Anna Akbaş

Akbaş, A, Hadyk, V, Bryk, P, Mazzei, S, Stanula, A, and Juras, G. Large-scale evaluation of performance and biological maturation in post-PHV youth soccer players: Sprinting, jumping, aerobic fitness, and functional movement. J Strength Cond Res XX(X): 000–000, 2026—This study aimed to provide an integrated developmental profile of adolescent soccer players by examining how chronological age, biological maturation, and functional movement quality interact to shape sprint, jump, and aerobic fitness performance. A total of 246 male athletes (U15–U17) from 5 elite youth soccer academies completed sprint, jump, change-of-direction (COD), and aerobic tests alongside Functional Movement Screen (FMS) and Y-Balance Test (YBT) assessments. Maturity offset (years from peak height velocity, PHV) was used to estimate biological age, and group differences were analyzed using analysis of variance and analysis of covariance, with statistical significance set at p ≤ 0.05. Significant improvements with age were observed in sprinting, jumping, and aerobic fitness ( p < 0.001); however, after controlling for PHV, differences in jumping and COD performance were no longer significant, whereas sprint performance and aerobic fitness remained age-dependent. Functional movement and balance showed small age-related differences that were largely explained by maturational variation. Weak and inconsistent correlations between FMS, YBT, and performance (|r| ≈ 0.20–0.35) suggested partial independence between movement quality and motor output. Notably, in older players, higher scores in mobility-related FMS components were associated with slower sprinting, a pattern that may reflect—rather than cause—reduced mechanical efficiency associated with greater flexibility. These findings indicate that post-PHV players are not a homogeneous group and support the use of maturity-informed, multidimensional athlete monitoring to guide individualized training even after PHV.

Although manual asymmetries are well known, their role in coordinated reach-to-grasp actions remains unclear. We show that interlimb differences are minimal under stable conditions but emerge selectively during mechanical perturbations. The dominant hand exhibits greater distal reorganization, whereas the nondominant hand shows stronger proximal deceleration and triceps activation. These findings suggest that motor lateralization is context-dependent and expressed through distinct responses to mechanical uncertainty.

Hand dominance influences motor control, yet the nature of asymmetries in reach-to-grasp coordination remains unclear. We used an immersive, haptic-free virtual environment to examine how hand dominance, object size, and distance shape kinematics and muscle activity during reach-to-grasp actions. Twelve right-handed participants performed unilateral movements with both hands toward virtual objects varying in size and distance. Kinematic and electromyographic data were collected from transport- and grasp-related muscles. A 2 (Hand: dominant, non-dominant) × 3 (Distance: near, middle, far) × 3 (Size: small, medium, large) repeated-measures ANOVA evaluated effects on movement parameters. Transport with the non-dominant hand showed higher peak velocities and accelerations and greater variability in 3-D position compared with the dominant hand. These differences were accompanied by increased triceps brachii activation during late transport, likely reflecting compensatory deceleration and stabilization before grasp. In contrast, grasp kinematics and grasp-related electromyographic activity did not differ significantly between hands. Task parameters modulated both transport and grasp, but object distance more strongly influenced transport, whereas object size more consistently affected grasp. Reach-to-grasp coordination in virtual reality revealed functional specialization between the hands, with asymmetries evident in transport but not grasp. These findings support models proposing a proximal–distal division of motor function between limbs. The results also demonstrate the utility of haptic-free VR as a methodological tool for investigating and potentially training limb-specific motor strategies in healthy individuals.

Background: Grip control is a critical determinant of fencing performance, requiring both stability and precision. Traditional measures of hand strength, such as dynamometry, provide only a global estimate and cannot capture finger-specific load distribution. Yet, upper-extremity overuse syndromes, tendinopathies of the wrist and digital flexors are common in fencers, underscoring the need for more granular assessments that may inform clinical practice, especially in prehension contexts. Methods: This pilot study included eight elite épée fencers from the Polish National Team (age: 23.9 ± 4.9 years; training experience: >10 years) tested using a novel épée handle instrumented with five force-sensitive resistors (FSRs) embedded beneath each finger. Participants performed two 5-s maximal voluntary contractions (MVCs) for each of the three conditions—Pinch (thumb + index), Trio (middle + ring + small), and Whole (all digits). Standard handheld dynamometry was also performed to provide a global reference measure. Results: Maximal grip strength measured with a dynamometer (65.3 ± 11.7 kgf) was substantially higher than finger-specific forces captured with the FSR handle (14.4 ± 4.4 kgf). Isolated Pinch contractions (83.0 ± 29.2 N) were significantly stronger than their integrated contribution within the Whole-hand condition (54.7 ± 16.3 N; Z = 2.52, p = 0.012), whereas Trio forces did not differ significantly (p = 0.263). On average, radial digits (thumb + index) contributed ~39% and ulnar digits (middle, ring, small) ~61% of Whole output, with the thumb and middle finger producing the largest forces. Conclusions: This pilot study demonstrates the feasibility of using an FSR-instrumented épée handle to capture finger-specific grip contributions in elite fencers. Despite limited statistical power (n = 8), the observed effects provide initial quantitative evidence for sport-specific, digit-level assessment, showing potential clinical utility in detecting maladaptive load-transfer mechanisms and informing rehabilitation and injury-prevention programs.

Background: Hand function is critical for daily living, occupational performance, and sports. Optimal training approaches for healthy adults remain unclear. Objective: To evaluate the effects of hand-focused strength and proprioceptive training on grip strength, pinch strength, manual dexterity, maximum voluntary contraction, joint position sense, and force sense in healthy younger and older adults. Methods: PubMed, Google Scholar, Semantic Scholar, Web of Science, Cochrane CENTRAL and registers were searched until July 2025 for randomized controlled trials (RCTs) involving adults (≥18 years) without upper limb dysfunction. Studies with clinical populations, single-session interventions, or lacking pre–post outcome data were excluded. Risk of bias was assessed using the Cochrane RoB 2 tool. Random-effects meta-analyses (Hedges’ g) pooled pre–post change score differences for each outcome; subgroup analyses examined age, training type, and comparator. Results: Twenty-two RCTs (n = 1017 participants; 19–78 years) met the inclusion criteria. Strength and proprioceptive training produced a small-to-moderate improvement in grip strength (g = 0.44, 95% CI [0.23–0.64], 95%PI [–0.09, 0.96]) and a large improvement in manual dexterity (g = 1.11, 95% CI [0.52–1.71], 95%PI [–0.01, 2.23]). Effects on pinch strength were positive but non-significant (g = 0.63, 95% CI [–0.09–1.35], 95%PI [–1.38, 2.63]) and showed substantial heterogeneity. Moderator analyses indicated greater effects in older adults (g = 0.97) compared to younger adults (g = 0.18). Strength-only protocols showed significant effects, while combined protocols yielded smaller, non-significant effects; however, the difference between them was not statistically significant. Effects were also larger when compared with passive controls than with untrained hands. Limitations: Evidence quality was limited by high risk of bias, measurement variability, and small study numbers for some outcomes. Conclusions: Strength-focused hand training, particularly in older adults, yields meaningful improvements in grip strength and dexterity. Further high-quality RCTs are needed for under-studied outcomes.

Background: This study aimed to examine differences in muscle activity and activation timing in wheelchair fencers across disability categories A and B to better understand the neuromuscular dynamics involved in their performance. Methods: Sixteen right-handed wheelchair fencers from the Polish National Paralympic Team, grouped into categories A and B, participated in the study. Muscle activity and activation timing (reaction time) were recorded during a visual-cue task using a surface electromyography system and a 3D accelerometer. Eight upper body muscles, including the deltoid, triceps, biceps, forearm extensors/flexors, latissimus dorsi, and obliques, were assessed. Data were processed using MyoResearch and MATLAB, and statistical analyses utilized the Wald-Wolfowitz runs test. Results: Intergroup differences in reaction time and muscle activity were found: category A fencers tended to achieve lower reaction times and higher muscle bioelectric tension values than category B fencers. Significant differences between the groups were found in the activity of the left latissimus dorsi and the deltoid muscles (p < 0.05). Conclusions: The study indicates the important role of the back and abdominal muscles as stabilizing postural muscles in wheelchair fencing. The significant differences in muscle activity for the back and deltoid muscles suggest distinct neuromuscular profiles between disability categories A and B. These findings could enhance classification accuracy and inform training strategies for para-athletes, optimizing performance and targeting specific muscle groups for improvement.

Introduction: This study investigated the influence of sociodemographic factors on the dietary habits of athletes of the Polish Biathlon Association. Focusing on age, education, employment status, and gender, this research assesses food choices, meal preparation, and nutritional awareness within a structured sports environment. A cross-sectional survey of 54 athletes was conducted using a modified “Eating Habits of Poles” questionnaire to explore food selection, preparation methods, consumption patterns, and nutritional perspectives. This focus on biathletes emphasizes their distinct dietary needs, which arise from the demanding combination of endurance and precision in their sport, providing valuable insights for tailored dietary strategies to enhance their performance and overall health. Results: The results indicate that age, education, and employment status significantly influence Polish biathletes’ dietary habits and nutritional awareness. Older athletes (under 23 years) demonstrated significantly higher nutritional awareness regarding modern dietary trends (p = 0.015). In contrast, 50% of higher-education athletes were more engaged in meal planning and healthier food choices than those with elementary education (p = 0.031). Employment status also played a role; 70% of the athletes were students who exhibited more convenience-based food choices, whereas 30% were employed and maintained more structured eating patterns (p = 0.008). Minimal gender differences were found, with 50% of male and 50% of female athletes showing similar dietary habits, likely due to standardized nutrition programs provided to all athletes. Conclusions: This indicates a potential need for further research to determine whether professional dietary support can effectively address typical gender-related variations in food behavior and lead to improvements in dietary outcomes. This study highlights the importance of targeted nutrition education and professional support for optimizing the nutritional habits of professional athletes. This emphasizes that socio-demographic factors such as age, education, and employment status significantly shape these behaviors, underscoring the need for personalized nutritional strategies within athletic programs.

Introduction: The purpose of this study was to investigate whether the anticipation of a mechanical perturbation applied to the arm during a reach-to-grasp movement elicits anticipatory adjustments in the reach and grasp components. Additionally, we aimed to evaluate whether anticipatory adjustments in the upper limb might be global or specific to the direction of the perturbation.Methods: Thirteen healthy participants performed reach-to-grasp with perturbations randomly applied to their dominant limb. Participants were presented with three types of trials: unperturbed (control), trials perturbed in a predictable manner (either Up or Down), or perturbed in a partially predictable manner (knowledge about the perturbation but not its specific direction). EMG activity of 16 muscles, as well as the kinematics of wrist, thumb, and index finger, were acquired and analyzed.Results and discussion: When the perturbation was expected, EMG activity of the triceps and pectoralis major muscles significantly increased about 50 – 200 ms before the perturbation onset. Peak acceleration of the reach was significantly higher and occurred earlier relative to control trials. Similar adjustments were observed in the grasp kinematics, reflected as significantly shorter time to peak aperture velocity and acceleration, as well as in increased activity of flexor and extensor digitorum 100–200 ms before perturbation onset. In summary, our data demonstrate that knowledge of an upcoming perturbation of reach during reach-to-grasp action triggers anticipatory adjustments not only in the muscles controlling the reach component, but also in those controlling grasp. Furthermore, our data revealed that the preparatory activations were generalized, rather than direction specific.

INPLASY202450053 Outcomes of Clinical Scores and Magnetic Resonance Imaging After Microfracture Treatment With and Without Scaffold Augmentation for Focal Chondral Lesions in the Knee: A Systematic…