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Background: Breaststroke performance in young swimmers is influenced by a complex interaction of anthropometric, physiological, and technical factors. However, existing studies predominantly focus on pre-selected or elite youth swimmers, limiting insight into performance development in non-elite populations without early selection bias. Purpose: This study aimed to identify key predictors of 50-m breaststroke performance and to examine longitudinal changes in selected characteristics in pre-adolescent, non-elite female swimmers. Methods: Fourteen female swimmers (baseline biological age: 10.52 ± 0.37 years) who entered swimming training without prior anthropometric or physiological selection were followed over three consecutive years. Measurements were collected at six time points and included anthropometric dimensions, body composition, aerobic and anaerobic capacity, respiratory volumes, and 50-m breaststroke performance. This investigation was a prospective longitudinal cohort study. Data were analysed using generalised estimating equations. Results: The correlation-filtered model explained 76% of the variance in 50-m breaststroke time. Chest depth (B = −0.16, p = 0.03), foot length (B = −0.17, p = 0.04), foot width (B = 0.30, p < 0.001), and shoulder width (B = −0.07, p = 0.04) emerged as significant anthropometric predictors. Maximal oxygen uptake also showed a significant association with performance (B = −0.33, p = 0.02). Conclusions: In pre-adolescent, non-elite female swimmers, selected anthropometric characteristics—particularly trunk dimensions and foot morphology—are associated with short-distance breaststroke performance. Aerobic capacity appears to play an indirect, supportive role. These findings highlight the importance of longitudinal monitoring without early selection and support a development-oriented approach to youth swimming training.

Background: Postural control in healthy young adults involves complex neuromuscular processes; however, the kinematic and kinetic consequences of small, forward leg perturbations in a defined population are not fully described. This study aimed to characterize the kinematic and kinetic consequences of forward leg perturbations during quiet standing. Methods: This investigation used a quasi-experimental repeated-measures design. Sixteen healthy young women (20.1 ± 0.7 years), all right-leg dominant, were tested using the Gait Real-Time Analysis Interactive Laboratory (GRAIL) system. Forward treadmill perturbations were applied to each limb during quiet standing, and joint angles, ground reaction forces, and torques were measured across baseline, perturbation, and response phases. As the data were non-normally distributed, paired comparisons were conducted using the Wilcoxon test, with significance set at p < 0.05 (Bonferroni corrected) and effect sizes (r) reported. Results: Joint angles remained symmetrical between limbs (no significant differences after correction). In contrast, kinetic measures showed clear asymmetries: at baseline, the dominant limb produced greater knee torque (p = 0.0003, r = 0.73), ankle torque (p = 0.0003, r = 0.76), and medio-lateral GRF (p = 0.0003, r = 0.87). During perturbation, it again generated higher knee (p = 0.0036, r = 0.43) and ankle torques (p = 0.0003, r = 0.53), with larger medio-lateral GRF (p = 0.0003, r = 0.87). In the response phase, the dominant limb showed greater hip torque (p = 0.0033, r = 0.43) and a small dorsiflexion shift at the ankle (p = 0.0066, r = 0.41). Anterior–posterior GRF changes were minor and non-significant after correction. Conclusions: Induced forward leg movements caused limb-specific kinetic adjustments while maintaining overall kinematic symmetry. The dominant leg contributed more actively to balance recovery, highlighting its role in stabilizing posture under small perturbations. These findings are specific to the studied demographic and should not be generalized to males, older adults, left-dominant individuals, or clinical populations without further research.

The response to perturbations in the gait of elderly and young individuals can differ due to various factors, such as age-related changes in sensorimotor function, muscle strength, and balance control. This study aimed to identify and compare compensatory kinematic and kinetic gait strategies in response to sudden treadmill perturbations applied during the Pre-Swing phase in young and older adults. The analysis focused on determining age-related differences in joint behavior and force production under perturbation stress, with implications for fall prevention. Twenty-one young and an equal number of elderly healthy females walked on a treadmill in a virtual environment (GRAIL, Motek). Unexpected perturbations were applied five times. Principal Component Analysis (PCA) and k-means clustering identified three distinct compensatory strategies per limb. Young adults primarily employed Strategies I (42.2%) and II (40%), while older adults most often selected Strategy II (45.5%). Statistical analysis (SPM and Mann-Whitney U test, p = 0.05) showed significant between-group differences in joint angles and torques across the gait cycle. For instance, in Strategy I, young participants had significantly lower ankle plantarflexion angles (p < 0.01) and hip extension torques (p < 0.05) compared to the elderly. Strategy II in older adults showed significantly higher vGRF minimums (p < 0.01) and anterior-posterior GRF peaks (p < 0.001). The elderly adopted strategies compatible with their neuromuscular capacity rather than those minimizing joint load, as observed in the young group. These findings offer novel insights into age-related compensatory mechanisms and highlight the importance of tailored fall-prevention strategies based on biomechanical response patterns.

Objectives: The aim of this study was to indicate which variables are the most important determinants of swimming results in the 50 m front crawl among non-elite pre-pubertal female swimmers. Methods: The study group consisted of 14 female swimmers (at the time of the research commencement—biological age: 10.52 ± 0.37 years; body mass: 34.99 ± 2.77 kg; height: 146.00 ± 3.05 cm). The study was conducted over three years. The swimmers performed capacity training recommended by the British Swimming Federation. Every 6 months, in the participants the following parameters were measured: percentage of body fat; anthropometric measurements; aerobic and anaerobic capacity; and respiratory parameters: vital capacity—VC, forced expiratory volume—FEV1, and forced vital capacity—FVC. Additionally, a 50 m front crawl swim test was performed. Results: After adjusting for multicollinearity, the most influential determinants of swimming performance were anthropometric measures: shoulder width was the most influential predictor, with a regression coefficient of −0.66, followed by foot length (with a beta of −0.15) and chest depth (with a beta of 0.008). The remaining anthropometric and physical predictors did not contribute to the prediction of 50 m freestyle performance. Conclusions: These research results suggest to coaches and trainers that sports performance in sprint distances in pre-pubertal girls is not determined by aerobic and anaerobic capacity or body fat but is based on the somatic build of the swimmer.

This study aimed to examine potential changes in the anthropometric and motor characteristics of volleyball players aged 17.98 ± 0.51 years after participation in a week-long sports camp. Potential changes in anthropometric characteristics were determined by bioelectrical impedance, and the players’ motor characteristics were assessed in a reaction time test, grip strength test, 5 × 20 s interval test on a rowing ergometer, and vertical, approach and standing long jump tests. A decrease was observed in body fat mass (difference (Δ) of 1.0 kg, p  = 0.015), percent body fat (Δ of 1.16%, p  = 0.008), and the waist-to-hip ratio (Δ of 0.02, p  = 0.001). An increase was noted in total body water (Δ of 1.0 L, p  = 0.002), proteins (Δ of 0.33 kg, p  = 0.001), minerals (Δ of 0.12 kg, p  = 0.003), fat-free mass (Δ of 1.46 kg, p  = 0.001), and skeletal muscle mass (Δ of 0.9 kg, p  = 0.001). In the group of motor abilities, a significant increase was observed only in the grip strength of the left hand. In conclusion, week-long sport camps can significantly affect the body composition characteristics of young volleyball players, but they do not induce significant changes in motor abilities.

Background: Upper limb functional performance depends on the interaction of strength, mobility, and neuromuscular control, while inter-limb asymmetries may increase injury risk. However, comprehensive analyses integrating these factors remain limited. This study aimed to evaluate sex differences and identify functional phenotypes in young adults using a multidimensional assessment approach. Methods: Forty-six healthy young adults (23 women, 23 men) underwent a comprehensive battery of upper limb assessments, including anthropometric measurements, maximal handgrip strength, isometric elbow flexion and extension torque, postural stability via the Fall Risk Index (FRI), and functional reach using the Upper Quarter Y-Balance Test (YBT-UQ). Inter-limb symmetry was calculated using the Limb Symmetry Index (LSI). K-means clustering was applied to standardized variables to identify latent functional phenotypes. Results: Men demonstrated significantly greater body mass, height, limb length, and absolute strength (p < 0.01), while functional performance (YBT-UQ composite scores) and inter-limb symmetry were similar between sexes. Strength asymmetry was most prevalent for elbow flexion and handgrip strength (up to 89%), whereas stability asymmetry was less frequent (≈54%). Three functional clusters were identified: Cluster 1—high strength and moderate stability, Cluster 2—lower anthropometry and strength, Cluster 3—high strength but reduced stability and increased asymmetry. Despite phenotypic differences, composite functional performance was comparable across clusters. Conclusions: Upper limb function reflects the interaction of morphological and neuromuscular factors rather than strength alone. Observed asymmetries should be interpreted within a functional context, as moderate asymmetries may represent normal variation in motor control, while larger asymmetries may indicate potential functional imbalance; however, due to the cross-sectional design of this study, no causal inferences regarding injury risk can be made. Functional phenotyping provides a framework for individualized training, screening, and rehabilitation strategies.

Anxiety could be felt even in objectively peaceful situations, but a vision of conflict could result in increased stress levels. In this article, we aimed to identify hidden patterns of mental conditions and create male profiles to illustrate the different subgroups as well as determinants of anxiety levels among them in accordance with proximity to a possibility of direct exposure to military action. A sample of Ukrainian males, in duty as conscripts to military service (n = 392, M±SD = 22.1±5.3) participated in a survey. We used the 36-Item Short Form Health Survey, and State-Trait Anxiety Inventory. In addition to psychological indices, social-demographic data were collected. To discover the number of clusters, the k-means algorithm was used, the optimal number of clusters was found by the elbow algorithm. For validation of the model and its use for further prediction, the random forest machine-learning algorithm, was used. By performing k-means cluster analyses, 3 subgroups were identified. High values of psychological indices dominated in Subgroup 2, while lowest values dominated in Subgroup 3. Subgroup 1 showed a more even distribution among the indices. The strength of the relevance and main determinants of the prediction of the presented model mostly consisted of mental qualities, while socio-demographic data were slightly significant. There is no clear relevance between proximity or even the experience of military actions and anxiety levels. Other factors, mostly subjective feelings about mental conditions, are crucial determinants of feeling anxiety.

This study examined kinetic differences between orthodox and southpaw boxing stances across four fundamental punches – jab, cross, lead hook, and rear hook – to determine whether stance orientation influences punching force and fist acceleration. Thirty trained male boxers (age: 29.2 ± 1.4 years; body mass: 86.4 ± 1.4 kg; height: 175.8 ± 7.9 cm; training experience: 6.0 ± 2.1 years) performed five maximal-force repetitions of each punch in both stances. Punching force was recorded using an AMTI MC12-2K force plate, and fist acceleration was measured with a Noraxon Ultium EMG inertial sensor. Data were analyzed using the Wilcoxon signed-rank and Kruskal–Wallis tests with effect size estimation (ε 2_H). Wilcoxon signed-rank tests revealed punch-specific differences between stances. The jab generated greater force in southpaw (median: 1387.8 N, IQR: 1205.9–1658.6) than in orthodox (1292.8 N, 1129.1–1581.7; p = 0.021). In contrast, the cross (orthodox: 1863.4 N, 1594.3–2307.7 vs southpaw: 1589.7 N, 1363.4–1941.0; p < 0.001) and rear hook (orthodox: 2198.8 N, 1888.2–2580.6 vs southpaw: 2007.5 N, 1680.5–2262.3; p < 0.001) produced greater forces in orthodox. Lead hook force showed no significant stance difference (p > 0.05). No significant stance differences were observed for fist acceleration in any technique. Across both stances, hook punches exhibited substantially higher forces and accelerations than straight punches. Boxing stance does not confer a universal biomechanical advantage but affects performance in a technique-specific way. Bilateral stance training may enhance technical versatility and better prepare athletes for opponents with different orientations.

Background: Movement symmetry in the lower limbs is critical for biomechanical efficiency, injury prevention, and athletic performance. Lateral (sideways) jumping challenges force production and control in the frontal plane and provide a unique assessment of neuromuscular coordination that may not be detected through sagittal-plane tasks such as running or vertical jumping. This study aimed to evaluate limb asymmetries in isometric knee muscle torque and ground reaction forces (GRFs) during lateral jumps in healthy young women, using the Symmetry Index (SI) to quantify differences between limbs. Methods: Twenty right-limb dominant females (mean age: 20.65 ± 4.51 years) participated in the study. Isometric torque of the knee flexors and extensors was measured using a dynamometric testing station. Lateral jumps were performed onto dual force platforms, with GRF components (vertical (PD), anterior–posterior (AP), mediolateral (ML)) recorded separately for rightward and leftward jumps. SI was calculated for all parameters to determine side-to-side asymmetries, and paired Student’s t-tests were used for statistical comparisons. Results: Right-limb dominance was evident in both knee flexor and extensor torque. Significant asymmetries were observed across all GRF components, varying with jump direction. The trailing limb in each jump direction typically generated greater propulsion forces. In lateral jumps, the trailing limb is generally the leg positioned opposite to the direction of travel, playing a primary role in generating propulsion and absorbing forces during take-off. SI values revealed both inter-individual variability and consistent direction-dependent asymmetry patterns. Conclusions: The or-posterior and vertical components, with greater loading on the dominant leg. Muscle torque measurements also revealed imbalances, with flexors showing more symmetry than extensors. These findings underline the importance of assessing load symmetry to prevent injury and guide rehabilitation.

Background: Diabetic foot ulcers (DFUs) affect millions worldwide, significantly increasing the risk of amputation, mortality, and reduced quality of life. While conventional interventions such as specialized footwear and podiatric care can mitigate ulceration risks, they do not address the biomechanical factors contributing to ulcer recurrence. Emerging evidence suggests that lower limb exercises may play a role in secondary DFU prevention. This scoping review aims to synthesize available research on home-based lower limb exercise programs for individuals with diabetes mellitus, focusing on feasibility, adherence, and their impact on foot biomechanics and ulcer prevention. Methods: A search was conducted across six electronic databases (PubMed, Web of Science, Cochrane Library, EBSCO, Scopus, and ScienceDirect) for studies published between January 2014 and December 2024. Eligible studies included those assessing home-based lower limb exercises in diabetic individuals, with interventions lasting at least four weeks. Studies focusing on supervised exercises, pharmacological interventions, or non-diabetic populations were excluded. Results: Nine studies met the inclusion criteria, featuring a range of home-based exercise interventions, such as muscle strengthening, stretching routines, proprioceptive training, functional mobility exercises, and range-of-motion activities. These interventions demonstrated notable effectiveness, leading to improved foot biomechanics, more even plantar pressure distribution, enhanced balance, and reduced ulcer recurrence (in some cases). One study, for instance, reported a significant decrease in ulcer recurrence, with only 16% of participants in the intervention group experiencing relapse compared to 72% in the control group after 24 weeks. Adherence rates varied across studies but were generally higher when programs included structured guidance through educational booklets, mobile applications, or consistent phone follow-ups ranging from 41% to 92.5%. Nonetheless, the findings tend to be tempered by methodological differences between studies and a lack of robust long-term follow-up data. Conclusions: Home-based lower limb exercises show promise in improving foot function and preventing DFU recurrence. Further research is needed to standardize protocols, enhance adherence, and confirm long-term effectiveness.