Journal of Functional Morphology and Kinesiology

16 pages, 495 KiB

Open AccessArticle

Hematological, Biochemical, and Performance Adaptations in Amateur Soccer Players Following a 4-Week Preseason Training Period

by Panagiotis Georgiadis, Pierros Thomakos, Ilias Smilios, Angeliki Papapanagiotou, Anastasia Evaggelatou and Gregory C. Bogdanis

J. Funct. Morphol. Kinesiol. 2025, 10(3), 314; https://doi.org/10.3390/jfmk10030314 - 14 Aug 2025

Abstract

Background: We examined changes in hematological, biochemical, and hormonal biomarkers, along with endurance and explosive performance indices, in amateur soccer players over a 4-week preseason period. Methods: Thirteen players (age: 19.7 ± 2.0 years; body mass: 73.0 ± 6.8 kg; height: [...] Read more.

Background: We examined changes in hematological, biochemical, and hormonal biomarkers, along with endurance and explosive performance indices, in amateur soccer players over a 4-week preseason period. Methods: Thirteen players (age: 19.7 ± 2.0 years; body mass: 73.0 ± 6.8 kg; height: 180 ± 0.1 cm; body fat: 8.6 ± 3.5%) were monitored during a 4-week preseason program, which included 21 training days, three friendly matches, and four days of rest. Before and after this period, endurance capacity was evaluated using the Yo-Yo IR1 test, and leg power was assessed using the CMJ. Blood samples were collected for three consecutive days in week 1 and after week 4 to assess hematological and biochemical parameters. Internal load during all weeks was assessed with session RPE (sRPE). Results: There was a 25.5% increase in Yo-Yo IR1 distance (2123 ± 413 vs. 1560 ± 356 m, p = 0.002), with the estimated VO₂max and the speed associated with VO₂max (vVO₂max) improving by 8.7% (49.5 ± 3.0 to 54.2 ± 3.5 mL/kg/min, p = 0.002) and 5.3% (16.0 ± 0.7 to 16.9 ± 0.6 km/h, p = 0.002), respectively. In contrast, CMJ performance in weeks 2–4 declined by 13.4–21.0% relative to baseline, while sRPE peaked during week 3 (4011 ± 440 AU). Hematological variables were mostly stable except for small increases in MCV and MCH (1.5–1.8%, p < 0.001), while there were significant reductions in urea (12%), uric acid (6.2%), and erythropoietin (33%). Conclusions: A 4-week preseason program substantially improved aerobic capacity yet compromised leg power. Changes in biomarker profiles suggest that the training load maintained an appropriate balance between overload and recovery. These findings provide valuable guidance for coaches seeking to optimize training protocols while minimizing the risk of overtraining and preventing injuries during the competitive season. Full article

(This article belongs to the Special Issue Optimizing Performance: Training Strategies to Improve Strength, Speed, Power, and Endurance)

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14 pages, 6782 KiB

Open AccessArticle

Effects of Short-Term Structural Exercise on Cardiopulmonary Function, Quality of Life, and Oxidative Status in Liver Transplant Recipients: A Case Series

by Narubet Mekkhayai, Jirakrit Leelarungrayub, Supatcha Konghakote, Rungtiwa Kanthain, Khanittha Wonglangka, Sunhawit Junrungsee and Mujalin Prasannarong

J. Funct. Morphol. Kinesiol. 2025, 10(3), 313; https://doi.org/10.3390/jfmk10030313 - 14 Aug 2025

Abstract

Background: Living donor liver transplantation (LDLT) poses significant physiological challenges, especially during early postoperative recovery. While the long-term benefits of structured rehabilitation are well documented, data on short-term effects—particularly during the critical early inpatient phase—remain limited. This study aimed to evaluate the short-term [...] Read more.

Background: Living donor liver transplantation (LDLT) poses significant physiological challenges, especially during early postoperative recovery. While the long-term benefits of structured rehabilitation are well documented, data on short-term effects—particularly during the critical early inpatient phase—remain limited. This study aimed to evaluate the short-term impact of a structured exercise program on cardiopulmonary function, respiratory muscle strength, physical performance, oxidative stress markers, and quality of life in LDLT recipients. Methods: Four LDLT recipients (2 males, 2 females; mean age 48.00 ± 18.35 years) underwent a 4-week inpatient rehabilitation protocol. Weeks 1–2 involved conventional care, while weeks 3–4 included structured exercise consisting of early mobilization and inspiratory muscle training. Outcome measures included cardiopulmonary exercise testing (CPET), spirometry, maximal inspiratory and expiratory pressures (PImax, PEmax), 6 min walk distance (6MWD), lower limb muscle strength, Chronic Liver Disease Questionnaire (CLDQ), and serum oxidative stress markers (total antioxidant capacity [TAC] and malondialdehyde [MDA]). Results: All patients demonstrated postoperative declines in VO₂ peak, PImax, PEmax, and TAC. Structured exercise yielded clinically meaningful improvements in respiratory muscle strength, notably in female and younger participants. Two younger patients showed increased 6MWD; however, no patient regained preoperative VO₂ peak. TAC levels decreased following the intervention, and MDA levels remained stable in most cases. Conclusions: A two-week structured exercise program during early postoperative recovery may provide partial benefits in respiratory muscle strength and physical performance but is insufficient to restore full cardiopulmonary function in LDLT recipients. Longer rehabilitation periods may be necessary to achieve preoperative recovery levels. Full article

(This article belongs to the Section Physical Exercise for Health Promotion)

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14 pages, 893 KiB

Open AccessArticle

Functional Profile Differences Across Diagnostic Categories Using WHODAS 2.0 in Adults with Neurological, Musculoskeletal, and Chronic Pain Conditions

by Patricio Barria, Asterio Andrade, Bessié Córdova Albayay, Felipe Covarrubias-Escudero, Carlos Cifuentes, Juan Camilo Moreno and Juan Pablo Appelgren-González

J. Funct. Morphol. Kinesiol. 2025, 10(3), 312; https://doi.org/10.3390/jfmk10030312 - 14 Aug 2025

Abstract

Background: Functional disability is a growing concern in aging populations with chronic health conditions, yet few studies have compared disability profiles across diagnostic categories using standardized tools. Objectives: This study aimed to characterize the functional profiles of adults with neurological, musculoskeletal, [...] Read more.

Background: Functional disability is a growing concern in aging populations with chronic health conditions, yet few studies have compared disability profiles across diagnostic categories using standardized tools. Objectives: This study aimed to characterize the functional profiles of adults with neurological, musculoskeletal, and chronic pain conditions using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) and to examine differences by age and sex. Methods: A total of 419 participants (median age = 73 years; 73% female) completed the 36-item WHODAS 2.0. Diagnoses were classified into three groups: neurological (n = 134), musculoskeletal (n = 230), and pain-related (n = 55). Domain-level scores were analyzed using non-parametric tests and Spearman correlations. Results: revealed that neurological conditions were associated with the highest disability levels, particularly in cognition, interpersonal relations, and participation. Musculoskeletal conditions showed greater impairments in mobility and self-care, while pain-related conditions demonstrated variable disability, especially in participation. Women reported higher disability scores in the neurologic group, with significant differences observed in the cognition domain among neurological cases (p = 0.048). Age was positively correlated with disability in self-care and mobility, especially in musculoskeletal conditions. Conclusions: These findings highlight the utility of WHODAS 2.0 in identifying domain-specific limitations across clinical populations. They support the need for individualized, diagnosis- and gender-sensitive rehabilitation strategies, and suggest that WHODAS 2.0 can inform targeted care planning and resource allocation in rehabilitation settings. Future research should incorporate longitudinal designs and explore contextual factors influencing functional outcomes. Full article

(This article belongs to the Section Functional Anatomy and Musculoskeletal System)

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13 pages, 675 KiB

Open AccessArticle

A Fully Replicable Exercise Program for Individuals with Sleep-Disordered Breathing: Protocol Design and Training Load Monitoring

by Jose M. Saavedra, Katrin Y. Fridgeirsdottir, Conor J. Murphy, Harald Hrubos-Strøm and Erna S. Arnardottir

J. Funct. Morphol. Kinesiol. 2025, 10(3), 311; https://doi.org/10.3390/jfmk10030311 - 12 Aug 2025

Abstract

Objectives. The objectives of this study were (i) to design in detail an exercise program for individuals with sleep-disordered breathing (SDB) that would be reproducible, and (ii) to present a system for monitoring training load (volume × intensity) within such a program. [...] Read more.

Objectives. The objectives of this study were (i) to design in detail an exercise program for individuals with sleep-disordered breathing (SDB) that would be reproducible, and (ii) to present a system for monitoring training load (volume × intensity) within such a program. Methods. A comprehensive exercise program was developed for individuals with SDB, detailing not only the session structure (warm-up, main part—circuit training and brisk walking—and cool-down) but also the specific exercises, training volume (actual exercise time excluding rest), intensity (Borg Rating of Perceived Exertion—RPE), and training load (calculated as time × RPE, in arbitrary units). This detailed program was previously implemented in a RCT (ISRCTN16974764). A comparison was also made between the planned and performed intensity, and training load through a paired t-test. Results. A fully replicable program was presented. No significant difference was found between the planned and performed training load (p = 0.482). When analyzed by week, a significant difference was found only for overestimation in weeks 9–12 (p < 0.001). Conclusions. In general terms, it can be concluded that a detailed exercise program was described for individuals with SDB. The program is reproducible in terms of content, training volume, intensity, and load. Moreover, the RPE proved to be a valid parameter for quantifying intensity, allowing for the integration of all parts of the session, as well as various types of content. The planned and performed programs (as quantified via participants’ RPE) matched appropriately. Therefore, this program can be reproduced and applied to this type of population. Full article

(This article belongs to the Special Issue Sports Medicine and Public Health)

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14 pages, 660 KiB

Open AccessArticle

Modified Stress Score and Sympathetic–Parasympathetic Ratio Using Ultra-Short-Term HRV in Athletes: A Novel Approach to Autonomic Monitoring

by Andrew D. Fields, Matthew A. Mohammadnabi, Michael V. Fedewa and Michael R. Esco

J. Funct. Morphol. Kinesiol. 2025, 10(3), 310; https://doi.org/10.3390/jfmk10030310 - 12 Aug 2025

Abstract

Background: Monitoring autonomic balance provides valuable insights into recovery status and physiological readiness, both of which are essential for performance optimization in athletes. The Stress Score (SS) and Sympathetic–Parasympathetic Ratio (SPS), derived from Poincaré plot heart rate variability (HRV) indices, have been proposed [...] Read more.

Background: Monitoring autonomic balance provides valuable insights into recovery status and physiological readiness, both of which are essential for performance optimization in athletes. The Stress Score (SS) and Sympathetic–Parasympathetic Ratio (SPS), derived from Poincaré plot heart rate variability (HRV) indices, have been proposed as practical markers of sympathetic activity and overall autonomic balance. However, these traditional calculations often require lengthy recordings and specialized software, limiting their feasibility in field settings. This study introduces modified versions of these metrics derived from ultra-short-term (1 min) time–domain HRV recordings: the Modified Stress Score (MSS) and Modified Sympathetic–Parasympathetic Ratio (MSPS). Methods: Competitive male athletes (n = 20, age = 21.2 ± 2.1 year, height = 183.6 ± 8.9 cm, weight = 79.2 ± 10.3 kg) completed a maximal exercise test with HRV recorded before and after exercise. Results: Following natural log-transformation, MSS and MSPS demonstrated strong correlations with SS and SPS across all time points (r = 0.87–0.94, all p < 0.01) and displayed the expected physiological responses to exercise and recovery. Conclusions: These findings suggest that MSS and MSPS are practical, accessible tools for assessing autonomic balance in athletes. Their application may enhance our ability to monitor recovery status, guide individualized training strategies, and optimize performance in applied sport settings. Full article

(This article belongs to the Special Issue Optimizing Performance: Training Strategies to Improve Strength, Speed, Power, and Endurance)

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15 pages, 1153 KiB

Open AccessCase Report

A Functional Recovery Program for Femoroacetabular Impingement in Two Professional Tennis Players: Outcomes at Two-Year Follow-Up

by Francesca Campoli, Lucio Caprioli, Ida Cariati, Saeid Edriss, Cristian Romagnoli, Vincenzo Bonaiuto, Giuseppe Annino and Elvira Padua

J. Funct. Morphol. Kinesiol. 2025, 10(3), 309; https://doi.org/10.3390/jfmk10030309 - 10 Aug 2025

Abstract

Background: Femoroacetabular impingement (FAI) increasingly affects professional and amateur tennis players. Therefore, understanding the optimal approach to follow in specific cases plays an important role in the return to sports activity. Methods: This case report describes a two-stage functional recovery program [...] Read more.

Background: Femoroacetabular impingement (FAI) increasingly affects professional and amateur tennis players. Therefore, understanding the optimal approach to follow in specific cases plays an important role in the return to sports activity. Methods: This case report describes a two-stage functional recovery program implemented by two professional tennis players returning to practice. One player (a) underwent two arthroscopic surgeries for FAI and reconstruction of the damaged acetabulum labrum, while the other (b) took a stop period due to pain symptoms related to coxarthrosis and FAI. The subjects were monitored through pain perception questionnaires and mobility tests. An interview was conducted two years after the injury. Results: In both cases, at the end of the program, the subjects had no pain during tennis practice and gained more than 90% of range of motion in hip extension. However, both interrupted the program, experiencing painful symptoms again. At a two-year follow-up, the subjects were no longer involved in professional sports. The factors perceived by the two players were investigated and presented. Conclusions: The program proved beneficial, as both athletes returned to sports practice without pain symptoms and with hip mobility close to physiological. Nevertheless, the pain arose after the program ended and continued over time. Several aspects connected to the injury might have significantly affected early retirement from professional activity. Full article

(This article belongs to the Section Functional Anatomy and Musculoskeletal System)

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7 pages, 634 KiB

Open AccessBrief Report

Whole-Body Electromyostimulation Coupled with Aerobic Exercise Boosts Serum Irisin Levels in Healthy Individuals: A Pilot Study

by Gianluca Vadalà, Giuseppina Di Giacomo, Fabrizio Russo, Veronica Tilotta, Raffaella Rosy Vescio, Claudia Colaiacomo, Giorgia Petrucci, Luca Ambrosio, Vincenzo Denaro and Rocco Papalia

J. Funct. Morphol. Kinesiol. 2025, 10(3), 308; https://doi.org/10.3390/jfmk10030308 - 8 Aug 2025

Abstract

Background: Irisin, a myokine secreted during physical activity, has garnered attention for its potential roles in cartilage homeostasis and musculoskeletal health. Whole-body electromyostimulation (WB-EMS) is an emerging exercise modality that enhances muscle recruitment and may stimulate greater irisin release. This study aimed to [...] Read more.

Background: Irisin, a myokine secreted during physical activity, has garnered attention for its potential roles in cartilage homeostasis and musculoskeletal health. Whole-body electromyostimulation (WB-EMS) is an emerging exercise modality that enhances muscle recruitment and may stimulate greater irisin release. This study aimed to compare the acute serum irisin response following aerobic exercise with and without WB-EMS in healthy individuals. Methods: A total of 24 healthy adults were enrolled and randomized to undergo either aerobic physical activity (PA) or WB-EMS (n = 12 each). Both groups performed identical exercise routines, with the WB-EMS group additionally receiving muscle stimulation via a standardized protocol. Serum irisin levels were measured at baseline (T0), 10 minutes post-exercise (T1), and 1 hour post-exercise (T2) using ELISA. Statistical analysis was performed using two-way ANOVA with post hoc testing. Results: At T1, serum irisin levels did not significantly differ from baseline in either group. At T2, the WB-EMS group demonstrated a statistically significant increase in irisin levels compared to both T0 and T1 (p < 0.01), as well as to the PA group (p < 0.01). In contrast, the PA group showed only a slight, non-significant rise at T2. These findings suggest that WB-EMS induces a more robust irisin response than traditional aerobic exercise. Conclusions: WB-EMS appears to enhance irisin release in healthy individuals following acute exercise. These results support further research into WB-EMS as a novel strategy to modulate myokine production with potential therapeutic relevance in musculoskeletal conditions such as osteoarthritis. Full article

(This article belongs to the Topic The Effect of Physical Activity on the Population's Health)

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21 pages, 583 KiB

Open AccessArticle

Gender Differences in the Relationship Between Fatigue, Different Types of Physical Activity, Postural Changes, and Sleep Quality in University Students—Part II Analyses from a Cross-Sectional Study

by Verner Marijančić, Silvije Šegulja, Mirela Vučković, Ivana Sović, Stanislav Peharec, Tanja Grubić Kezele and Gordana Starčević-Klasan

J. Funct. Morphol. Kinesiol. 2025, 10(3), 307; https://doi.org/10.3390/jfmk10030307 - 8 Aug 2025

Abstract

Background: Fatigue can be a useful tool to understand the effects of physical activity (PA) and sedentary behavior on musculoskeletal health in university students. Methods: The aim of this cross-sectional study was to examine gender differences in the relationships between fatigue and specific [...] Read more.

Background: Fatigue can be a useful tool to understand the effects of physical activity (PA) and sedentary behavior on musculoskeletal health in university students. Methods: The aim of this cross-sectional study was to examine gender differences in the relationships between fatigue and specific types and levels of PA, posture, sleep quality (SQ), and non-specific low back pain (NS-LBP) in young adult university students aged 18–25 years. A total of 180 students completed all required tests. Results: Female students had higher total fatigue as they generally engaged in more PA in contrast to male students, who had higher total fatigue when they engaged in less moderate and less vigorous PA. With increasing sedentary behavior, overall fatigue was pronounced in both sexes, although female students spent significantly more time sitting. Poorer SQ correlated with NS-LBP and higher levels of sleep-related fatigue in female students. Males with pronounced hypekyphosis and females with pronounced lordosis were more fatigued. In addition, fatigue was more pronounced in female students with a higher extensor/flexor ratio, suggesting that trunk extensors are more fatigued due to the need to maintain lumbar spine stability. Conclusions: Our findings suggest that the choice of PA should be gender-specific to prevent chronic musculoskeletal disorders and fatigue in young adult university students. Full article

(This article belongs to the Special Issue Physical Activity for Optimal Health: 2nd Edition)

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13 pages, 1370 KiB

Open AccessArticle

Heart Rate Variability Differences by Match Phase and Outcome in Elite Male Finnish Padel Players

by Rafael Conde-Ripoll, Antonin Jamotte, Jose A. Parraca and Álvaro Bustamante-Sánchez

J. Funct. Morphol. Kinesiol. 2025, 10(3), 306; https://doi.org/10.3390/jfmk10030306 - 8 Aug 2025

Abstract

Background: This study aimed to examine changes in heart rate variability (HRV) across three match-related time points (pre-match, during the match, and post-match) and to explore whether these physiological responses differed between winners and losers in competitive padel. Methods: Twelve matches were analyzed, [...] Read more.

Background: This study aimed to examine changes in heart rate variability (HRV) across three match-related time points (pre-match, during the match, and post-match) and to explore whether these physiological responses differed between winners and losers in competitive padel. Methods: Twelve matches were analyzed, involving 11 high-level Finnish padel players ranked within the national top 24. HRV was recorded before, during, and immediately after each match, with each measurement lasting a minimum of five min. Time-domain (e.g., SDNN, RMSSD, pNN50), frequency-domain (e.g., LF, HF), and non-linear (e.g., SD1, SD2) HRV metrics were extracted for analysis. All matches took place in Tampere, Finland, under controlled conditions. Results: Results revealed significant intra-match fluctuations in HRV across all domains. Moreover, losing players exhibited consistently higher relative heart rate during the match, suggesting greater physiological strain. Conclusions: This study contributes novel evidence on the dynamic nature of autonomic responses in padel and supports the integration of HRV monitoring in performance and recovery management protocols for high-level athletes. Full article

(This article belongs to the Special Issue Racket Sport Dynamics)

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17 pages, 391 KiB

Open AccessArticle

A Comparative Study of Paralympic Veterans with Either a Spinal Cord Injury or an Amputation: Implications for Personalized Nutritional Advice

by Ilaria Peluso, Anna Raguzzini, Elisabetta Toti, Gennaro Boccia, Roberto Ferrara, Diego Munzi, Paolo Riccardo Brustio, Alberto Rainoldi, Valentina Cavedon, Chiara Milanese, Tommaso Sciarra and Marco Bernardi

J. Funct. Morphol. Kinesiol. 2025, 10(3), 305; https://doi.org/10.3390/jfmk10030305 - 6 Aug 2025

Abstract

Background: Dietary advice for Paralympic athletes (PAs) with a spinal cord injury (PAs-SCI) requires particular attention and has been widely studied. However, currently, no particular attention has been addressed to nutritional guidelines for athletes with an amputation (PAs-AMP). This study aimed at [...] Read more.

Background: Dietary advice for Paralympic athletes (PAs) with a spinal cord injury (PAs-SCI) requires particular attention and has been widely studied. However, currently, no particular attention has been addressed to nutritional guidelines for athletes with an amputation (PAs-AMP). This study aimed at filling up this gap, at least partially, and compared veteran PAs-SCI with PAs-AMP. Methods: A sample of 25 male PAs (12 with SCI and 13 with AMP), recruited during two training camps, was submitted to the following questionnaires: allergy questionnaire for athletes (AQUA), Nordic Musculoskeletal Questionnaire (NMQ), Starvation Symptom Inventory (SSI), neurogenic bowel dysfunction (NBD), orthorexia (ORTO-15/ORTO-7), alcohol use disorders identification test (AUDIT), and Mediterranean diet adherence (MDS). The PAs were also submitted to the following measurements: dietary Oxygen Radical Absorbance Capacity (ORAC) and intakes, body composition, handgrip strength (HGS), basal energy expenditure (BEE), peak oxygen uptake (VO_2peak), peak power, peak heart rate (HR), post-exercise ketosis, and antioxidant response after a cardiopulmonary exercise test (CPET) to voluntary fatigue. Results: Compared to PAs-AMP, PAs-SCI had higher NBD and lower VO_2peak (p < 0.05), peak power, peak HR, peak lactate, phase angle (PhA) of the dominant leg (p < 0.05), and ORTO15 (p < 0.05). The latter was related to NBD (r = −0.453), MDS (r = −0.638), and ORAC (r = −0.529), whereas ORTO7 correlated with PhA of the dominant leg (r = 0.485). Significant differences between PAs-AMP and PAs-SCI were not found in the antioxidant response, glucose, and ketone levels after CPET, nor in dietary intake, AUDIT, AQUA, NMQ, SSI, BEE, HGS, and FM%. Conclusions: The present study showed that PAs-SCI and PAs-AMP display similar characteristics in relation to lifestyle, energy intake, basal energy expenditure, and metabolic response to CPET. Based on both the similarities with PAs-SCI and the consequences of the limb deficiency impairment, PAs-AMP and PAs-SCI require personalized nutritional advice. Full article

(This article belongs to the Special Issue New Perspectives and Challenges in Adapted Sports)

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18 pages, 1632 KiB

Open AccessArticle

Impact of an Eight-Week Plyometric Training Intervention on Neuromuscular Performance, Musculotendinous Stiffness, and Directional Speed in Elite Polish Badminton Athletes

by Mariola Gepfert, Artur Gołaś, Robert Roczniok, Jan Walencik, Kamil Węgrzynowicz and Adam Zając

J. Funct. Morphol. Kinesiol. 2025, 10(3), 304; https://doi.org/10.3390/jfmk10030304 - 5 Aug 2025

Abstract

Background: This study aimed to examine the effects of an 8-week plyometric training program on lower-limb explosive strength, jump performance, musculotendinous stiffness, reactive strength index (RSI), and multidirectional speed in elite Polish badminton players. Methods: Twenty-four athletes were randomly assigned to [...] Read more.

Background: This study aimed to examine the effects of an 8-week plyometric training program on lower-limb explosive strength, jump performance, musculotendinous stiffness, reactive strength index (RSI), and multidirectional speed in elite Polish badminton players. Methods: Twenty-four athletes were randomly assigned to either an experimental group (n = 15), which supplemented their regular badminton training with plyometric exercises, or a control group (n = 15), which continued standard technical training. Performance assessments included squat jump (SJ), countermovement jump (CMJ), single-leg jumps, sprint tests (5 m, 10 m), lateral movements, musculotendinous stiffness, and RSI measurements. Results: The experimental group showed statistically significant improvements in jump height, power output, stiffness, and 10 m sprint and lateral slide-step performance (p < 0.05), with large effect sizes. No significant changes were observed in the control group. Single-leg jump improvements suggested potential benefits for addressing lower-limb asymmetries. Conclusions: An 8-week plyometric intervention significantly enhanced lower-limb explosive performance and multidirectional movement capabilities in young badminton players. These findings support the integration of targeted plyometric training into regular training programs to optimize physical performance, improve movement efficiency, and potentially reduce injury risk in high-intensity racket sports. Full article

(This article belongs to the Special Issue Optimizing Performance: Training Strategies to Improve Strength, Speed, Power, and Endurance)

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4 pages, 176 KiB

Open AccessEditorial

Special Issue “Efficiency in Kinesiology: Innovative Approaches in Enhancing Motor Skills for Athletic Performance, 3rd Edition”

by Vincenzo Sorgente and Diego Minciacchi

J. Funct. Morphol. Kinesiol. 2025, 10(3), 303; https://doi.org/10.3390/jfmk10030303 - 5 Aug 2025

Abstract

The third edition of the Special Issue “Efficiency in Kinesiology: Innovative Approaches in Enhancing Motor Skills for Athletic Performance 3 [...] Full article

(This article belongs to the Special Issue Efficiency in Kinesiology: Innovative Approaches in Enhancing Motor Skills for Athletic Performance, 3rd Edition)

15 pages, 958 KiB

Open AccessArticle

Can Plantar Pressure Distribution During Gait Be Estimated from Quiet Stance in Healthy Individuals?

by Marta Mirando, Chiara Pavese, Valeria Pingue, Stefania Sozzi and Antonio Nardone

J. Funct. Morphol. Kinesiol. 2025, 10(3), 301; https://doi.org/10.3390/jfmk10030301 - 5 Aug 2025

Abstract

Objectives: We assessed the difference between quiet stance and gait in the spatial distribution and intensity of foot plantar pressures and whether it is possible to estimate the distribution during gait from data obtained during stance. Methods: A total of 60 [...] Read more.

Objectives: We assessed the difference between quiet stance and gait in the spatial distribution and intensity of foot plantar pressures and whether it is possible to estimate the distribution during gait from data obtained during stance. Methods: A total of 60 healthy subjects with a mean age of 31.0 ± 9.4 years performed two trials for quiet stance and four trials for gait on a baropodometric walkway with their eyes open. Foot plantar pressures were recorded from 10 areas of the foot sole. Results: During quiet stance, the highest plantar pressure occurred at metatarsal heads (M2 to M4) and the medial (MH) and lateral halves of the heel (LH). During gait, the profile of plantar pressure values was like that during stance, but significantly higher. The differences concentrated at the big toe (T1), M2 to M4, MH, and LH, whilst toes (T2,3,4,5) and midfoot (MF) showed the smallest difference. A significant positive correlation was found between the corresponding areas of foot pressure during gait and stance. Conclusions: During quiet stance and gait, the overall profile of plantar pressure distribution was similar. During quiet stance, the subjects loaded more on the heels, in keeping with the known position of the center of pressure just in front of the ankles. During gait, higher pressures on the metatarsal areas are related to the forward propulsion of the center of mass. The correlation between the corresponding areas of foot pressure during gait and stance suggests that the pressure distribution during gait can partly be estimated from that during stance. This finding might be useful in most clinical settings when a single sensorized platform rather than a complete walkway is available. Full article

(This article belongs to the Special Issue Posture, Balance, and Gait: Assessment Techniques and Rehabilitation Strategies)

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11 pages, 881 KiB

Open AccessArticle

Evaluation of Race Pace Using Critical Swimming Speed During 10 km Open-Water Swimming Competition

by Yasunori Fujito, Tomomi Fujimoto, Reira Hara, Ryuhei Yoshida and Kazuo Funato

J. Funct. Morphol. Kinesiol. 2025, 10(3), 302; https://doi.org/10.3390/jfmk10030302 - 3 Aug 2025

Abstract

Background: Estimating race times for open-water swimming based on pool swimming times could be useful for talent identification and training optimisation. We aimed to compare the swimming speeds of the world’s top and other swimmers in the 2023 Aquatics Championship men’s 10 [...] Read more.

Background: Estimating race times for open-water swimming based on pool swimming times could be useful for talent identification and training optimisation. We aimed to compare the swimming speeds of the world’s top and other swimmers in the 2023 Aquatics Championship men’s 10 km OWS race. Methods: Sixty-five swimmers were divided into four groups: G1 (1st–10th positions), G2 (11st–30th positions), G3 (31st–47th positions), and G4 (48th–65th positions). Swimming speed, stroke frequency (SF), and stroke length (SL) for each lap (laps 1–6) were recorded. Critical speed (CS) was calculated from each participant’s personal best times in the 400, 800, and 1500 m freestyle events in the pool. Swimming speed against CS was calculated (%CS). Results: The top performance group (G1) maintained their swimming speed from beginning (lap 1, 1.53 m/s) to end (lap 6, 1.50 m/s), at 92.7 ± 1.9% of CS, characterised by longer SL (1.26 m) and lower SF (72.86 rpm). G3 and G4 were unable to maintain their swimming speed, which decreased from G3: 97.64 ± 1.62% and G4: 96.10 ± 1.96% of CS at lap 1 to G3: 88.39 ± 3.78% and G4: 85.13 ± 5.04% at lap 6. This reduction in swimming speed is consistent with the increased reliance on anaerobic metabolism reported in previous studies under similar conditions. Conclusions: Race pacing for maintaining speeds of 92%CS throughout the race could be an important resilient index in open-water swimming. %CS might be a useful index for estimating the athletic performance level in open-water swimming. Full article

(This article belongs to the Section Athletic Training and Human Performance)

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17 pages, 5464 KiB

Open AccessArticle

Association Between Stiffness of the Deep Fibres of the Tibialis Anterior Muscle and Seiza Posture Performance After Ankle Fracture Surgery

by Hayato Miyasaka, Bungo Ebihara, Takashi Fukaya, Koichi Iwai, Shigeki Kubota and Hirotaka Mutsuzaki

J. Funct. Morphol. Kinesiol. 2025, 10(3), 300; https://doi.org/10.3390/jfmk10030300 - 1 Aug 2025

Abstract

Background: Seiza, a traditional sitting posture requiring deep ankle plantarflexion and knee flexion, often becomes difficult after ankle fracture surgery because of restricted mobility. Increased stiffness of the tibialis anterior (TA) muscle, particularly in its deep and superficial fibres, may limit [...] Read more.

Background: Seiza, a traditional sitting posture requiring deep ankle plantarflexion and knee flexion, often becomes difficult after ankle fracture surgery because of restricted mobility. Increased stiffness of the tibialis anterior (TA) muscle, particularly in its deep and superficial fibres, may limit plantarflexion and affect functional recovery. This study aimed to investigate the relationship between TA muscle stiffness, assessed using shear wave elastography (SWE), and the ability to assume the seiza posture after ankle fracture surgery. We also sought to determine whether the stiffness in the deep or superficial TA fibres was more strongly correlated with seiza ability. Methods: In this cross-sectional study, 38 patients who underwent open reduction and internal fixation for ankle fractures were evaluated 3 months postoperatively. Seiza ability was assessed using the ankle plantarflexion angle and heel–buttock distance. The shear moduli of the superficial and deep TA fibres were measured using SWE. Ankle range of motion, muscle strength, and self-reported seiza pain were also measured. Multiple linear regression was used to identify the predictors of seiza performance. Results: The shear moduli of both deep (β = −0.454, p < 0.001) and superficial (β = −0.339, p = 0.017) TA fibres independently predicted ankle plantarflexion angle during seiza (adjusted R², 0.624). Pain during seiza was significantly associated with reduced plantarflexion, whereas muscle strength was not a significant predictor. Conclusions: TA muscle stiffness, especially in the deep fibres, was significantly associated with limited postoperative seiza performance. Targeted interventions that reduce deep TA stiffness may enhance functional outcomes. Full article

(This article belongs to the Section Functional Anatomy and Musculoskeletal System)

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14 pages, 1227 KiB

Open AccessArticle

Reliability and Inter-Device Agreement Between a Portable Handheld Ultrasound Scanner and a Conventional Ultrasound System for Assessing the Thickness of the Rectus Femoris and Vastus Intermedius

by Carlante Emerson, Hyun K. Kim, Brian A. Irving and Efthymios Papadopoulos

J. Funct. Morphol. Kinesiol. 2025, 10(3), 299; https://doi.org/10.3390/jfmk10030299 - 1 Aug 2025

Abstract

Background: Ultrasound (U/S) can be used to evaluate skeletal muscle characteristics in clinical and sports settings. Handheld U/S devices have recently emerged as a cheaper and portable alternative to conventional U/S systems. However, further research is warranted on their reliability. We assessed [...] Read more.

Background: Ultrasound (U/S) can be used to evaluate skeletal muscle characteristics in clinical and sports settings. Handheld U/S devices have recently emerged as a cheaper and portable alternative to conventional U/S systems. However, further research is warranted on their reliability. We assessed the reliability and inter-device agreement between a handheld U/S device (Clarius L15 HD₃) and a more conventional U/S system (GE LOGIQ e) for measuring the thickness of the rectus femoris (RF) and vastus intermedius (VI). Methods: Cross-sectional images of the RF and VI muscles were obtained in 20 participants by two assessors, and on two separate occasions by one of those assessors, using the Clarius L15 HD₃ and GE LOGIQ e devices. RF and VI thickness measurements were obtained to determine the intra-rater reliability, inter-rater reliability, and inter-device agreement. Results: All intraclass correlation coefficients (ICCs) were above 0.9 for intra-rater reliability (range: 0.94 to 0.97), inter-rater reliability (ICC: 0.97), and inter-device agreement (ICC: 0.98) when comparing the two devices in assessing RF and VI thickness. For the RF, the Bland–Altman plot revealed a mean difference of 0.06 ± 0.07 cm, with limits of agreement ranging from 0.21 to −0.09, whereas for the VI, the Bland–Altman plot showed a mean difference of 0.07 ± 0.10 cm, with limits of agreement ranging from 0.27 to −0.13. Conclusions: The handheld Clarius L15 HD₃ was reliable and demonstrated high agreement with the more conventional GE LOGIQ e for assessing the thickness of the RF and VI in young, healthy adults. Full article

(This article belongs to the Section Kinesiology and Biomechanics)

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21 pages, 1306 KiB

Open AccessArticle

Dual Quaternion-Based Forward and Inverse Kinematics for Two-Dimensional Gait Analysis

by Rodolfo Vergara-Hernandez, Juan-Carlos Gonzalez-Islas, Omar-Arturo Dominguez-Ramirez, Esteban Rueda-Soriano and Ricardo Serrano-Chavez

J. Funct. Morphol. Kinesiol. 2025, 10(3), 298; https://doi.org/10.3390/jfmk10030298 - 1 Aug 2025

Abstract

Background: Gait kinematics address the analysis of joint angles and segment movements during walking. Although there is work in the literature to solve the problems of forward (FK) and inverse kinematics (IK), there are still problems related to the accuracy of the estimation [...] Read more.

Background: Gait kinematics address the analysis of joint angles and segment movements during walking. Although there is work in the literature to solve the problems of forward (FK) and inverse kinematics (IK), there are still problems related to the accuracy of the estimation of Cartesian and joint variables, singularities, and modeling complexity on gait analysis approaches. Objective: In this work, we propose a framework for two-dimensional gait analysis addressing the singularities in the estimation of the joint variables using quaternion-based kinematic modeling. Methods: To solve the forward and inverse kinematics problems we use the dual quaternions’ composition and Damped Least Square (DLS) Jacobian method, respectively. We assess the performance of the proposed methods with three gait patterns including normal, toe-walking, and heel-walking using the RMSE value in both Cartesian and joint spaces. Results: The main results demonstrate that the forward and inverse kinematics methods are capable of calculating the posture and the joint angles of the three-DoF kinematic chain representing a lower limb. Conclusions: This framework could be extended for modeling the full or partial human body as a kinematic chain with more degrees of freedom and multiple end-effectors. Finally, these methods are useful for both diagnostic disease and performance evaluation in clinical gait analysis environments. Full article

(This article belongs to the Special Issue Biomechanics and Neuromuscular Control of Gait and Posture—2nd Edition)

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13 pages, 910 KiB

Open AccessArticle

Annual Performance Progression in Swimming Across Competition Levels and Race Distances

by Jesús J. Ruiz-Navarro and Dennis-Peter Born

J. Funct. Morphol. Kinesiol. 2025, 10(3), 297; https://doi.org/10.3390/jfmk10030297 - 31 Jul 2025

Abstract

Objective: As performance progression provides an essential indicator for talent selection and development, this study aimed to compare annual swimming performance progression between different competitive levels and to establish benchmarks for long-term athlete development. Methods: Annual best times of swimmers who competed up [...] Read more.

Objective: As performance progression provides an essential indicator for talent selection and development, this study aimed to compare annual swimming performance progression between different competitive levels and to establish benchmarks for long-term athlete development. Methods: Annual best times of swimmers who competed up to the age of 21 years and achieved over 450 World Aquatics points were extracted from the database of European Aquatics. A total of 13,310 male and 7798 female pool swimmers of all race distances were grouped into three performance levels. Results: The results showed a continuous decline in annual performance progression throughout the years across all race distances (all p < 0.001) and in both sexes. There were differences between performance level across the age groups for all race distances in male swimmers, but only for the 100–400 m races in females (p < 0.05). Absolute performance showed significant main effects for level and age over all race distances for both sexes (all p < 0.001). Conclusions: Annual performance progression of swimmers consistently decreases across the competitive lifetime in both sexes, regardless of race distance and performance level. The event-specific benchmarks should be used as a framework to set realistic goals for both sexes and swimmers of different competitive levels, as well as to guide swimmers throughout their careers. Full article

(This article belongs to the Special Issue Innovative Approaches in Monitoring Individual Sports)

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14 pages, 1173 KiB

Open AccessArticle

Biomechanical Alterations in the Unweight Phase of the Single-Leg Countermovement Jump After ACL Reconstruction

by Roberto Ricupito, Marco Bravi, Fabio Santacaterina, Giandomenico Campardo, Riccardo Guarise, Rosalba Castellucci, Ismail Bouzekraoui Alaoui and Florian Forelli

J. Funct. Morphol. Kinesiol. 2025, 10(3), 296; https://doi.org/10.3390/jfmk10030296 - 30 Jul 2025

Abstract

Background: Anterior cruciate ligament reconstruction (ACLr) often leads to asymmetries between limbs, with variable return-to-performance rates in athletes. The single-leg countermovement jump (SLCMJ) is commonly used to assess postoperative knee function. However, limited research has explored deficits specifically during the unweighting phase of [...] Read more.

Background: Anterior cruciate ligament reconstruction (ACLr) often leads to asymmetries between limbs, with variable return-to-performance rates in athletes. The single-leg countermovement jump (SLCMJ) is commonly used to assess postoperative knee function. However, limited research has explored deficits specifically during the unweighting phase of the jump. Methods: This study assessed 53 recreational athletes (11 females, 42 males) between 6 and 9 months post-ACLr using a dual force plate system (1000 Hz). Each participant performed three maximal-effort SLCMJs per limb. Outcome measures included jump height, negative peak velocity, minimum force, and center of mass (COM) displacement. Paired t-tests and Wilcoxon tests were used to compare the ACLr limb with the contralateral limb. Results: Compared to the healthy limb, the ACLr limb showed significantly lower negative peak velocity (−0.80 ± 0.40 m/s vs. −0.94 ± 0.40 m/s, p < 0.001), higher minimum force (36.75 ± 17.88 kg vs. 32.05 ± 17.25 kg, p < 0.001), and reduced COM displacement (−17.62 ± 6.25 cm vs. −19.73 ± 5.34 cm, p = 0.014). Eccentric phase duration did not differ significantly. Conclusions: Athletes post-ACLr demonstrate altered neuromuscular control during the early SLCMJ phase. These findings highlight the importance of rehabilitation strategies targeting eccentric strength and symmetry restoration. Full article

(This article belongs to the Special Issue Movement Analysis in Sports and Physical Therapy)

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Journal of Functional Morphology and Kinesiology

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