Journal of Functional Morphology and Kinesiology最新文献

Objectives: This study aimed to compare the hydrodynamic profile between triathletes and competitive swimmers and to establish associations with short- and middle-distance performance. Methods: A total of 18 male athletes, including 10 swimmers and 8 triathletes, all registered in their respective federations, underwent assessments of passive drag, active drag and power, tethered swimming force, kinematics, and performance over a 200 m and 25 m front crawl. Group comparisons were performed using either Student's t-test or the Mann-Whitney U test at a significance level of p ≤ 0.05. Results: The triathletes presented higher passive drag and lower levels of force and power to overcome drag. Correlation analysis showed that, among the triathletes, both times at 200 m and 25 m were associated with mean passive drag (r = 0.68 to 0.86) and power (r = -0.58 to -0.80), whereas in swimmers, the mean in-water force was the single variable associated with time at 25 m (r = -0.51). Conclusions: There is a clear hydrodynamic superiority of swimmers compared to triathletes, reflecting their higher mean swimming velocity due to a greater ability to apply force. This suggests that specific technical interventions for triathletes, focusing on drag reduction and improvements in propulsive power, are needed to close this gap with swimmers.

Background: Passing in lacrosse is a fundamental skill essential for both offense and defense, directly influencing game flow. Although the speed-accuracy trade-off is well recognized in motor control, its features in lacrosse passing-particularly regarding directional aspects and skill differences-remain unclear. This study quantified the relationship between pass speed, accuracy, bias, and consistency and examined directional effects and skill-level differences. Methods: Twenty-two female university players (skilled: n = 9; unskilled: n = 13) executed overhand passes to a 5 cm × 5 cm target from 11 m under three effort conditions: warm-up, game intensity, and full effort. Ball speed was derived from lateral video, and landing coordinates from posterior footage. Accuracy, bias, and consistency were assessed using radial error (RE), centroid error (CE), absolute CE (|CE|), and bivariate variable error (BVE). Directional patterns were analyzed through lateral and vertical components and the 95% confidence intervals of the major and minor axes of an error ellipse. A two-way analysis of variance was performed with condition as the within-subject factor and skill level as the between-subject factor. Results: Ball speed increased significantly across conditions. RE, |CE|, and BVE increased with speed, showing directional dependence: variability expanded mainly along the major axis, while the minor axis remained stable. Skilled players showed smaller RE and BVE, with differences most evident vertically and along the major axis. CE direction stayed consistent, indicating that reduced accuracy stemmed from greater bias magnitude and lower consistency rather than shifts in the mean landing point. Conclusions: Findings confirm a speed-accuracy trade-off in lacrosse passing, characterized by directional specificity and skill-related effects. Combining RE, CE, BVE, and ellipse-axis analyses clarified error structure, showing variability concentrated along the movement axis. These results support training focused on vertical control and timing and highlight the value of directional metrics for assessing lacrosse performance. Future research should include male athletes, advanced levels, and in-game scenarios to extend generalizability.

Background: Physical exercise (PE) has emerged as a promising intervention for depressive disorder (DD), yet its efficacy and optimal implementation remain under investigation. Objective: To thoroughly assess the effectiveness of supervised PE as a conventional intervention for adults with DD. Methods: A comprehensive literature search was conducted across PubMed/MEDLINE, EBSCOhost, Ovid, Web of Science, and Scopus. Randomized controlled trials (RCTs) published between 2010-2025 involving adults with DD without other comorbidities under supervised exercise interventions were selected. Methodological rigor was ensured through two independent reviewers and adherence to PRISMA 2020 guidelines. The influence of moderating variables [total work performed (workload) and the instrument used to evaluate DD (instrument)] was analyzed using meta-regression. The pooled effect size was estimated using both frequentist and Bayesian meta-analyses. Results: From 15,542 screened records, 20 RCTs were selected. Workload and instrument account for 60% and 15% of the variance in the effect size, respectively. Both frequentist and Bayesian meta-analyses showed that supervised PE reduces depressive symptoms (standardized mean difference = 0.82; 95% CI: 0.54-1.11; I² = 76%, and 0.61; 95% CI: -0.06-0.95; I² = 51, respectively). Conclusions: PE could be a valuable complementary intervention to reduce depressive symptoms in adults with depression. PROSPERO (CRD420251121919).

In recent years, machine learning (ML) has emerged as one of the most influential methodological advances in sports medicine, physical activity, posture assessment, and rehabilitation [...].

Objectives: The present study compared the amplitude and spatial distribution of muscle excitation between a seated row performed with a fixed scapular position (fixed-SR) and a free scapular position (free-SR) in resistance-trained men, analyzing concentric and eccentric phases separately using high-density surface EMG (HD-sEMG). Methods: Fourteen resistance-trained males (age: 25 ± 4 years; stature: 1.74 ± 0.06 m; body mass: 76.22 ± 5.73 kg) performed fixed-SR and free-SR in a randomized cross-over design using 8-repetition maximum as the load for both variations. HD-sEMG grids recorded the activity from the upper/middle/lower trapezius, latissimus dorsi, lateral/posterior deltoid, biceps brachii, triceps brachii, and erector spinae. Normalized root mean squared (RMS) amplitude and excitation centroids in the mediolateral and craniocaudal planes were computed for the concentric and eccentric phases. Data were analyzed using repeated-measures statistical models, with significance set at p < 0.05. Results: During the concentric phase, nRMS amplitude was greater for the posterior deltoid in fixed-SR compared with free-SR (effect size [ES] = 0.66), whereas no between-condition difference was observed for the remaining muscles. During the eccentric phase, nRMS amplitude was greater in the fixed-SR for the middle trapezius (ES = 0.67) and the latissimus dorsi (ES = 0.85), with no between-condition differences detected for the remaining muscles. The centroid position analysis revealed that, during the eccentric phase, the middle trapezius centroid was located more laterally in the fixed-SR condition (ES = 0.54), while the posterior deltoid centroid was positioned more caudally in the fixed-SR compared with the free-SR condition (ES = 0.22). Conclusions: The fixed-SR and free-SR conditions produce comparable overall muscle excitation patterns, while showing some quantitative and spatial differences in selected upper-back muscles. These results suggest that scapular constraint influences the distribution of muscular excitation rather than overall excitation levels. Accordingly, both variations can be effectively used in resistance training, selecting to fix or free the scapulae depending on the emphasis on the scapular movements rather than a substantial difference in muscle excitation.

Objectives: We examined the effects of sex and inertia on within-session reliability of flywheel half-squat performance outcomes. Methods: A total of 21 males and 25 females (aged 24.9 and 23.6, respectively) performed two sets of six valid repetitions using four inertial loads. Mean force, mean and peak power, impulse, and work were recorded during concentric and eccentric phases. Intraclass correlation coefficient (ICC), coefficient of variation (CV), typical error (TE), smallest worthwhile change (SWC), and minimal detectable change were calculated. A three-way repeated measures ANOVA was used to identify systematic differences and interaction effects. Results: Regardless of inertia or contraction phase, both males and females demonstrated excellent between-set reliability (ICC > 0.803 in males and superior to 0.946 in females) across all variables. Although males showed slightly higher CV values, CVs were good for all variables (≤9%). Overall, good sensitivity (SWC > TE) was observed in the four inertias, with marginal sensitivity (TE > SWC) more frequently observed for the power-related outcomes. Whereas no interactions between Sex × Set × Inertia were observed among the variables, significant interactions between Inertia × Sex were observed in both contraction phases for power-related variables (eccentric peak power, p < 0.001; concentric mean power, p = 0.032). Conclusions: reliability was excellent across all moments of inertia and contraction phases for both sexes, highlighting the importance of considering inertia configuration and sex differences when profiling performance outcomes.

Background: Robotic assistive devices are increasingly used in post-stroke gait rehabilitation, yet quantitative evaluations of synchronization between human and robotic joint motion remain limited. This study examined gait kinematics in post-stroke hemiplegic patients using two exoskeleton-type devices-HAL^® (Cyberdine Inc., Tsukuba, Japan) and curara^® (AssistMotion Inc., Ueda, Japan)-based on synchronized IMU measurements. Methods: Two post-stroke patients performed treadmill walking under non-assisted and assisted conditions with HAL^® and curara^®. Only the paretic knee joint was analyzed to focus on the primary control joint during gait. Inertial measurement units (IMUs) simultaneously recorded human and robotic joint angles. Synchronization was assessed using Bland-Altman (BA) analysis, root mean square error (RMSE), and mean synchronization jerk (MSJ). The study was designed as an exploratory methodological case study to verify the feasibility of synchronized IMU-based human-robot joint measurement. Results: Both assistive devices improved paretic knee motion during gait. RMSE decreased from 7.8° to 4.6° in patient A and from 8.1° to 5.0° in patient B. MSJ was lower during curara-assisted gait than HAL-assisted gait, indicating smoother temporal coordination. BA plots revealed reduced bias and narrower limits of agreement in assisted conditions, particularly for curara^®. Differences between HAL^® and curara^® reflected their distinct control strategies-voluntary EMG-based assist vs. cooperative gait-synchronization-rather than superiority of one device. Conclusions: Both devices enhanced synchronization and smoothness of paretic knee motion. curara^® demonstrated particularly smooth torque control and consistent alignment with human movement. IMU-based analysis proved effective for quantifying human-robot synchronization and offers a practical framework for optimizing robotic gait rehabilitation. The novelty of this study lies in the direct IMU-based comparison of human and robotic knee joint motion under two contrasting assistive control strategies.

Background: Reserve Officer Training Corps (ROTC) Cadets undergo biannual Field Training Exercises (FTX) that impose substantial physiological demands, necessitating adequate nutritional intake to support performance and recovery. Methods: Energy Expenditure (EE) measured by actigraphy and self-reported nutritional intake (NI) of ROTC Cadets during a Fall FTX were obtained and compared to Military Dietary Reference Intake (MDRI) guidelines. Energy balance and nutrient adequacy were assessed using paired sample t-tests. Results: Cadets demonstrated significant caloric deficits, consuming fewer kilocalories than both their active metabolic rate (t = -12.07, df = 42, p < 0.001) and Low Energy Availability thresholds (t = 6.47, df = 57.54, p < 0.001). Macronutrient analysis revealed widespread deficiencies. Neither male nor female cadets met minimum carbohydrate gram recommendations. Protein intake in grams was significantly below MDRI guidelines for 94% of males (t = -10.03, p < 0.001) and 90% of females (t = -4.62, p = 0.001). Fat intake was generally adequate for all cadets, with 94% of males (t = 6.50, p < 0.001) and 90% of females (t = 4.19, p = 0.002) meeting or exceeding recommended fat intake. Conclusions: These findings underscore the prevalence of under-fueling during FTX and highlight the need for improved nutritional strategies to mitigate energy deficits and support cadet performance and health.

Objectives: This study aimed to investigate the skating force-velocity (F-V) mechanical characteristics of trained youth ice hockey players at different stages of their maturational development. Methods: A total of 52 male trained ice hockey players (14.6 ± 1.4 years) from U13, U15, U17, and U18 competitive teams of the same hockey program were classified into three maturation groups-Pre-, Mid-, and Post-peak height velocity (PHV). Participants performed two 40 m maximal skating efforts while velocity data were collected using a radar device to derive F-V parameters (e.g., theoretical maximal force (F₀), velocity (V₀), power (P_max), and related metrics). The maturation offset was computed using the following formula: Maturity offset = -8.128741 + (0.0070346 · (Chronological age · Sitting height)). Results: Results revealed significant effects of puberty on most performance variables (F_(2,49) = [5.58, 31.72]; p ≤ 0.07; η² = [0.19, 0.56]). Differences in acceleration (0-10 m time) and F₀ improved markedly between Mid- and Post-PHV stages (|d| = [1.38, 1.92]), while V0 and maximal sprint velocity (30-40 m time) improved constantly across maturation stages (|d| = [1.03, 1.99]). Conclusions: This is the first study to provide reference skating F-V profile values across puberty in trained youth male ice hockey players. Coaches and practitioners are encouraged to prioritize acceleration and skating technique early during puberty to maximize velocity development and emphasize strength development after reaching peak height velocity. Conclusions should be considered with care as the Pre-PHV group was small (n = 5) and the used F-V method remains to be validated on ice.

Background: Paralympic athletes represent a highly heterogeneous athletic population, which poses unique challenges for body composition assessment. This study evaluated the accuracy of Bioelectrical Impedance Analysis (BIA), Air Displacement Plethysmography (ADP), and a set of skinfold equations in estimating relative fat mass (%FM) in Paralympians, using Dual-Energy X-Ray Absorptiometry (DXA) as reference method. Methods: Sixty-six male and sixty-seven female Paralympians underwent body composition assessments on the same day. The %FM estimated using BIA, ADP, and six existing skinfold equations was compared with %FM measured by DXA (%FM_DXA). Accuracy and agreement between the methods were evaluated using two-tailed paired-sample t-tests, concordance correlation coefficients, reduced major axis regression, and Bland-Altman analysis. Linear regression analyses with the %FM_DXA as dependent variable and anthropometric measurements as independent variable were also carried out. Results: BIA, ADP, and skinfold equations exhibited poor agreement with DXA and significantly underestimated %FM_DXA, with systematic biases ranging from -1.8% to -10.7% in both men and women. In both groups, skinfold sums showed strong correlations with %FM_DXA (r > 0.7), with the nine-skinfold model providing the best prediction (adjusted R² approximately 0.8). Conclusions: The results of this study indicate a lack of transferability of available methods for assessing body composition (skinfold equations, BIA, and ADP) in estimating %FM_DXA in both male and female Paralympians, as these methods proved inaccurate. Future research is needed to further investigate the accuracy of methods for assessing body composition in this population, taking into account the specific impairment and health condition of the athletes.