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 A. 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.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020152

Authors: Velimir Jeknic Milivoj Dopsaj Nenad Koropanovski

Objectives: Agonist–antagonist coordination is traditionally defined as simultaneous neural activation assessed by electromyography (EMG). The present study adopts a mechanical perspective, examining twitch-derived contractile ratio indexes between antagonistic muscle groups using tensiomyography (TMG). The aim was to determine whether sport expertise differentiates mechanical agonist–antagonist coordination in karate athletes. Methods: Fifty male participants were divided into four groups: elite karate athletes (EK; n = 7), national team members (NK; n = 14), basically trained karate practitioners (BK; n = 16), and physically active non-athlete controls (CG; n = 13). Bilateral TMG assessment of rectus femoris, vastus lateralis, vastus medialis, biceps femoris, and semitendinosus was performed. Contraction time (Tc), total contraction time (TcT), and rate of muscle tension development (RMTD) were extracted. Twelve twitch-derived contractile ratio indexes (CRI) were calculated separately for dominant (D) and non-dominant (ND) limbs. Results: Significant between-group differences were observed in the temporal coordination of the non-dominant leg. EK demonstrated the lowest index for average contraction time (CRI_Tc_AVG_ND = 17.13%; ANOVA p = 0.005; EK vs. NK p = 0.003) and total contraction time (CRI_TcT_AVG_ND = 9.72%; ANOVA p = 0.003; EK vs. NK p = 0.002). In contrast, velocity-related coordination in the dominant leg was highest in EK (CRI_RMTD_cV_D = 63.66%; ANOVA p = 0.002), differing from NK (p = 0.003), BK (p = 0.002), and CG (p = 0.009). Conclusions: Elite karate athletes exhibit distinct twitch-derived mechanical coordination profiles characterized by highly efficient temporal interplay in the non-dominant (supportive) limb and elevated velocity-related contractile ratio in the dominant (executive) limb. These findings suggest that sport expertise is associated with task-specific mechanical modulation between antagonistic muscle groups detectable through involuntary contractile responses.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020151

Authors: Adrian Odriozola Cristina Tirnauca Adriana González Francesc Corbi Jesús Álvarez-Herms

Background: Conventional analyses of physiological recovery often rely on discrete metrics that assume independence across time points, thereby ignoring intrinsic temporal continuity and masking substantial interindividual heterogeneity. This proof-of-concept study assesses the efficacy of Functional Data Analysis (FDA) as a promising framework for characterizing individual response dynamics following a functional threshold power (FTP) test. Methods: Physiological time-series data (including blood lactate, heart rate, blood pressure, and glucose levels) collected from 21 trained cyclists (10 professionals, 11 amateurs) were represented as functional objects using FDataGrid on the original sampling grid (0, 3, 5, 10, 20 min), without basis expansion or smoothing. We conducted unsupervised functional clustering (K-means; Fuzzy K-means) and supervised classification (Maximum Depth with Modified Band Depth, K-Nearest Neighbors, Nearest Centroid, functional QDA with parametric Gaussian covariance). Model performance was estimated via Repeated Stratified 5-Fold Cross-Validation with 10 repetitions (50 folds), reporting accuracy, balanced accuracy (mean ± SD), 95% CIs, permutation p-values, and sensitivity/specificity from aggregated confusion matrices. Results: Lactate (CL) and diastolic blood pressure (DBP) provided useful and statistically significant discrimination across several classifiers (e.g., KNN, Nearest Centroid, functional QDA), whereas heart rate showed modest discriminative value and glucose intermediate performance. Unsupervised analyses revealed distinct lactate recovery profiles and graded membership for hemodynamic/metabolic variables, supporting the value of FDA for resolving heterogeneity beyond group-average trends. Conclusions: FDA offers a feasible and informative approach for classifying recovery phenotypes while preserving temporal structure. Findings are promising but should be interpreted with caution due to the small sample size, sparse time points, and the need for external validation in larger, independent cohorts before translation into routine decision-making.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020150

Authors: Chishan Shiao Olga Dubey Michael A. Petrie Clayton L. Rosinski Matthew A. Howard Richard K. Shields

Background: Human physiology-based biomarkers, such as transcortical long-latency reflexes (LLRs) and movement control performance, are measurements used to evaluate human performance. We developed a method to assess human performance variables using a custom-designed visuomotor control device with the capability to examine performance accuracy and neurophysiological responses to unexpected perturbations. We assessed the internal consistency and reproducibility of this device during a shoulder tracking task including the performance accuracy and the transcortical long-latency reflexes during unexpected perturbations. Methods: 86 healthy young adults (49 females, right-handed, mean age 25.8 ± 9.5 years) were assessed for internal consistency across varying resistance and velocity conditions. We next determined test–retest reliability among 31 participants (17 females, right-handed, mean age 24.13 ± 3.8 years). We then determined the predictability of the LLRs and performance error during perturbations using the receiver operating characteristic analysis (ROC). Results: Our results supported excellent internal consistency, fair-to-good test–retest reliability for task performance accuracy, and fair-to-good transcortical LLR responses to perturbations (McDonald’s omega > 0.9; intraclass correlation coefficients (ICCs, 0.63–0.82)). Tracking accuracy, changes in movement velocity, and infraspinatus LLRs were effective predictors of perturbation conditions (receiver operating characteristics: AUC 0.72–0.90). Conclusions: These findings support that performance-based biomarkers have moderate-to-good reliability and neurophysiology-based biomarkers have fair-to-good reliability when assessing human shoulder performance among healthy adults. Studies are currently underway to determine if these measures are reproducible across other joint movements and among people with musculoskeletal and central nervous system injury.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020149

Authors: Noemi Marchini de Souza Couto João Vitor Martins Bernal Tábata de Paula Facioli Daniel dos Santos Hugo Celso Dutra de Souza

Background: COVID-19 has been associated with persistent impairments in autonomic modulation of heart rate variability (HRV). However, whether disease severity during the acute phase influences the magnitude of these impairments remains insufficiently explored. In turn, aerobic physical training (APT) has been proposed as a countermeasure to autonomic dysfunction of HRV in different conditions, although its effects in individuals with COVID-19 are not yet well established. To address these gaps, this study investigated the consequences of COVID-19 on autonomic modulation of HRV according to disease severity and evaluated the effects of APT on this parameter. Methods: One hundred and sixteen individuals (58 men and 58 women) aged between 30 and 55 years were included, allocated into three groups according to the severity of the disease in the acute phase: Mild group (n = 38, mean age: 48 ± 7 years); Moderate group (n = 52, mean age: 43 ± 5 years); and Severe group (n = 26, mean age: 45 ± 6 years). All groups had anthropometric and hemodynamic parameters evaluated before and after the 16-week APT period, as well as parameters of autonomic modulation of HRV analyzed using linear (time and frequency domain) and non-linear (symbolic analysis) methods obtained from R–R interval (RRi) recordings in the supine position for 30 min. Results: Initially, all groups presented similar anthropometric and hemodynamic values. In contrast, the Moderate and Severe groups presented lower values for standard deviation of normal RRi (SDNN; Moderate: 38 ± 14 ms; Severe: 33 ± 12 ms vs. Mild: 55 ± 28 ms; p < 0.001), root mean square difference between adjacent normal RRi (RMSSD; Moderate: 28 ± 13 ms; Severe: 22 ± 7 ms vs. Mild: 47 ± 38 ms; p < 0.001), total variance (Moderate: 203 ± 127 ms2; Severe: 303 ± 157 ms2 vs. Mild: 526 ± 347 ms2; p < 0.001), and high-frequency (HF) oscillations in absolute units (Moderate: 259 ± 270 ms2; Severe: 153 ± 74 ms2 vs. Mild: 438 ± 421 ms2; p < 0.001), both compared to the Mild group. In turn, the Severe group, when compared to the other groups, also presented lower HF oscillations (Severe: 29 ± 12 nu vs. Mild: 44 ± 17 nu and Moderate: 42 ± 17 nu; p < 0.001) and higher low-frequency (LF) oscillations (Severe: 71 ± 12 nu vs. Mild: 60 ± 17 nu and Moderate: 58 ± 17 nu; p < 0.001), but in normalized units. After the 16-week APT, all groups showed increases in HF oscillations (Mild: −206 ms2 and −19.12 nu; Moderate: −236 ms2 and −26.7 nu; Severe: −211 ms2 and −31.0 nu; p < 0.001) and reductions in LF oscillations (Mild: 198 ms2 and 19.01 nu; Moderate: 98 ms2 and 26.7 nu; Severe: 218 ms2 and 31.1 nu; p < 0.001), both in absolute and normalized units. In this case, there were no further differences in LF and HF oscillations between the groups. Conclusions: Individuals who had COVID-19 and developed moderate to severe cases showed greater impairments in the autonomic modulation of HRV, characterized by increased sympathetic autonomic modulation and reduced vagal modulation. In turn, APT as a countermeasure appears to increase vagal autonomic modulation and reduce sympathetic autonomic modulation of HRV, regardless of the previous severity of COVID-19.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020148

Authors: Carlos Enrique Barrón-Gámez Tomás Javier Martínez-Cervantes José Alberto Barrón-Gámez José Ángel Garza-Cantú Enrique Barrón-Hernández Brisa Ochoa-Castillo Karina Salas-Longoria Antonino Aguiar-Barrera Ángel González-Cantú Alberto Garrido-Esquivel José Raúl Hoyos-Flores Carlos R. Montes-de-Oca-Saucedo Marina Medina-Corrales

Background: Compound muscle action potential (CMAP) parameters provide objective information on peripheral neuromuscular function, yet comparisons between track athletes and sedentary individuals remain limited, particularly when stratified by sex. This exploratory study examined whether CMAP parameters differ between sprinters and sedentary controls, with a secondary descriptive analysis of female middle-distance runners. Methods: A total of 48 participants (27 females, 21 males) aged 15 to 28 years were recruited by convenience from a restricted-access athletic population. The main comparisons focused on sprinters versus sex-matched sedentary controls, analyzed separately in females (9 sprinters, 10 controls) and males (10 sprinters, 11 controls). Female middle-distance runners (n = 8) were retained as an exploratory subgroup. Bilateral peroneal nerve conduction studies were performed in the extensor digitorum brevis. Outcomes included latency, amplitude, nerve conduction velocity, and CMAP duration. Main comparisons used Welch’s t-tests, supplemented by Mann–Whitney U tests. Effect sizes (Hedges’ g) and 95% confidence intervals were reported. A BMI-adjusted model examined whether the main female finding remained after accounting for BMI. Results: Female sprinters showed significantly higher right-sided CMAP amplitude than sedentary females (Welch p = 0.017; Hedges’ g = 1.32; 95% CI of the mean difference, 0.68 to 5.44 mV), supported by non-parametric testing (p = 0.025). The group effect remained significant after BMI adjustment. No other comparisons reached statistical significance. In males, no significant differences were observed. Conclusions: The main finding was a higher right-sided CMAP amplitude in female sprinters compared with sedentary controls, reasonably consistent across complementary parametric, non-parametric, and BMI-adjusted analyses. Given the small sample and exploratory design, these findings warrant cautious interpretation and replication in larger studies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020147

Authors: Athanasios Tsoukos Theodoros Iakovidis Sofia Georgopoulou Gregory C. Bogdanis

Background: This study examined the associations between dynamic maximum strength (front squat [FS] and clean [CL]), lower-limb vertical force–velocity (F–V) profile characteristics, and both absolute and scaled measures of competitive weightlifting performance in trained weightlifters. Methods: Fourteen competitive male weightlifters (age: 27.6 ± 4.2 years; height: 1.74 ± 0.05 m; body mass: 85.1 ± 6.7 kg; body fat: 11.7 ± 2.8%) completed three testing sessions separated by 48–72 h, including 1-RM assessment in the FS and CL, as well as vertical countermovement jump trials to determine individual force–velocity profile parameters (F0, V0, and Pmax). Official competition results obtained within the same competitive season were recorded for the snatch (SN), clean and jerk (C&J), total (TOT), and Sinclair score. Participants were additionally divided into higher and moderate jump performance groups using a median split of unloaded countermovement jump height. Results: Very strong correlations were found between 1-RM strength (FS and CL) and weightlifting performance, with CL showing the strongest associations with SN (r = 0.82), C&J (r = 0.93), and TOT (r = 0.94). Among F–V parameters, V0 and Pmax were significantly associated with competitive outcomes (r = 0.63–0.70), whereas F0 was not. V0 was significantly associated with SN (r = 0.69), C&J (r = 0.63), and TOT (r = 0.70), while F0 showed trivial-to-small associations (r = 0.08–0.28). When participants were divided using a median split of CMJ height, higher jumpers exhibited greater V0 (3.02 ± 0.30 vs. 2.61 ± 0.23 m·s−1, p = 0.014, g = 1.4) and relative Pmax (32.44 ± 2.65 vs. 27.28 ± 1.06 W·kg−1, p = 0.001, g = 2.4), despite similar F0 (p = 0.67). Higher jumpers also demonstrated superior SN (p = 0.016, g = 1.4), C&J (p = 0.041, g = 1.1), TOT (p = 0.018, g = 1.4), and Sinclair scores (p = 0.001, g = 2.1). Conclusions: In trained weightlifters, performance was strongly associated with maximal strength, while velocity- and power-oriented characteristics (V0 and Pmax) were also associated with performance outcomes. In contrast, F0 showed no meaningful associations with performance within this sample. These findings suggest that, among already strength-trained athletes, the ability to express force at higher contraction velocities may be associated with differences in competitive performance.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020146

Authors: Wajdi Dardouri Raouf Hammami Abdelkader Mahmoudi Roland van den Tillaar

Objective: This randomized controlled trial aimed to investigate how volume-matched unilateral and bilateral jump training affects physical performance in prepubertal and pubertal male youth soccer players and to examine whether maturational status influences these training adaptations. Methods: Sixty-five male soccer players (age 10.5 ± 2.9 years; height 136.7 ± 17.8 cm; body mass 32.8 ± 8.6 kg; maturity offset −1.6 ± 1.0 years) completed an 8-week training program (two sessions/week). Participants were randomly assigned to a bilateral jump group (n = 22), unilateral jump group (n = 22), or control group (n = 21). Performance was evaluated in a single testing session, which included horizontal jump tests (bilateral standing long jump and single-leg hop distance), linear sprint tests over 10 m (acceleration) and 30 m (maximal sprint performance) using timed trials, and change-of-direction (COD) ability assessed via a standardized timed COD test. Results: Significant main effects of time, maturation, and time × group interactions were observed for all outcomes (p ≤ 0.013). A maturation × group interaction was found for bilateral jump performance (p = 0.045), a group effect for 10 m sprint time (p = 0.015), and a time × maturation × group interaction for COD performance (p < 0.001). Both training groups had improved jump performance (jump distance) and 10 m sprint time across maturity levels, while no changes were observed in the control group. For 30 m sprint time, improvements were observed in both training groups in prepubertal players, whereas only the unilateral group showed improvements in pubertal players. COD performance (completion time) improved in the unilateral group at both maturity levels and in the bilateral group at the pubertal level. Conclusions: Structured jump training enhances horizontal jump distance, sprint performance, and COD ability in youth soccer players. Adaptations appear to be influenced by training modality and maturation, although these effects may vary depending on the specific performance task.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020145

Authors: Ligia Cuciorovschi Denisa-Iulia Brus Ștefan Teriș Răzvan Sandu Enoiu

Background: Javelin throw performance is strongly influenced by the coordination of the kinetic chain and by key biomechanical parameters related to technique execution. Understanding the functional biomechanical characteristics of javelin throw technique in junior athletes is essential for optimizing performance. Methods: This study investigated the biomechanical characteristics of javelin throw technique in junior athletes using an applied motion analysis approach. Kinematic, spatiotemporal, and performance-related variables were assessed during throwing trials at two evaluation time points, before and after a structured biomechanics-informed training period, using motion analysis tools and wearable measurement systems as instruments. Results: Significant pre–post changes were observed in technique-related variables (release angle and coordination indices) and in performance outcomes (throwing distance and ball throw speed). Conclusions: These findings highlight the functional relationships between biomechanical technique variables and javelin throw outcomes in junior athletes and suggest that field-based biomechanical monitoring can be useful for tracking technique-related changes during structured training in junior throwers.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020144

Authors: Emily S. Pounds Scott W. Snyder Rebecca R. Billings Haley M. Nguyen Christopher G. Ballmann

Listening to music is a well-established strategy to enhance exercise capacity, yet the specific mechanisms linking music choice to performance enhancement remain fragmented. This scoping review systematically summarizes the existing literature on the effects of music choice (i.e., self-selected, preferred music) on performance and psychophysiological determinants of exercise capacity to establish an updated rationale for the use of personalized music interventions in training. Following PRISMA-ScR guidelines, a systematic search of five databases (PubMed, Web of Science, Embase, Scopus, CINAHL) was performed for studies published between January 2000 and April 2025. Peer-reviewed articles investigating the ergogenic effects of self-selected or preferred music with psychophysiological outcomes were included. Thirty-two studies met inclusion criteria. Overall, evidence supports consistent performance enhancement from choice music (CM) across modes of exercise including aerobic endurance, anaerobic power, and muscular endurance activities while maximal strength was largely unaffected. The most robust and consistent mechanisms underpinning the benefits of CM during exercise were psychological in nature, including improvements in affect, arousal, motivation, and perception of exertion. Notable physiologic benefits were also identified, including altered cortical excitability, autonomic modulation, and improvements in neuromuscular efficiency. Herein, this review provides a psychophysiological framework whereby CM acts as a primary mediator to induce psychological and physiological cascades which synergistically contribute to ergogenic benefits. Evidence heavily supports the superiority of CM to improve exercise performance across various modalities.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020143

Authors: Artemis Zarkadoula Themistoklis Tsatalas Anthony D. Kay Anthony J. Blazevich Christos Kokkotis Spyridon Plakias Brett Anthony Baxter Alex J. Van Enis Giannis Giakas Minas A. Mina

Background: The back squat is a key strength and conditioning exercise used to develop lower-limb strength and power, yet little is known about how movement velocity influences its acute performance-enhancing effects, such as improvements in countermovement jump height and power. The present study examined the acute effects of slow (vslow) versus fast (vfast) eccentric-phase velocity during back squats performed withmaximal concentric velocity on subsequent countermovement jump (CMJ) performance, using a randomized, crossover design. Methods: Fourteen male subjects (age = 22.9 ± 1.9 years; height = 1.8 ± 0.1 m; mass = 76.4 ± 8.3 kg) visited the laboratory on two separate days and completed a comprehensive task-specific warm-up followed by three vslow or vfast back squats at 70% of one-repetition maximum. Three CMJs were performed before and 30 s, 4 min, 8 min, and 12 min after the interventions. Jump height, peak power, kinetic energy, maximum knee angle, and knee angular velocities in both eccentric (downward) and concentric (upward) phases were recorded. Results: No significant (p > 0.05) between-condition differences were detected in any measure. Compared to pre-intervention, significant increases (collapsed data) were detected in jump height (6.0%; d = 0.68–0.83), power (3.6–6%; r = 0.32–0.38), and kinetic energy (5.0–8.0%; d = 0.62–0.86) at 30 s and 4 min. Conclusions: Given the lack of between-condition differences, the eccentric movement velocity of moderate conditioning back squats with maximal concentric velocity exercises does not appear to influence subsequent jump performance enhancements. Thus, either conditioning activity can be used to improve subsequent jump performance. However, as performance was enhanced only at 30 s and 4 min post-intervention, the window of opportunity is narrow, and timing should be carefully considered when including such activities in pre-competition routines.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020142

Authors: Iván Sotelo-Besada Sergio López-García Pelayo Diez-Fernández Brais Ruibal-Lista

Background: This study aimed to analyze the acute effects of an official Muay Thai championship on neuromuscular performance, assessing changes in upper- and lower-limb power before and after competition, as well as differences according to competitive outcome (winners vs. losers). Methods: Thirty-three amateur Muay Thai athletes (17 men and 16 women) performed a countermovement jump (CMJ) and a reactive push-up test (RPU) immediately before and after their bouts. Neuromuscular performance changes were analyzed using mixed-design ANOVA, and a binary logistic regression was conducted to examine the association between post-competition performance and match outcome. Results: Significant post-competition declines were observed in both CMJ and RPU performance (p < 0.001), indicating acute neuromuscular fatigue. Men exhibited higher performance values than women in both tests, with sex-specific differences in CMJ fatigue magnitude. When analyzed by competitive outcome, losers showed substantially greater performance decrements than winners, particularly in CMJ. Logistic regression revealed that post-competition CMJ performance was a significant predictor of winning, with higher CMJ values associated with greater odds of competitive success. Conclusions: An official Muay Thai bout induces marked acute neuromuscular fatigue affecting both upper and lower limbs, with greater impairments observed in non-winning athletes. The ability to maintain lower-limb explosive power under fatigue appears to be associated with competitive success. Simple neuromuscular assessments such as CMJ and RPU may be useful tools for monitoring fatigue, guiding tactical decisions, and informing post-competition recovery strategies in Muay Thai athletes.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020141

Authors: Du-Hwan Oh Jang-Kyu Lee

Background: Middle-aged women with obesity frequently exhibit postural misalignment and impaired balance control, which may increase the risk of functional limitations and falls. This study aimed to compare the effects of Pilates circuit training and weight circuit training on body composition, pelvic alignment indices, and balance performance in obese middle-aged women. Methods: Eighteen women (body fat ≥ 30%) were randomized to either a Pilates circuit training group (PCG, n = 9) or a weight circuit training group (WCG, n = 9) in an exploratory comparative study. Both groups performed supervised exercise three times per week for eight weeks. Outcome measures included body composition, pelvic alignment indices, dynamic balance (Y-Balance Test), and static balance (BESS). Data were analyzed using a two-way mixed ANOVA to examine time, group, and interaction effects. Results: Both groups showed significant reductions in body weight (PCG: −3.09 kg; WCG: −2.00 kg), percentage body fat (PCG: −1.85%; WCG: −1.53%), and waist-to-hip ratio (PCG: −0.05; WCG: −0.04) (p < 0.01). Significant improvements in pelvic alignment indices were observed primarily in the PCG, whereas the WCG showed smaller changes. Dynamic and static balance improved in both groups, with greater improvements observed in the PCG. Conclusions: Both training modalities improved body composition and balance outcomes in obese middle-aged women. Pilates circuit training may be associated with greater improvements in pelvic alignment and balance; however, these findings should be interpreted cautiously due to the exploratory design and small sample size. Further adequately powered randomized controlled trials are required to confirm these findings.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020140

Authors: Konstantinos Papadopoulos Gavriil G. Arsoniadis Argyris G. Toubekis

Background: Stroke rate (SR) is a critical determinant of swimming speed and performance; however, the relationship between upper-limb movement frequency assessed on land and SR in water remains unclear. Methods: This preliminary study examined the association between dry-land upper-limb movement frequency and in-water kinematics in ten male competitive swimmers (15.23 ± 1.06 years). Dry-land upper-limb movement frequency was evaluated through two maximum-effort trials consisting of 10–12 circular arm movements performed under a straight-arm condition (STRSR) and a swimming-technique-simulated bend-arm condition (TECHSR). All trials were video-recorded for analysis. In-water testing included a maximum-effort 50 m sprint and 8–12 × 25 m progressively increasing speed tests to elicit maximum swimming speed and maximum SR. SR, swimming speed, stroke length, and stroke index were calculated for all trials. Results: No relationship was observed between dry-land upper-limb movement frequency and SR of the 50 m test (p > 0.05). However, the percentage difference between STRSR and maximum SR was associated with stroke index at maximum speed (r = −0.66, p = 0.04), maximum SR (r = −0.65, p = 0.04), and swimming speed at maximum SR (r = −0.72, p = 0.01) οf the 8–12 × 25 test. Similarly, TECHSR was correlated with stroke index at maximum speed, SR, and stroke length in the 8–12 × 25 test (r = −0.67 to −0.71, p = 0.01). Conclusions: These findings suggest that faster and more efficient swimmers exhibit a greater difference between their maximum dry-land movement frequency in upper limbs and the SR adopted in water, allowing a greater potential to adjust in a more comfortable and submaximal manner in water movements.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020139

Authors: Vassilis Paschalis Nikos V. Margaritelis Panagiotis N. Chatzinikolaou Anastasios A. Theodorou Michalis G. Nikolaidis

At the dawn of the 20th century, seminal studies revealed that muscle fibers produce less heat and generate greater force during elongation than during shortening actions, laying the foundation for contemporary research on eccentric exercise. Today, eccentric exercise is widely used by athletes to enhance strength and by older adults to maintain functional capacity, yet it may cause muscle damage, particularly in unaccustomed muscles. Despite more than a century of investigation, the precise mechanisms of eccentric exercise-induced muscle damage remain incompletely resolved. Nevertheless, eccentric exercise serves as a valuable model for studying muscle injury and repair and adaptation. This review organizes current evidence into nine key themes: (1) eccentric exercise-induced muscle damage and flawed biomarkers, (2) satellite cell-mediated and alternative repair pathways, (3) high-force, low-cost contractions and metabolic impact, (4) repeated bout effect and protective adaptations, (5) architectural remodeling of fascicles, sarcomeres and tendon, (6) distinct neural control, proprioception, and cross-education adaptations, (7) mitochondrial, sarcoplasmic reticulum, and cytoskeletal stress remodeling, (8) connective tissue perturbation, remodeling, and joint stability, and (9) targeted, cautious use of antioxidant supplementation. Rather than offering a comprehensive overview, this review highlights pivotal experiments, concepts, and controversies within these themes to guide readers to the most impactful discoveries in eccentric exercise and muscle damage.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020138

Authors: Raúl Espejo Jesús Martínez-Sobrino Jesús Santos del Cerro Santiago Veiga

Background: The power profile is a reliable tool for monitoring performance in the cycling segment of triathlon. This study aimed to analyze the evolution of Mean Maximal Power (MMP) in international triathletes and to examine its relationship with external load-based training characteristics. Methods: Cycling training and competition data from 14 junior and U23 international triathletes (seven males: 21 ± 1 years, 69 ± 3 kg, and 181 ± 7 cm; seven females: 22 ± 3 years, 54 ± 5 kg, and 166 ± 3 cm) were analyzed longitudinally for three consecutive seasons. The MMP from the power profile was recorded, along with the training volume accumulated in each 2.0 W·kg−1 power band. Results: All the MMP values, except values of 10 s, 30 s and 5 min, increased (p < 0.05) over the three seasons (Δ = 0.9% to 4.8%; ES = 0.30–0.47), as did the total time (Δ = 22.1%; ES = 0.42) and total distance (Δ = 32.8%; ES = 0.61). Specifically, the percentage of time spent in the 4–6 W·kg−1 power band (ES = 0.42) and MMP values for 1–20 min durations (ES = 0.25–0.47) increased (p < 0.05) from the second to the third season. MMP values ≤ 30 s showed a very large correlation (above r = 0.74) with the percentage of time spent in power bands of 12–14 W·kg−1. All the MMP values showed a negative correlation with the percentage of time spent in the 0–2 W·kg−1 power band. Conclusions: Improvements in MMP ≥ 1 min values over consecutive seasons were associated with greater total training volume and time spent in moderate-intensity power bands, whereas MMP ≤ 30 s were linked to very high-intensity power outputs.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020137

Authors: Plaiwan Suttanon Praewpun Saelee Sudarat Apibantaweesakul

Background: Knee osteoarthritis (KOA) is a major cause of pain, mobility limitation, and increased fall risk among older adults. Gait dysfunction, characterized by spatiotemporal and kinematic alterations, is a key functional consequence of KOA. While sagittal-plane gait deviations are well-established, multiplanar kinematic changes—particularly in the frontal and transverse planes—remain less clearly understood. This study aimed to compare three-dimensional gait characteristics between older adults with and without KOA. Methods: Ninety older adults (45 with KOA and 45 controls) completed gait assessments using a VICON™ motion capture system. Participants walked at a self-selected speed along a straight walkway without turning movements during data collection. Spatiotemporal parameters and lower-limb joint kinematics (hip, knee, and ankle) were recorded during key gait phases: initial contact, mid-stance, toe-off, and mid-swing. Group comparisons were performed using independent t-tests with statistical significance set at p < 0.05. Results: Compared with controls, participants with KOA demonstrated significantly slower gait velocity (p = 0.001), reduced cadence (p = 0.020), shorter stride length (p = 0.011), increased step time (p = 0.006), prolonged double support time (p = 0.009), and reduced single support time (p = 0.012). Kinematic analysis revealed greater knee adduction at initial contact (p = 0.001), reduced hip adduction (p = 0.002) and greater knee adduction (p = 0.003) during mid-stance, and increased ankle plantarflexion at toe-off (p = 0.004) in the KOA group. No significant between-group differences were observed during the mid-swing phase. Conclusions: Older adults with KOA exhibit distinct spatiotemporal and multiplanar kinematic gait alterations, particularly during weight-bearing phases. These changes may reflect adaptive gait patterns associated with joint dysfunction rather than definitive compensatory mechanisms. Three-dimensional gait analysis may provide valuable biomechanical insights to support early identification of mobility impairments and inform targeted rehabilitation planning in individuals with KOA.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020136

Authors: Jordan Saag Jonathan Bergeron Julianna Bailey Kathryn Monroe Heather Hathorne George M. Solomon John D. Lowman Surya P. Bhatt Bryan Garcia Stefanie Krick

Background: The Cystic Fibrosis Foundation (CFF) recognizes exercise as a critical part of managing cystic fibrosis (CF). This becomes even more important in the era of highly effective modulator therapy (HEMT) due to many people with cystic fibrosis (pwCF) having decreased symptom burden and a newfound ability to tolerate exercise better. Our single-center pilot study was designed to assess the implementation of a remotely delivered, individualized, and comprehensive exercise program for pwCF. We aimed to determine the feasibility, safety and acceptance of this intervention. Methods: PwCF ≥ 18 years old were recruited and consented at the University of Alabama in Birmingham in 2022 and 2023. Basic fitness was assessed for each participant, and an individualized exercise prescription was prepared for each participant, who was expected to exercise three times weekly on a remote basis with the exercise physiologist for 12 consecutive weeks. Subjects were reassessed at 4 and 7 months for post-exercise evaluation. Patient demographics and clinical parameters, including exacerbation rate, FEV1 percent predicted, 6-min walk test (6MWT), and modified shuttle test (MST) were collected. Questionnaire data from the CFQ-R, PRAISE, and IPAQ were also recorded. The study was registered with ClinicalTrials.gov (NCT04680403) and was submitted on 17 December 2020. Results: Our goal was to enroll 12 participants over the 2-year study period. We were able to recruit nine people for the study, with four participants finishing the program. From the 36 sessions offered over the 12-week program, participants completed an average of 15 sessions. Clinical outcome data was observed, including lung function and exacerbation frequency, but not statistically analyzed due to the small sample size. Conclusions: Implementation of an individualized telehealth-based exercise program for pwCF was well received by participants, safe, and appreciated by the participants. Recruitment and adherence were challenging, which was partially due to the ongoing pandemic. Follow-up studies are needed to assess whether improvements in reducing the amount or supervision of weekly exercise sessions and/or extending the total time might help with adherence.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020135

Authors: Noboru Chiba Kazuki Ogawa Ai Suzuki Tadayoshi Minamisawa

Background: Wrist–forearm orthoses used during self-feeding may alter scapular and shoulder mechanics and increase proximal load, but this has not been quantified. Methods: Seventeen right-hand-dominant young adults performed a spoon-feeding task under free and restricted conditions. A thermoplastic wrist–forearm orthosis positioned the wrist at approximately 30° dorsiflexion at rest and was intended to constrain wrist motion during the task without rigidly immobilizing forearm pronation–supination. Three-dimensional kinematics (scapula, shoulder, trunk, and distal joints) were recorded using inertial sensors, and surface electromyography was obtained from the upper trapezius, middle deltoid, and biceps brachii. Maximum joint angles and mean %MVC over the feeding cycle were compared between conditions (α = 0.05). Results: The restriction condition resulted in a more anteriorly tilted and downwardly rotated scapular posture, greater shoulder abduction and external rotation, and increased thoracic flexion, whereas maximum distal joint angles did not differ, suggesting a functional distal constraint rather than rigid immobilization. Middle deltoid and biceps brachii activities increased significantly, with a nonsignificant trend toward higher upper trapezius activation. Conclusions: In healthy young adults, limited wrist motion and forearm rotation during spoon-feeding were associated with altered proximal coordination, including scapular, shoulder/trunk, and proximal muscle changes.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020134

Authors: Roberto Palazzo Melissa Orlandi Federico Fu Vittorio Bini Laura Stefani

Background: Intramyocardial bridge (MB) is a coronary anomaly characterized by a segment of the artery tunneling within the myocardium. While often asymptomatic, it may lead to ischemic events. Despite traditional disqualification from competitive sports, 2023 guidelines now permit participation for athletes with MBs that do not meet specific high-risk morphological criteria. This study aims to evaluate a novel combined provocative test, integrating Cardiopulmonary Exercise Testing (CPET) and stress echocardiography for the assessment of myocardial deformation (twist), to assess the functional impact of MB in asymptomatic athletes. Methods: This cross-sectional case–control study included 18 participants (nine cases with “significant” MB diagnosed via Computed Tomography (CT) coronary angiography and nine healthy, trained controls), aged 18–78 years. All subjects underwent evaluation at our facility for competitive certification. Assessment protocols included resting echocardiography, Global Longitudinal Strain (GLS), and Cardiopulmonary Exercise Testing (CPET) to quantify exercise capacity and dynamic myocardial function. Results: No significant differences in echocardiographic parameters were observed between groups at rest. However, during exercise, athletes with MB demonstrated a significant reduction in GLS and ventricular twist compared to the control group. These findings indicate a notable loss of apical reserve in the MB cohort during physical stress. Conclusions: The integration of CPET and myocardial deformation analysis provides an effective diagnostic tool for identifying functional impairment in asymptomatic athletes with MB. This combined approach offers a superior follow-up strategy for managing athletes who may be at risk for ischemic events despite lack of clinical symptoms.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020133

Authors: Kristian Plazibat Tihomir Vidranski Renata Barić

Background: Early childhood is a critical period for the development of motor competence, which is closely related to later physical activity, educational readiness, and broader developmental outcomes. However, the temporal dynamics of motor skill acquisition in preschool children, particularly the time required to reach initial and early refinement phases of learning, remain insufficiently described. The aim of this study was to examine whether different levels of previous participation experience in an organized kinesiology program are associated with differences in the speed and quality of novel motor skill acquisition in preschool children, and to explore the relationship between baseline motor proficiency and phase-based indicators of motor learning. Methods: A total of 161 preschool children aged 5–6 years participated in the study and were grouped according to their previous participation experience in an organized kinesiology program (0 h, ~120 h, ~350 h, and ~470 h). Following BOT-2 assessment, all participants completed a standardized 7-week motor learning program that included nine previously unfamiliar motor tasks. Using a phase-based video analysis protocol, three learning indicators were recorded: time to Phase 1 (F1; first successful execution), time to Phase 2 (F2; initial refinement of performance), and final performance quality (K). Group differences and associations were first examined descriptively and correlationally, after which additional multivariable regression models were performed to determine whether previous participation experience and baseline motor proficiency were independently associated with motor learning outcomes. Results: The findings showed consistent differences across groups, with children who had greater previous participation experience generally reaching F1 and F2 more rapidly and achieving higher final performance quality scores. Higher BOT-2 scores were also associated with shorter learning times and better final performance quality. In the multivariable models, both previous participation experience in an organized kinesiology program and BOT-2 total score were independently associated with Phase 1 attainment time and final performance quality, whereas only previous participation experience remained independently associated with Phase 2 attainment time. The applied phase-based observational protocol demonstrated good to excellent inter-rater reliability across the evaluated motor learning variables. Conclusions: These findings provide phase-based temporal indicators of motor learning progression in preschool children and suggest that previous participation experience in an organized kinesiology program and baseline motor competence are meaningfully associated with the speed and quality of acquiring new motor tasks. The findings also demonstrate the potential of phase-based approaches for quantifying motor learning dynamics in early childhood settings. Such indicators may offer useful reference information for instructional pacing and the planning of motor learning activities, while also serving as practically relevant predictors for adapting future kinesiology programs to children’s motor readiness. Future research should further examine these relationships using longitudinal and analytically expanded designs.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020132

Authors: Pedro Forte

Biomechanics continues to represent a fundamental pillar for understanding human movement, athletic performance, injury mechanisms, and rehabilitation processes [...]

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11020131

Authors: David Luedeka Keila Strick Nickolas Roche Caroline Williams

This review examines rotator cuff and shoulder complex dysfunction through an evolutionary framework and aims to translate these concepts into practical resistance training applications for strength and conditioning and rehabilitation professionals. Comparative anatomy and functional biomechanics of the human and non-human primate shoulder complexes are reviewed to illustrate how evolutionary pressures shaped an upper extremity system optimized for stability and force transmission under closed kinetic chain (CKC) loads. In contrast, many contemporary resistance training practices emphasize high-load, open kinetic chain (OKC) exercises that may impose elevated soft tissue strain and shear forces while potentially diminishing the engagement of the scapulothoracic and trunk stabilization mechanisms evolved to protect the shoulder complex. This proposed evolutionary mismatch may contribute to the high prevalence of shoulder dysfunction observed in the modern human population. Rotator cuff pathology arises through a combination of mechanisms, including, but not limited to, age-related tendon degradation, anatomical variations, mechanical overload factors, as well as systemic comorbidities. The contribution of habitual loading patterns to this multifactorial etiology has been considered in the literature, but this review advances a novel evolutionary mismatch hypothesis as one framework through which a primary biomechanical cause of overuse shoulder pathology may be examined. Applications of these concepts to exercise program design are presented. Specifically, training modifications consider moderately loaded CKC exercises performed at higher volumes with an emphasis on movement velocity and power generation. Incorporating moderate-load, high-volume, high-velocity CKC exercises may preserve rotator cuff integrity and optimize upper extremity function across the lifespan while potentially reducing the loading demands and associated mechanical stress that, under high-load or high-volume conditions, traditional OKC training models place on the shoulder and therefore, challenge the shoulder’s evolved structural tolerance.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010130

Authors: Albert Buchalski Michael Jeanfavre Colby Altorelli Gretchen Leff

Background: Tendons adapt to mechanical loading by increasing cross-sectional area (CSA), stiffness, and matrix organization, with structural remodeling critical for both rehabilitation and performance. Collagen supplementation has been proposed to enhance this process by supplying key amino acids for collagen synthesis; however, inconsistent results across trials have limited its clinical and athletic application. Methods: A systematic review of randomized controlled trials evaluating collagen supplementation in humans was conducted. PubMed, EMBASE, CINAHL, and Web of Science were searched from database inception through May 2025. Risk of bias was assessed using the PEDro scale (≥6/10 classified as good-to-excellent quality). Due to substantial heterogeneity in supplementation protocols, training modalities, and outcome measures, results were synthesized narratively without meta-analysis. Data extraction included collagen type, dose, training modality, intervention duration, and outcome measures. Results: Of 887 unique citations, eight RCTs (n = 257; ages 18–52; 246 M:11 F) met the inclusion criteria. All studies incorporated resistance or plyometric training (3–15 weeks). Three of four studies reported significantly greater increases in tendon CSA in collagen groups versus placebo. Four studies investigated tendon stiffness and Young’s modulus; the two using higher doses (15–30 g/day) demonstrated significant between-group improvements favoring collagen, while lower-dose studies (~5 g) showed only within-group effects. Muscle strength improved with training in all trials, but no additive effects of collagen were observed. One study reported improvements in eccentric rate of force development and deceleration impulse with collagen, though gross explosive metrics (e.g., jump height) were unaffected. Conclusions: Collagen supplementation (15–30 g) with vitamin C (≥50 mg) may enhance tendon remodeling when combined with high-intensity resistance training (≥70% 1 RM). The current literature suggests strong evidence (GRADE A) for increases in tendon CSA and stiffness, strong evidence (GRADE A) against an effect on muscle strength, and conflicting evidence (GRADE C) for muscle cross-sectional area and physical performance. Limitations include small sample sizes, heterogeneous protocols, and short intervention durations.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010129

Authors: Ana Ramos Jordi Zafra Jordi Villalba

Background: High tibial osteotomy (HTO) is a joint-preserving alternative for patients with medial compartment knee osteoarthritis (KOA), although its use has declined in recent decades in favor of total knee arthroplasty (TKA). This study aimed to evaluate HTO outcomes in patients treated at a tertiary center over the past decade. Methods: We conducted a single-center, retrospective, observational cohort study of patients with medial femorotibial KOA and genu varum who underwent HTO. Failure was defined as conversion to TKA. A comparative analysis regarding HTO survival was conducted with preoperative variables and KOA stages in the follow-ups up to 5 years. Univariate and multivariate Cox regression models were built to assess their effect on HTO survival time. The Kaplan–Meier method was used to estimate overall and subgroup survival. Disease progression over time was evaluated with the Bhapkar test. In all cases, p < 0.05 was considered statistically significant. Results: HTO was successful in 74.6% of the 63 patients. Age was significantly higher in the failure group (p = 0.006), and each additional year increased the hazard of failure by 8% (95% CI, 1.01–1.16, p = 0.033), although this significance was lost in multivariate analysis (p = 0.104). Kaplan–Meier estimated survival was 76.7% at 5 years, with a median survival time of 10.1 years. KOA stage progression was significant 5 years after HTO (p < 0.001). Conclusions: HTO demonstrated 76.7% survival at 5 years, with radiographic KOA progression over time. The association between age and failure was not maintained after multivariable adjustment.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010128

Authors: Cristian Hernández María Alejandra Camacho-Villa Nuria Sánchez-Hernández Luis Gabriel Rangel Caballero Jorge Gómez-Camacho Juan Carlos Saavedra Jorge Enrique Buitrago-Espitia Adrián De la Rosa

Background: Ultimate Frisbee (UF) is an intermittent team sport with distinct positional roles (cutters and handlers), yet evidence integrating anthropometric, body composition, and physical performance profiles by playing position remains limited. This study aimed to examine positional differences in these variables among male UF players. Methods: Forty male players (age: 25.13 ± 3.76 years; 7.0 ± 2.5 years of training experience) participated in this cross-sectional design, including 20 cutters and 20 handlers. Anthropometry, body composition, and dynamic balance variables were analyzed using independent-samples t-tests or Mann–Whitney U tests, as appropriate. Positional differences in somatotype and physical performance were analyzed using a one-way multivariate analysis of variance (MANOVA). Results: No positional differences were observed in general anthropometric variables (p > 0.05). However, handlers exhibited higher body fat percentage (14.32 ± 2.37 vs. 11.95 ± 2.45; p = 0.028), fat mass (11.08 ± 2.51 vs. 8.95 ± 2.67 kg; p = 0.049), and endomorphy (4.15 ± 1.22 vs. 2.99 ± 1.30; p = 0.002) than cutters. In contrast, cutters demonstrated higher speed (20 m sprint: 3.11 ± 0.17 vs. 3.21 ± 0.15 s; p < 0.05), agility (10.16 ± 0.69 vs. 10.69 ± 0.61 s; p < 0.05), and vertical jump performance (Counter Movement Jump: 40.93 ± 6.54 vs. 36.38 ± 4.71 cm; p < 0.05; Abalakov: 46.39 ± 7.88 vs. 40.20 ± 4.68 cm; p < 0.01). No differences were found in intermittent endurance (Yo-Yo Intermitent Recovery Test1): 982 ± 354 vs. 940 ± 348 m), upper-limb power, or dynamic balance. Conclusions: These findings indicate that playing position in UF is characterized by distinct body composition and lower-limb neuromuscular performance profiles, whereas intermittent endurance, upper-limb power, and balance represent shared physical requirements across positions.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010127

Authors: Alexandros Kastrinis Nikolaos Strimpakos George A. Koumantakis Dionysios Tzatzaliaris Marianna Oikonomaki Zacharias Dimitriadis

Background: Adolescent idiopathic scoliosis (AIS) is often associated with central nervous system disorders and deficits in sensorimotor function. While the Schroth method is a common clinical intervention, research evidence regarding its effectiveness in enhancing sensorimotor control remains limited. This study aimed to evaluate the impact of the Schroth method on sensorimotor control and quality of life (QoL) in AIS patients. Methods: Sixty female participants (mean age 13.4 years) with Cobb angles between 10° and 45° were divided into an intervention group (n = 30), receiving Schroth exercises and bracing for 10 weeks, and a control group (n = 30), receiving bracing alone. Outcome measures included static and dynamic balance, spine lateral flexion joint position sense (JPS), upper-limb functional proprioception, and the GR-BSSQ Brace questionnaire. Results: Statistical analysis using two-way mixed ANOVA revealed significant Group × Time interactions across several parameters. The Schroth group showed significant improvements in static and dynamic balance, with ellipse area reduction (p = 0.005) and reduced Fukuda test distance (p = 0.007), respectively. Significant enhancements were noted in spine lateral flexion JPS (Bilateral p = 0.008) and upper-limb proprioception (Bilateral p = 0.000). Furthermore, the intervention group reported a significant improvement in QoL scores compared to the control (p = 0.000). Conclusions: The findings demonstrate that the Schroth method was associated with enhanced sensorimotor control, supporting its use as a targeted approach to improve functional outcomes in individuals with AIS. These results highlight the clinical value of the method, beyond spinal curve correction.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010126

Authors: Marco Montemagno Luigi Zaffarana Flora Maria Chiara Panvini Ludovico Lucenti Alessandra Di Nora Egidio Avarotti Angelo Di Giunta Gianluca Testa Vito Pavone

Objectives: Arthroscopic surgery requires complex visuospatial coordination and psychomotor skills, which are traditionally acquired through mentorship and cadaveric training. High-fidelity simulators are effective but often costly and inaccessible. This study evaluates the technical effectiveness of a novel home-based 3D-printed arthroscopic simulator (“Arthrozero”) for improving basic arthroscopic skills among orthopedic residents. Methods: Thirty-three orthopedic residents (25–36 years) from two Italian university centers were randomized into three groups: ZERO (Arthrozero training), ARTHRO (real arthroscope training), and CONTROL (theoretical session). Training was performed on a FAST-like workstation through four progressively complex tasks. Performance metrics included task completion time, number of looks down, and skill progression during a final Shoulder Challenge (SHO-CHA) assessment. A web-based Likert questionnaire evaluated participant satisfaction and perceived educational value. Results: Both ZERO and ARTHRO groups demonstrated significant improvement across training sessions (p < 0.05) for all tasks, while the CONTROL group showed minimal gains. In the SHO-CHA assessment, mean completion times were 394.1 ± 140.7 s (ZERO), 456.1 ± 123.2 s (ARTHRO), and 745.5 ± 190.7 s (CONTROL) (p < 0.01). No significant difference was observed between ZERO and ARTHRO groups (p = 0.276). Conclusions: The home-based Arthrozero simulator demonstrated improvements in basic arthroscopic skill performance, suggesting that it may represent an accessible training tool to support early arthroscopic skill acquisition alongside traditional training methods.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010125

Authors: Stavroula Kalyva Dionysia Argyropoulou Panagiotis Koulouvaris Charilaos Tsolakis Gerasimos Terzis Tzortzis Nomikos Nickos D. Geladas Anastasios A. Theodorou Vassilis Paschalis

Background: Type 2 diabetes mellitus (T2DM) is linked to accelerated losses in muscle function. The aim of the present investigation was to evaluate the effect of chronic higher-protein intake on isokinetic knee performance in the older adults with type 2 diabetes mellitus (T2DM). Methods: Thirty adults (15 men and 15 women) aged 60–80 years with non-insulin-treated T2DM and sarcopenia-related deficits were randomized for 12 weeks to a higher-protein diet (1.2–1.5 g·kg−1·day−1) or a recommended protein diet (0.8–1.0 g·kg−1·day−1), with meal plans designed to maintain body mass. Protein was increased mainly through Mediterranean-style protein sources while diet was monitored using repeated 3-day recalls. Isokinetic knee extensors and flexors peak torque (angular velocity 60°/s) was assessed at baseline and at week 6 and at the end of the 12th week of intervention. Fatigability (20 maximal contractions at an angular velocity at 180°/s) and DXA body composition were assessed at baseline and at the end of the 12th week of intervention. Data were analyzed using two-way repeated-measures ANOVA with repeated measures on time (2 groups × 3 time points), followed by post hoc analysis when significant difference was occurred. Results: Thirty participants completed the trial. Energy intake and body mass remained stable in both groups. At the end of week 12, peak torque declined in the control group (p < 0.05) but remained stable in the higher-protein group. The fatigue index worsened over time in controls but was preserved in the higher protein group, resulting in a significant group d7 time interaction at week 12 (p < 0.05) (post hoc between-group difference at week 12, p < 0.05). Fat-free mass and blood pressure did not change. In fat mass, a decrease was observed with higher protein intake, whereas it remained stable in the control group. Conclusions: Higher protein intake for 12 weeks preserved knee muscle performance in older adults with T2DM without weight gain, supporting dietary protein optimization to counter functional decline.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010124

Authors: Mabliny Thuany Mayara Silva Matheus Fernandes Beat Knechtle Katja Weiss Thomas Rosemann Thayse Natacha Gomes Ramiro Rolim Marcos André Moura dos Santos

Background: We aimed to (i) identify the factors associated with performance in non-elite runners, (ii) present the terms and definitions/attributes used to characterize runners, and (iii) identify how performance has been operationalized. Methods: Our search was conducted using the databases PubMed, Web of Science, Medline Ovid, Cochrane, PsycInfo, Scielo, Scopus, and SportDiscus in October 2023 and updated in February 2026. Original articles that assessed factors associated with performance in non-elite runners competing in distances ranging from 5 km to ultramarathons were included. The findings were summarized by race distance. The Joanna Briggs Institute Analytical Cross-Sectional Studies critical appraisal tool was used for quality assessment. Results: A total of 4151 studies were identified, and 66 studies were included in the final selection. “Recreational” and “athletes” were the most used terms, and finish time was the most common indicator of performance. Performance decline was influenced by arm circumference and mid-axillary skinfold thickness, smoking, body mass index, alcohol consumption, and weather characteristics. Training variables, physiological determinants, and social variables were positively related to performance. Conclusions: The field struggles with a lack of clarity regarding the nomenclature and criteria used to categorize runners. The relevance of a predictor differs according to race distance, with physiological aspects becoming less important at higher distances (i.e., marathon and ultramarathon).

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010123

Authors: Yunfeng Sun Caterina Fede Xiaoxiao Zhao Federico Giordani Hannes Müller-Ehrenberg Carmelo Pirri Carla Stecco

This narrative review synthesizes evidence from 108 studies to provide the first comprehensive overview of extracorporeal shockwave therapy (ESWT) for plantar fasciitis across three key domains. First, assessment methodologies were evaluated, identifying 36 distinct tools classified into six categories, including pain (with the Visual Analog Scale being the most frequently used), function (most commonly the Foot Function Index), plantar fascia thickness, and other measures. Second, treatment protocols were analyzed, revealing commonly applied parameters of 2000 impulses per session and an energy flux density of 0.2 mJ/mm2 or 3.0 bar. Third, the comparative status of ESWT relative to other interventions was examined. Across 18 alternative treatments, corticosteroid injections, platelet-rich plasma (PRP), dextrose prolotherapy, laser therapy, and ultrasound were the most frequently compared modalities. ESWT and comparator interventions demonstrated differential advantages across specific outcomes; however, these findings cannot be directly translated into clinical recommendations, due to the limitations of the available evidence. By consolidating fragmented data, the present review clarifies the current research landscape and provides a foundational reference to support outcome evaluation and individualized treatment selection.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010122

Authors: Gianmarco Gemini Antonio Mazzotti Elena Artioli Laura Langone Federico Sgubbi Alberto Arceri Gianmarco Di Paola Simone Ottavio Zielli Cesare Faldini

Background: Chronic Recalcitrant Plantar Fasciopathy (CRPF) is resistant to conservative treatments and has historically been managed with Open Plantar Fasciotomy (OPF). This systematic review aims to evaluate the role of the Gastrocnemius Release Procedures (GRPs) in treating CRPF, focusing on its indications, surgical techniques and clinical outcomes. Methods: A systematic literature search was conducted following PRISMA guidelines using MEDLINE, Cochrane and Scopus. Studies pertinent to the topic were screened, and those that reported clinical outcomes of GRPs in patients with CRPF were retrieved. The quality assessment was carried out using the Newcastle–Ottawa Scale. Results: Eighteen studies met the inclusion criteria, analyzing a total of 901 patients with a mean follow-up of 27.8 months. Indications for performing GRPs subsisted if conservative treatment failed to relieve pain and if Isolated Gastrocnemius Contracture (IGC) was present. All GRPs significantly reduced pain, with Visual Analogue Scale (VAS) scores decreasing from a mean of 7.3 pre-operatively to 2.56 post-operatively (64.93% reduction). American Orthopaedic Foot & Ankle Society (AOFAS) scores improved from 50.1 to 84.7 on average. Ankle dorsiflexion increased by an average of 7.75°. Patient satisfaction was high, with an average rate of 85% (range 61.6% to 100%). Minor complications were reported but resolved in most cases. Conclusions: Indications for performing GRPs still need to be clarified, and the best surgical technique remains to be defined. Nevertheless, the GRP seems to offer sustained pain relief and functional improvement in patients with CRPF.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010121

Authors: José L. Sánchez-Sánchez Pedro Belón-Pérez Xavier Grevol-Coll Miguel Robles-García Gustavo Plaza-Manzano César Fernández-de-las-Peñas Laura Calderón-Díez

Background: The pectoralis minor muscle can be a source of musculoskeletal-related chest pain by contributing to thoracic outlet syndrome. Needling interventions applied to chest wall muscles have an inherent risk of puncturing sensitive structures, e.g., the pleura. Objective: The objective of this study was to preliminarily investigate the safety and accuracy of two needling approaches targeting the pectoralis minor muscle. Methods: A pincer- and flat-needle approach targeting the pectoralis minor muscle was conducted in five Thiel-embalmed cadavers and 10 healthy volunteers by an experienced and a novice clinician. The needle was inserted until the clinician considered that the pectoralis minor muscle was reached. Each clinician conducted 10 needle insertions with each approach. In cadavers, the accuracy of needle placement was identified with both ultrasound imaging and anatomical dissection. In healthy volunteers, needle placement accuracy was evaluated with ultrasound imaging. Results: Accurate needle penetration of the pectoralis minor muscle was 80–90% and 40–70% for experienced and novice clinicians, respectively, with the pincer approach. One pleural puncture was observed in one cadaver specimen with this approach by the novice clinician. Accurate needle penetration of the pectoralis minor muscle was 100% and 90% for experienced and novice clinicians, respectively, with the flat approach. The novice clinician required 3.5 times longer to perform the flat approach than the experienced clinician. Conclusions: The results of this pilot feasibility study suggest that a pincer-needle approach seems to be less accurate than the flat-needle approach and substantially more error-prone for a novice clinician, which, in a clinical context, could pose a potential risk of pneumothorax based on the pleural puncture observed in one cadaver specimen. In contrast, our preliminary results revealed that the flat-needle approach could have better accuracy and safety, particularly when performed under real ultrasound guidance.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010120

Authors: Ivan Drviš Dario Vrdoljak Nikola Foretić Željko Dujić

Sports performance in aquatic environments is governed by biomechanical, physiological, neuromuscular and perceptual–mental constraints that differ fundamentally from those encountered on land. As a result, athletes with comparable general physiological or motor capacities may achieve markedly different performance outcomes in aquatic sports. Within functional kinesiology and sport science, aquatic performance is still frequently interpreted through isolated physiological, biomechanical, or technical variables, which limits both explanatory depth and applied relevance. This Perspective article introduces aquaticity as an integrated latent construct representing a multidimensional determinant of sports performance specific to the aquatic environment. Aquaticity is conceptualized as a functional framework that modulates how general physiological and motor capacities are expressed under aquatic constraints, integrating key domains of exercise physiology, sport biomechanics, neuromuscular control, energetic regulation, and perceptual–mental stability. The relative contribution of these domains is considered discipline-specific and dependent on task and environmental demands. Breath-hold diving is presented as a particularly suitable model for examining aquaticity, as apnea and hypoxic–hypercapnic stress amplify interactions between physiological regulation, neuromuscular control, and biomechanical efficiency. Training and diagnostic tasks performed in real aquatic settings are interpreted as manifest indicators of aquaticity, enabling ecologically valid athlete monitoring and performance assessment. Within this framework, energetic aquaticity is highlighted as a central functional sub-construct linking metabolic regulation, movement efficiency, and neural control during performance under respiratory constraints. The proposed conceptual framework has important implications for functional kinesiology, sport biomechanics, exercise physiology, and applied athlete monitoring in aquatic sports. Aquaticity is advanced not merely as a descriptive concept, but as a unifying framework that can guide future experimental research, discipline-specific diagnostics, individualized training design, and safety-oriented performance assessment in aquatic environments.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010119

Authors: Eleanna Strongylou Dimitra Karadimitri Maria Moutzouri Magdalini Stamou Christina-Anastasia Rapidi Yannis Dionyssiotis Eleni Moumtzi-Nakka Vasiliki Sakellari

Background: Spinal cord injury (SCI) is a leading cause of chronic disability. Loss of upper extremity (U.E.) function is central to limitations, in mobility, postural control, transfers, and self-care. The aim of this exploratory pilot study was to investigate whether self-reported UE function is associated with independence in activities of daily living (ADLs) in people with motor-incomplete tetraplegia. Methods: Eleven (n = 11) individuals with motor-incomplete tetraplegia (AIS C–D; neurological levels C4–T1; injury duration ≥ 1 year), recruited through convenience sampling from five specialist rehabilitation centres, participated in an exploratory cross-sectional pilot study designed to generate hypotheses rather than test them. U.E. function was assessed using the Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaire, selected for its ability to capture pain and task-related functional difficulty in the elbow, wrist, and hand; its application in this neurological population is considered exploratory. Independence in ADLs was evaluated using the Spinal Cord Independence Measure III (SCIM III). Given the small sample, all analyses were primarily descriptive and along with bivariate associations (Spearman correlations). Regression findings are reported strictly for exploratory purposes. Results: The median age was 50 years (interquartile range [IQR] 43–55). A strong negative correlation was observed between PRTEE total score and SCIM III (rs = −0.76). In an exploratory univariate analysis, each 1-point increase in PRTEE total score was associated with a 1.3-point lower SCIM III score (β = −1.3, 95% CI −2.34 to −0.26, p = 0.02). Age also showed a positive association (β = 1.31, 95% CI 0.04 to 2.58, p = 0.05) with SCIM III; however, this finding is highly likely to reflect a statistical artefact of the small and unrepresentative sample. Multivariable regression was not conducted as a primary analysis due to insufficient statistical power. All findings should be treated as strictly exploratory and hypothesis-generating. Conclusions: Self-reported U.E. function appears to be associated with ADL independence in motor-incomplete tetraplegia. U.E. capacity may contribute to functional tasks requiring postural stability and mobility-related activities, but no predictive inferences can be made from this underpowered, convenience sample. Future studies with larger cohorts and performance-based measures are needed to confirm these preliminary observations and clarify the role of U.E. function in rehabilitation planning.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010118

Authors: Diego A. Alonso-Aubin Ester Jiménez-Ormeño César Gallo-Salazar Verónica Giráldez-Costas Diana Ruiz-Vicente Sara Zafra-Díaz Francisco Areces-Corcuera Carlos Ruiz-Moreno

Background: CrossFit® has gained widespread popularity as a high-intensity training modality, yet evidence describing neuromuscular performance characteristics in this population remains limited. This study aimed to evaluate isometric and ballistic strength profiles in trained CrossFit® athletes and to identify sex-based differences in absolute and relative neuromuscular performance. Methods: Seventy-two athletes participated (41 males and 31 females) participated in the study, completing two maximal isometric mid-thigh pull (IMTP) tests and three countermovement jump (CMJ) tests within a single testing session. Assessments were conducted using a dual force plate system (Hawkin Dynamics, Westbrook, ME, USA). Results: In the IMTP, males exhibited substantially higher absolute isometric force outputs, including peak force (3059 ± 576 vs. 1899 ± 324 N; p < 0.001) and relative peak force (36.34 ± 6.74 vs. 30.99 ± 4.41 N/kg; p < 0.001). Rates of force development were also greater in males for both early (0–50 ms: 7665 ± 5420 vs. 4001 ± 3021 N/s; p < 0.001) and late phases (0–250 ms: 5350 ± 1832 vs. 3035 ± 886 N/s; p < 0.001). However, no significant sex differences were detected in time to peak force (2.31 ± 1.27 vs. 1.94 ± 1.04 s) or dynamic strength index (0.72 ± 0.12 vs. 0.73 ± 0.12 a.u.). In ballistic performance using CMJ, males achieved higher jump height (0.33 ± 0.07 vs. 0.23 ± 0.05 m; p < 0.001), jump momentum (215 ± 27.9 vs. 131 ± 19.1 kg·m/s; p < 0.001), and modified reactive strength index (0.46 ± 0.11 vs. 0.32 ± 0.08 a.u.; p < 0.001). Relative propulsive and braking forces were also moderately greater in males. Notably, sex differences were reduced when variables were normalized to body mass or peak force, indicating comparable relative neuromuscular function across sexes. Conclusions: These findings provide descriptive neuromuscular performance data for CrossFit® athletes and show that sex-based differences primarily reflect disparities in absolute force-production capacity rather than intrinsic neuromuscular efficiency. Such insights may support more precise, evidence-informed, and sex-specific training prescriptions to optimize performance.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010117

Authors: Marta María Moreno-Fresco Stephen Mizzi Pedro V. Munuera-Martínez Priscila Távara-Vidalón

Background: The origin of hallux abducto valgus (HAV) is considered to be multifactorial; however, evidence regarding the factors involved in its development is scattered and often contradictory. Understanding the factors that contribute to the onset of HAV is crucial for informing both prevention and clinical management strategies. This review aims to explore the etiological factors associated with the development of HAV. Methods: A literature search was conducted in PubMed, Embase, Web of Science and Scopus. The search included observational studies that investigated etiological or risk factors related to the development of HAV. Methodological quality was assessed using the Joanna Briggs Institute (JBI) checklists, and the level of evidence was classified according to the Oxford Centre for Evidence-Based Medicine (OCEBM). Results: A total of 36 observational studies (20 cross-sectional and 16 case–control) were included, involving 14,500 participants, predominantly females. Genetic evidence indicated strong familial aggregation and variants in collagen- and extracellular matrix-related genes as potential hereditary determinants. The most consistent biomechanical factors were first-ray hypermobility, abnormal foot pronation and reduced activity of the abductor hallucis muscle. Additionally, female sex, older age and prolonged use of narrow or inadequate footwear were identified as recurring predictive variables. Overall, the findings support a complex etiological model based on the interaction of intrinsic and extrinsic factors. Conclusions: The development of HAV appears to be determined by the interaction of genetic, structural and biomechanical factors that alter first-ray stability and forefoot function. Current evidence supports a multifactorial etiological model with a strong hereditary component and higher susceptibility in women. Longitudinal studies employing standardized methods are needed to establish causal relationships and quantify the relative contribution of each factor.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010116

Authors: Molly E. Coventry Andrea B. Mosler Paola T. Chivers Brady D. Green Ebonie K. Rio Myles C. Murphy

Background: Voluntary activation testing quantifies the ability of the motor nervous system to produce maximal force. Laboratory assessment of ankle plantar flexor voluntary activation is common, but field testing in practical settings is limited by equipment portability. We aimed to compare plantar flexor voluntary activation and maximal voluntary contraction (MVC) using a portable device with a standardised laboratory method and evaluate the test–retest reliability of the portable protocol. Methods: We performed a pseudo-randomised, crossover design. Participants completed two protocols: (1) portable force plate testing and (2) a laboratory-based isokinetic dynamometer. Voluntary activation was assessed using twitch interpolation via tibial nerve stimulation. Differences between protocols were analysed using generalised estimating equations. Reliability was assessed with the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV). Results: Twenty healthy participants (8 females, 12 males; median age 28.5 years) were included. No difference between protocols was detected for voluntary activation (β = 0.6, p = 0.68). The portable protocol demonstrated good reliability (ICC = 0.85) and low measurement error (SEM = 2.56%, CV = 2.79%). Conclusions: We demonstrated that the portable protocol is a valid and reliable method for assessing plantar flexor voluntary activation. It is suitable for assessing within-subject changes over time and can reduce participant attendance burden for neurophysiological muscle testing.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010115

Authors: Lewis A. Gough Rachel Tan Stephen J. Bailey Craig Perrin Charlie J. Roberts Freya Gibbons

Background: Citrulline malate (CM) supplementation has been shown to improve resistance exercise performance. However, there is limited research on the dose–response effects of CM ingestion. The aim of this study was to investigate a moderate (8 g; CM-MOD) and high (12 g; CM-HIGH) dose of CM on resistance exercise performance. Methods: Twelve resistance-trained individuals (7 females, 5 males, age = 24 ± 2 years; body mass = 70 ± 10 kg; height = 172 ± 7 cm) volunteered for this randomised, double-blind, crossover trial. Following a familiarisation trial that consisted of determining one repetition maximum, participants completed barbell bent-over rows and leg presses following acute ingestion of either 8 g CM (CM-MOD), 12 g CM (CM-HIGH), or a placebo 1 h prior to exercise. Each exercise comprised two sets of 10 repetitions (70% one-repetition maximum (RM)) and a third set to exhaustion at 70% 1 RM. Results: The linear mixed-effect model found no significant differences in the completed repetitions between exercise type but did reveal a significant main effect of CM-HIGH on repetitions completed (p = 0.032), which was not found for CM-MOD, and only increases in leg press repetitions were observed (estimated marginal means: placebo = 17; CM-MOD = 19; CM-HIGH = 20). Conclusions: In conclusion, CM-HIGH resulted in small improvements to total repetitions performed during resistance exercise performance and likely only during leg press activity, though the underlying mechanisms remain unclear and further investigation is warranted.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010114

Authors: Andreea Ancuta Talinga Roxana Ramona Onofrei Ada-Maria Codreanu Alexandra Laura Mederle Veronica Aurelia Romanescu Marius-Zoltan Rezumes Oana Suciu Dan-Andrei Korodi Claudia Borza

Background: Lumbar spondylosis is a frequent cause of chronic low back pain, often associated with radiculopathy. Although imaging evaluation is widely used, it does not always reflect the degree of functional impairment of the nerve roots. Electrophysiological assessments, such as nerve conduction studies (NCS) and surface electromyography (sEMG), can provide additional information on neuromuscular function under conservative treatment. Methods: This quasi-experimental study included 60 patients with lumbar spondylosis and 25 healthy subjects, who underwent clinical, imaging, and electrophysiological assessments. NCS and sEMG parameters were assessed in the patient group before and six months after rehabilitation treatment. The control group was assessed only once, at baseline. We analyzed the nerve conduction velocity of the tibial and peroneal nerves and the sEMG activity of the tibialis anterior muscle bilaterally. Statistical analysis used nonparametric tests, Spearman’s coefficient, and Hodges–Lehmann estimates. Results: Compared to the control group, patients presented increased residual latencies and reduced CMAP amplitude and motor conduction velocity values (p < 0.001). After rehabilitation treatment, significant improvements in NCS parameters were observed, with decreased latencies and increased CMAP amplitude and motor conduction velocity bilaterally (p < 0.001). Also, sEMG amplitude and recruitment pattern scores increased significantly at the 6-month follow-up (p ≤ 0.004). Correlations between electrophysiological parameters and the severity of imaging changes were limited, with modest associations for left tibial latencies (ρ = 0.401–0.467; p < 0.050). Conclusions: In patients with lumbar spondylosis, rehabilitation treatment was associated with functional improvements in nerve conduction velocity parameters and muscle activity.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010113

Authors: Martina Sortino Bruno Trovato Rita Chiaramonte Antonio Carrera Marco Sapienza Federico Roggio Giuseppe Musumeci

Background: Adapted Physical Activity (APA) prescription is a complex decision-making process that integrates clinical guidelines and individual patient characteristics and remains strongly dependent on clinician experience. Generative artificial intelligence (AI) has recently emerged as a potential decision-support tool in exercise prescription; however, its interaction with professional expertise is still unclear. This study compared the perceived quality of APA protocols developed by expert professionals, novice professionals supported by AI, and AI operating autonomously across multiple orthopedic conditions. Methods: In this observational cross-sectional study, five real orthopedic prescriptions (scoliosis, low back pain, osteoporosis, high risk of falls, and osteoarthritis) were used to generate three APA protocols per condition: expert professional (EP), novice professional with AI support (NAI), and AI alone. All protocols were created using an identical standardized prompt and anonymized. A multidisciplinary panel of 135 professionals blindly evaluated the protocols using a structured questionnaire assessing effectiveness, safety, appropriateness, clarity, and progression. Overall quality scores were compared using Friedman tests with post hoc Wilcoxon signed-rank tests. Results: Across all conditions, EP protocols achieved the highest quality scores, followed by NAI, while AI-alone protocols consistently received the lowest ratings (all p < 0.05). NAI protocols showed intermediate performance, partially reducing the expertise gap. Post hoc analyses showed that EP protocols received significantly higher rating than AI protocols in all conditions (p < 0.01). NAI protocols received significantly higher rating than AI protocols in most conditions (p < 0.01) except osteoporosis (p = 0.362). Differences between EP and AI were most pronounced for safety (p < 0.01), appropriateness (tailoring p < 0.01), and progression (p < 0.05), whereas EP–NAI differences were smaller and condition-dependent. AI-alone protocols showed greater variability across pathologies. Conclusions: Professional expertise remains the main determinant of APA protocol quality. AI support can improve protocol structure and perceived quality when used by novice professionals but does not replace expert clinical reasoning. AI-generated protocols without human oversight are not yet suitable for autonomous APA prescription, supporting a complementary, expertise-dependent role of AI in exercise programming.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010112

Authors: Veronica Potosi-Moya Ronnie Paredes-Gómez Shulianna Burgos-Vera Samantha Báez-Narváez

Background: Hypertension is a multifactorial condition influenced by physiological, behavioral, and psychosocial factors. Muscle strength, physical activity, sleep quality, and perceived stress may contribute to blood pressure variability, although their relative influence remains unclear. This study examined associations between systolic blood pressure (SBP) and demographic, anthropometric, neuromuscular, behavioral, and psychosocial variables in adults with primary hypertension, with secondary analyses for diastolic blood pressure (DBP) and sex differences. Methods: A cross-sectional study was conducted in 391 adults with hypertension (165 men, 226 women). Predictors included age, body mass index, lower-limb muscle strength, physical activity (GPAQ), sleep quality (PSQI), and perceived stress. Associations were analyzed using correlation analyses and sex-stratified multivariable regression models. Results: In men, SBP correlated positively with age and negatively with lower-limb strength. In women, SBP showed associations with physical activity and perceived stress. Regression analyses indicated that sleep quality and perceived stress were independently associated with SBP in women (adjusted R2 = 0.13), whereas hamstring strength was associated with DBP in men with low explanatory capacity (R2 = 0.05). Moderate-to-high collinearity was observed among strength variables. Conclusions: Blood pressure variability was associated with neuromuscular and psychosocial factors with sex-specific patterns; however, the modest explained variance suggests these factors act as complementary rather than primary determinants. Longitudinal studies are needed to clarify causal relationships.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010111

Authors: Adrián González-Jiménez Diego Muñoz Adrián Castaño-Zambudio Bernardino J. Sánchez-Alcaraz Iván Martín-Miguel

Objectives: The physical and physiological characteristics of padel players are essential for appropriate training load prescription; however, this area remains underexplored. Therefore, this hypothesis-driven study aimed to analyse physical and physiological differences in male padel players according to playing side. A secondary objective was to observe the influence of training volume on these parameters. Methods: Fourteen high-level male players competing in professional circuits or top-level regional competitions participated in this cross-sectional study using directional (one-tailed) testing. Results: Vertical jump performance differed significantly between the countermovement jump (CMJ) and the Abalakov jump (ABK) (p < 0.001), with lower values in the CMJ (40.98 cm) compared with the ABK (46.96 cm). Isometric handgrip strength showed significant inter-limb differences (p < 0.001), with greater force in the dominant hand (49.08 kg) than in the non-dominant hand (44.22 kg). Mean completion time in the agility t-test was 10.40 s (95% CI: 10.06–10.74 s). The Yo-Yo Intermittent Recovery Test showed a mean distance of 404.28 m, corresponding to an estimated VO2max of 50.79 mL·kg−1·min−1. Playing side significantly affected Yo-Yo performance and estimated VO2max (p = 0.036), with higher values in left-side players. Although no significant differences were found in handgrip strength according to playing side. As expected, weekly training frequency did not significantly influence any variable. Conclusions: These findings help characterise the physical and physiological profile of high-level padel players and provide practical reference values to support training prescription and performance monitoring.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010110

Authors: Rossana Gnasso Antonio Picone Ayda Tavakkolifar Stefano Palermi Roberta Naddei Simona Di Gennaro Alessandro Nunzio Velotti Mario Fusari Tullio Alliegro Marco Caruso Maria Alessio

Background: Juvenile Idiopathic Arthritis (JIA) is the most prevalent rheumatological disease in childhood. It is classified into seven subtypes, each with specific clinical features. The pathogenesis of JIA involves an increased inflammatory response. Treatment options include pharmacological therapy, patient education, physical therapy, and rehabilitation. Methods: Patients received IAC injections and were subsequently divided into two groups: one group underwent HKT, while the other did not. The effects of HKT were assessed before treatment and one month after the IAC injections and initiation of HKT, using the Child Health Assessment Questionnaire (CHAQ), Visual Analogue Scale (VAS), and the Child Health Questionnaire—Parent Form 50 (CHQ-PF50). Results: Data were analyzed using the t-test. The HKT group showed non-statistically significant improvements in CHAQ and VAS scores compared to the non-HKT group. However, statistically significant differences were observed in the CHQ-PF50, particularly in the self-esteem and pain subscales. Conclusions: Although global differences between groups were not statistically significant, the group that underwent HKT demonstrated better scores, suggesting that HKT may reduce pain and contribute to improved quality of life in children with JIA.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010109

Authors: Luis Gerardo Vázquez-Villarreal Wiliam Carvajal-Veitía Gustavo Guevara-Balcázar Claudia Maceroni Pedro López-Sánchez María del Carmen Castillo-Hernández

Background: This cross-sectional observational study aimed to describe the position-specific kinanthropometric characteristics of Mexican professional American football players competing in the 2019–2020 seasons of the Liga de Fútbol Americano. Methods: A total of 189 athletes were assessed following International Society for the Advancement of Kinanthropometry standards. Twenty-six anthropometric variables were measured to estimate body composition (five-way fractionation), somatotype, proportionality indices, and tissue-specific masses. Positional differences were examined using ANOVA or Kruskal–Wallis tests with corresponding effect sizes (η2 or ε2). An exploratory stepwise discriminant analysis identified the anthropometric dimensions contributing most to positional differentiation, and classification accuracy was calculated. Results: Offensive and defensive linemen showed the greatest absolute size and higher adipose, muscle, and bone mass compared with other positions. The overall somatotype corresponded to a balanced endomorphic mesomorph (3.8–7.0–0.8), with wide receivers and defensive backs presenting lower endomorphy. The discriminant model identified arm relaxed girth, biiliocristal breadth, and sitting height as the variables contributing most to positional differentiation, achieving a classification accuracy of 57.7%. Given its exploratory nature and the absence of cross-validation, the discriminatory capacity of the model should be interpreted with caution. Somatotype Attitudinal Mean indicated greater interpositional heterogeneity among linemen. Conclusions: This study provides population-specific reference data for Mexican professional American football players, highlighting clear positional morphological characteristics. These findings may support talent identification and positional profiling; however, the exploratory discriminant model and league-specific sample limit generalization to other populations.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010108

Authors: Rebecca Davis Benjamin C. Brewer Martha Hall Jill S. Higginson

Background: Despite the high prevalence of adductor injury in soccer, there is limited injury-specific predictive modeling to identify common risk factors. The objective of this study was to create an adductor strain prediction model utilizing injury, game, and performance data collected from a cohort of professional Major League Soccer (MLS) players. Methods: We identified potential risk factors for soft tissue, non-contact adductor strain using a predictive machine learning model framework. Performance and injury data were collected between the 2019 to 2022 seasons of one professional MLS team. We utilized Random Forest (RF) machine learning models with Synthetic Minority Oversampling (SMOTE) to predict soft tissue, non-contact adductor strain injury amongst the cohort. Features chosen to be implemented in the model included injury, game, and performance data. Results: From the four models constructed in this study, the best performing model included Catapult Global Position System (GPS)/Internal Measurement Unit (IMU), strength, injury, and game data using a weekly structure determined by F1 score. Multiple models indicated that not having a previous injury lowers the odds of a future injury in the following week or month. Forwards had greater odds of injury whereas defenders had lower odds of injury. Greater hamstring max force lowered odds of injury whereas a greater amount of change of direction efforts increased the odds of injury in the following week or month. Adductor-to-abductor max strength ratio showed conflicting results regarding the odds of future injury. Conclusions: Through the utilization of RF and SMOTE, we were able to successfully predict adductor injuries in an MLS cohort utilizing injury, game, and performance metrics. Validation in a larger cohort would be highly recommended before utilizing the findings of this study in the design of injury prevention protocols.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010107

Authors: Tingxu Zhang Hanyan Yan Ziwen Mu Ang Ni Haoxiang Wang Zhiqiang Han Kazuhiro Imai Xiao Zhou

Background: Physical functional capacity plays a critical role in sports performance and changes markedly from adolescence to adulthood. This study aimed to compare the physical functional characteristics between adolescent and collegiate soccer athletes. Methods: Fifty elite male soccer athletes (30 adolescents, 20 college students) were assessed for joint range of motion, muscle flexibility, dynamic balance, and trunk functional capacity. Results: Adolescent athletes achieved significantly greater general joint laxity score than collegiate athletes (p = 0.01), with significantly greater hip range of motion across all planes (abduction, internal rotation, and external rotation; all p < 0.01). College athletes had significantly lower SLR degree (left: p < 0.01, right: p < 0.05) but significantly greater degrees on passive Ely’s test (p < 0.01) than adolescent athletes. Collegiate athletes delivered significantly superior dynamic balance performance in the Y-balance test, particularly in the posterolateral and posteromedial directions (all p < 0.05). Unexpectedly, trunk functional capacity was significantly lower in collegiate athletes compared with adolescents (p < 0.01). Limb asymmetry was observed in both groups: collegiate athletes showed asymmetry only in the anterior reach direction of the Y-balance test (p = 0.018), whereas adolescents exhibited asymmetry across multiple joints (ankle, hip, hamstrings, and quadriceps; all p < 0.05) and in the posterolateral direction of the Y-balance test (p < 0.01). Conclusions: Adolescent athletes demonstrated significantly superior joint range of motion and lower limb flexibility, whereas collegiate players exhibited better balance performance, indicating distinct functional profiles between the two cohorts, which may be associated with differences in training experience and developmental stages.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010106

Authors: Gianpiero Greco Alessandro Petrelli Luca Poli Francesco Fischetti Stefania Cataldi

Machine learning (ML) is increasingly influencing the assessment and delivery of movement and exercise, yet its role within adapted physical activity (APA) for individuals with chronic conditions has not been comprehensively synthesized. ML-based approaches have the potential to enhance functional assessment, support individualized exercise prescription, and facilitate scalable monitoring across preventive, community-based, and long-term adapted exercise settings, particularly in populations characterized by functional heterogeneity and variable responses to exercise. The aim of this narrative review is to synthesize and critically discuss current ML applications relevant to the core professional processes of APA practice. A structured narrative review was conducted using searches in PubMed/MEDLINE, Scopus, and Web of Science, complemented by targeted searches in engineering-oriented sources to capture ML methods not consistently indexed in biomedical databases. The search covered the period in which contemporary ML approaches have been increasingly applied to human movement and exercise research and was last updated in January 2026. Evidence was synthesized thematically into application-oriented domains relevant to APA practice. ML applications in APA include markerless motion and gait analysis, wearable-sensor data processing, balance and fall-risk assessment, and functional classification. Predictive and adaptive models support individualized regulation of exercise intensity, progression, and workload, including remote and hybrid delivery models. Applications span oncology, cardiometabolic, respiratory, neuromuscular conditions, and adapted sport contexts. Ethical, legal, and governance issues, such as algorithmic bias, data privacy, and professional accountability, emerge as central considerations for safe and equitable implementation. ML represents a promising decision-support layer for APA, complementing professional expertise through enhanced assessment, personalization, and monitoring. Its effective integration requires robust validation, interpretability, and responsible governance to ensure that ML augments, rather than replaces, professional judgment in APA practice.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010105

Authors: Flavia Pereira Scott C. Forbes Victor Romano Paul Christopher Juan Carlos Santana Jose Antonio

Background: Beach volleyball is a high-intensity, intermittent sport requiring repeated explosive actions and rapid changes of direction performed on an unstable sand surface. Creatine monohydrate (CrM) supplementation has consistently been shown to enhance short-duration, high-intensity performance; however, evidence in female athletes and sport-specific contexts in beach volleyball remains limited. The purpose of this study was to examine the effects of CrM supplementation delivered in gummy form on physical performance outcomes, body composition, and reaction time in female beach volleyball athletes. Methods: Thirty-two female collegiate and professional beach volleyball athletes completed a 10-week randomized controlled trial and were assigned to either CrM, 5 g·day−1 group (n = 17) or control group (n = 15). Countermovement jump (CMJ) height, change-of-direction speed (CODS), body composition, and reaction time were assessed before and after the intervention. Outcomes were analyzed using mixed-model analyses of variance. Results: Significant Group × Time interactions were observed for CMJ height and CODS, with the CrM group demonstrating improvements in jump height (p < 0.001, ηp2 = 0.34) and faster change-of-direction performance (p = 0.009, ηp2 = 0.21), while the control group showed no improvement or performance declines. Significant Group × Time interactions were also observed for body fat mass (p = 0.024, ηp2 = 0.16), body fat percentage (p = 0.015, ηp2 = 0.18), and total body water (p = 0.038, ηp2 = 0.14). No significant interactions were observed for lean body mass, skeletal muscle mass, total body mass, or reaction time. Conclusions: CrM supplementation delivered in gummy form enhanced selected performance outcomes and helped maintain body composition in female beach volleyball athletes. These findings support creatine gummies as a practical supplementation strategy in this population.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010104

Authors: José Carlos Cabrera Linares Pedro Ángel Latorre Román Juan Antonio Párraga Montilla

Objective: This study aimed to (i) examine the test–retest reliability of a holistic motor competence test (HOLMOT) in adults aged 30–60 years, and (ii) evaluate its ability to discriminate performance according to sex and age group. Methods: A total of 435 adults (206 women and 229 men; Mean age: 43.49 ± 7.55 years; Weight: 69.10 ± 9.88 kg; BMI: 23.81 ± 2.42 kg/m2) participated in this cross-sectional study. Motor Competence was assessed using the HOLMOT, a time-based protocol integrating motor-cognitive, locomotor, and manipulative domains. Test–retest reliability was examined in a subsample of 217 participants over a one-week interval using relative (ICC, Pearson’s r) and absolute (SEM, MDC) reliability indices. Sex and age-group differences were analyzed using independent t-tests and analysis of variance. Results: The HOLMOT demonstrated good to excellent reliability for the motor-cognitive (ICC = 0.89), locomotor (ICC = 0.94), and total time (ICC = 0.84) outcomes, with low SEM and MDC values. Reliability was lower for the manipulative section (ICC = 0.44). Men exhibited shorter completion times than women across all sections (p < 0.001), and adults over 50 years showed significantly longer times in the motor-cognitive and locomotor domains (p < 0.05). Conclusions: The HOLMOT is a feasible and reliable tool for assessing motor competence in mid-adulthood, demonstrating sensitivity to sex- and age-related differences and supporting holistic, lifespan-oriented models of motor competence.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010103

Authors: Silas Dech René Kittel

Background: Sport climbing, encompassing lead, bouldering, and speed disciplines, has transformed from a niche activity to a widely popular trend, notably after its Olympic debut at the Tokyo Games 2021. This recognition spurred an increase in publications. Despite the emerging scientific interest, terminology in climbing textbooks often relies on experiential rather than scientific understanding, leading to inconsistencies. This paper aims to standardize terminology by applying sports science frameworks, including biomechanics, training science, and sports medicine. Methods: The study reinterprets general sports science concepts for climbing-specific applications, proposing a structure of climbing skill that covers physical fitness components, biomechanical principles and techniques (body positioning), and specific components (hand and foot positioning). This integrated approach seeks to establish a coherent nomenclature, facilitating research, training, prevention, and rehabilitation within the climbing discipline. Results: Five primary climbing principles are proposed: optimal wall contact, maintained stability, center of mass shift, movement initiation from the legs and optimal climbing speed. Two technique categories—frontal and rotational—are defined in consideration of the spatial position of the pelvic frontal plane in relation to the wall surface. Each climbing technique can be described by applying the three-phase model of acyclic movements. Principles and techniques both aim to maximize efficiency in moving and resting on the climbing wall. Conclusions: A unified understanding of climbing principles and techniques is vital for progressing research, training programs, prevention strategies, and rehabilitation efforts in sport climbing. Adopting a comprehensive sports science framework promises enhanced clarity and efficacy in climbing practices, benefiting both theoretical analyses and practical applications.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010102

Authors: Benjamin J. Mendelson David J. Cornell Scott D. Brau Nathan T. Ebersole Robert J. Flees Kyle T. Ebersole

Background: The purpose was to determine the ventilatory and metabolic demands in percentage-based heart rate (HR) zones in active-duty firefighters. Methods: Male career firefighters (n = 48, 38.17 ± 9.02 years, 1.79 ± 0.05 m, 88.27 ± 12.50 kg) completed a maximal treadmill test while wearing chest strap monitors to measure physiological responses corresponding to Zone 1 (50–59%), Zone 2 (60–69%), Zone 3 (70–79%), Zone 4 (80–89%), and Zone 5 (90–100%) based on age-predicted maximal HR. Aerobic capacity (VO2PEAK, mL·kg−1·min−1), average minute ventilation (VE, L·min−1), and respiratory exchange ratio (RER) in each zone was measured via indirect calorimetry. Linear mixed models determined significant differences in VE, RER, and time in zone (min). Results: Significant relationships emerged between VO2PEAK and average RER in Zone 5 (r = −0.33) and time in Zone 3 (r = 0.45), Zone 4 (r = 0.41), and Zone 5 (r = 0.41). A significant HR zone effect emerged in VE (F = 516.01, p < 0.001) indicating that VE increased as zone intensity increased. After controlling for VO2PEAK, a significant HR zone effect emerged in RER (F = 11.90, p < 0.001), indicating that average RER increased as zone intensity increased. No HR zone effect was found for time in zone (F = 1.18 p = 0.332) after controlling for VO2PEAK. Conclusions: A practical cardiovascular workload measure, such as percentage-based HR zones determined from treadmill testing, have distinct ventilatory and metabolic responses. Higher aerobic capacity is related to greater time spent working in higher HR zones.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010101

Authors: Lucas Bertoluci Zuquieri Gabriel de Souza Zanini Danilo Alexandre Massini Eliane Aparecida de Castro Wellington Segheto Cassiano Merussi Neiva Pedro José Benito Dalton Müller Pessôa Filho

Background: Resting energy expenditure (REE) represents 60–75% of total daily energy expenditure and is mainly determined by fat-free mass (FFM). Indeed, the predictive equations vary according to FFM techniques and population characteristics. Therefore, this study aimed to explore the influence of dual-energy X-ray absorptiometry (DXA)-derived FFM on REE prediction by different predictive equations in a large and diverse cohort. Methods: A total of 1987 active and sedentary participants of both sexes (43.8 ± 19.4 years) underwent body composition assessment by DXA. REE was predicted using the Harris–Benedict, Schofield, Mifflin–St Jeor (weight- and height-based), and Mifflin (FFM-based) equations. Statistical analyses included Kruskal–Wallis, Spearman correlations, and linear regression. Results: Men presented higher absolute FFM, whereas women exhibited higher relative fat mass (FM) (p < 0.01). Across age groups, FFM declined progressively, while FM increased (p < 0.01). The REE differed significantly (p < 0.001) between equations, with the lowest values predicted from the FFM-based model, while the Harris–Benedict and Schofield equations showed the highest REE, especially in women. Strong correlations were observed between FFM and REE (r = 0.77–0.98; p < 0.01) for all age groups and equations, whereas FM showed strong correlations (r = 0.77–0.85; p < 0.01) only for the ≥60 years group. REE tended to be higher in active than sedentary participants, with the correlations to FFM and FM exhibiting a similar profile to that observed for the whole group. Conclusions: FFM showed a strong association with the estimate of REE in active and sedentary participants from both sexes and different age groups, but FM showed a similar trend in older participants only. Therefore, the increase or the maintenance of FFM with an active lifestyle is important to keep REE at high and efficient levels regardless of sex and age.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010100

Authors: Jordan Allan Piper Koko Faen Andy Cai Ali Ghahreman Samuel Rajadurai Giuseppe Musumeci Alessandro Castorina

Low back pain (LBP) remains a leading cause of disability worldwide, imposing substantial socioeconomic burdens. Among its many causes, facetogenic pain accounts for a significant proportion of cases and is generally attributed to irritation of the richly innervated facet joint capsule, mediated by the medial branches of the dorsal rami. This narrative, hypothesis-driven review synthesises the current anatomical, biomechanical, neurophysiological, and clinical literature and advances a conceptual framework proposing a novel anatomical mechanism that may contribute to LBP. We hypothesise that ossification of the mamillo-accessory ligament (MAL) may be a plausible but under-recognised anatomical variant that may influence lumbar biomechanics and neural interfaces. The MAL connects the mammillary and accessory processes of lumbar vertebrae, serving as a stabilising anchor for deep paraspinal muscles and forming a conduit for the medial branch of the dorsal ramus (MBDR). Ossification of the MAL, resulting in a mamillo-accessory foramen, may theoretically impair spinal biomechanics via three principal mechanistic domains: (1) disruption of muscle attachment and segmental stabilisation, (2) potential compression of the MBDR causing denervation and muscle atrophy, and (3) chronic nerve entrapment leading to asymmetrical postural adaptations and persistent pain. Collectively, these pathways may contribute to spinal instability, facet degeneration, and variable response to standard interventional treatments such as radiofrequency ablation. Recognition of MAL ossification may have potential implications for clinical assessment, targeted imaging strategies, and treatment stratification in patients with chronic, non-specific LBP.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010099

Authors: Khairi Salim El Mouahid Khalid Chmura Paweł Rfaki Abderrazak

Background: This systematic review critically examined how vertical force–velocity profiling has been used and interpreted in soccer research, with particular attention to methodological limitations and practical constraints. Methods: Following PRISMA guidelines, four databases were searched up to January 2025, and eleven studies met the inclusion criteria. Results: Several studies reported statistical associations between vertical F–V variables (particularly Pmax and V0) and jump- and sprint-related outcomes; however, these associations were heterogeneous, task-dependent, and sensitive to modeling assumptions. Age- and maturity-related studies demonstrate progressive increases in F0 and Pmax across developmental stages, explaining much of the inter-individual variability in youth populations. Positional and sex-based analyses reveal distinct neuromuscular profiles, with wide and attacking players displaying more velocity-oriented characteristics, and female players showing lower Pmax values. Indirect links with match-related demands, inferred from positional profiles and external load literature, suggest potential ecological relevance; however, direct evidence linking vertical F–V parameters to match-derived GPS metrics remains limited. Intervention studies show that individualized F–V-based training can modify selected vertical mechanical parameters, but improvements in sprint or match performance are not systematic. Conclusions: Vertical F–V profiling may provide descriptive information under tightly controlled conditions; however, evidence supporting its use for individualized or deficit-based training prescription in soccer remains limited and inconsistent. For this reason, vertical F–V profiling should not be interpreted as a mechanistic model of soccer performance, but rather as a context-dependent descriptive framework with restricted ecological validity.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010098

Authors: Ismael Martínez-Guardado Diego A. Alonso-Aubin Juan Hernández-Lougedo Domingo J. Ramos-Campo

Background: Previous research suggests that resistance training in hypoxia can cause physiological and muscle adaptations. However, this method may not be efficient for individuals who are training to optimize maximal strength and power. Objective: This study aimed to investigate the effects of 8 weeks of high-intensity resistance circuit in normobaric hypoxic conditions on maximal and explosive measures of muscle strength in upper and lower limbs. Methods: A total of 28 subjects were randomly assigned to either hypoxia (fraction of inspired oxygen [FIO2] = 15%; HRChyp: n = 15; age: 24.6 ± 6.8 years; height: 177.4 ± 5.9 cm; weight: 74.9 ± 11.5 kg) or normoxia [FIO2] = 20.9%; HRCnorm: n = 13; age: 23.2 ± 5.2 years; height: 173.4 ± 6.2 cm; weight: 69.4 ± 7.4 kg) groups. Training sessions consisted of two blocks of three exercises and the training intensity was fixed performed at six repetition maximum. Participants exercised twice weekly for 8 weeks, and upper and lower body power tests were performed before and after the training program. The statistical analysis applied was a two-way analysis of variance with repeated measures and Bonferroni post hoc. Results: No significant differences were observed between groups. However, the hypoxia group showed higher intra-group differences in absolute (N) (F = 7.97; Δ7.3%; p < 0.05; ES = 0.49) and relative (N/Kg) (F = 8.34; Δ7.2%; p < 0.05; ES = 0.49) maximum push-up force after the training period. Conclusions: Hypoxic circuit training may improve a specific upper body performance outcome, but no clear advantage over normoxia was observed.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010097

Authors: João Galrinho Marco Batista Marta Gonçalves-Montera Ana Rita Matias Orlando Fernandes

Background: Age-related cognitive decline is linked to reduced gait complexity and higher fall risk. Traditional linear gait measures may miss subtle motor-cognitive deficits in older adults with dementia. This study examined whether an 8-week motor-cognitive exercise program could improve gait adaptability in institutionalized older adults with cognitive impairment. Gait complexity, measured using Sample Entropy, was the primary outcome. Methods: Forty-two institutionalized older adults completed follow-up assessments, including 26 with cognitive impairment and 16 controls. Gait was assessed during normal walking (single-task) and while performing cognitive tasks (dual-task), such as naming animals or counting backward. Inertial sensors recorded stride intervals, and Sample Entropy was calculated to evaluate gait regularity and adaptability, (gait complexity). The intervention included 24 structured sessions combining physical and cognitive exercises targeting balance, coordination, and executive function. Non-parametric tests (Wilcoxon) were used, with Bonferroni correction for multiple comparisons. Results: Participants with cognitive impairment showed increased gait complexity, especially during dual-task walking. Significant improvements were found in both limbs under dual-task conditions (left: p = 0.015, effect size = 0.34; right: p = 0.030, effect size = 0.31). During single-task walking, a significant improvement was observed in the left limb (p = 0.006, effect size = 0.39). Conclusions: Motor-cognitive exercise may enhance non-linear gait complexity in institutionalized older adults with cognitive impairment. The use of dual-task training in rehabilitation and highlight the value of entropy-based gait assessment for detecting subtle functional changes. However, the lack of a randomized non-exercising cognitive impairment control group limits definitive conclusions about causality.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010095

Authors: Bjørn Johansen Roland van den Tillaar

Background: This systematic review examined the relationship between horizontal multi-step jumps and sprint performance, and whether training interventions including these exercises improve sprinting. Methods: A systematic literature search was conducted in SPORTDiscus and PubMed (MEDLINE) and included English-language studies of athletes aged ≥14–15 years that assessed at least one horizontal multi-step jump and reported sprint outcomes over distances up to 100 m. Methodological quality and risk of bias were assessed using design-appropriate critical appraisal tools. Of 316 records identified, 19 studies met the inclusion criteria (10 intervention studies and 9 correlational studies). Results: Across correlational studies, horizontal multi-step jump performance showed associations ranging from weak to very large with sprint performance, with the strongest relationships typically observed during acceleration (≤20–30 m). In trained sprinters, correlations were often large to very large (r ≈ −0.65 to −0.88), whereas team-sport athletes showed more moderate associations, and younger or less specialized populations showed weak or non-significant relationships. Across intervention studies, horizontal multi-step jump training generally improved short-distance sprint performance, with the largest improvements reported for acceleration (up to ~7–12% in some studies), while effects at longer sprint distances and maximal-speed performance were smaller, inconsistent, or not different from comparison training. Conclusions: Overall, the evidence suggests that the association between horizontal multi-step jumps and sprint performance is strongest during the acceleration phase and is influenced by athlete population and training status. Horizontal multi-step jumps appear to be useful for assessing and potentially developing sprint acceleration. However, the findings should be interpreted with caution due to heterogeneity in study design and variable methodological quality, and associations with maximal sprint speed are less consistent across studies.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010096

Authors: Christoph Schärer Fabio Strauss Nubya Baio Caterina Barloggio Anne-Sarah Dysli

Background: Explosive and reactive strength of the lower extremities are essential performance determinants in artistic gymnastics. This study analyzed ten years of performance diagnostic data from Swiss junior and elite gymnasts to describe age- and sex-specific development patterns of lower-limb strength and to examine whether early strength levels predict later selection to the Swiss national elite team. Methods: Longitudinal performance data from 234 Swiss gymnasts (125 females, 109 males; 7–30 years) were analyzed. Explosive and reactive strength were assessed using countermovement, squat, single-leg, and drop jumps. Age- and sex-related differences, as well as associations with later national team selection, were examined. Results: Explosive and reactive strength increased significantly across age categories in both sexes (p < 0.001). In females, the greatest improvements occurred between U14 and U16 (explosive strength: +8.7–12.9%; reactive strength: +15.6–21.2%), followed by stagnation in explosive strength at older ages. In males, both strength qualities increased continuously from U14 to U18 (+9.3–15.7% per category; p < 0.001), with smaller gains at the elite level. Sex differences in explosive strength emerged from U16 and became pronounced from U18 onwards, favoring males (+11.3–19.2%). Reactive strength showed smaller and partly reversed sex differences, with females demonstrating higher values in U16 and elite athletes (up to +16.5%). Differences between athletes later selected for the national team and non-selected athletes were small and mostly non-significant. Conclusions: Lower-limb strength development in gymnastics follows distinct age- and sex-specific patterns. Systematic training appears to moderate sex-related differences, particularly in reactive strength. While physical capacities form an important foundation, technical proficiency seems to play a more decisive role in elite selection and long-term athlete development.

Journal of Functional Morphology and Kinesiology doi: 10.3390/jfmk11010094

Authors: Koji Iwasaki Kento Sabashi Hidenori Koyano Yuji Kodama Shigeyuki Sakurai Kengo Ukishiro Ryusuke Ito Hisashi Matsumoto Yuichiro Abe Noriaki Mori Chiharu Inoue Yasumitsu Ohkoshi Tomohiro Onodera Eiji Kondo Norimasa Iwasaki

Background: Osteotomy around the knee (OAK) is a joint-preserving surgery for knee osteoarthritis, yet some patients experience suboptimal outcomes. Preoperative identification of high-risk patients remains challenging. This study aimed to develop a machine learning model to predict clinical outcomes after OAK using preoperative gait acceleration data from inertial measurement units (IMUs). Methods: This multicenter prospective study enrolled patients undergoing OAK. Preoperative gait was recorded using synchronized IMUs placed on the lumbar spine and tibia. Lumbar and tibial signals were used for gait-cycle segmentation, while wavelet-based time–frequency features were extracted from tibial acceleration only. Outcomes were defined by achievement of the minimal clinically important difference in ≥3 KOOS subscales at 2-year follow-up (Good vs. Poor). Continuous wavelet transform features (5–20 Hz) were summarized as mean and standard deviation across six stance subphases. A Random Undersampling Boost classifier was trained and evaluated using nested leave-one-subject-out cross-validation. A sensitivity analysis using logistic regression confirmed that the IMU-based prediction score was independently associated with outcome after adjustment for baseline KOOS (p = 0.047). Results: Of 67 enrolled patients, 37 were classified as Good and 30 as Poor outcome. For machine learning analysis, 1173 tibial acceleration gait-cycle waveforms were usable. The model achieved an AUC of 0.744 (95% CI, 0.610–0.860) using a median of 15 features (range, 5–25) with sensitivity of 0.69 and specificity of 0.72. The most informative predictors were the mean magnitude in the 5–8 Hz band during loading response (0–17%) and variability in the 5–8 Hz band during late stance (67–83%). No significant differences in baseline demographics or radiographic parameters were found between outcome groups. Conclusions: Preoperative IMU-derived gait acceleration features showed moderate-to-good discrimination between outcome groups and may support preoperative risk stratification and individualized perioperative management.