Acta of Bioengineering and Biomechanics Feed

Effects of 10k distance running on lower limb biomechanics and plantar pressure distribution

Wed, 28 Oct 2026 00:00:00 GMT

PurposeTo investigate the time-series changes in lower limb joint kinematics, kinetics, and plantar pressure pre-10 km and post-10 km running, and report the biomechanical changes in the lower limb following long-distance running and provide a theoretical basis for injury prevention.MethodsTwenty healthy male recreational runners completed a 10 km treadmill run at a speed of 12 km/h. Lower limb kinematics, kinetics, and plantar pressure were collected pre-10 km and post-10 km running using Vicon motion capture system, Kistler force platform, and Footscan pressure plate. Paired t-tests were used to analyze changes in joint range of motion (ROM) and moments, and Statistical Parametric Mapping (SPM1d) was applied to examine the time-series differences.ResultsFollowing a 10k run, the multi-dimensional biomechanical alterations were observed. Bilateral hip and knee adduction-abduction ROM increased significantly, while left hip internal-external rotation ROM decreased. Right hip extension, abduction, and internal rotation moments increased; and the left hip extension moment increased, but abduction and internal rotation moments decreased. Right knee flexion moment decreased and abduction moment increased, while left knee abduction moment increased. Right ankle plantarflexion moment increased significantly. Plantar loadings showed increased total pressure during early stance, elevated medial heel pressure, and reduced pressure in the first metatarsal and other toe regions.ConclusionA 10k distance run led to significant alterations in lower limb joint control, moment distribution, and plantar pressure patterns. These changes may be associated with increased injury risks, highlighting the importance of addressing biomechanical adaptations under fatigue conditions during training session and injury prevention strategies.

Design and analysis of rehabilitation training mechanism based on upper limb rehabilitation movements

Wed, 28 Oct 2026 00:00:00 GMT

PurposeTo conduct a comparative analysis of the trajectory and joint torque differences between exoskeleton type and end–effector type upper limb rehabilitation training mechanisms during rehabilitation movements, and to identify the more suitable mechanism type for passive upper limb rehabilitation training.MethodsBased on the Brunnstrom rehabilitation approach, upper limb rehabilitation movements for the passive training phase were selected. Muscle force simulations were conducted using OpenSim software to identify movements with high muscular engagement. The structures of the two mechanisms were designed through degree–of–freedom analysis, and motion trajectory simulations were completed in Automatic Dynamic Analysis of Mechanical Systems (ADAMS). In MATLAB, discrete Fréchet distance is used to evaluate trajectory similarity. The error of comparing simultaneously the trajectories of two mechanisms with the trajectory of the human body model using R 2 was calculated. In ADAMS, the rotational torque changes of the shoulder, elbow, and wrist joints between two mechanisms were compared.ResultsThe movement trajectory of the exoskeleton mechanism closely matched the natural motion of the human upper limb, with error ≤2 mm and trajectory R 2 ≥ 0.9975. Its joint torque distribution was balanced, with a maximum torque ≤40 Nm. The trajectory error of the end–effector mechanism was ≤5 mm and trajectory R 2 ≥ 0.9910 and torques were concentrated at the wrist and elbow joints, some values being ≥40 Nm.ConclusionThe exoskeleton–type upper limb rehabilitation training mechanism demonstrates superior performance in terms of movement trajectory adaptability and joint protection compared to the end–effector–type mechanism, making it more suitable for passive movement assistance and joint range of motion recovery training.

Algorithmic determination of femoral neck axis in Birmingham hip resurfacing: A parametric CAD-based method

Wed, 28 Oct 2026 00:00:00 GMT

PurposeBirmingham hip resurfacing requires precise determination of the femoral head-neck axis to minimize risks of neck fracture, cortical notching, and component malposition. Existing methods rely on intraoperative estimation, generic guides, or semi-manual planning, all susceptible to anatomical variability. This study presents an automated parametric algorithm for determining the femoral neck axis from computed tomography (CT)-derived models to support patient-specific surgical planning.MethodsThe method utilizes segmented CT data converted to Standard for the Exchange of Product model data format. Following artifact removal, the algorithm performs iterative cross-sectional analysis along the neck axis, identifying characteristic anatomical points: the neck isthmus, head centroid, and head apex. The axis is approximated from these points and refined through rotational optimization in 5 degree and 0.5 degree increments. The algorithm was evaluated on 4 femoral models in 5 spatial orientations each (20 test cases).ResultsThe algorithm achieved a mean validation score of 4.1/5.0 (82%). Three models with high-quality meshes scored 4–5, while one model with extensive artifacts scored 1–2, confirming sensitivity to input data quality. Repeatability was plus/minus 0.5 degrees in angular orientation and plus/minus 0.2 mm in isthmus position. Error propagation analysis indicated that CT-induced uncertainty (approximately 1.6 degrees upper bound) constitutes the limiting factor, not algorithmic precision. Physical prototyping confirmed viability for patient-specific instrument design.ConclusionThe method provides reproducible, automated femoral neck axis determination with plus/minus 0.5 degrees repeatability – approximately three times smaller than CT-induced uncertainty and an order of magnitude below the 5–7 degree errors of conventional jigs. Future work should validate the method against clinical outcomes in larger cohorts.

Influence of the allocation and force of distraction springs on the head shape of a child with sagittal craniosynostosis

Tue, 27 Oct 2026 00:00:00 GMT

PurposeThis study presents the application of numerical methods, for preoperative planning and determining the force and placement of distraction springs, as well as the cranial incision sites, in a newborn with a congenital disability involving cranial suture fusion.MethodsThis study employs a multifaceted methodology based on the work of an interdisciplinary team. The procedure involves: (1) patient-specific finite element method numerical analysis to simulate varying distraction spring forces and allocations, (2) non-invasive 3D optical surface scanning for the precise analysis of post-operative anatomical changes, and (3) clinical verification of the numerical predictions.ResultsNumerical studies were verified against clinical trials, resulting in substantial changes in the head shape of a 4-month-old child, an expansion of the external cranial vault, and a measurable improvement in the cephalic index and overall skull geometry.ConclusionBased on this single-patient numerical case study, it is hypothesized that the design of craniosynostosis treatment planning can be configured to introduce personalized force into critical areas. The proposed alternative spring allocation suggests potential biomechanical advantages, including stress reduction and improved shape optimization. However, these findings serve as a proof-of-concept and require validation in larger clinical trials. Achieving a clinical effect that is sustained over time by reducing stress values can also be significant, because the bone remodeling process can be designed so that bones multiply along the direction of principal stresses, thereby allowing for the optimization of the skull shape envisioned by the neurosurgeon.

Effect of a water rescue course on lower limb power parameters and functional performance in the aquatic environment in women

Sat, 17 Oct 2026 00:00:00 GMT

PurposeThe aim of this study was to assess the effect of completing a water rescue course on lower limb power parameters assessed using the countermovement jump (CMJ) test and on performance on task-based tests in the water.MethodsNineteen female lifeguard candidates (aged 18.68 ± 5.89 years) participated in the study. A repeated measures design was used, with assessments conducted before (PRE) and after course completion (POST). The following CMJ variables were analyzed: jump height, push-off force, landing force, maximum concentric power, maximum speed, and take-off velocity. Functional performance in the water was assessed using tests in the 50 m, freestyle, front crawl, breaststroke, and backstroke.ResultsAfter completing the course, significant improvements were observed in selected CMJ parameters, including jump height (+8.47%; p = 0.008), rebound force (+23.42%; p = 0.006), maximum concentric power (+8.72%; p = 0.047), maximum velocity (+2.81%; p = 0.017), and rebound speed (+3.77%; p = 0.022). In the water rescue trials, significant reductions in completion times were observed for the front crawl (−4.23%; p = 0.013), 50 m kick (−5.48%; p < 0.001), two-hand pull (−7.30%; p = 0.004), one-handed chin pull (−5.40%; p < 0.001), and chest pull (−3.89%; p = 0.006).ConclusionsParticipation in a water rescue course significantly improves both lower limb strength and functional performance in the water. However, transfer of lower limb strength from land-based tasks to rescue tasks is moderate, and performance in the water depends more on specific functional adaptations and task-specific skills than on limb strength.

Design and assessment of the feasibility of a diagnostic and rehabilitation device for gait re-education

Fri, 16 Oct 2026 00:00:00 GMT

PurposeGait after a stroke is characterized by a number of abnormalities, such as reduced walking speed, impaired stability, as well as asymmetry. This study presents a novel assistive device designed to aid gait training in stroke survivors by providing integrated visual, auditory, and tactile stimuli informing about lower limb weight-bearing and step length symmetry.MethodsNine patients with hemiparesis at an early stage post-stroke were included in the study. A markerless 3D system was applied to assess gait. Participants walked at self-selected pace and were wearing their own orthotic devices. Gait speed, step length, gait phase duration, and cadence were measured. A symmetry index was calculated for step length and lower limb weight-bearing. The program consisted of ten gait training sessions with the assistive device, each session taking 30 min.ResultsImproved gait parameters were observed when acoustic and visual prompting was applied alone or in combination with tactile prompting. At the end of the program, decrease in step length asymmetry was observed and there was no statistically significant difference in the mean step length between the paretic and non-paretic lower limb (p = 0.002). An improvement was shown in the distribution of lower limb weight-bearing in a standing position, and the mean value of limb weight-bearing symmetry index was significantly lower compared to the baseline (p = 0.0001).ConclusionIntegrated tactile, auditory, and visual prompting may beneficially affect post-stroke gait rehabilitation, by inducing improvements in gait pattern, symmetry, body balance, and walking speed.

Kinematic adaptations of the uppercut punch following an eight-week biomechanics-based training intervention in amateur boxers

Fri, 16 Oct 2026 00:00:00 GMT

Background and study aimThe uppercut is a complex close-range punching technique that relies on efficient proximal-to-distal sequencing and coordinated kinetic chain function. In amateur boxers, insufficient joint angular velocity may compromise strike effectiveness and mechanical efficiency. The aim of this study was to examine the kinematic adaptations following an 8-week biomechanics-based training intervention during execution of the right-hand uppercut.Material and methodsTwenty-four male amateur boxers (21.25 ± 3.12 years) with 3–4 years of training experience were randomly allocated to an experimental group (EG, n = 12) and a control group (CG, n = 12). The EG completed a structured 8-week (24-session) training program targeting joint-specific angular velocity and intersegmental coordination, while the CG maintained regular training. Three-dimensional motion capture was used to quantify maximal angular velocity of the shoulder, elbow, pelvis, hip, knee, and ankle joints before and after the intervention. Intervention effects were analyzed using a two-way mixed-design ANOVA (Group × Time), followed by paired and independent Student’s t-tests with Holm–Bonferroni correction; effect sizes were calculated using Cohen’s d (p < 0.05).ResultsPost-intervention analysis revealed significant increases in maximal angular velocity across upper and lower body segments in the EG (p < 0.05–0.01), with moderate-to-large effect sizes (d = 0.62–1.42). These kinematic improvements were accompanied by enhanced punch force and accuracy, whereas no significant changes were observed in the CG.ConclusionsAn 8-week biomechanics-based training program effectively enhances joint angular velocity and kinetic chain efficiency during uppercut execution in amateur boxers. Incorporating coordination-oriented, joint-specific velocity training into combat sport conditioning programs may substantially improve strike performance.

Biomechanical assessment of repetitive brain injury in pedestrian collisions based on wavelet packet energy analysis

Fri, 16 Oct 2026 00:00:00 GMT

PurposeExisting brain injury criteria mainly focus on assessing injuries in a single collision and lack of assessment of injuries in real-world multiple collisions.MethodsBased on the head kinematics signals of rats in repeated collisions and pedestrian accident data, the frequency domain characteristics of linear and rotational motion signals were analyzed by wavelet packet transform. Finally, the ROC curve was used to evaluate the effectiveness of injury index prediction.ResultsThe results of animal experiments show that as the impact intensity increases, the energy in the frequency domain during the rotational motion increases accordingly. In linear motion, there is a threshold of impact strength. The prediction results show that the prediction effect of metrics based on frequency domain features is better than that of traditional brain injury criteria.ConclusionsThe new metrics based on wavelet packet energy accumulation can better predict the injury in multiple head impact scenarios in pedestrian collisions. When combined with the acceleration response signal's amplitude-frequency accumulation characteristics, they can be used as a potential method to assess repetitive head injury.

Multi-dataset benchmarking and preliminary transfer learning for lower-limb EMG classification toward adaptive prosthesis control

Fri, 16 Oct 2026 00:00:00 GMT

PurposeReliable decoding of lower-limb motor intent from surface electromyography signals remains challenging due to electrode placement variability, muscle fatigue, inter-subject differences, and differences between able-bodied and amputee populations. This study evaluates the robustness of commonly used machine-learning approaches for lower-limb electromyography classification under these sources of variability.MethodsA unified benchmarking analysis was conducted across four lower-limb electromyography datasets: UCI lower limb electromyography, vastus medialis electromyography, K2MUSE, and the above-knee sit-to-stand (STS) amputee dataset. Three classification models – support vector machine, random forest, and multilayer perceptron – were evaluated using standardized preprocessing and feature extraction pipelines. Cross-subject robustness was assessed using leave-one-subject-out (LOSO) validation on the K2MUSE dataset. A preliminary transfer-learning experiment was also performed by fine-tuning a multilayer perceptron pretrained on able-bodied data using the amputee STS dataset.ResultsThe random forest model achieved the highest performance in datasets with lower variability, with macro F1 scores of 0.9033 ± 0.0048 on the UCI dataset and 0.6000 ± 0.0087 on the vastus dataset. Under cross-subject non-ideal acquisition conditions, performance decreased for all models. The multilayer perceptron showed competitive robustness in the K2MUSE ideal-versus-fatigue LOSO evaluation (0.476 ± 0.058 macro-F1), while random forest showed the most compact subject-wise distribution (median 0.476 [interquartile range 0.049]). In the transfer-learning experiment, fine-tuning improved performance on the above-knee STS dataset relative to training from scratch (macro-F1 0.5540 ± 0.0141 vs. 0.5203 ± 0.0371).ConclusionsThese results highlight the different strengths of classical and neural machine-learning models under varying electromyography variability conditions and provide a foundation for more robust intention-decoding systems for adaptive lower-limb prosthetic control.

Research on the effects of varied loading frequencies on solute particle transport in firefighters’ LCS

Fri, 16 Oct 2026 00:00:00 GMT

PurposeTo elucidate the underlying bone injuries in firefighters exposed to long-term high-frequency training, this study investigates the nutrient transport characteristics of the lacunar-canalicular system (LCS), which is critical for sustaining bone cell activity and bone remodeling.MethodsA two-dimensional fluid-solid coupling model was constructed combined with the particle tracking method, to quantitatively evaluate the effects of three loading frequencies (0.5, 1, 2 Hz) and five porosity levels (covering sclerotic, normal and osteoporotic bone) on LCS transport efficiency, with comparative analyses against the general population.ResultsThe results demonstrate that 1 Hz represents the optimal loading frequency for LCS nutrient transport in firefighters. Nutrient transport efficiency elevates with increasing frequency in normal and osteoporotic bone, whereas modifying frequency yields no improvement in sclerotic bone due to its dense pore structure.ConclusionsThis study provides a theoretical basis for optimizing training parameters and developing hierarchical bone health interventions to reduce exercise-related bone injury risk in firefighters.

The acute effect of expert video modelling on tennis serve performance in 7- to 9-year-old players

Fri, 16 Oct 2026 00:00:00 GMT

PurposeThis study aimed to determine the acute impact of employing expert modelling on tennis serve performance in 7- to 9-year old boys.MethodsSeventeen players undertook three conditions sequentially: control condition (traditional training), video modelling condition 1, and condition 2. Each participant performed 16 serves per condition (8 per diagonal), with 1 week between each condition. Serve performance outcomes were evaluated under each condition.ResultsRepeated-measure analyses of variance revealed significant main effects for conditions (F (2, 32) = 85.61, p < 0.001, η 2 p = 0.843) and point areas (F (2, 32) = 274.76, p < 0.001, η 2 p = 0.945), with a significant interaction (F (4, 64) = 7.08, p < 0.001, η 2 p = 0.307). Both video modelling conditions outperformed the control condition, with VMC2 showing the greatest benefits for successful serve (F (2, 32) = 85.61, p < 0.001, η 2 p = 0.843) and ball impact (F (2, 32) = 70.29, p < 0.001, η 2 p = 0.815), while no effect was observed for ball speed (p = 0.116–0.458). Significant condition × test interactions were observed for point areas 1, 3, and 5 (p < 0.001, η 2 p = 0.614–0.720). Pairwise comparisons with Bonferroni correction revealed significant differences between all conditions (p < 0.001), with VMC2 producing the largest gains across all point areas.ConclusionOur findings support that the adoption of expert video modelling for coaching/learning tennis serves to expedite the process of technique refinement and facilitate performance enhancement.

Comparative assessment of AD8232- and MAX30003-based ECG acquisition paths using synthetic ECG signals

Fri, 16 Oct 2026 00:00:00 GMT

PurposeThis study presents a comparative technical evaluation of two implemented electrocardiogram (ECG) acquisition paths based on AD8232 and MAX30003 under controlled laboratory conditions. The analog front-end paths were designed in accordance with the reference circuits and design recommendations specified in the manufacturer’s documentation for the AD8232 and MAX30003 devices.MethodsSynthetic ECG signals were generated using a patient simulator for heart rates of 30, 60, 80, and 100 beats per minute and were recorded simultaneously from both acquisition paths at a sampling frequency of 128 Hz. The processing pipeline comprised time-axis standardization, baseline correction, local cross-correlation-based synchronization, linear amplitude alignment, QRS detection using a simplified Pan–Tompkins-inspired procedure, and median-centered amplitude standardization. Signal similarity after preprocessing was assessed using time-domain metrics, including Pearson correlation, mean absolute error, root mean square error (RMSE), and normalized RMSE. In addition, spectral analysis based on Welch’s method was performed using absolute bandpower values and relative bandpower indices.ResultsAfter synchronization and normalization, both acquisition paths showed very high morphological agreement, with Pearson correlation exceeding 0.99 across all tested heart-rate settings. Error metrics remained low and comparable between recordings. Spectral analysis revealed marked differences in absolute power, reflecting properties of the complete acquisition chains rather than signal quality alone. Relative spectral indices showed implementation-specific differences between the complete acquisition paths, particularly in the 50 Hz component band, whereas the 40–60 Hz band was retained only as an auxiliary descriptive upper-band index because of the different filtering and digitization architectures of the two paths.ConclusionsUnder the tested synthetic and controlled conditions, both implemented ECG acquisition paths provided comparable post-processed morphological representations of the ECG signal, while differing in spectral characteristics. The examined paths differed in the relative distribution of spectral energy under the applied configuration. However, these findings should be interpreted as implementation-specific technical observations rather than evidence of general device superiority. Further validation in human recordings and real-world conditions is required.

Influence of hematocrit-dependent blood viscosity on hemodynamics of mitral paravalvular leak

Fri, 16 Oct 2026 00:00:00 GMT

PurposeParavalvular leak (PVL) is a pathological condition that may arise following prosthetic mitral valve implantation and is characterized by regurgitant blood flow through a gap between the prosthetic valve ring and the native cardiac tissue. High-velocity flow jets generated within the leak region may produce elevated shear stresses capable of inducing mechanical damage to erythrocytes and subsequent hemolysis. The purpose of this study is to investigate the influence of blood viscosity, modulated by hematocrit variability, on flow characteristics and hemolytic potential in mitral PVL.MethodsA computational fluid dynamics model was developed to simulate pulsatile blood flow through mitral PVL channel. The model included a time-varying left ventricular geometry, a kinematically constrained left atrium, and a simplified representation of a mechanical mitral valve with a localized paravalvular defect. Multiple physiological hematocrit levels were considered to account for viscosity variations. Non-Newtonian rheological behavior of blood was incorporated to capture shear-dependent viscosity effects.ResultsThe simulations showed a strong dependence of shear stress on hematocrit. Increasing hematocrit led to higher effective viscosity, resulting in elevated shear stress levels within the PVL jet. A near-linear relationship between hematocrit and maximum shear stress was observed, with stress values exceeding the hemolysis threshold at higher hematocrit levels. Additionally, higher hematocrit values resulted in earlier onset of critical shear stress conditions.ConclusionThe results demonstrate that hematocrit significantly influences hemodynamic conditions and hemolysis risk in mitral PVL.

Influence of musculoskeletal model implemented in the AnyBody Modeling System on calculated loadings acting in the lower extremity during gait

Thu, 15 Oct 2026 00:00:00 GMT

PurposeAn evaluation of the influence of different musculoskeletal models implemented in the AnyBody Modeling System on muscle forces and joint reaction forces in the lower limb, calculated as the result of numerical simulation of gait, was the main aim of the paper, using identical scaling and optimisation procedures. The study investigated whether the models predict significant differences in muscle forces and joint reaction forces.MethodsKinematic parameters and ground reaction forces were recorded for 20 healthy adults of both sexes (21–24 years), walking at a self-selected speed and used as inputs for musculoskeletal modelling and simulation in AnyBody. Two musculoskeletal models (Twente Lower Extremity Model [TLEM]) available in the AnyBody repository, TLEM 1.1 and TLEM 2.0, were used. Time waveforms of force generated by 20 muscles and hip, knee and ankle joint reaction forces were obtained. Statistical parametric mapping and root-mean-square differences were used to evaluate differences between the two models.ResultsSignificant differences between models were observed in both muscle force and joint reaction force waveforms. The greatest differences were visible in pelvic stabilisers, hip flexors and muscles responsible for a push-off and lower limb stabilisation, as well as in the medio-lateral components of joint reaction forces.ConclusionsThe results confirm that the geometrical model of the musculoskeletal system has a significant influence on the calculated muscle and joint reaction forces. Recognising these model-dependent differences is essential for the correct interpretation of simulation results and the informed use of musculoskeletal modelling in future studies.

Functional recovery of athletes through rehabilitation training after anterior cruciate ligament reconstruction

Thu, 15 Oct 2026 00:00:00 GMT

PurposeThis article aims to introduce neuromuscular electrical stimulation into rehabilitation training after anterior cruciate ligament reconstruction and to assess its impact on the functional recovery of the knee joint.MethodsTwenty athletes undergoing anterior cruciate ligament reconstruction were allocated into a neuromuscular electrical stimulation group (neuromuscular electrical stimulation + rehabilitation training) and a conventional group (conventional rehabilitation training) for a 10-week training program. Indicators such as Lysholm scores and thigh circumference were assessed before and after training for comparison.ResultsAfter training, the neuromuscular electrical stimulation group demonstrated a Lysholm score of 86.56 ± 11.67 points, a thigh circumference on the affected side of 47.15 ± 2.56 cm, and an active knee flexion angle of 105.12 ± 9.87°. Moreover, the score of the Y-balance test under left- and right-foot support was 93.67 ± 0.43 and 91.72 ± 0.48 points, respectively. It achieved a 10-meter walk speed of 1.01 ± 0.15 m/s. It achieved a performance of 264.39 ± 29.36 cm in three consecutive single-leg jumps on the healthy side and a performance of 178.16 ± 21.26 cm on the affected side. Its anterior cruciate ligament return-to-sport after injury scale score was 84.21 ± 5.32 points. These outcomes were significantly superior to those of the conventional group.ConclusionsNeuromuscular electrical stimulation combined with rehabilitation training yields positive effects on functional recovery after anterior cruciate ligament reconstruction, surpassing the outcomes of conventional rehabilitation training. This approach holds promise for practical application.

Influence of ankle-foot orthoses on gait symmetry in children with hemiplegic cerebral palsy: A prospective, cross-sectional study

Thu, 15 Oct 2026 00:00:00 GMT

PurposeThe main objective of the study was to analyse gait kinematics in terms of symmetry among groups of children with hemiplegic cerebral palsy (CP).Material and methodsThe study was conducted using the BTS SMART three-dimensional (3D) gait analysis optoelectronic system. Passive reflective markers were placed on subjects’ bodies in accordance with the Davis protocol. The study involved 43 children, aged 7 years. Group 1 (n = 18) comprised patients not using any orthopaedic equipment. Group 2 (n = 14) consisted of children using a unilateral ankle-foot orthosis on the affected side. Group 3 (n = 11) included children using bilateral ankle-foot orthoses.ResultsImprovement in gait symmetry was observed in orthosed children, and the majority of changes were significant (p < 0.05). Thus, it appears that this type of orthopaedic equipment affects not only the ankle joint, but also higher levels of the biokinematic chain.ConclusionsIn accordance with the results, it was shown that in patients using bilateral ankle-foot orthoses, a more positive effect of the described phenomena could be expected.

Dynamic stability in sit-to-walk transition: A quantitative analysis based on age-related momentum distribution and lower extremity kinematics

Wed, 14 Oct 2026 00:00:00 GMT

PurposeThe sit-to-walk (STW) transition serves not merely as a highly prevalent functional movement in activities of daily living but also as a pivotal task paradigm for elucidating overall motor control strategies. The objective of this study was to comparatively evaluate the stability control characteristics between two groups during STW transitions and to explore the underlying mechanisms associated with potential fall risks.MethodsLower-limb differences between the two groups were assessed using independent samples t-tests, statistical parametric mapping, and phase-average comparisons, supplemented by correlation analyses.ResultsPeak horizontal momentum (HM) showed significant differences between the two groups across the entire phase (p < 0.05). The anteroposterior margin of stability (MOS) differed significantly during the extension and swing phases (p < 0.03), whereas knee range of motion and center of pressure excursion velocity exhibited significant differences only in the unloading phase (p < 0.05). In the young group, the MOS, HM, and joint kinematics demonstrated significant strong negative correlations (r < −0.5, p < 0.05), whereas these correlations were generally attenuated in the older adult group.ConclusionsOlder adults tend to adopt a conservative postural control strategy during STW transitions, prioritizing enhanced stability by restricting forward HM and prolonging movement duration. These findings elucidate the characteristics underlying fall risks during STW in older adults, providing a scientific rationale for the design of targeted biomechanical interventions.

Effects of an 8-week core-strength program on smash accuracy in female badminton athletes

Mon, 05 Oct 2026 00:00:00 GMT

BackgroundTo investigate the effects of an 8-week core-strength training program on smash accuracy in female badminton athletes.MethodsForty female badminton players were randomly assigned to an experimental group (EG) and a control group (CG). Both groups continued regular badminton training, while the EG additionally completed an 8-week structured core-strength program. Smash accuracy was assessed under three conditions – stationary, jumping, and moving smashes – at baseline, mid-intervention (posttest 1), and post-intervention (posttest 2). Data were analyzed using generalized estimating equations (GEE) to examine group effects, time effects, and group × time interactions, with age, training experience, height, and body mass included as covariates.ResultsGEE analysis revealed significant group, time, and group × time interaction effects for in situ, jumping, and moving smash accuracy (p < 0.05). Post hoc analyses showed that the EG demonstrated significant improvements in smash accuracy from baseline to posttest 2 across all three smash conditions, whereas improvements in the CG were limited or non-significant. Effect size analysis further indicated that the magnitude of improvement in smash accuracy was substantially greater in the EG than in the CG. None of the covariates showed a significant influence on smash accuracy outcomes.ConclusionsAn 8-week core-strength training program significantly enhances in situ, jumping, and moving smash accuracy in female badminton athletes. These findings highlight the importance of core stability and strength in optimizing technical performance and suggest that systematic core training should be incorporated into routine badminton training programs to improve smash accuracy and overall competitive performance.

Effects of the lower visual field obstruction on adaptive gait during obstacle crossing in healthy young adults

Tue, 29 Sep 2026 00:00:00 GMT

PurposeObstacle navigation represents a critical challenge in daily locomotion, with failed balance recovery during crossing frequently leading to falls. This study investigated the effects of lower visual field obstruction on adaptive gait during obstacle crossing in healthy young adults using a novel “box-carrying obstruction method.”MethodsFifteen male participants (age, 20.9 ± 1.3 years; height, 178.6 ± 5.0 cm; weight, 71.7 ± 7.5 kg; leg length, 91.7 ± 5.1 cm) walked with or without a box (30 × 30 × 25 cm or 30 × 30 × 35 cm) while crossing obstacles at heights of 10, 20, and 30% of leg length in randomized order. Measured gait parameters included step length, step width, step velocity, penultimate foot placement (PFP), toe distance (TD), heel distance (HD), and lead/trail limb vertical toe clearance (LTC/TTC). Statistical analyses included repeated-measures ANOVA and Pearson correlations.ResultsNo significant interactions between LVF obstruction and obstacle height were observed (all P > 0.05). Obstacle height significantly reduced step velocity (P = 0.002), while LVF obstruction independently affected TD (P < 0.001), HD (P < 0.001), LTC (P < 0.001), and TTC (P < 0.001). Negative correlations were found between TD and HD (r = −0.46; P < 0.001), and positive correlations between LTC and TTC (r = 0.60; P < 0.001).ConclusionsLVF Obstruction had a broader impact on spatial gait adjustments than obstacle height, with step velocity serving as the primary adaptive strategy for higher obstacles. The strong coupling between lead and trail limb clearances suggests interlimb coordination, highlighting the role of shared sensorimotor information in obstacle negotiation.

Correlation analysis between ankle proprioception and biomechanical characteristics in patients with chronic ankle instability

Mon, 28 Sep 2026 00:00:00 GMT

PurposeTo compare ankle proprioception and biomechanical features between individuals with chronic ankle instability (CAI) and healthy controls, and to investigate the interplay between proprioceptive deficits and biomechanical alterations in CAI.MethodsThirty-six male participants (18 CAI, 18 healthy controls) were recruited. Proprioception was evaluated using a joint position reproduction test, quantifying absolute errors. For biomechanical assessment, participants performed six single-leg hopping tests. An infrared motion-capture system (Vicon T40, 200 Hz) and a force platform (Kistler, 1,000 Hz) simultaneously captured ankle kinematics/kinetics. Ankle muscle activation was recorded via surface electromyography (Noraxon, 2,000 Hz).ResultsParticipants with CAI demonstrated significantly greater joint position sense errors in plantarflexion (P = 0.002), dorsiflexion (P = 0.001), inversion (P = 0.011), and eversion (P = 0.022) compared with controls. Compared with healthy controls, individuals with CAI exhibited greater peak ankle inversion angles (P = 0.039), reduced peak ankle dorsiflexion angles (P = 0.029), and lower activation of the tibialis anterior (P = 0.019) and peroneus longus (P = 0.033) during single-leg landing. Correlation analyses indicated significant associations between inversion position sense errors and both peak ankle dorsiflexion angle (r = −0.584, P = 0.011) and peak ankle inversion angle (r = −0.622, P = 0.006) in the CAI group.ConclusionsIndividuals with CAI exhibit impaired ankle proprioception and altered biomechanical characteristics compared with healthy controls. Decreased proprioception in the ankle was correlated with biomechanical defects. These findings suggest that proprioceptive impairments may contribute to persistent biomechanical abnormalities in CAI. Comprehensive interventions targeting proprioceptive enhancement may improve ankle biomechanics in this population.