Authors: Ya’ara Rozenbaum Yeshayahu Hutzler Sharon Barak

Objective: The goal was to investigate the relationship between methodological adherence and clinical outcomes in Progressive Resistance Training (PRT) for Parkinson’s Disease (PD), specifically identifying why findings of “superiority” over active controls remain inconsistent. Methods: This umbrella review utilized a multi-stage process to identify a sample of the primary literature for methodological analysis. An initial search identified 38 systematic reviews published within the specified timeframe. From the reference lists of these reviews, a subset of 34 primary clinical studies was purposefully selected. Inclusion was prioritized for studies providing comprehensive methodological data on PRT protocols and standardized clinical outcomes. Interventions were evaluated using a three-tiered framework: (1) training protocol with specifications of Frequency, Intensity, Time, Type, Volume, and Progression (FITT-VP) (General Exercise), (2) FITT-VP integrated with the American College of Sports Medicine (ACSM) Supplementary Guidelines (Integrated Guidelines), and (3) principles of progression (mechanistic growth). Studies were categorized by control type (active (e.g., aerobic or balance), n = 26; passive (e.g., standard care or no exercise), n = 8). Results: In trials that compared PRT with an active control group, PRT achieved clinical superiority in 57% (n = 15) of trials and 46% (n = 12) when focusing on trials with an effect on specific functional or balance outcomes. Among these successful interventions, 75% maintained high adherence (≥70%) to the Integrated Guidelines, and 58% maintained high adherence to the principles of progression. In the 53% (n = 14) of studies where PRT was found non-superior (equivalent or inferior in functional or balance outcomes) to an active control, 0% met the high adherence threshold for progression. While general FITT-VP compliance remained high (78%), the failure to implement systematic load, specificity, and variation served as a definitive barrier to competitive superiority. In the 100% of studies where PRT outperformed passive controls, high progression was present in 57% of cases. This may suggest that while a baseline resistance stimulus outperforms inactivity, it is fundamentally insufficient to outperform other active clinical therapies. Conclusions: This umbrella review indicates that adherence to the principles of progression may be an important factor influencing the clinical outcomes of PRT in individuals with PD. The variability observed in the current literature suggests that inconsistent application of established exercise frameworks—rather than the failure of the modality itself—could be a contributing element to the reported “inconclusiveness.” To potentially enhance functional outcomes and the comparative effectiveness of PRT, future research should consider prioritizing structured adherence to FITT-VP, Integrated Guidelines, and progression-based frameworks. Establishing a 70% adherence threshold is proposed as a potential benchmark to improve protocol consistency and support rehabilitation efficacy in this population.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020177

Authors: Adem Preljević Saša Bubanj Dušan Stanković Miladin Okičić Dalila Preljević Emilija Petković Miodrag Kocić Tomislav Gašić Bojan Bjelica Ivana Parčina Sanja Krsmanović Veličković Milan Mihajlović Tatiana Dobrescu Adrian Mihai Sava

Objectives: This study aimed to examine the structure of anthropometric characteristics, motor skills and specific motor skills in young football players. Methods: Study participants (427 male football players) were divided into pre-pioneers (11–13 y), n = 133; pioneers (13–15 y), n = 160; and cadets (15–17 y), n = 134. The entire sample of subjects was evaluated using 13 anthropometric and seven motor variables. The factor structure for each chronological age group was determined using Hotelling’s method. Results: Anthropometric characteristics showed three extracted factors in the pre-pioneers group, four factors in the pioneer group and two factors in the cadet group. Motor skills displayed three factors for the youngest group, two factors for the pioneers and three factors for the cadet group. Four factors were determined for specific motor skills in pre-pioneers, four in pioneers and three in cadet age. Conclusions: This study revealed structural variability and non-uniformity in the latent dimensions across age groups, with the total number of factors fluctuating between two and four. This study revealed two consistent latent dimensions in anthropometric data across all age groups: general morphological parameters and subcutaneous fat tissue. In motor skills, an initial universal factor is separated into central and energetic regulation of movements. Finally, specific motor skills demonstrated a transition from a highly differentiated four-factor structure in younger players toward a more integrated functional system in the oldest cohort, comprising intermuscular coordination, running speed with and without a ball; segmental speed of the lower extremities with a ball; and explosive force in hitting a ball with the foot and head.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020176

Authors: Chris Gaviglio Christian J. Cook Stephen P. Bird

Background: Blood flow restriction (BFR) resistance exercise has emerged as a training methodology capable of inducing muscular adaptations comparable to traditional high-load training despite substantially lower mechanical loads. While low-load BFR protocols (20–50% 1RM) are well-established, emerging evidence supports applications across the full loading spectrum, including moderate-to-high loads (>50–90% 1RM), contralateral training effects, and proximal–distal adaptations. In this second installment of the Blood Flow Restriction in Athletic Populations series, we review current evidence on BFR resistance exercise in athletic populations, with emphasis on morphological, neuromuscular, and functional adaptations across diverse application contexts. Methods: A narrative review of research examining BFR resistance exercise in trained and athletic populations was conducted via a PubMed/MEDLINE search. Search terms: (“blood flow restriction” OR “BFR” OR “occlusion training” OR “KAATSU”) AND (“resistance training” OR “resistance exercise” OR “strength training”) AND (“athletes” OR “athletic” OR “trained” OR “elite” OR “sport”) AND (“cross-education” OR “contralateral” OR “cross transfer” OR “proximal” OR “distal”). Studies investigating low-load (20–50% 1RM) and moderate-to-high load (>50% 1RM) protocols, contralateral cross-education effects, and proximal–distal adaptations were evaluated. Primary outcomes included muscle hypertrophy, strength, power, and sport-specific performance measures. Results: Low-load BFR resistance exercise has been shown to produce significant improvements in muscle hypertrophy and strength gains over 4–12 week interventions compared to low-load control conditions. Moderate-to-high load BFR enhanced barbell velocity and power output, particularly at loads > 80% 1RM with intermittent inflation protocols. Contralateral and cross-transfer effects of BFR training demonstrate variable efficacy across muscle groups, with the most consistent evidence supporting cross-transfer enhancement of training adaptations when BFR is applied to one body region while exercising another. Proximal BFR application induced adaptations in both proximal and distal musculature, suggesting systemic mechanisms beyond local vascular restriction. Conclusions: BFR resistance exercise represents a versatile training modality producing meaningful morphological and neuromuscular adaptations across the loading spectrum. Contralateral and proximal–distal effects expand practical applications for injury rehabilitation and targeted adaptation. These findings support BFR integration within periodized training programs when mechanical load management is prioritized.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020175

Authors: Chris Gaviglio Christian J. Cook Stephen P. Bird

Background: Blood flow restriction (BFR) training induces morphological and neuromuscular adaptations using low-intensity exercise (20–40% 1RM), offering a reduced mechanical load alternative to traditional high-load resistance training. Safe and effective implementation, however, requires a clear understanding of physiological mechanisms, contraindications, and pressure determination methodologies. In this three-part series, we provide a comprehensive review of BFR for athletic populations and provide strength and conditioning coaches with a structured framework for screening, safety, and methodological considerations to support BFR integration in high-performance settings. Methods: A narrative review of the literature examining BFR safety, contraindication screening, adverse event reporting, and occlusion pressure determination was conducted using a PubMed and MEDLINE search. Search terms included combinations of (“blood flow restriction” OR “BFR” OR “occlusion training” OR “KAATSU”) AND (“safety” OR “contraindications” OR “risk stratification”) AND (“arterial occlusion pressure” OR “limb occlusion pressure” OR “occlusion pressure” OR “Doppler” OR “handheld Doppler” OR “pulse oximetry” OR “cuff width” OR “capillary refill time” OR “monitoring”). Studies examining contraindication screening systems, arterial occlusion pressure calculation methods, and real-time monitoring protocols were evaluated. Primary considerations included risk stratification frameworks, pressure determination accuracy, and control parameter validation for ensuring vascular safety during application. Results: Risk stratification systems can effectively identify absolute and relative contraindications requiring medical clearance prior to BFR use. Epidemiological data indicate that adverse events are transient and non-serious, while serious events appear rare when evidence-informed protocols are applied. Doppler-based assessment remains a criterion approach for determining inflation pressure, although validated estimation methods using limb circumference and systolic blood pressure offer a pragmatic and comparable alternative for applied environments. Inflation pressures of 50–80% arterial occlusion, adjusted for cuff width, produce effective and safe stimulus. Real-time monitoring through capillary refill time, pulse strength palpation, and skin coloration can support iterative pressure optimization and help identify excessive restriction pressures. Conclusions: BFR implementation in athletic populations requires systematic screening protocols, individualized inflation pressure determination using validated methods, and real-time monitoring parameters. These foundations provide the essential safety infrastructure required before progressing to specific training applications across resistance, cardiovascular, and other performance and rehabilitation modalities.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020174

Authors: Laurence Mille-Hamard Murielle Garcin Stéphane Dufour Véronique L. Billat

Background: Race walking, an Olympic discipline, produces an increase in energy cost and a change in the recruitment pattern of muscle fibres compared with running, yet the cardiorespiratory responses of elite race walkers to severe-intensity exercise remain poorly characterised. Objectives: (i) To determine whether exhaustive exercise performed at vΔ50 elicits VO2max in young elite race walkers, and (ii) to compare the temporal and metabolic profiles of this effort with those of similarly trained runners. Methods: Fourteen elite junior athletes (seven race walkers and seven runners) completed an incremental test to determine velocity at the lactate threshold (vLT), vVO2max, and VO2max, followed by a constant-velocity trial at individual vΔ50 performed to voluntary exhaustion on a 400 m track. Breath-by-breath VO2, heart rate, capillary blood lactate concentration, and time to exhaustion, time limit (Tlim) were measured. Results: At vΔ50 (≈94% vVO2max), the race walkers reached VO2max, with no detectable VO2 slow component (SC) in six of seven participants. In contrast, runners exhibited a significant SC (8 ± 3% of total VO2). The energy cost (EC) was 16% higher in race walking than in running (p < 0.01). Conclusions: In elite junior race walkers, it seems that vΔ50 reliably elicits VO2max primarily due to a high baseline oxygen cost rather than a progressive VO2 SC, contrasting with the kinetic response observed in running. These discipline-specific responses suggest that interval training in race walking should be prescribed using walking-specific thresholds. This study is preliminary, given the small sample size; further studies with larger cohorts are warranted.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020173

Authors: Nikola Stamenov Boycho Landzhov Maria Piagkou Ahmed Al-Sadek Lyubomir Gaydarski Kristina Petrova Georgi Luchev Julian Ananiev Iva N. Dimitrova Georgi P. Georgiev

Background: The epiligament (EL) of the medial collateral ligament (MCL) has recently attracted increasing attention as a biologically active structure. Emerging evidence suggests that it may contribute to ligament healing by providing progenitor cells, vascular components, and signaling mediators. However, its cellular composition and possible regional variability remain insufficiently characterized. Aim: This study evaluated the expression of vimentin, S100 protein, and epithelial membrane antigen (EMA) to better characterize the EL compared with the ligament proper (LP). Methods: Twelve human MCLs obtained from twelve deceased donors were divided into proximal, middle, and distal segments. Thirty-six paraffin blocks were prepared, from which 180 sections were obtained and equally assigned for immunohistochemical staining of vimentin, S100 protein, and EMA (60 slides for each marker). Systematic quantification of seven to eight non-overlapping microscopic fields per slide generated 900 standardized observations for each investigated marker. This sampling strategy provided 150 measurements for each sub-region (EL and LP across the three anatomical segments). Immunoreactivity was quantified using ImageJ software. Statistical differences were analyzed using a robust two-way analysis of variance (ANOVA), while biological associations between markers were assessed using Spearman’s rank correlation analysis. Results: Vimentin and S100 expression were consistently higher in the EL than in the LP across all anatomical regions (p < 0.0001). The highest vimentin values were observed in the proximal region (median 17.34 vs. 10.14) and distal region (median 19.34 vs. 11.23), whereas S100 showed the greatest expression in the proximal (median 16.9 vs. 7.2) and distal regions (median 14.1 vs. 8.9). EMA expression was generally lower overall; however, it remained significantly higher in the EL than in the LP within the proximal (median 6.87 vs. 5.77) and middle regions (median 4.80 vs. 3.26). No significant difference was identified in the distal region. Spearman rank correlation analysis demonstrated significant positive associations among all investigated markers (p < 0.001), with the strongest relationship observed between vimentin and S100 protein (Spearman correlation coefficient = 0.430). Conclusions: The EL of the MCL is a structurally and biologically distinct component, characterized by significantly higher expressions of vimentin, S100, and EMA than the LP. The significant positive correlations observed among these markers support the concept that the EL functions as an integrated biological microenvironment with clear regional heterogeneity, particularly within the proximal and distal segments. Further studies are warranted to clarify the functional relevance of these findings and their potential implications for clinical management and ligament healing strategies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020172

Authors: Dimo S. Stoyanov Tsvetomir E. Kachovski Kamelia Bratoeva Anton B. Tonchev Emil G. Kovachev Stoyan P. Pavlov

Background: Anatomical variations are inevitable part of studying the human body. Very often, muscles of the limbs may show atypical attachments, extra or fewer muscle bellies. These variations are likely rooted in limb development. Our goal was to thoroughly study and describe the variations in the lateral wrist extensors. Our initial goal was to attempt to explain the developmental processes that occur before the formation of these variations, with a focus on the interconnecting tendons. Methods: We used a standard dissection technique, paying extra attention to the space between the two radial wrist extensors to properly visualize interconnecting tendons. Taking advantage of the chi square test, we compared the observed vs the expected random distribution of interconnecting tendons. Results: In this article, we systematically studied the variations in the interconnecting tendons of the lateral carpal extensors in 58 upper limbs of our cadaver donors used for the education of medical students. The main variation we found is interconnecting tendons between the extensor carpi radialis longus and extensor carpi radialis brevis. The insertion and origin of the interconnecting tendons were consistent: it either originates from the middle of the ECRB body and inserts medial to ECRL tendon or it originates from the ventral side ECRL and inserts ventral to the ECRB tendon. We supplemented them with two dissections of fetal upper limbs (at GW 12 and GW 17). Statistical analysis of the distribution of single vs double interconnecting tendons suggests that they are dependent events, consistent with literature data. Conclusions: Based on our observations and the literature, we propose that oblique muscle division and a mismatch between the muscle fission plane and the initial distal tendon fission plane may result in the observed phenotype. We also suggest that the origin of the extra numerary tenons form ECRL body may play a role when choosing which one to mobilize for tendon transfer.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020171

Authors: Camille Eyssartier Pierre Billard Patricia Thoreux Christophe Sauret

Background: Gymnasts are reported as a population at high risk of low back pain. The prevention and treatment of low back pain often rely on improving the effectiveness of deep stabilizer muscles through exercises that aim to reach spinal alignment and axial lengthening. However, the scientific evidence regarding the effect of the specific instructions used during exercises on the spinopelvic complex is still lacking. To address this gap of knowledge, the aim of this pilot study was to examine the effect of specific postural and breathing instructions (spine straightening, forced expiration and perineal contraction) on the sagittal alignment of the spine before and after fifteen weeks of a specific muscle strengthening program. Methods: Low-dose biplanar radiographic images were taken in neutral position and in the five specific postures before and after the program and associated skeletal 3D reconstructions were performed allowing calculation of sacral slope, pelvic tilt, lumbar lordosis and thoracic kyphosis. Results: Sixteen gymnasts completed the entire protocol and were included in the analysis. At the end of the program, most of the postures tested led to a decrease in sacral slope, an increase in pelvic tilt, a reduction in lumbar lordosis, and a decrease in thoracic kyphosis, but with varying efficiency; the condition combining spine straightening, perineal contraction and forced expiration appeared to be the most effective in influencing all parameters simultaneously. Conclusions: The results strongly encourage combining an instruction of spine straightening with instructions of both expiration and perineal contraction, which is information of interest for coaches, physiotherapists and medical professionals.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020170

Authors: Oscar Villanueva-Guerrero Bruno Travassos Hadi Nobari Rafael Albalad-Aiguabella Elena Mainer-Pardos

Objectives: The primary objective of this systematic review and meta-analysis was to analyze the effects of training programs on different parameters of physical performance in futsal players. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a systematic search was conducted using PubMed, Web of Science, and SportDiscus databases. The search was conducted for the studies published between 2014 and 2024, and 13 studies were selected that met the inclusion criteria. The random-effects model with inverse variance weighting was used for the meta-analysis. Effect sizes (ES) were reported as standardized mean differences and presented with 95% confidence intervals (CI). Results: The effects of such programs showed a primary small effect size for vertical jump (ES = 0.38; 95% CI = 0.11, 0.64; Z = 2.76; p = 0.01); for sprints ≤ 15 m (ES = −0.55; 95% CI = −0.81, −0.29; Z = 4.15; p < 0.01); for sprints ≥ 20 m (ES = −0.56; 95% CI = −0.87, −0.24; Z = 3.49; p < 0.01); for repeated sprint ability (RSA) mean (ES = −0.33; 95% CI = −0.61, −0.05; Z = 2.34; p = 0.02); and for RSA % decrement (ES = −0.38; 95% CI = −0.74, −0.02; Z = 2.06; p = 0.04). However, most included studies were based on pre–post designs without a control group, and additional analyses with control groups showed smaller or non-significant effects. Conclusions: The results indicate that training programs incorporating methods such as strength training, plyometrics, and high-intensity interval training (HIIT) improve performance in vertical jump, short- and long-sprint speed, and RSA scores. These findings highlight the importance of developing evidence-based interventions to maximize physical performance in futsal players.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020169

Authors: Liliana Gutiérrez-Lopéz Ivonne María Olivares-Corichi José Rubén García-Sánchez

Background: Metabolic syndrome (MetS) is a cluster of pathologies (obesity, dyslipidemia, insulin resistance, hypertension) that affects over one quarter of old adults. MetS is a condition that markedly increases the susceptibility of various organs to dysfunctionality and is associated with the development of oxidative stress. The existing guidelines point out that exercise is highly advantageous for patients with MetS. However, there is a need for specific guidance and clinical evidence. Objective: This study aimed to investigate the effects of a moderate aerobic exercise program on older women without and with MetS. Methods: A total of 120 women aged 60–70 years old were recruited and divided into two groups: healthy old women (HOW, N = 60) and old women with MetS (OW-MetS, N = 60). Anthropometric values, biochemical parameters and markers of oxidative damage were evaluated before and after moderate aerobic exercise. Exercise was performed five days per week for three months (64 sessions). Each exercise session consisted of 40 min and included the following: (a) five minutes of warm-up exercise; (b) ten minutes of flexibility exercise with resistance using own weight and coordination; (c) twenty minutes of moderate-intensity aerobic exercise (heart rate max between 60% and 70%); and (d) five minutes to cool down/stretching with respiratory techniques. Results: A significant decrease in anthropometric variables was generated by the exercise program [waist circumference 4.35 cm (p < 0.05) in OW-MetS, body fat −1.55, −1.39% (p < 0.05) and muscle mass 0.8, 1.1% (p < 0.05) in HOW and OW-MetS, respectively]. The exercise program resulted in beneficial changes in all biochemical parameters in both groups. Importantly, HOMA values showed a significant decline of −0.85 and −6.17 in HOW and OW-MetS, respectively. Furthermore, oxidative stress was present in the OW-MetS group, which was reduced by the exercise program, resulting in a decrease in protein damage [formazan 45% and 42% in HOW and OW-MetS respectively] and an increase in antioxidant defenses (thiol groups 36%, 99% and GPx 55%, 20% in HOW and OW-MetS, respectively). Conclusions: The data of this study show that moderate aerobic exercise may be potentially useful in treating and preventing MetS in older patients.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020168

Authors: Aday Infante-Guedes María del Carmen Carcelén-Fraile Paulino Vico-Rodríguez Marta Cano-Orihuela

Background: Childhood is a key period for the development of body composition and physical activity habits that may influence health throughout life. Although physical activity has been widely associated with adiposity indicators, the role of enjoyment of physical activity as a motivational and affective component remains less explored. Therefore, the aim of this study was to analyze the relationship between several anthropometric indicators and both the level of physical activity and enjoyment of physical activity in schoolchildren. Methods: An observational, analytical, cross-sectional study was conducted with 386 schoolchildren (176 boys and 210 girls) with a mean age of 11.15 ± 0.66 years. Anthropometric indicators included body mass index, waist circumference, hip circumference, waist-to-hip ratio, and triceps and subscapular skinfold thickness. Physical activity level was assessed using the Physical Activity Questionnaire for Children (PAQ-C), and enjoyment of physical activity was evaluated using the Physical Activity Enjoyment Scale (PACES). Multiple linear regression analyses were performed, adjusting for age and sex. Results: Higher levels of physical activity were significantly associated with lower body mass index (B = −1.592; p < 0.001), waist circumference (B = −8.010; p < 0.001), hip circumference (B = −8.227; p < 0.001), waist-to-hip ratio (B = −0.008; p < 0.001), triceps skinfold thickness (B = −0.910; p = 0.002), and subscapular skinfold thickness (p < 0.05). Greater enjoyment of physical activity was significantly associated with lower body mass index (B = −1.778; p < 0.001), reduced waist circumference (B = −8.944; p < 0.001), hip circumference (B = −9.185; p < 0.001), waist-to-hip ratio (B = −0.008; p < 0.001), and triceps skinfold thickness (B = −1.100; p = 0.001). Greater enjoyment was also associated with lower anthropometric indicators of central adiposity (waist circumference and waist-to-hip ratio), whereas no significant association was observed with subscapular skinfold thickness (p = 0.066). Conclusions: Physical activity level and enjoyment of physical activity were associated with multiple anthropometric indicators in children, although physical activity showed more consistent associations, whereas enjoyment demonstrated a more selective pattern depending on the specific adiposity measure. These findings highlight the importance of considering both behavioral and affective dimensions of physical activity when promoting healthy morphofunctional development during childhood.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020167

Authors: Hongqiang Liu Feifei Ma

Objectives: This study aims to investigate the correlations between changes in skin temperature and surface electromyography (sEMG) parameters during fatigue induced by varying exercise intensities. The study uses infrared thermal imaging and sEMG to explore whether skin temperature fluctuations can indicate muscle fatigue states. Methods: Two static contraction fatigue tests were administered on the right biceps brachii muscle group of 30 healthy male subjects at 30% and 70% MVC (Maximum Voluntary Contraction) intensity levels. Tests were separated by a 5-day interval and continued until complete fatigue was achieved. The left arm served as a control and was not subjected to any load. Infrared thermal imaging was employed to record continuous skin temperature, capturing data from 120 s pre-exercise to 480 s post-exercise commencement at ten frames per second. Concurrently, sEMG parameters (RMS—Root Mean Square, MPF—Mean Power Frequency, and MF—Median Frequency) were synchronously collected at a sampling frequency of 1 kHz. Results: During 70% MVC exercise, skin temperature on the exercised arm consistently decreased, reaching its nadir by the end of the exercise, with a statistically significant divergence from the baseline (p < 0.05). At 30% MVC, skin temperature initially slightly declined before gradually increasing. The control arm’s temperature significantly declined across exercise intensities and during recovery. A significant temporal correlation was observed between skin temperature and sEMG parameters. Conclusions: 1. Variability in skin temperature patterns during muscular fatigue is contingent on the level of exercise intensity. 2. The strong correlation between skin temperature and sEMG parameters suggests that infrared thermal imaging is a promising, rapid technique for monitoring exercise-induced muscle fatigue.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020166

Authors: Anastasios Lykidis Rafail Georgios Pechlivanos Anthi Angelou Nikolaos Varvariotis Chrysostomos Sahinis Ioannis G. Amiridis Roger M. Enoka

Objective: The purpose of this study was to compare the influence of biological maturity status and training experience on motor performance in young athletes of different sport disciplines. Methods: Youth athletes (n = 84, 23 females) from five different sports (basketball, volleyball, track and field, wrestling, and badminton) participated in this study. Jump height was measured for the squat jump (SJ) and countermovement jump (CMJ). Peak torque during maximal voluntary contractions (MVCs) and torque steadiness at 20% MVC were assessed during plantar flexion (PF) and dorsiflexion (DF). Postural control was assessed with the one-leg test for both the right and left legs. K-means clustered analysis categorized participants into groups of low and high performers. Results: High performers had greater training experience than low performers for the SJ (p < 0.05), with no difference in maturity status (p > 0.05). Similarly, high performers had greater training experience (p < 0.05) than low performers for the CMJ, with no difference in maturity status (p > 0.05). High performers were more mature than low performers for MVC torque of DF (p < 0.001) and PF (p < 0.001), with no group differences in training experience (DF: p > 0.05; PF: p > 0.05). Maturity status for torque steadiness differed only for DF (p < 0.001), whereas there was no difference for PF (p > 0.05). There were no differences in either maturity status or training experience for one-leg-stance time (p > 0.05). Conclusions: These findings suggest that maturity status and training experience are linked to performance, although their relative roles differ across tasks. These findings reflect an interaction between biological maturity, training background and sports performance in youth athletes.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020165

Authors: Italo Sannicandro Luigi Armiento Nicola Trotta Federico Abate Daga

Background: This study aimed to examine whether a physical education program based on the ecological dynamics approach, implemented through small-sided games (SSG), produces greater improvements in motor skills, daily physical activity levels, and perceived physical fitness in middle school students. Methods: Forty-eight students were assigned to an SSG group (ecological dynamics lessons including small-sided games, n = 26) or a Control group (traditional lessons based on teacher-centered instruction and analytical exercises, n = 22). The intervention lasted 12 weeks, with two sessions per week. Motor performance was assessed using the standing broad jump, 5-standing broad jump, 20 m sprint, 10 × 5 m shuttle run, 5-0-5 agility test, and sit-and-reach test. Daily physical activity was evaluated using the International Physical Activity Questionnaire—Short Form (IPAQ-SF), and perceived physical fitness was assessed using the Visual Analogue Fitness Perception Scale for Adolescents (FPVASA). Results: Significant group-by-time interactions were found in all motor tests. IPAQ-SF data revealed significant group-by-time interactions for vigorous and moderate physical activity. Perceived physical fitness showed significant group-by-time interactions for all items except flexibility. Conclusions: Physical education lessons structured according to the ecological dynamics approach and implemented through SSG-based protocols led to greater improvements than traditional methods. The dynamic and variable nature of SSG likely enhances neuromuscular stimulation, motor engagement, and motivation during physical education lessons.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020164

Authors: Irene-Chrysovalanto Themistocleous Charalambos Michael Stelios Hadjisavvas Elena Papamichael Michalis A. Efstathiou Christina Michailidou Manos Stefanakis

Background: Stretching exercises are strongly recommended as part of exercise training programs; however, their effects on blood pressure (BP) and other related cardiovascular parameters in adult individuals with elevated BP (pre-hypertension) or hypertension remain unclear. Methods: A systematic search was conducted in PubMed and databases accessed via the EBSCO platform up to 30 September 2025, following the PRISMA guidelines. An additional search of Scopus was performed on 8 April 2026. Studies eligible for inclusion were randomized controlled trials, randomized crossover trials, non-randomized clinical trials and single-arm trials investigating stretching interventions in adults with pre-hypertension and or hypertension. Risk of bias assessment was performed using RoB 2 for randomized trials and ROBINS-I for the non-randomized trials. A random-effect meta-analysis was performed when at least two studies reported sufficiently comparable BP outcomes. The quantitative synthesis was considered exploratory. Results: Eleven records published between 2014 and 2025 met the eligibility criteria and were included. All protocols used static stretching, although only a small number were clearly described as active stretching. The results were heterogeneous across the design, duration of intervention and outcomes. Chronic interventions more often reported favorable changes in indices of arterial stiffness, whereas acute interventions demonstrated more variable immediate BP responses. In the exploratory meta-analysis, the pooled estimate suggested a reduction in systolic blood pressure (SBP) in favor of stretching; however, this effect did not reach statistical significance (mean difference (MD) = −5.39 mmHg, 95% confidence interval (CI): −11.32 to 0.53; I2 = 0%). For diastolic blood pressure (DBP), the pooled estimate favored stretching and reached statistical significance (MD = −3.93 mmHg, 95% CI: −7.25 to −0.60; I2 = 0%). In sensitivity analyses including a third study, the pooled effects remained in favor of stretching for systolic BP (MD = −6.6 mmHg, 95% CI: −12.2 to −1.0; I2 = 56%) and diastolic BP (MD = −5.4 mmHg, 95% CI: −7.1 to −3.7; I2 = 8%). These pooled estimates should be interpreted with caution due to the small number of studies, heterogeneity in study design and participant characteristics, and overall limitations in methodological quality. Secondary findings suggested possible improvements in selected vascular parameters, including brachial–ankle pulse wave velocity, augmentation index, and cardio–ankle vascular index, whereas acute responses were more variable and protocol-dependent. Overall, the level of evidence was limited, with most randomized trials judged as having some concerns and non-randomized studies judged as having a critical risk of bias. Conclusions: Stretching interventions may improve BP and selected vascular parameters in adults with pre-hypertension and hypertension and may represent a practical adjunct within the non-pharmacological management of BP. However, the current evidence is limited by methodological heterogeneity, risk of bias, and the small number of studies available for quantitative synthesis. Therefore, the pooled findings should be considered exploratory and hypothesis-generating rather than definitive. Further high-quality randomized controlled trials are required to determine the optimal type, dose, and long-term clinical relevance of stretching interventions in this population.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020163

Authors: Sara Ascic Mijo Curic Iva Sklempe Kokic

Background: Percussive massage therapy (PMT) with handheld massage guns is widely used to support recovery and flexibility, but the short-term behavior of skeletal muscle contractile properties and the relative contribution of application duration versus frequency remain unclear. This study investigated the 10 min post-intervention time course of tensiomyography (TMG)-derived contractile properties of non-fatigued vastus medialis (VM) after clinically realistic PMT protocols and examined whether longer duration is associated with persistent deviations from baseline than frequency. Methods: In a two-session, within-subject repeated-measure design, 32 participants completed four PMT conditions to the VM (35 Hz–3 min, 35 Hz–6 min, 45 Hz–3 min, and 45 Hz–6 min). TMG parameters (Td, Tc, Ts, Tr, and Dm) were recorded at baseline and repeatedly over 10 min post-intervention. Linear mixed-effect models with frequency and duration as fixed factors and time as continuous and categorical were used to characterize temporal patterns, with emphasis on effect sizes and consistency across parameters. The fixed protocol order (35 Hz in session one, 45 Hz in session two, 3 vs. 6 min assigned to contralateral legs) means that frequency was confounded with session and duration with leg side. Results: Compared with the 3 min protocols, the 6 min protocols were associated with slightly higher Td and Ts, a modest increase in Tr and a slightly greater Dm (e.g., Dm + 0.55 mm), whereas Tc showed no clear duration effect. Across conditions, Td increased immediately after PMT, Tc remained elevated for most of the first 8 min, Ts increased from mid to late post-intervention, Tr changed inconsistently, and Dm was reduced relative to baseline for most of the 10 min period. Differences between 35 and 45 Hz were small and non-significant for all TMG parameters. Conclusions: Clinically realistic PMT protocols at 35–45 Hz in non-fatigued muscle induce small but statistically detectable, duration-sensitive changes in TMG-derived contractile behavior over approximately 10 min. Within the constraints of the fixed, non-randomized design and the small effect sizes observed, these findings support viewing massage gun use as a recovery-oriented adjunct that subtly modulates contractile dynamics, rather than as a strong, standalone performance-enhancing stimulus.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020162

Authors: Lúcia Sousa Daniel Canedo Pedro Santos António Neves

Objective: Functional training exercises involve complex multi-joint movements that challenge traditional rule-based or data-driven recognition systems. This paper introduces a Movement Description Language (MDL) designed to formally represent, analyze, and evaluate such exercises using camera-based pose estimation and interpretable, composable structures. Methods: The proposed MDL models each exercise as a finite-state machine defined by pose-derived angle proxy transitions, allowing movements to be described in a modular and reusable way. Demonstrated with MediaPipe landmark extraction from monocular video, while the MDL remains compatible with any pose estimation algorithm, the framework focuses on exercise phase detection and repetition counting. Experimental validation was conducted on a dataset of 1513 videos of 12 functional exercises (squats, deadlifts, lunges, shoulder presses, planks, push-ups, pull-ups, bent-over rows, box jumps, thrusters, overhead squats, and burpees) obtained from public pose datasets, competition footage, and recordings of 9 participants in real-world environments. Results: Automated repetition counts were compared against manually annotated ground truth, showing an overall repetition-counting accuracy of 97.2%, with a mean per-exercise accuracy of 98.8% (range 95–100%). The MDL successfully handled both simple and compound exercises, maintaining reliable phase detection despite variations in execution speed, camera perspective, and environmental conditions. Conclusions: The system was implemented using real-time pose estimation to demonstrate the practical execution of the MDL framework. The proposed MDL provides a transparent, extensible, and computationally efficient framework for functional exercise analysis. By bridging human-readable movement semantics with executable motion logic, it enables interpretable automatic repetition counting and phase detection, offering an alternative to black-box recognition approaches. The results support its potential for scalable deployment in training, monitoring and movement analysis applications. The proposed system is not intended for biomechanical measurement or clinical-grade kinematic analysis, but rather for interpretable modeling of exercise structure and repetition detection using approximate pose-derived signals.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020161

Authors: Martin E. Barra-López Carlos López-de-Celis Erik Garcia-Ribell Sergi Rodríguez-Rodríguez Miguel Malo-Urriés Jacobo Rodríguez-Sanz

Background: Although several studies have compared muscle activity in ‘healthy’ and ‘unhealthy’ shoulders, studying ‘healthy’ shoulders alone could improve the understanding of shoulder biomechanics. Objective: This study aims to describe the electromyographic activity of several shoulder muscles during a full range of free active flexion, as well as during abduction and scaption movements, and to compare gender differences in subjects with no history of shoulder pain or pathology. Methods: A cross-sectional descriptive study was conducted with 34 subjects aged between 18 and 60 years of both genders. The activity of the anterior, middle, and posterior deltoid, serratus anterior, infraspinatus, latissimus dorsi, and teres major muscles was measured using surface electromyography. Root Mean Square (RMS) values were calculated as a percentage of Maximal Voluntary Isometric Contraction (MVIC). Results: Regardless of whether they are considered agonists or antagonists, these muscles were active, with no statistically significant differences (Mann–Whitney U test), during both the lifting and lowering phases of the studied movements. Statistically significant differences between movements were observed only in the deltoid (Kruskal–Wallis H test, p < 0.004), which was more active during abduction. Women showed statistically significant muscle activity increase compared with men in some movements, except in the infraspinatus muscle—for example, in the three parts of the deltoid during the lifting phase of scaption (ANCOVA, p = 0.002–0.024). Conclusions: In this sample, the shoulder muscles studied showed comparable activity, acting as agonists or antagonists during shoulder elevation. These findings are exploratory and may help inform future studies on muscle activation in healthy shoulders during more varied functional tasks.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020160

Authors: Patrick W. R. Norton Stephen J. Norton Kevin I. Norton

Background: Talent identification (TID) programmes aim to detect adolescents with high physical potential, yet the efficiency of finding high-performance talent across different testing environments in an Australian context is unknown. The current study aim was to calculate the likelihood of participants scoring at or above the 90th percentile in anthropometric or physical performance measures across different testing settings. Methods: We analysed retrospective, cross-sectional physical and performance data from 10,134 Australian adolescents aged 12–17 years (4427 girls; 5707 boys) tested in either schools (2992; 3500), advertised come-and-try TID “Select” sessions (1235; 1622), or community-based amateur sports clubs (200; 585). Standardised measures used across all settings included height, body mass, and five physical performance tests of strength, speed, agility, leg power and aerobic fitness. We used a threshold of “higher physical performance” or “physical talent” as an age- and sex-specific ≥90th percentile ranking in any of the performance tests when compared against our international normative database. Anthropometry measures were also compared using the same approach across settings. Results: Chi-square tests showed girls had significantly higher (p < 0.001) prevalence of ≥90th percentile scores in all performance results in Select, and all except speed in Sport settings compared to Schools testing. No differences were found for either height or body mass across settings (p = 0.078 and 0.17, respectively). Boys exhibited smaller differences, with Sport settings yielding significantly higher sprint and agility scores ≥90th percentile (p < 0.05), relative to both Schools and Select testing environments. Differences were found for height and body mass across settings (p < 0.001 for both analyses, respectively). Conclusions: Select environments enhance the identification of physically talented girls, while boys demonstrate broader distribution of performance talent across settings. Findings inform resource allocation for future TID programmes when the primary aim is to maximise the efficiency of finding higher-performance physical talent relative to the number of tests conducted.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020159

Authors: Yuta Tsubouchi Takashi Kataoka Ryota Takase Takefumi Otsu Ryoji Hamanaka Masashi Kataoka Nobuhiro Kaku

Background: The combination of pharmacological therapy and exercise is frequently recommended for osteoporosis management; however, whether antiresorptive agents may interfere with exercise-induced bone adaptation remains unclear. This study aimed to investigate the independent and combined effects of zoledronate and treadmill exercise on bone microarchitecture and mechanical strength in an ovariectomized rat model. Methods: Twenty-four female Sprague Dawley rats underwent ovariectomy and were assigned to four groups: Control, zoledronate (ZA), treadmill exercise (T), and combined zoledronate and exercise (ZA + T). An additional sham-operated group was included. Zoledronate was administered as a single subcutaneous injection, and a 6-week treadmill exercise routine was implemented. Bone microarchitecture was assessed using micro-computed tomography, and a three-point bending test was employed for evaluation of mechanical properties. Results: The combined ZA + T group demonstrated significant improvements in trabecular bone parameters, including bone volume/tissue volume and trabecular number, compared with the Control group. Mechanical strength parameters, including maximum load and stiffness, were also significantly enhanced in the ZA + T group. Cortical bone parameters exhibited no significant changes. Conclusions: Treadmill exercise did not attenuate the effects of zoledronate, and may offer additive benefits in enhancing trabecular bone microarchitecture and mechanical strength. These findings suggest that exercise therapy can complement bisphosphonate treatment and contribute to optimizing therapeutic strategies for osteoporosis, supporting the potential utility of combined pharmacological and exercise-based interventions for improving bone health.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020158

Authors: Inês Neves Serôdio Olalla Saiz-Vázquez Hilario Ortiz-Huerta Lucia Simón-Vicente Montserrat Santamaría-Vázquez

Background: Complex regional pain syndrome (CRPS) is a disabling post-traumatic pain condition that may occur after distal radius fracture (DRF), potentially impairing recovery and upper-limb function. Identifying effective preventive strategies after DRF is therefore clinically important. Objective: To synthesize and critically appraise interventions intended to prevent CRPS after DRF, including rehabilitation protocols and clinical prophylaxis strategies. Methods: This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses PRISMA and was registered in the International Prospective Register of Systematic Reviews PROSPERO (CRD42023408499). Five databases (PubMed, Web of Science, Scopus, ScienceDirect, and B-on) were searched for studies published from January 2013 to 22 September 2023 in English, Portuguese, or Spanish. The primary outcome was CRPS incidence after DRF. Findings were synthesized narratively due to heterogeneity in interventions and diagnostic criteria, and risk of bias was assessed using design-appropriate tools. Results: Nine studies were included (total N = 7075; CRPS cases n = 127). Interventions comprised vitamin C supplementation (2 studies), probiotics, aspirin, polarized/polychromatic light therapy plus conventional treatment, early rehabilitation/home-exercise programs, and general CRPS-prevention protocols after DRF. Probiotics and aspirin did not reduce CRPS incidence. Vitamin C showed mixed findings across the included studies and remains debated in the broader literature. Light therapy was associated with reduced CRPS occurrence in a single study, while early active home-exercise programs appeared promising but were supported by a limited number of studies. Study designs and CRPS diagnostic criteria varied, and risk of bias was moderate-to-serious in several non-randomized studies. Conclusions: Evidence remains insufficient to support a single standardized prevention protocol for CRPS after distal radius fracture. Early active rehabilitation and progressive mobilization appear promising, but the available evidence is still limited and heterogeneous. Adjunctive strategies such as vitamin C and light therapy should be interpreted with caution, as findings for vitamin C remain debated in the literature and the evidence for light therapy is currently based on a single study. Other approaches, including probiotics and aspirin, have shown inconclusive results.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020157

Authors: Artur Terbalyan Karol Skotniczny Marcin Żak Jakub Jarosz Robert Roczniok

Objectives: Post-activation performance enhancement (PAPE) has been explored for its potential to improve performance in combat sports. This part II of the systematic review and meta-analysis investigated the acute effects of PAPE protocols on sport-specific performance outcomes and evaluated the influence of moderating variables, specifically competitive level and training experience. Methods: A PRISMA-guided search (2010–2024) identified 13 studies examining PAPE in combat sports athletes. Inclusion criteria required human trials using defined PAPE protocols and evaluating sport-specific tests, primarily the Frequency Speed of Kick Test (FSKT-10) and the Taekwondo-Specific Agility Test (TSAT). A random-effects meta-analysis (Hedges’ g) was conducted on data from 176 athletes. Results: The meta-analysis revealed a profound moderating effect of training status on PAPE responsiveness. For the FSKT-10, amateur athletes demonstrated large, significant improvements (g = 1.28, p < 0.001), whereas elite athletes showed trivial, non-significant changes (g = 0.11, p = 0.357). Similarly, athletes with <6 years of training experience exhibited substantially larger enhancements in both FSKT-10 (g = 1.60) and TSAT agility (g = −1.64) compared to their more experienced (>6 years) counterparts (g = 0.42 and g = −0.65, respectively). Furthermore, dynamic and biomechanically specific conditioning activities (e.g., repeated high-intensity techniques) were most effective at driving sport-specific potentiation. Conclusions: PAPE protocols may enhance acute sport-specific performance when utilizing dynamic, highly specific conditioning activities. However, a possible “ceiling effect” may blunt this potentiation in elite and highly experienced athletes, suggesting a potential need for highly individualized priming strategies at the top competitive levels, specifically in taekwondo.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020156

Authors: Giovanni Fiorilli Andrea Buonsenso

In recent years, physical activity has increasingly been recognised as an integral component of public health, contributing substantially to the prevention, management, and treatment of major non-communicable diseases [...]

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020155

Authors: Gregory Gordon Taygan Nadar Andrew Green

Background: Sprint performance, including acceleration, maximal velocity and deceleration, is crucial for athletic success in field and court-based sports; however, deceleration remains understudied despite its role in change of direction (COD) and match performance. Methods: This study addressed this gap by comparing eccentric metrics from countermovement jumps (CMJ), drop jumps (DJ) and the Nordic hamstring exercise (NHE) to 30 m sprint and deceleration ability in 28 university athletes (Age: 20 ± 1 years; Mass: 68 ± 9 kg; Height:166 ± 6 cm). Correlations were analysed with Pearson’s r for normal data and Spearman’s r for non-normal data. Results: Significant negative correlations were found between the CMJ and DJ heights and the modified reactive strength index (RSIMOD), as well as the reactive strength index (RSI) with sprint time (r = −0.54 to −0.83, p < 0.05), while positive correlations were obtained with sprint velocity (r = 0.57 to 0.83, p < 0.05). The eccentric mean forces from CMJs and DJs were positively correlated with sprint time and deceleration momentum (r = 0.62 to 0.84, p < 0.05). However, there were no significant correlations between NHE eccentric force and any sprint or deceleration metrics. The CMJ and DJ heights, RSI and eccentric mean forces strongly predicted sprint time, velocity, and momentum, but not deceleration performance, highlighting the role of explosive power and reactive strength. The NHE eccentric force had no significant relationships with sprint or deceleration metrics. Conclusions: These results highlight that CMJ and DJ are effective predictors of sprint performance, while deceleration efficiency may rely on other biomechanical factors.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020154

Authors: Vanessa Wellauer Johannes Benrath Rens Baeyens Erich Hohenauer Ron Clijsen

Background: Adequate muscle perfusion, particularly at the level of muscle microcirculation (MM), is essential for muscle function, recovery, and tissue health. Percussive therapy (PT) is increasingly used to support recovery and injury prevention and has shown consistent benefits for range of motion and perceived recovery. However, the underlying physiological mechanisms remain insufficiently understood, and evidence regarding its effects on MM is limited. This study investigated the acute effect of a single PT session on MM and muscle oxygen saturation (SmO2). Methods: Twenty-two healthy volunteers (24.2 ± 3.0 years) underwent a single PT application (two or four minutes) to the thigh using a handheld percussive device. MM, SmO2, and the perceived somatosensory sensation (PSS) were assessed at baseline and at five-minute intervals up to 40 min post-application. Data were analyzed using linear mixed models adjusted for age, lower-body fat percentage, and intervention duration. Results: A significant main effect of time was found for both MM and SmO2. MM increased significantly compared to baseline from 5 to 15 min post-application (all p < 0.001), while SmO2 increased immediately after PT and remained elevated throughout the 40-min observation period (all p < 0.001). PSS increased significantly during the first 20 min (all p < 0.02) before returning to baseline. Conclusions: A single PT application was associated with transient increases in MM and sustained elevations in SmO2, along with associated subjective sensations. These time-associated changes suggest that PT may enhance local muscle perfusion and therefore contribute to the understanding of its physiological mechanisms.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020153

Authors: Iosif-Alexandros Kouidis Pantazis Deligiannis Anastasia Theofanous Maria Anifanti Evangelia Kouidi

Background: Μetabolic syndrome (MetS)—comprises central adiposity, elevated blood pressure, dyslipidaemia, and dysglycaemia, increasing the risk of type 2 diabetes and cardiovascular disease. Exercise training improves cardiorespiratory fitness and several MetS components, but real-world effectiveness is limited by poor adherence, restricted supervision, and insufficient personalisation. Objective: This scoping review mapped the clinical intervention evidence on technology-enhanced exercise and structured physical activity relevant to MetS, while distinguishing direct MetS evidence from translational evidence. Methods: In accordance with PRISMA-ScR, we searched PubMed and extended the search to Scopus and Web of Science; a supplementary IEEE Xplore search and a post hoc Embase check were also conducted. Eligible studies were interventions using web-based delivery, wearables, telemonitoring/mobile health (mHealth), artificial intelligence (AI) coaching, virtual reality (VR)/exergaming, or continuous glucose monitoring (CGM) alongside exercise training or structured physical activity. Results: Nineteen studies met the eligibility criteria. The evidence base was weighted toward wearable/app-based feedback and telemonitoring/mHealth/web-based approaches, with fewer studies on VR/exergaming, CGM-enabled exercise, and AI coaching. Most studies were randomised or cluster-randomised, but interventions were usually short term. Across categories, technology most consistently supported adherence, self-monitoring, accountability, remote supervision, and, in selected cases, physiology-informed personalisation. Direct MetS evidence was strongest for wearables with structured feedback, telemonitoring, mHealth, and web-based delivery, whereas AI coaching and CGM were supported by adjacent translational evidence. Conclusions: Technology-enhanced exercise and structured physical activity show promising but heterogeneous and still preliminary potential for MetS management. Key limitations include short follow-up, uneven representation across categories, inconsistent reporting of exercise dose/intensity fidelity and adverse events, and limited equity and implementation outcomes.