Journal of Functional Morphology and Kinesiology

13 pages, 1620 KB

Open AccessArticle

Robotic Training Using a Novel Upper-Limb Hybrid Assistive Limb After Brachial Plexus Injury: An Electrophysiological Observational Case Series Study

by Shigeki Kubota, Hideki Kadone, Yukiyo Shimizu and Masashi Yamazaki

J. Funct. Morphol. Kinesiol. 2026, 11(3), 332; https://doi.org/10.3390/jfmk11030332 - 25 Aug 2026

Abstract

Background and Objectives: The hybrid assistive limb (HAL) is a wearable robotic device used for rehabilitation that assists the voluntary movements of the user by detecting muscle action potentials and driving actuators positioned next to the hip and knee joints. Although upper-limb HAL [...] Read more.

Background and Objectives: The hybrid assistive limb (HAL) is a wearable robotic device used for rehabilitation that assists the voluntary movements of the user by detecting muscle action potentials and driving actuators positioned next to the hip and knee joints. Although upper-limb HAL training has been studied for brachial plexus injury (BPI), its electrophysiological influence remains unclear. The purpose of this study was to assess the electrophysiological influences of upper-limb HAL-assisted biofeedback (BF) training during elbow flexion rehabilitation in patients with BPI. Methods: Five patients with BPI (average age, 37.2 years) were enrolled after undergoing elbow flexor reconstruction through intercostal nerve-to-musculocutaneous nerve transfer. All participants received outpatient elbow flexion training with the upper-limb HAL at frequencies ranging from once weekly to once monthly. All patients started upper-limb HAL training when re-innervation was observed, and a biceps brachii muscle strength of grade 1 was achieved. Muscle activity was measured using surface electromyography in five patients during upper-limb HAL training, when the biceps brachii muscle strength was graded as Medical Research Council grades 1 and 2, to compare activity with and without HAL. Results: In five patients, electromyographic activity of the biceps brachii during elbow flexion reached 74.9 ± 22.7% of maximal contraction while using the HAL device, compared with 60.3 ± 16.7% without HAL assistance, indicating significantly greater muscle activation during HAL-assisted movement. Conclusions: Robotic BF training for elbow flexion with the upper-limb HAL may serve as a high-quality electromyographic rehabilitation approach for patients recovering from BPI. Full article

(This article belongs to the Special Issue Wearable Technology and Movement Analysis in Athletic Performance and Rehabilitation)

► Show Figures

Figure 1

5 pages, 172 KB

Open AccessEditorial

Special Issue “Exercise Training on Cardiovascular Risk Factors in Primary and Secondary Prevention”

by Giuseppe Caminiti

J. Funct. Morphol. Kinesiol. 2026, 11(3), 331; https://doi.org/10.3390/jfmk11030331 - 25 Aug 2026

Abstract

Cardiovascular diseases remain the leading cause of morbidity and mortality worldwide and continue to impose a substantial burden on individuals, healthcare systems, and society [...] Full article

(This article belongs to the Special Issue Effects of Exercise Training on Cardiovascular Risks Factors in Primary and Secondary Prevention)

20 pages, 569 KB

Open AccessArticle

The Effects of Social Dance on Muscular Fitness and Longevity-Related Circulating Biomarkers in the Elderly

by Annamaria Mancini, Francesca Greco, Daniela Vitucci, Federico Quinzi, Maria Grazia Tarsitano, Loretta Francesca Cosco, Andreina Alfieri, Domenico Martone, Sara Dei, Rosa Ghirelli, Luca Gentile, Giulia Scalia, Pasqualina Buono and Gian Pietro Emerenziani

J. Funct. Morphol. Kinesiol. 2026, 11(3), 330; https://doi.org/10.3390/jfmk11030330 - 24 Aug 2026

Abstract

Background: Aging is characterized by functional decline in different organs and systems. The present study aimed to evaluate the effects of 6-month low-to moderate intensity supervised Social Dance (SD) program on muscular fitness, and clinical–biochemical and hematological parameters associated with healthy aging. [...] Read more.

Background: Aging is characterized by functional decline in different organs and systems. The present study aimed to evaluate the effects of 6-month low-to moderate intensity supervised Social Dance (SD) program on muscular fitness, and clinical–biochemical and hematological parameters associated with healthy aging. Circulating CD34+ and serum antioxidant potential were assessed as exploratory outcomes. Methods: Seventy-nine elderly (aged > 65 years) were enrolled and randomized. Analyses included 49 participants who provided baseline and follow-up data and were assigned to the SD group (SDG, n = 24) or control group (CG, n = 25). Clinical–biochemical and hematological profiles, oxidative stress markers, circulating CD34+ cells, Physical fitness components and Physical Activity Scale for the Elderly (PASE) and EuroQol five-dimensional (EQ-5D) questionnaires were assessed at T0 and T1 to both groups. Results: Significant group × time interactions favored the SDG for HDL cholesterol (

p = 0.003

), Hemoglobin (p = 0.031), and Hematocrit (p = 0.005). A significant increase in BAP (∆% = 33.3; p < 0.001) and PASE (∆%= 79.6 vs. 56.9; p < 0.05) were observed among the SDG; conversely, only a positive trend (∆% = 12.9 SDG vs. −5.1 CG) was observed for EQ-VAS at T1; these findings were not supported by significant group × time interaction. CD34+ cells increased significantly only in the CG. Isometric muscular performance declined in both groups. Conclusions: a 6-month SD program may provide beneficial effects on selected biochemical markers (i.e., a positive impact on HDL, hematological profile, antioxidant defenses) and perceived health outcomes in the elderly. However, it appears insufficient to preserve isometric muscular performance, suggesting that complementary resistance-based strategies may be needed to optimize neuromuscular adaptations. Full article

(This article belongs to the Special Issue 10th Anniversary of JFMK: Advances in Physical Exercise for Health Promotion)

► Show Figures

Figure 1

11 pages, 323 KB

Open AccessArticle

Acute Effects of External, Internal, and Holistic Attentional Focus on Javelin-Throwing Performance in Novices: The Role of Visual Information

by Ayoub Asadi, Somayeh Bahrami, Mostafa Bahrami and Esmaeel Saemi

J. Funct. Morphol. Kinesiol. 2026, 11(3), 329; https://doi.org/10.3390/jfmk11030329 - 24 Aug 2026

Abstract

Background and Objectives: Sports performance is influenced by a variety of perceptual, cognitive, and motor factors. A better understanding of these factors can help coaches optimize training and improve athletic performance. The present study examined the acute effects of internal, external, and [...] Read more.

Background and Objectives: Sports performance is influenced by a variety of perceptual, cognitive, and motor factors. A better understanding of these factors can help coaches optimize training and improve athletic performance. The present study examined the acute effects of internal, external, and holistic attentional focus instructions on javelin-throwing performance under different visual conditions in novice performers. Methods: Twenty-four university students (12 females and 12 males; mean age: 21.50 ± 1.47 years) with no prior javelin-throwing experience completed 30 throws under six experimental conditions (5 throws per condition) based on three attentional focus instructions (internal, external, and holistic) and two visual conditions (vision-present and vision-absent) using a within-subject repeated-measures design. Throwing distance was measured as the primary performance outcome. Results: The results revealed significant main effects of both vision (F_{(1, 23)} = 14.49, p = 0.001, ηp² = 0.38) and attentional focus (F_{(2, 46)} = 5.73, p = 0.006, ηp² = 0.20). Overall throwing performance was superior when visual information was available compared to when vision was occluded (p = 0.001). In addition, both external and holistic focus conditions produced significantly greater throwing distances than the internal focus condition (p = 0.03; p = 0.04, respectively), with no significant differences observed between external and holistic focus (p > 0.05). No significant interaction was found between attentional focus and vision (F(_{2, 46}) = 0.74, p = 0.48, ηp² = 0.03), indicating that the effect of attentional focus did not significantly differ between the visual conditions. Conclusions: The present findings extend the attentional focus literature to a complex, whole-body ballistic skill, demonstrating that the adoption of external and holistic attentional focus instructions resulted in greater throwing distances than the internal focus condition in novice javelin throwers. Full article

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

► Show Figures

Figure 1

10 pages, 1065 KB

Open AccessArticle

Intra-Cyclic Variation of Velocity in Swimming: Association and Consistency Between the Most-Used Measurements

by Jorge E. Morais and Tiago M. Barbosa

J. Funct. Morphol. Kinesiol. 2026, 11(3), 328; https://doi.org/10.3390/jfmk11030328 - 23 Aug 2026

Abstract

Background and Objectives: Intra-cyclic variation in swimming velocity is one of the variables most commonly used to assess swimming performance, providing simple, straightforward information for coaches and swimmers. Therefore, the main aim of this study was to assess the consistency and association [...] Read more.

Background and Objectives: Intra-cyclic variation in swimming velocity is one of the variables most commonly used to assess swimming performance, providing simple, straightforward information for coaches and swimmers. Therefore, the main aim of this study was to assess the consistency and association between the two most commonly used methods for calculating the intra-cyclic variation in velocity in swimming (coefficient of variation—dv1; and range: the difference between the maximum and minimum instantaneous velocities—dv2). Methods: Twenty-one young butterfly swimmers (11 males and 10 females) with an average age of 17.3 ± 2.8 years were recruited for analysis. The measurements were done in the butterfly stroke at maximal velocities. The consistency and association criteria included the intraclass correlation coefficient (ICC) and simple linear regression between the two methods. Results: The ICC between dvs was excellent for the overall sample (ICC = 0.972, p < 0.001), males (ICC = 0.978, p < 0.001), and females (ICC = 0.955, p < 0.001). The linear regression between methods was very high (overall: R² = 0.93, p < 0.001; males: R² = 0.91, p < 0.001; females: R² = 0.86, p < 0.001). Conclusions: Overall, coaches and researchers should be aware that although both methods yielded highly concordant results, they are based on different mathematical formulations and quantify distinct characteristics of the velocity signal. Therefore, their consistency and association should not be interpreted as mathematical equivalence or universal interchangeability. Full article

(This article belongs to the Collection Feature Papers in Journal of Functional Morphology and Kinesiology)

► Show Figures

Figure 1

22 pages, 342 KB

Open AccessArticle

Using the Relative Pitch Size, Internal Floaters, and External Floaters During Different Small-Sided Games in Professional Soccer in the Return-to-Play Process

by Michael C. Rumpf, Johannes Jäger, João Renato Silva and Matthias Lochmann

J. Funct. Morphol. Kinesiol. 2026, 11(3), 327; https://doi.org/10.3390/jfmk11030327 - 23 Aug 2026

Abstract

Background and Objectives: The aim was to investigate the external load of different types of floaters and regular players in small-sided games (SSG) with different relative pitch sizes to inform the return-to-play process. Methods: Twenty-four professional soccer players from a Greek [...] Read more.

Background and Objectives: The aim was to investigate the external load of different types of floaters and regular players in small-sided games (SSG) with different relative pitch sizes to inform the return-to-play process. Methods: Twenty-four professional soccer players from a Greek top-tier soccer club played SSG as regular players, internal floaters, and external floaters. Global-positioning units were utilized to investigate total distance (TD), as well as high-intensity running distances (HID), which was further divided into HID1 (15.0–19.9 km/h and HID2 (20.0–24.9 km/h). High-intensity running (HIR) was analyzed by distance and number of efforts (HIRnb) greater than 19.8 km/h. Velocity zones were categorized into zones such as 10.8–14.4 km/h (Zone3), 14.5–19.8 km/h (Zone4), 19.9–24.9 km/h (Zone5), >25 km/h (Zone6). Sprint metrics included number of sprints (Sprint/Nm) and sprint distance (Sprint/Dist). Acceleration bands were defined as high >4 m/s² (ACC4), moderate 3–3.9 m/s² (ACC3), and low 0–2.9 m/s² (ACC2); and decelerations were defined as high <−4 m/s² (DEC4), moderate −3.9–3 m/s² (DEC3), and low −2.9–0 (DEC2 m/s²). All data were reported as relative value (standardized over a 1 min playing period). Results: Regular players showed the highest value, followed by internal floaters and external floaters for all variables, except for Zone5 distance. The majority of variables differed significantly between the regular players and the internal floaters except for TD, distance in Zone3 and Zone6, and number of ACC3, ACC4, and DEC4. ACC4 was the only variable found to be not significantly different between the regular players and the external floaters. In games with both floater types, internal floaters showed significantly higher values in all variables except for HIR, Zone6 distance, Sprint/Dist, Sprint/Nm, ACC3, ACC4, and DEC4. The comparison of external load variables between internal and external floaters when each player type was playing against regular players only revealed significantly higher values for all variables except for Sprint/Dist, Sprint/Nm, Zone6 distance, ACC3, and ACC4 for the internal floaters. Regression analyses were provided for all player types in the appropriated game format (RP with IF, RP with EF, RP with IF and EF). Conclusions: The on-field return-to-play process for individual players in the final stages incorporating SSG with different relative pitch sizes benefits from the utilization of different types of floaters. Increasing external load is ensured through starting with external floaters followed by internal floaters easing into the final role, the regular player role. Full article

(This article belongs to the Special Issue Training and Performance in Soccer)

18 pages, 830 KB

Open AccessArticle

Comparison of Anthropometric Equations to Estimate Body Composition in Chilean Male Adolescent Soccer Players

by Álvaro Farfán-Díaz, Miguel Alarcón-Rivera, Marcelo Andrade Oyarzun, Daniel Tapia-Villanueva, Exal Garcia-Carrillo, Iván Molina-Márquez, Rodrigo Yáñez-Sepúlveda, Dario Barrera-González and Felipe Montalva-Valenzuela

J. Funct. Morphol. Kinesiol. 2026, 11(3), 326; https://doi.org/10.3390/jfmk11030326 - 22 Aug 2026

Abstract

Background: Anthropometric body-composition assessment in youth soccer commonly relies on equations developed in different source populations and based on distinct body-composition models, potentially altering nutritional and sport-related interpretation. This study compared body-fat estimates from equations intended to report the same outcome, body [...] Read more.

Background: Anthropometric body-composition assessment in youth soccer commonly relies on equations developed in different source populations and based on distinct body-composition models, potentially altering nutritional and sport-related interpretation. This study compared body-fat estimates from equations intended to report the same outcome, body fat percentage, but based on different operational models, and quantified muscle-mass outputs from anthropometric approaches targeting total-body skeletal, whole-body, and tissue-level muscle compartments in a cohort of Chilean male U-15 and U-16 players. Methods: This secondary cross-sectional method-comparison study analyzed anonymized anthropometric records collected in 2018 from 50 male players. Slaughter, Faulkner, Carter, Deurenberg, and Sloan–Siri estimates of body fat were compared, together with Poortmans, Lee, Doupe, and Kerr muscle-mass approaches. Absolute agreement among adiposity equations was evaluated using a two-way random-effects, absolute-agreement, single-measure ICC [ICC(A,1)] and Bland–Altman analyses. Muscle-mass approaches were compared with repeated-measures analysis; pairwise difference-versus-mean summaries across different muscle constructs were interpreted descriptively rather than as formal agreement tests. Sensitivity analyses excluded Deurenberg and examined a maturation-related Slaughter scenario. Results: Deurenberg yielded the highest body-fat estimate (18.97 ± 3.07%), followed by Slaughter (13.32 ± 3.35%), Faulkner (10.84 ± 1.40%), Sloan-Siri (8.01 ± 2.80%), and Carter (7.91 ± 1.49%). Global differences were large (χ²(4) = 182.96; p < 0.001; Kendall’s W = 0.915), and individual absolute agreement was low [ICC(A,1) = 0.157; bootstrap 95% CI 0.102–0.212]. Excluding Deurenberg did not remove the between-method differences (χ²(3) = 124.44; p < 0.001; W = 0.830). For muscle mass, mean estimates ranged from 25.11 ± 3.07 kg with Poortmans to 31.26 ± 4.94 kg with Doupe, with a significant method effect after Greenhouse–Geisser correction (p < 0.001). Conclusions: The adiposity equations yielded substantially different numerical estimates of the same reported outcome, body fat percentage, and showed low individual-level absolute agreement. Muscle-mass approaches also produced large numerical differences, partly expected because they target different compartments. Outputs from different equations or constructs should not be treated as numerically interchangeable. Because no criterion reference method was included, this study quantifies method dependence rather than validity and cannot identify the most accurate equation. Full article

(This article belongs to the Special Issue Body Composition Assessment: Methods, Validity, and Applications)

► Show Figures

Figure 1

20 pages, 779 KB

Open AccessArticle

Long-Term Flywheel Resistance Training Enhances Cognitive Flexibility in Older Women: A 36-Week Randomized Controlled Trial

by Maria Luiza da Cruz Santos, Pablo Augusto Garcia Agostinho, Wanderson Matheus Lopes Machado, Thalia Miranda Rufino, Leonardo Silveira Goulart Silva, Isabella Evangelista Leite, Cláudia Eliza Patrocínio de Oliveira, Édison Andrés Pérez-Bedoya and Osvaldo Costa Moreira

J. Funct. Morphol. Kinesiol. 2026, 11(3), 325; https://doi.org/10.3390/jfmk11030325 - 21 Aug 2026

Abstract

Background: Executive functions (EFs) decline with aging, impacting functional independence. While resistance training (RT) is a promising non-pharmacological intervention, the optimal modality and duration for cognitive benefits remain unclear. Flywheel RT (FRT) imposes greater motor control and attentional demands than traditional RT [...] Read more.

Background: Executive functions (EFs) decline with aging, impacting functional independence. While resistance training (RT) is a promising non-pharmacological intervention, the optimal modality and duration for cognitive benefits remain unclear. Flywheel RT (FRT) imposes greater motor control and attentional demands than traditional RT (TRT), potentially enhancing EFs. Objective: To compare the effects of a 36-week FRT versus TRT program on executive function and serum insulin-like growth factor 1 (IGF-1) levels in healthy older women. Methods: This parallel-group randomized controlled trial allocated 64 older women (overall mean age 66.8 ± 4.6 years; FRT group: 68.0 ± 4.8 years; TRT group: 65.5 ± 4.1 years) to either FRT (n = 25) or TRT (n = 21) for two weekly sessions over 36 weeks. Executive function was assessed using the Victoria Stroop Test (inhibitory control), Digit Span Test (working memory), and Trail Making Test (cognitive flexibility). Serum IGF-1 was quantified via chemiluminescence. Intention-to-treat analyses with ANCOVA were performed. Results: After 36 weeks, both groups showed significant within-group improvements in inhibitory control (mean reduction from pre to post: FRT: 15.2 ± 10.4 to 14.8 ± 7.4 s; TRT: 20.4 ± 11.8 to 15.6 ± 7.3 s; p = 0.028, ηp² = 0.38) and working memory (Digit Span Forward: FRT: 6.2 ± 1.7 to 7.9 ± 2.0; TRT: 6.7 ± 1.5 to 8.7 ± 1.8; p < 0.001, ηp² = 0.84). The B/A ratio of the Trail Making Test improved significantly more in the FRT group (73.0 ± 65.2 to 87.5 ± 68.1 s) compared to the TRT group (67.3 ± 54.1 to 137.7 ± 83.6 s; group × time interaction: p = 0.001, ηp² = 0.13). No significant changes in serum IGF-1 concentrations were observed in either group (FRT: 112.9 ± 25.4 to 115.3 ± 21.3 ng/mL; TRT: 104.7 ± 27.5 to 103.0 ± 28.9 ng/mL; p = 0.88, ηp² = 0.002). Adherence was high (only 4 out of 46 participants did not complete all 72 sessions), and no severe adverse events were reported. Conclusions: Flywheel training appears particularly effective for enhancing cognitive flexibility, likely due to its higher cognitive-motor demands. The absence of significant changes in circulating IGF-1 suggests that the observed cognitive benefits may not be mediated by systemic endocrine pathways, although this does not exclude the possibility of local central nervous system adaptations or changes in other neurotrophic factors not assessed in this study. Full article

(This article belongs to the Special Issue Innovations in Resistance Training: From Inertial Overload to Performance Optimization)

► Show Figures

Figure 1

13 pages, 282 KB

Open AccessArticle

Intra- and Inter-Rater Reliability of Primitive Reflex Assessments in Youth Football Athletes

by Julie Bastiere, Aurélien Patoz, Thibault Lussiana, Marvin Subryan, Cyrille Gindre and Laurent Mourot

J. Funct. Morphol. Kinesiol. 2026, 11(3), 324; https://doi.org/10.3390/jfmk11030324 - 21 Aug 2026

Abstract

Background: Primitive reflex (PR) assessments based on the Institute for Neuro-Physiological Psychology (INPP) framework are increasingly used in developmental and athletic populations. However, the reproducibility of these observer-based assessments remains insufficiently documented. This study investigated the intra- and inter-rater reliability of subjective [...] Read more.

Background: Primitive reflex (PR) assessments based on the Institute for Neuro-Physiological Psychology (INPP) framework are increasingly used in developmental and athletic populations. However, the reproducibility of these observer-based assessments remains insufficiently documented. This study investigated the intra- and inter-rater reliability of subjective PR assessments and examined the potential influence of evaluator expertise in elite youth football athletes. Methods: Sixty-nine male youth football players from an elite academy (age: 18 ± 2 years) participated in this study. PR assessments included the Moro reflex, asymmetrical tonic neck reflex, symmetrical tonic neck reflex, and tonic labyrinthine reflex, evaluated using standardized INPP procedures (0–4 ordinal scoring scale). Intra-rater reliability was assessed by an experienced examiner across three testing sessions performed over six months. Inter-rater reliability was evaluated using standardized video recordings independently scored by two novice raters. Relative reliability was assessed using intraclass correlation coefficients (ICCs) with corresponding 95% confidence intervals (95% CIs), while absolute reliability was quantified using the standard error of measurement (SEM) and the minimal detectable change at the 95% confidence level (MDC95). Results: Good to excellent intra-rater relative reliability (ICC = 0.86–0.98; 95% CI = [0.81–0.99]) was observed, with SEM values of 0.1–0.6 and MDC95 values of 0.3–1.7 points. Moderate to excellent video-based inter-rater reliability was found (ICC = 0.69–0.99; 95% CI [0.56–0.99]), with SEM values of 0.1–0.7 and MDC95 values of 0.3–2.0 points. Pairwise comparisons among raters showed moderate to excellent relative reliability (ICC = 0.57–0.99; 95% CI [0.35–0.99]), with SEM values of 0.1–0.5 and MDC95 values of 0.2–1.3 points. Conclusions: Subjective PR assessments performed using the INPP framework demonstrated good to excellent intra-rater relative reliability and moderate to excellent video-based inter-rater relative reliability, together with generally low absolute measurement error in elite youth football athletes. These findings provide preliminary psychometric support for the use of standardized PR assessments in research and applied sport settings. Full article

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

14 pages, 276 KB

Open AccessArticle

Associations Between Anthropometric Characteristics, Jump Performance and Recorded Tendon-Related Disorders in Youth Volleyball Players

by Gaetano Raiola, Giovanni Esposito, Francesco Laterza, Giuseppe Caminiti, Rosario Ceruso and Vincenzo Manzi

J. Funct. Morphol. Kinesiol. 2026, 11(3), 323; https://doi.org/10.3390/jfmk11030323 - 20 Aug 2026

Abstract

Background: Patellar tendon complaints and other tendon-related disorders are common in jumping sports; however, the relationship between recorded tendon problems, anthropometric characteristics, and neuromuscular performance in youth athletes remains poorly understood. This study explored the association between height, body mass, competitive age [...] Read more.

Background: Patellar tendon complaints and other tendon-related disorders are common in jumping sports; however, the relationship between recorded tendon problems, anthropometric characteristics, and neuromuscular performance in youth athletes remains poorly understood. This study explored the association between height, body mass, competitive age category, a retrospectively recorded history of tendon-related disorders, and jumping performance in youth volleyball players. Methods: Thirty-three male youth volleyball players competing in the Under-15, Under-17, and Under-19 categories participated in this cross-sectional study. For each athlete, Reach (maximum standing reach height), Vertec (maximum height attained during a maximal vertical jump), and vertical jump height, calculated as the difference between Vertec and Reach, were recorded. The presence or absence of tendon-related disorders was determined retrospectively from medical history information and club documentation. Data were analyzed using a multivariate general linear model, followed by univariate analyses and Bonferroni-adjusted post hoc comparisons. Results: Height showed a highly significant effect on the set of performance variables (Wilks’ λ = 0.066; p < 0.001), and competitive age category was also significantly associated with performance (Wilks’ λ = 0.655; p = 0.049). In contrast, neither body mass (p = 0.854) nor the tendon-related disorder variable (p = 0.293) demonstrated significant associations. Univariate analyses revealed significant effects of competitive age category on Vertec performance (p = 0.018) and vertical jump height (p = 0.008), but not on Reach (p = 0.542). Bonferroni-adjusted post hoc comparisons showed significant differences between the Under-19 and Under-15 categories for Vertec performance (p = 0.017), and between Under-19 and Under-15 (p = 0.007) as well as Under-17 and Under-15 (p = 0.034) for vertical jump height. Conclusions: Jumping performance in youth volleyball appears to be primarily influenced by anthropometric characteristics and developmental factors associated with competitive age category, whereas the dichotomous retrospective classification of tendon-related disorders adopted in the present study did not discriminate performance level. These findings highlight the importance of integrating functional, clinical, and training-load monitoring to better understand athletic development and tendon vulnerability. Full article

(This article belongs to the Special Issue Biomechanics of Human Movement in Sports and Analysis of Sport Techniques)

20 pages, 1032 KB

Open AccessArticle

Hip Hinge Kinematics and Movement Confidence Before and After Founder Exercise Instruction in Healthy Adults: A Preliminary Study

by William J. Hanney, Julia Chase, Tysen Coates, Christian Rodriguez-Rolas, Michael Massaracchio and Abigail W. Anderson

J. Funct. Morphol. Kinesiol. 2026, 11(3), 322; https://doi.org/10.3390/jfmk11030322 - 20 Aug 2026

Abstract

Background: Impaired lumbopelvic control and inefficient bending mechanics are associated with low back pain and functional limitations. The Founder Exercise is a movement retraining strategy intended to promote hip-dominant movement, trunk control, and postural awareness during forward bending. However, empirical evidence examining [...] Read more.

Background: Impaired lumbopelvic control and inefficient bending mechanics are associated with low back pain and functional limitations. The Founder Exercise is a movement retraining strategy intended to promote hip-dominant movement, trunk control, and postural awareness during forward bending. However, empirical evidence examining movement performance following Founder Exercise instruction is limited. This study examined immediate pre-to-post differences in hip hinge kinematics and movement confidence surrounding a standardized Founder Exercise instructional session in healthy adults. Methods: A within-subject pretest-posttest design was used. Thirty-three healthy adults (72.7% female; mean age, 25.1 ± 2.9 years) completed assessments of foot orientation, sagittal-plane joint kinematics, and movement confidence before and after a single Founder Exercise instructional session. Joint kinematics were assessed using two-dimensional video analysis. Paired-samples t-tests or Wilcoxon signed-rank tests, as appropriate based on the distributions of the paired differences, were used to evaluate the kinematic outcomes. The exploratory summed confidence score and individual ordinal confidence items were evaluated using Wilcoxon signed-rank tests. Holm adjustments were applied separately to the 11 kinematic comparisons and the 10 individual-item comparisons. Results: Statistically significant immediate pre-to-post differences were observed in several kinematic variables. Hip flexion increased from 80.7° ± 18.1° at pretest to 104.6° ± 14.3° at posttest, shoulder flexion increased from 62.8° ± 23.9° to 145.3° ± 13.9°, and craniovertebral angle decreased from 25.7° ± 12.9° to 11.2° ± 10.0° (all p < 0.001). The summed score from the unvalidated, study-specific confidence scale was higher at posttest (median = 49.0, IQR = 40.0–50.0) than at pretest (median = 40.0, IQR = 36.0–50.0; p < 0.001). After Holm adjustment of the individual ordinal-item analyses, statistically significant differences remained for five of the 10 items; all confidence findings were considered exploratory. No statistically significant differences were observed in knee flexion or ankle motion after Holm adjustment. Conclusions: A brief Founder Exercise instructional session was followed by immediate differences in selected two-dimensional hip hinge angles and higher exploratory movement-confidence scores in healthy adults. These findings do not establish changes in lumbopelvic control, muscle activation, spinal loading, movement efficiency, or clinical outcomes. Controlled studies incorporating direct measures of lumbar and pelvic motion, muscle activity, external forces, and clinically relevant outcomes are needed before biomechanical or clinical conclusions can be drawn. Full article

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

► Show Figures

Figure 1

16 pages, 1072 KB

Open AccessArticle

Estimated Muscle Fiber Type and Blood Lactate Responses in NCAA Division III Sprint and Distance Swimmers: An Exploratory Feasibility Study

by Justin A. DeBlauw, Elissa Miller, Kyle D. Heise, Will K. Quinn and Stephen J. Ives

J. Funct. Morphol. Kinesiol. 2026, 11(3), 321; https://doi.org/10.3390/jfmk11030321 - 19 Aug 2026

Abstract

Background and Objectives: Swimming has sprint and distance events, with current performance often driving selection rather than physiological characteristics of the athlete (e.g., muscle fiber type, blood lactate, etc.), especially among NCAA Division III swimmers, where these characteristics are unknown. We aimed to [...] Read more.

Background and Objectives: Swimming has sprint and distance events, with current performance often driving selection rather than physiological characteristics of the athlete (e.g., muscle fiber type, blood lactate, etc.), especially among NCAA Division III swimmers, where these characteristics are unknown. We aimed to characterize the differences in estimated muscle fiber types (% fast twitch, %FT) and blood lactate (B_lac) response to the maximal anaerobic lactate swim test (MANLT) between collegiate distance and sprint collegiate swimmers. Methods: Twenty-two college-aged (19.7 ± 1.0 yr) DIII swimmers (n = 13 sprint, n = 9 distance) performed an isokinetic muscular fatigue protocol to estimate their %FT, as well as their maximal and minimum B_lac values and clearance rate (B_lac recovery) (3 and 12 min post) after the MANLT was performed on two separate days (>48 h between). Results: There were no significant differences between sprint swimmers and distance swimmers in maximal B_lac levels (11.6 ± 2.5 vs. 10.5 ± 3.4 mM, p = 0.38, d = 0.3), minimal B_lac levels (9.3 ± 2.9 vs. 8.3 ± 3.3 mM, p = 0.45, d = 0.3), and percent decreases from 0 to 3 min (0.9 ± 13.1 vs. 9.9 ± 9.5, p = 0.09, d = 0.7), 0–12 min (15.4 ± 15.6 vs. 19.7 ± %, p = 0.52, d = 0.2), and 3–12 min (14.7 ± 12.5 vs. 11.04 ± 11.2%, p = 0.48, d = 0.3) B_lac recovery. No significant differences were identified in estimated %FT between sprinters and distance swimmers (52 ± 6.4 vs. 45 ± 10.51, p = 0.056). Both extensor and flexor %FT estimations showed 69.2% and 66.7% accuracy in matching coach-identified event, with their respective estimated fiber type. A positive relation was identified between %FT knee flexor fibers and B_lac (r = 0.44) and between %FT knee extensor fibers and B_lac (r = 0.48) for all swimmers. Conclusions: This preliminary study suggests that athlete specialization is generally accurate to the physiology of the swimmer, namely anaerobic capacity and estimated fiber type. Full article

(This article belongs to the Special Issue Advances in Performance Analysis and Monitoring in Sport and Exercise: Bridging the Research–Practice Gap)

► Show Figures

Figure 1

21 pages, 1109 KB

Open AccessArticle

The Influence of Dual Source Cerebellar Transcranial Direct Current Stimulation on Muscle Fatigue

by Janriek A. Bognot, Eliza Clinton, Erik W. Wilkins, Richard J. Young, Mina Rezaeian Jam, Ryder Davidson, George Alhwayek, Reese Krider, Jonathan A. Park, Zachary A. Riley and Brach Poston

J. Funct. Morphol. Kinesiol. 2026, 11(3), 320; https://doi.org/10.3390/jfmk11030320 - 18 Aug 2026

Abstract

Background: Transcranial direct current stimulation (tDCS) applied unilaterally to the cerebellum (c-tDCS) can improve several aspects of human motor performance. The purpose of the study was to examine the influence of dual source tDCS delivered bilaterally over the cerebellar cortices (dsc-tDCS) on the [...] Read more.

Background: Transcranial direct current stimulation (tDCS) applied unilaterally to the cerebellum (c-tDCS) can improve several aspects of human motor performance. The purpose of the study was to examine the influence of dual source tDCS delivered bilaterally over the cerebellar cortices (dsc-tDCS) on the time to task failure (TTF) of a fatiguing contraction in young adults. Methods: The study utilized a double-blind, randomized, SHAM-controlled, within-subjects, crossover design, and participants were given either dsc-tDCS or SHAM stimulation in two different experiments held 7 days apart in a fully counterbalanced order. Every aspect of the two experiments was the same except the type of stimulation (dsc-tDCS or SHAM) delivered during the fatiguing contraction. The fatiguing contraction was executed with a precision grip at 15% of the maximum voluntary contraction (MVC) force, and participants were instructed to maintain the contraction for as long of time as possible. Results: The TTF and fatigue index were both similar for the dsc-tDCS and SHAM stimulation conditions. In addition, the electromyographic (EMG) activity, force error, and standard deviation (SD) of force measured during the fatiguing contraction were also not statistically different between the dsc-tDCS and SHAM stimulation conditions. Conclusions: The findings suggest that dsc-tDCS does not decrease the rate of progression of muscle fatigue. Full article

(This article belongs to the Section Kinesiology and Biomechanics)

► Show Figures

Figure 1

18 pages, 9234 KB

Open AccessArticle

Training Sequence Matters: Neuromuscular Training Followed by Small-Sided Games Enhances Physical Fitness and Soccer-Specific Performance in Prepubertal Soccer Players

by Sofiene Bouguerra, Mohamed Amine Selmi, Lotfi Bouguerra, Yassine Negra, Roland van den Tillaar and Raouf Hammami

J. Funct. Morphol. Kinesiol. 2026, 11(3), 319; https://doi.org/10.3390/jfmk11030319 - 16 Aug 2026

Abstract

Background: Physical and technical development in youth soccer depends on the integration of neuromuscular and small-sided games (SSG) training. However, the influence of training sequence on adaptations remains unclear in prepubertal players. Therefore, this study aimed to compare the effects of performing neuromuscular [...] Read more.

Background: Physical and technical development in youth soccer depends on the integration of neuromuscular and small-sided games (SSG) training. However, the influence of training sequence on adaptations remains unclear in prepubertal players. Therefore, this study aimed to compare the effects of performing neuromuscular training before or after SSG on physical fitness and soccer-specific performance in trained prepubertal soccer players. Methods: Twenty-two trained prepubertal male soccer players were randomly assigned to either neuromuscular training followed by SSG or SSG followed by neuromuscular training. Both groups completed a 6-week in-season intervention, including two weekly sessions, with each group performing 3 weeks of neuromuscular training and 3 weeks of SSG training in a different order. Physical fitness (back extensor strength, five-jump test, 10 m sprint, and Yo-Yo IR1) and soccer-specific performance (change of direction with ball and Loughborough Soccer Passing Test) were assessed before and after the intervention. Results: All 22 participants completed the intervention (n = 11 per group). Both groups demonstrated significant improvements over time in most physical fitness and soccer-specific performance variables (p < 0.01). However, significant group × time interactions indicated that the magnitude of improvement was consistently greater when neuromuscular training preceded small-sided games (p ≤ 0.041). Compared with the SSG-before-neuromuscular group, the neuromuscular-before-SSG group achieved larger improvements in back strength (+9.8% vs. +2.7%), five-jump test (+17.1% vs. +10.0%), 10 m sprint (−10.3% vs. −6.3%), Yo-Yo IR1 distance (+35.4% vs. +20.4%), change of direction with ball (−7.4% vs. −1.0%), and Loughborough Soccer Passing Test (−16.0% vs. −7.8%). Conclusions: Training sequence may influence the magnitude of short-term adaptations in prepubertal soccer players. Although both training orders improved performance, performing neuromuscular training before SSG resulted in greater improvements in several physical fitness and soccer-specific performance outcomes. These findings suggest that training order may represent an important factor in youth soccer training design; however, further research is required to confirm the consistency of this sequencing effect and to explore the mechanisms underlying these adaptations. Full article

(This article belongs to the Special Issue Athletic Training and Its Impact on Body Composition and Physical Fitness)

► Show Figures

Figure 1

10 pages, 252 KB

Open AccessArticle

Sex-Specific Analysis of Quadriceps and Hamstring Strength Following Anterior Cruciate Ligament Reconstruction With or Without Meniscal Repair

by Christopher J. Cleary, Olivia Federico, Lexy N. Farrington, Nicholas S. Dombrowski, Christopher D. Bernard, Zachary D. Denton, Bryan G. Vopat and Ashley A. Herda

J. Funct. Morphol. Kinesiol. 2026, 11(3), 318; https://doi.org/10.3390/jfmk11030318 - 15 Aug 2026

Abstract

Background and Objectives: Strength deficits are extremely common following anterior cruciate ligament reconstruction (ACLR). These deficits may be further impacted by concomitant meniscus repair during ACLR. However, there remains limited evidence investigating the effect of meniscus repair on lower-limb strength after ACLR, [...] Read more.

Background and Objectives: Strength deficits are extremely common following anterior cruciate ligament reconstruction (ACLR). These deficits may be further impacted by concomitant meniscus repair during ACLR. However, there remains limited evidence investigating the effect of meniscus repair on lower-limb strength after ACLR, and particularly if there are between-sex differences in strength after ACLR with and without meniscus repair. Therefore, the purpose of this study was to investigate sex-specific differences in meniscus repair during ACLR on quadriceps and hamstring isometric strength. Methods: Eighty-five (37 females; 19.0 ± 6.6 years old) patient charts were retrospectively evaluated after undergoing ACLR. Variables documented included meniscal status, maximal isometric quadriceps and hamstring strength of the operative (OP) and non-operative (NOP) legs. Three separate 3-way [leg (OP vs. NOP) × sex (males vs. females) × meniscus repair status (yes vs. no)] mixed-factorial analyses of variance (ANOVA) assessed differences in quadriceps and hamstring strength, and the hamstring-to-quadriceps strength ratio (H:Q), at an alpha level of p ≤ 0.05. Results: For H:Q there was a sex by meniscus repair status interaction (p = 0.007). Females who underwent meniscus repair had lower H:Q (18.2%) than those without. Females without meniscus repair had a 20.3% greater H:Q than males without meniscus repair. Males had greater quadriceps strength than females (mean difference ± standard error; 0.58 ± 0.28 N∙kg⁻¹) and the NOP leg was stronger than OP for quadriceps (0.34 ± 0.08 N∙kg⁻¹) and hamstring (0.14 ± 0.04 N∙kg⁻¹) strength across sex. Conclusions: These findings suggest that the H:Q ratio differed according to sex and meniscus repair status. Further, there was a between-limb difference for strength in the quadriceps and hamstrings along with sex-related differences in strength. However, meniscus repair status did not influence raw strength values. Full article

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

22 pages, 1202 KB

Open AccessArticle

Effects of Functional Magnetic Stimulation on Pain, Function, and MRI-Derived Outcomes in Athletes with Tibial Bone Stress Injury: A Randomized Controlled Trial

by Dimitrios Lytras, Ioannis Algiounidis, Vasileios Georgoulas, Konstantinos Kasimis, Georgia Maria Kamparoudi, Georgios Tsigaras, Georgia Vergidou, Nikolaos Sidiropoulos, Georgia Tarfali, Ilias Kallistratos and Paris Iakovidis

J. Funct. Morphol. Kinesiol. 2026, 11(3), 317; https://doi.org/10.3390/jfmk11030317 - 14 Aug 2026

Abstract

Background: Tibial bone stress injury (TBSI) with associated bone marrow edema (BME) is a common and clinically challenging condition in athletes, often requiring prolonged load restriction and delayed return to sport. Evidence for adjunctive interventions that improve both symptoms and MRI-derived recovery remains [...] Read more.

Background: Tibial bone stress injury (TBSI) with associated bone marrow edema (BME) is a common and clinically challenging condition in athletes, often requiring prolonged load restriction and delayed return to sport. Evidence for adjunctive interventions that improve both symptoms and MRI-derived recovery remains limited. The aim of this study was to investigate whether adding Functional Magnetic Stimulation (FMS) to standardized rehabilitation improves pain, function, and MRI-derived outcomes over 16 weeks in athletes with MRI-confirmed TBSI. Materials and Methods: Forty athletes with Fredericson grade 2–3 TBSI were randomized to FMS plus rehabilitation (n = 20) or rehabilitation alone (n = 20). Both groups completed a 4-week load-based rehabilitation program, while the FMS group additionally received eight 30 min FMS sessions at 40 Hz. Outcomes were assessed at baseline, 4 weeks, and 16 weeks. The primary outcome was activity-related pain (NPRS), while secondary outcomes included lower-limb function (LEFS-GR), BME extent, and Fredericson grade. Continuous outcomes were analyzed using two-way mixed ANOVA, whereas Fredericson grade was analyzed using an ordinal generalized estimating equation model. The level of statistical significance was set at p < 0.05. Results: Groups were comparable at baseline. Significant group × time interactions favored FMS for NPRS, F(2, 76) = 12.46, p < 0.001, η²p = 0.247; LEFS-GR, F(1.08, 41.09) = 81.56, p < 0.001, η²p = 0.682; and BME extent, F(1.44, 54.85) = 49.33, p < 0.001, η²p = 0.565. At 16 weeks, the FMS group showed lower NPRS scores, higher LEFS-GR scores, and lower BME extent than controls. Fredericson grade also showed a significant group × time effect, Wald χ²(2) = 20.38, p < 0.001. The FMS group had significantly lower cumulative odds of classification in a higher Fredericson grade at 4 weeks (OR = 0.045, 95% CI: 0.012–0.163, p < 0.001), whereas the corresponding difference at 16 weeks remained directionally favorable but did not reach statistical significance (OR = 0.033, 95% CI: 0.001–1.029, p = 0.052). Conclusions: The addition of FMS to load-based rehabilitation was associated with greater clinical and functional improvements, greater reductions in BME extent, and a more favorable longitudinal trajectory in MRI severity classification than rehabilitation alone in athletes with TBSI. However, because the study did not include a sham-FMS condition and participants could not be blinded, the self-reported pain and functional outcomes should be interpreted cautiously. FMS may represent a useful adjunct to structured rehabilitation, although sham-controlled and longer-term studies should determine its effects on return-to-sport progression and recurrence risk. Full article

(This article belongs to the Special Issue From Injury to Recovery: Rehabilitation Strategies for Athletes)

► Show Figures

Figure 1

19 pages, 545 KB

Open AccessReview

Efficacy and Cost-Effective Treatment of Isometric Resistance Training for Blood Pressure Control: A Narrative Review in Healthy Individuals and People with Cardiovascular Diseases

by Matteo Vitarelli, Domenico Mario Giamundo, Alberto Grossi, Giuseppe Caminiti, Gabriele Morganti, Francesca Strassoldo di Villanova, Bruno Ruscello, Elvira Padua, Maurizio Volterrani, Valentina Morsella, Marco Alfonso Perrone, Vincenzo Manzi, Gennaro De Rosa, Lorenzo Loffredo and Enrico Maggio

J. Funct. Morphol. Kinesiol. 2026, 11(3), 316; https://doi.org/10.3390/jfmk11030316 - 13 Aug 2026

Abstract

Isometric resistance training (IRT) has emerged as a promising non-pharmacological intervention for blood pressure (BP) management. Although current hypertension guidelines primarily recommend aerobic and dynamic resistance exercise, growing evidence indicates that IRT is an effective, feasible, and time-efficient alternative. This narrative review summarizes [...] Read more.

Isometric resistance training (IRT) has emerged as a promising non-pharmacological intervention for blood pressure (BP) management. Although current hypertension guidelines primarily recommend aerobic and dynamic resistance exercise, growing evidence indicates that IRT is an effective, feasible, and time-efficient alternative. This narrative review summarizes the current evidence on the efficacy, physiological mechanisms, and clinical applications of IRT. We reviewed randomized controlled trials, systematic reviews, and meta-analyses evaluating the effects of different IRT modalities, including isometric handgrip (IHG), isometric wall squat (IWS), and isometric leg extension (ILE), on BP in normotensive individuals, patients with hypertension, and those with cardiovascular disease. IRT consistently reduces resting systolic BP by approximately 5–8 mmHg and diastolic BP by 3–4 mmHg; these effects may approach those reported with first-line antihypertensive therapy and potentially be equivalent to those of other exercise modalities. These benefits have been demonstrated across normotensive and hypertensive populations and appear largely independent of age, sex, medication use, and the muscle groups involved. Preliminary evidence also supports the feasibility and safety of appropriately prescribed IRT in selected patients with ischemic heart disease and heart failure with preserved ejection fraction. Proposed mechanisms include improvements in endothelial function, nitric oxide bioavailability, autonomic regulation, oxidative stress, arterial baroreflex sensitivity, and myocardial efficiency. IRT has emerged as an effective, safe, and practical adjunct to lifestyle modification for BP control, particularly in older adults and individuals with limited ability to perform conventional exercise. However, current evidence derives from relatively small studies with limited follow-up; further large-scale randomized trials are needed to define the optimal exercise prescription, clarify the underlying mechanisms, and establish the role of IRT in patients with cardiovascular disease. Full article

(This article belongs to the Special Issue 10th Anniversary of JFMK: Advances in Physical Exercise for Health Promotion)

► Show Figures

Figure 1

24 pages, 591 KB

Open AccessReview

Electromyographic Analysis of Latissimus Dorsi Activation During Common Resistance Training Exercises: A Narrative Review

by Domenico Di Fonza, Gloria Di Claudio, Gianmaria Colantuono, Lorenzo Persichini, Nicola Cerulo, Benedetta Sangregorio, Andrea Buonsenso, Giovanni Fiorilli, Giuseppe Calcagno and Alessandra di Cagno

J. Funct. Morphol. Kinesiol. 2026, 11(3), 315; https://doi.org/10.3390/jfmk11030315 - 12 Aug 2026

Abstract

Background: The latissimus dorsi (LD) is a primary muscle involved in pulling exercises used in resistance training, contributing to shoulder extension, adduction and internal rotation, with relevance to athletic performance, injury prevention and rehabilitation as well as to upper-body aesthetics. Aim: [...] Read more.

Background: The latissimus dorsi (LD) is a primary muscle involved in pulling exercises used in resistance training, contributing to shoulder extension, adduction and internal rotation, with relevance to athletic performance, injury prevention and rehabilitation as well as to upper-body aesthetics. Aim: to identify which exercise configurations are most consistently associated with greater latissimus dorsi electromyographic (EMG) amplitude. Methods: This SANRA-informed narrative review synthesized surface and high-density EMG evidence across major pulling exercises, for the lat pull-down, pullover, seated row, barbell row, bent-over row and pull-up. Twenty-three eligible studies were included and appraised using a six-criterion methodological checklist. Results: In the lat pull-down, an anterior bar path was the configuration most consistently associated with greater LD EMG amplitude, whereas the effects of grip width were inconsistent. In the seated row, a narrower grip and a lower shoulder-abduction angle were each associated with greater LD amplitude in separate studies; these two variables have not been tested in combination and should not be read as a single validated configuration. Among rowing variants, the inverted row produced the highest LD amplitude in a single, small preliminary study that requires replication. Pull-up variations showed broadly similar LD activation across grip configurations, while the pullover appeared to preferentially activate the pectoralis major rather than selectively target the LD. Conclusions: Current evidence tentatively supports the anterior lat pull-down and, within the seated row, a narrower grip and a lower shoulder-abduction angle (evaluated independently) as the configurations most consistently associated with greater LD EMG amplitude; these findings reflect acute EMG amplitude rather than longitudinal training outcomes and should be treated as an evidence-informed starting point rather than a definitive exercise prescription. Across pulling exercises, the humerus-to-trunk relationship may be a key biomechanical determinant of muscular load distribution. Full article

(This article belongs to the Special Issue Biomechanical and Neuromuscular Perspectives in Resistance Training)

► Show Figures

Figure 1

19 pages, 18314 KB

Open AccessPerspective

Multilevel Determinants of Acromiohumeral Distance Within a Systems-Based Functional Morphology Framework and Their Implications for Personalized Neuromusculoskeletal Modelling

by Luis Alfonso Arráez-Aybar, Carlos Miquel García-de-Pereda-Notario, Luis Palomeque-Del-Cerro and Juan José Montoya-Miñano

J. Funct. Morphol. Kinesiol. 2026, 11(3), 314; https://doi.org/10.3390/jfmk11030314 - 12 Aug 2026

Abstract

Background: The acromiohumeral distance (AHD) is a widely used imaging parameter for evaluating the subacromial region and shoulder function. Traditionally, it has been interpreted as a static anatomical measurement reflecting the available subacromial space and associated with rotator cuff pathology, superior humeral migration, [...] Read more.

Background: The acromiohumeral distance (AHD) is a widely used imaging parameter for evaluating the subacromial region and shoulder function. Traditionally, it has been interpreted as a static anatomical measurement reflecting the available subacromial space and associated with rotator cuff pathology, superior humeral migration, and subacromial impingement. However, inconsistent relationships between AHD, symptoms, and function suggest that purely structural interpretations may be insufficient. Objectives: To propose a systems-based functional morphology framework that reinterprets AHD as an emergent functional state variable reflecting the instantaneous state of the glenohumeral system. Methods: A conceptual synthesis integrated evidence from shoulder biomechanics, functional morphology, movement science, connective tissue research, systems theory, and personalized neuromusculoskeletal modelling. Structural, connective tissue, neuromuscular, and mechanical determinants of AHD were integrated within a multilevel systems perspective. Results: The proposed framework conceptualizes AHD as emerging from the dynamic interaction of four organizational domains: structural constraints, connective tissue properties, neuromuscular regulation, and mechanical context. Rather than representing a fixed anatomical space, AHD is interpreted as a potential systems-level functional biomarker whose value varies according to the functional state of the glenohumeral system. This perspective explains the variability observed across imaging studies and the frequent discordance between structural findings, symptoms, and functional outcomes. Conclusions: Reframing AHD as an emergent functional state variable provides a theoretical basis for integrating anatomy, biomechanics, movement behavior, and neuromuscular control within personalized shoulder assessment. This systems-based perspective may help bridge the traditional gap between structural imaging and clinical presentation while supporting future developments in precision rehabilitation and subject-specific computational modelling. Full article

(This article belongs to the Special Issue Functional Morphology and Human Functional Anatomy as the Foundation of Personalised Neuromusculoskeletal Model)

► Show Figures

Graphical abstract

Journal Description

Journal of Functional Morphology and Kinesiology

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI