Journal of Functional Morphology and Kinesiology最新文献

Objectives: This study investigated the prevalence and severity of musculoskeletal injuries within South Africa's most popular karate style, Shotokan, a previously unexamined area. As an exploratory study, it aimed to generate hypotheses by determining the prevalence, severity, and nature of these injuries to address this significant gap in the national combat sports literature. Methods: A descriptive, cross-sectional design was employed, utilizing a confidential online questionnaire distributed through various Shotokan organizations. The study gathered 155 responses (26.85% response rate). Results: The findings revealed a high injury prevalence, with 47.3% of participants reporting at least four injuries. These injuries occurred equally in training and competition (56.5%) and developed both acutely and over time (53.4%). Experienced practitioners at the Shodan level were particularly affected. The knee was the most frequently injured body part (11.6%), and muscle strains were the most common injury type (19.3%). Notably, 26.2% of karatekas continued training despite being injured. A significant weak positive correlation was found between years of training experience and injury levels (rs = 0.275, p = 0.007). However, no significant associations were found between injury prevalence and age, BMI, or training frequency. General practitioners were the most consulted healthcare professionals (22.0%). Conclusions: This study establishes a high prevalence of musculoskeletal injuries among South African Shotokan karatekas, particularly associated with experienced practitioners. These findings are hypothesis-generating, and the cross-sectional design precludes causal inferences. The data provides a crucial foundation for future longitudinal research to investigate causality and for developing evidence-based injury prevention protocols, particularly for the knee.

Inhaled medications, commonly prescribed for respiratory conditions such as asthma and exercise-induced bronchoconstriction, are increasingly scrutinized in sports medicine due to their potential performance-enhancing effects. Bronchodilators, in particular, may improve lung function, increase oxygen delivery, and influence muscle contractility, potentially enhancing athletic performance. However, supratherapeutic use raises concerns about cardiovascular risks, including tachyarrhythmias and altered autonomic balance, as well as muscle hypertrophy and sprint capacity gains. These effects blur the line between therapeutic use and doping, creating challenges for fair competition. This review explores the mechanisms by which inhaled drugs affect the cardiovascular and muscular systems, summarizes notable doping cases, and evaluates current detection methods. Despite regulatory thresholds established by the World Anti-Doping Agency, assay interpretation remains complicated by inter-individual variability, short drug half-lives, and enantiomeric differences. Addressing these gaps requires refined pharmacokinetic modeling, enantioselective assays, and metabolomic fingerprinting to safeguard both athlete health and the integrity of sport.

Background: Cavus foot, defined by an increased medial longitudinal arch and often forefoot plantarflexion, alters biomechanics and increases peak plantar pressures, raising the risk of musculoskeletal disorders such as metatarsalgia, Achilles tendinopathy, and gait instability. Custom foot orthoses are the preferred conservative treatment, offering plantar support, pressure redistribution, and reduction in compensatory muscle activity. This study evaluated the medium- and long-term effectiveness of custom orthoses in 71 patients with cavus feet using surface electromyography (sEMG) and the same shoes. Methods: Muscle activity of the peroneus longus, peroneus brevis, and gastrocnemius was recorded during treadmill gait after one and four months of orthotic use. Results: Significant reductions in muscles were observed, especially after four months, confirming greater long-term effectiveness. No residual benefits were found when participants walked without orthoses. Conclusions: These findings support the clinical value of insoles in reducing the compensatory muscle activity in cavus feet and emphasize the importance of investigating their long-term role in biomechanics and potential pathology risk reduction.

Objectives: We examined how opposing running slopes can modulate interval training effects on aerobic performance and reduction-oxidation (REDOX) determinants. Methods: Fourteen physically active volunteers, assigned to either the Uphill group (UG) or the Downhill group (DG), completed 16 workouts of ten 30-s runs, at either +10% or -10% grade, with a work-to-rest ratio of 1:2 at 90% of their Maximum Aerobic Speed (MAS) over 8 weeks. Maximal oxygen uptake (VO_2max), MAS, Running Economy (RE), time to exhaustion at MAS (Tmax), respiratory exchange ratio (RER), and blood lactate at rest, 5th, and 10th runs were evaluated pre-, mid-, and post-training. Also, REDOX markers [Total Antioxidant Capacity (TAC), Protein Carbonyls (PCs) were assessed in blood samples taken at rest and 3 min post-exercise of the first and last workouts. Results: VO_2max was unchanged in both groups; in the DG, MAS increased (from 14.2 ± 1.7 to 15.0 ± 1.5 km/h, d = 0.43), and post-training RER significantly increased (from 1.06 ± 0.07 to 1.12 ± 0.03). In the last training session, blood lactate levels increased in the UG (from 9.30 ± 2.69 mmοl/L to 13.34 ± 4.64 mmοl/L) but remained low and unchanged in DG (<2 mmοl/L). Post-training, resting TAC decreased in both groups, and the exercise-induced rise in PC levels was attenuated. Conclusions: Despite the brief intervention, VO₂max levels were maintained in both groups, with divergent changes in metabolic, REDOX, and performance indicators; uphill HIIT may serve for enhancing lactate tolerance, while downhill intermittent running may improve running economy.

Objective: The aim of the study was to investigate the effect of eight weeks of in-season training with wearable resistance attached to the forearm on spike velocity in female volleyball players. Methods: A total of 13 senior female volleyball players belonging to the same team (age 23.5 ± 3.2 years, body mass 66.8 ± 6.9 kg, and height 174.7 ± 5.8 cm) participated and were divided into an experimental group (n = 7) or a control group (n = 6). Both groups participated in the same training sessions, but the experimental group trained with wearable resistance attached to the forearm, while the control group wore wearable resistance on the calf during the training sessions. Before and after an eight-week training period, spike velocity was tested. Results: The main findings were that spike velocity did not increase in either group, which was contrary to our hypothesis. In fact, neither the forearm-loaded experimental group nor the calf-loaded control group showed any performance improvement; instead, both groups demonstrated small, non-significant declines in spike velocity over the 8-week period (on average, about 2.1% in both groups). These outcomes occurred with high individual variability, with no significant difference between the groups (time × group: F(1, 11) = 0.008, p = 0.929). The between-group contrast was trivial, reinforcing that the forearm-loading intervention offered no clear benefit over normal training in practical terms. Conclusions: Taken at face value, this protocol does not support using wearable resistance during the competitive season to enhance spike velocity. It may be that off-season or individualized-load protocols could elicit more positive effects when overall training and fatigue levels are better controlled.

Background: The Relative Age Effect (RAE) refers to the advantage conferred to athletes born earlier within a selection year. In karate, particularly at the highest level, evidence is lacking. This study aimed to examine the presence of RAE among male and female karate athletes competing at the Tokyo 2020 Olympic Games, in two competitive disciplines: kata and kumite. Methods: Data from 81 athletes (42 males, 39 females) were retrieved from open-access databases. Birthdates were grouped into quartiles (Q1-Q4) and semesters (S1-S2). Chi-squared tests and odds ratios (ORs) were used to assess deviations from a uniform distribution, while binary logistic regression examined the association between semester of birth and medal attainment. Results: The overall distribution of birth quartiles significantly deviated from a uniform distribution (χ²(3) = 9.81, p = 0.020), indicating a higher proportion of athletes born in Q1 (38%) compared with Q4 (19%; OR = 2.07). RAE was particularly evident in kumite (χ²(3) = 17.87, p < 0.001; OR = 3.50 for Q1 vs. Q4) and among female athletes (χ²(3) = 9.92, p = 0.019), whereas no significant effect was found in kata or among males. Logistic regression revealed no significant association between semester of birth and medal success (OR = 0.49, 95% CI [0.20-1.21], p = 0.125). Conclusions: This study provides the first evidence of RAE in Olympic karate, especially among females and in kumite. However, relative age did not predict performance outcomes, suggesting that once athletes reach the Olympic level, technical and tactical factors outweigh birthdate advantages.

Background: This study investigates how both jump-related (jump height and flight time) and ball-related parameters (release height, release angle, and velocity) influence shooting accuracy in basketball under different contextual constraints. Methods: Eighteen senior players competing in the national championship (11 females and 7 males; 22.0 ± 3.7 years) performed 90 shots each across three positions (left 45°, middle 90°, right 45°) and three shooting conditions (baseline, simulated gym audience noise, and simulated opposition). Jump variables were derived from force platforms, while ball kinematics were extracted using a high-speed Qualisys camera system. Results: A three-way ANOVA revealed no systematic effects of position or opposition, and only a small effect of noise on flight time (p = 0.019), which was not confirmed by the Linear Mixed Model. Comparisons between successful and missed shots indicated significantly higher flight time, jump height, and release height, and a tendency for higher release velocity in successful attempts, with no differences in release angle. Spearman correlation showed weak associations between biomechanical variables and shooting accuracy (R² = 0.005-0.012). Conclusions: These findings suggest that while adaptive biomechanical changes occur under contextual constraints, their isolated impact on shot success is limited. Successful performance appears to rely more strongly on release-related parameters, emphasizing the need for a holistic approach to training that integrates technical, perceptual, and psychological dimensions.

Posture, balance, and gait are central determinants of human movement, independence, and quality of life [...].

Background: Delayed Onset Muscle Soreness (DOMS) is a transient, exercise-induced condition characterized by muscle pain, stiffness, and functional impairment, particularly following eccentric or high-intensity physical activity. Recent advances in diagnostic imaging, neurophysiology, and therapeutic techniques have led to a reassessment of DOMS pathophysiology and management. Objective: This scoping review aims to critically evaluate non-pharmacological strategies for DOMS management, focusing on clinical studies published between 2020 and 2025. Emphasis is placed on physical, thermal, neurophysiological, and nutritional interventions in athletic populations. Methods: A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science. Included studies were randomized controlled trials, systematic reviews, meta-analyses, and high-quality scoping reviews. Methodological quality was assessed using PEDro, AMSTAR 2, and ROBIS tools. Key outcome measures included pain (VAS), functional recovery (ROM, performance), biochemical markers (CK, IL-6), and neuromuscular activation (iEMG). Results: Twenty-five studies met the inclusion criteria. Emerging strategies such as cryosauna, vibration therapy, percussive massage, and polyphenol supplementation demonstrated significant benefits in reducing DOMS-related symptoms and enhancing recovery. Evidence supports the integration of multimodal, personalized interventions over monotherapies. Imaging techniques (7T MRI, ultrasound) confirmed microstructural muscle changes consistent with DOMS, strengthening diagnostic precision. Conclusions: Non-pharmacological approaches to DOMS have evolved considerably, highlighting the importance of combining mechanical, thermal, and nutritional modalities. Personalized, multimodal recovery strategies appear most effective for symptom relief and performance restoration. Future studies should aim to standardize treatment protocols and outcome measures to improve clinical applicability.

Objectives: An objective evaluation of balance abilities is crucial in research, rehabilitation, sport, and daily life. With ongoing technical advancements, the number of innovative evaluation tools is continuously increasing. This study assessed the methodological quality of various differential balance assessments in young, healthy adults. Methods: Two technically sophisticated balance assessments using a force plate (Single-Leg Landing Test, Single-Leg Squat Test) and a conventional balance assessment using a simple test kit (Y-Balance Test) were applied to 42 students at two different time points. Test-retest reliability, parallel test reliability, and internal consistency were evaluated for each test and item. Results: All tests and (almost) all items showed excellent to acceptable test-retest reliability. In all tests, internal consistency was detected for only some items, while the other items were internally inconsistent. Only a small proportion of tests and/or their items demonstrated acceptable parallel test reliability. The balance performance of the right and left legs showed excellent or good reliability for each item. Conclusions: Significant test-retest reliability and consistency between right and left leg performance suggest good methodological quality of the assessments. The lack of parallel test consistency aligns with previous studies that emphasise the multi-faceted nature of balance tasks, suggesting that balance ability is task-specific rather than a "general ability". Future studies should investigate and compare the biological and neural backgrounds of differential balance tasks to provide further insights into this topic.