Sports Biomechanics最新文献

Eccentric finger movements have been identified as risk factor in the injury mechanism of pulley ruptures during climbing. So far, they have mainly been associated with inadvertent events. Whether eccentric movements also occur as regular motion patterns was not assessed. Main purpose of this study was to examine eccentric finger movements during typical climbing tasks. Therefore, kinematics and interaction force of eleven elite climbers was recorded during a sequence of four climbing moves. Participants were instructed to use crimp, half-crimp, open-hand grip and campusing. Change of flexion angle in the proximal interphalangeal (PIP) joints from the start to the end of the holding phase (ΔPIP_P2) was calculated. Mean ΔPIP_P2 was -1.5° (SD 6.6°), 0.2° (5.1°), -2.9° (3.4°) and -6.0° (9.6°) for the open-hand, half-crimp, crimp and campusing task, respectively, whereby negative values represent eccentric movements. Eccentric finger joint movements (ΔPIP_P2 < 0°) during the holding phase were very common (59-73%) across all grip types. The loading rate was highest during campusing and lowest using the crimp grip. Climbers exhibit eccentric finger movements not only during accidental slips or when fatigued, but also as consistent patterns. Further research is needed to assess whether these differences are associated with an individual's risk of pulley injury.

This article aimed to perform a meta-analysis and systematic review on the effect of dual-task landing on potential ACL loading. Repeated measures assessments of landings with concurrent, unrelated cognitive tasks were included. Databases were searched (SPORTDiscus, ScienceDirect and PubMed, searched June 2023). Results were synthesised and presented using custom R code. Twenty-five articles were included, 12 eligible for the meta-analysis, involving single or double-leg landings alongside various cognitive tasks. Funnel plots, regression testing and selection modelling detected no publication bias. The systematic review identified most authors concluded dual-task landing potentially increased ACL loading, due to small, inconsistent, biomechanical impacts on the trunk and lower extremity consistent with potentially increased ACL loading. However, robust variance estimation showed no significant effect (g = -0.001, 95% CI [-0.093, 0.09], p = 0.97) on frontal or transverse plane knee loading, only identifying a small decrease in IC knee flexion angles (g = -0.13, p = 0.03). Diverse research methodologies make summarising this research area difficult. While dual-task landings can evoke mechanical changes associated with potentially increased ACL loading, this increased loading is not consistently seen. Further research with consistent methodologies is required to clarify this. This paper was registered (PROSPERO: CRD42023425191).

Alterations in foot position, such as heel elevation, can alter squat multi-joint kinematics, though a definitive dose-response meta-analysis is unavailable. This systematic review and meta-analysis investigated the effect of heel elevation magnitude on sagittal-plane range of motion (ROM) during squatting. Databases were searched until September 2025. Fourteen studies (n = 177 participants) were included. Random-effects meta-analysis revealed that heel elevation significantly increased ankle (Hedges' g = 0.370, p = 0.020, mean difference (MD) = 4.33°) and knee ROM (Hedges' g = 0.288, p < 0.001, MD = 4.94°), but not hip or trunk ROM. Subgroup analysis revealed a dose-response effect at the ankle, with significant increases only at high heel elevations (>2.5 cm or >5°; MD = 5.09°). Knee ROM increased with both low and high elevations (MD = 3.39° and 6.65°, respectively). Meta-regression suggested greater heel height was associated with reduced hip (β = -0.028, p = 0.030) and trunk ROM (β = -0.067, p = 0.018). The findings elucidate kinematic adaptations to heel elevation, highlighting a proximal-to-distal gradient in joint responsiveness. This evidence can inform the prescription of heel elevations in biomechanical applications to modify loading patterns during rehabilitation and training.

This study aimed to identify differences in upper-limb coordination by integrating vector coding with joint kinetics across three round-off (RO) techniques to better explain potential injury mechanisms. Twelve female gymnasts performed six trials of each RO technique (Parallel, Reverse, T-shape). The kinematic and kinetic data were collected. All analyses focused on the contact phase of the second hand. Elbow and Wrist joint flexion/extension (E_F/E-W_F/E) and rotation (E_ROT-W_ROT) couplings were assessed using modified vector coding to determine coupling angle (CA) and variability (CAV). Elbow joint adduction/abduction moments (M_elbow) and joint power (JP_elbow) were calculated using inverse dynamics. Joint kinetics and CA were overlaid on the same plots to visualise how kinetic patterns corresponded with coordination dynamics. Results showed decreased M_elbow using the T-shape technique (p < 0.001) with E_ROT-W_ROT in-phase, while Reverse and Parallel techniques exhibited anti-phase with increased M_elbow (p < 0.001) and lower CAV using Reverse technique. Furthermore, E_F/E-W_F/E coupling revealed technique-specific control strategies; notably, the T-shape technique exhibited a different transition from anti-phase to in-phase motion, indicating a potentially more effective transfer from JP_elbow absorption to generation. The result provides new insights into the underlying mechanism of these differences through integration of coordination analysis with traditional biomechanics.

To assess the biomechanical differences between Randall foils and Big blades in rowing sprints, 12 experienced rowers (10 males) with 25.9 ± 8.7 vs. 24.5 ± 9.2 y, 179.8 ± 4.3 vs. 175.0 ± 2.8 cm of height, 74.2 ± 4.8 vs. 65.5 ± 6.2 kg of body mass and 23.0 ± 1.4 vs. 26.6 ± 1.4 kg/m² of body mass index (for males and females) performed two randomised maximal-intensity 500 m bouts using Randall foils and Big blades. Biomechanical variables were recorded using GPS and IMU-based systems. Randall foils presented lower race time (108.3 ± 5.10 vs. 109.90 ± 4.93 s, p = 0.04), higher mean velocity (4.62 ± 0.20 vs. 4.55 ± 0.19 m/s, p = 0.03) and velocity coefficient of variation (11.38 ± 5.10 vs. 10.14 ± 3.68, p = 0.01). Velocity-time profiles showed higher velocity with Big blades from ~62-68% and ~82-98% of the cycle, particularly at the start (10-30%, 60-72% and 80-92%) and finish (20-25% and 60-65%). Overall, Randall foils provided a consistent advantage that may be decisive in races where outcomes are decided by fractions of a second.

The development of wearable technology in swimming has enabled easier collection of greatly detailed stroke metrics across researchers and practitioners alike. In particular, the use of pressure sensors on swimmers' palms allows for a nuanced analysis of the stroke cycle previously only available via time-intensive video analysis. This study aimed to evaluate whether triaxial force magnitudes recorded via wearable sensors could predict sprint swimming performance. Twenty-five NCAA Division I swimmers (13 female, 12 male; age 20.5 ± 1.6 years) participated in three maximal-effort 50-metre front crawl swims. Force data were summarised into three directional magnitudes-propulsive, vertical, and lateral. Multiple regression analysis indicated that greater propulsive (p = 0.03) and downward (p = 0.01) force on the left hand were significantly associated with faster swim times (R² = 0.38, p < 0.01), whereas right-hand forces were not significant predictors of performance (p = 0.05). These findings suggest that swimmers and coaches may benefit from emphasising propulsive and downward force production during sprint front crawl. Further research is needed to understand how the asymmetries between hands, particularly relating to hand dominance and breathing preference, affect propulsion.

The purpose of this study was to use a bivariate functional principal component analysis (bfPCA) to quantify hip-knee joint movement patterns and assess their relationship with power clean performance. Thirty strength-power athletes completed a one repetition maximum (1RM) power clean test where hip and knee joint angle data from the heaviest successful lift were recorded and analysed using bfPCA. Three principal components were extracted, primarily reflecting variability in hip joint angle throughout the pull (pattern 1), knee joint angle at the starting position (pattern 2), hip-knee joint motion from the middle of the first pull through to the end of the second pull (pattern 3). Correlation analyses revealed no significant or meaningful correlations between power clean performance and patterns 1 or 2 (r = -0.10 and 0.04, p = 0.60 and 0.85, respectively), suggesting that inter-individual differences in starting position may not negatively impact power clean performance. However, pattern 3 was weakly but significantly correlated with power clean performance (r = 0.39, p = 0.03), with higher-performing lifters displaying movement patterns characterised by a more upright torso at the power position and a more controlled, prolonged first pull. These findings suggest that coaches focus on these aspects of the movement to potentially maximise power clean performance.

The objective was to examine how phase-specific abdominal antagonist co-activation (CoA) influences trunk rotational kinematics in skilled golfers. Thirty male amateurs (19.7 ± 0.7 years; handicap 9.6 ± 2.4) performed 6 iron swings with synchronised motion capture and surface electromyography of the external obliques (EO). Pearson correlations and linear regression were applied. CoA showed distinct phase-dependent effects. During take-away, higher CoA correlated with greater peak pelvic velocity (r = 0.460; r² = 0.21), indicating stabilising function. Early downswing CoA was negatively associated with X-factor at impact (r = -0.516; r² = 0.26) and peak pelvic velocity (r = -0.540; r² = 0.29), suggesting that reduced CoA facilitates proximal acceleration and elastic energy transfer. During downswing acceleration, CoA positively predicted peak thoracic velocity (r = 0.397; r² = 0.15) and thoracic deceleration (r = 0.450; r² = 0.20), reflecting a dual role in energy transfer and active braking. Early follow-through CoA was positively associated with thoracic deceleration (r = 0.440; r² = 0.19), supporting post-impact trunk control. These findings suggest that skilled golfers modulate EO CoA across swing phases to balance stability, energy transfer and controlled segmental deceleration, highlighting the functional significance of abdominal CoA for swing performance and injury prevention.

The aim of this study was to assess the influence of lower limb muscle activity and postural stabilisation during landings after various motor tasks. Seventeen gymnasts (aged 13.7 ± 2.0 years) performed landings after four tasks: drop landing, forward somersault, backward somersault, backward acrobatic series. Postural stabilisation during landing was assessed using an inertial sensor placed on the lumbar spine, from which data was used to determine the dynamic stability index and time to stabilisation. Muscle activity was assessed using surface electromyography in six lower limb muscles. The results showed that the muscle activity of the lower limbs differs according to the difficulty and direction of the motor task preceding the landing. The activity of the knee flexors and plantar flexors during landing after forward and backward motor tasks proved to be more beneficial for improving postural stabilisation. The study shows the importance of balanced muscle activation of the hip, knee and ankle flexors and extensors during landing, especially for injury prevention and effective execution of difficult gymnastic landings.

Repetitive head impact exposure in contact sports such as ice hockey has been shown to modify motor performance which could impact the control of head movement and result in perceptual deficits. However, how such exposure influences the coordination dynamics underlying head stability control, and thus visual perception, is not well understood. The purpose of this study was to assess whether contact sport participation affects coordination variability and stability during locomotion as a function of different levels of visual task constraints. Ice hockey (contact) and baseball (noncontact) athletes completed treadmill walking tasks with varying levels of visual task constraints. Head and trunk local dynamic stability and whole-body coordination variability were assessed at preferred and fast speeds with and without a dynamic visual acuity task. While no group differences in dynamic visual acuity were present, contact athletes displayed reduced vertical head local dynamic stability compared to non-contact athletes while walking at a fast speed without the visual task. Contact athletes also displayed lower whole-body coordination variability compared to noncontact athletes. These findings suggest that contact sport participation may lead to changes in head stability control and lower levels of coordination variability, suggestive of reductions in movement flexibility and adaptability.