Search Results (396)

This paper investigates trajectory tracking and collision-avoidance problems for unmanned surface vehicles (USVs) in maritime sports support scenarios. These tasks require accurate tracking, disturbance rejection, safe motion around static and moving obstacles, and predictable transient performance within task-level time constraints. To address these requirements, an adaptive predefined-time sliding mode control (APTSMC) strategy is formulated for the considered CyberShip II-based USV tracking error system. A predefined-time sliding surface and reaching law are used to provide an explicit convergence-time design parameter for the nominal tracking subsystem, while an adaptive compensation mechanism estimates the unknown bound of lumped disturbances without requiring prior knowledge. To support collision avoidance, a velocity-modulated artificial potential field correction is incorporated as a reactive avoidance layer. The modulation term strengthens repulsion when the USV approaches an obstacle and reduces unnecessary deviation when the relative motion is safe. Numerical results in a constructed maritime sports boundary-tracking simulation scenario with multiple static and moving obstacles further demonstrate the potential effectiveness of the integrated framework in balancing tracking accuracy and collision avoidance safety. Full article

Shear Thickening Fluid (STF), as a typical intelligent material, offers a novel approach for developing adaptive protective equipment due to its unique “shear thickening” effect. This review examines STF-based composite materials, encompassing both surface coatings (where STF is dispersed in a polymer matrix applied as a layer) and impregnated structures (where STF is integrated into porous fabric or foam substrates via saturation). It elaborates on design principles, preparation methods, mechanical property modulation, and applications in adaptive protectors for knees, elbows, wrists, ankles, and sports equipment. The review emphasizes how composite strategies overcome STF encapsulation and processing challenges, facilitating laboratory-to-market transition. The core mechanisms underlying the “flexible under normal conditions, rigid upon impact” behavior are discussed at molecular and rheological levels. Key limitations—including fluid leakage, long-term aging, and temperature sensitivity—are critically examined alongside future development trends toward multifunctional, intelligent protective systems. Full article

Objectives: Karting imposes high neuromuscular demands on the forearm during dynamic steering, gripping and braking. This study examined whether a single high-velocity, low-amplitude (HVLA) manipulation of the elbow acutely modified surface EMG_RMS amplitude and EMG median frequency responses during standardized isometric forearm testing after simulated karting load, rather than EMG activity during dynamic driving itself. Methods: In this randomized, sham-controlled, within-subject trial, 15 drivers completed a single-session within-participant protocol in which one upper limb was randomly allocated to receive elbow HVLA manipulation (manipulated limb) and the contralateral limb received a standardized sham procedure (sham limb) involving therapist contact and low-grade oscillatory movement without end-range pre-tension or thrust. Drivers completed two 8 min simulated races separated by the allocated manual procedure. Surface electromyography (EMG) from four forearm muscles was collected outside the karting task during standardized laboratory-based isometric forearm contractions at baseline, after race 1, post-intervention, and after race 2. EMG was not recorded during real-time steering, braking, vibration exposure or competitive driving. The extensor carpi radialis (ECR) was specified as the principal muscle of interest because the HVLA technique pre-tensioned the common extensor origin and radial wrist extensors. The primary outcome was ECR mean EMG_RMS amplitude, expressed in µV, across the four measurement time points; the primary statistical test was the condition × time interaction. ECR maximal EMG_RMS amplitude and ECR median frequency were treated as secondary outcomes, whereas ECU, FCR, and FCU outcomes were treated as exploratory anatomical specificity outcomes. Mixed-model ANOVAs compared maximal and mean EMG amplitudes and median frequency between manipulated and sham limbs, treating limb condition and time as repeated within-participant factors. Results: For the primary outcome, ECR mean EMG_RMS amplitude showed a main effect of condition (p = 0.023) and a condition × time interaction (p < 0.001). As a secondary amplitude outcome, ECR maximal EMG_RMS amplitude showed a main effect of time (p = 0.009) and a condition × time interaction (p < 0.001), with higher post-manipulation values in the manipulated limb. No consistent limb-condition effects were found for the other muscles, and EMG median frequency showed only modest time-related changes (p = 0.031) without between-condition differences. Conclusions: A single-elbow manipulation produced short-lived, muscle-specific increases in ECR activation after simulated racing, whereas broader neuromuscular changes were not evident. These findings indicate only transient modulation of ECR surface EMG amplitude in a small sample of screened karting drivers and do not demonstrate improved recovery, neuromuscular efficiency, sport performance, or injury prevention. Because EMG was assessed during standardized isometric contractions rather than during dynamic steering, braking, vibration exposure or competitive racing, the findings should not be interpreted as direct evidence of altered neuromuscular behaviour during actual kart driving. Larger studies including force, performance, clinical, fatigue-specific and dynamic driving EMG outcomes are required. Full article

Understanding muscle activation patterns during sport-specific skills is essential for optimizing performance and training strategies. In basketball, upper limb actions such as passing and receiving require precise coordination and effective neuromuscular control. The main goal of this study was to analyze and compare the muscle activity of the biceps brachii and triceps brachii during the execution and reception of the two-handed chest pass in basketball players with different levels of competitive experience. Surface electromyography (EMG) data were collected from 14 federated athletes, aged between 11 and 29 years, using the BioSignal Plux system. Participants were allocated into two groups according to their playing experience. Muscle activation was analysed in terms of activation time (AT) and percentage of muscle activation (%MA), normalised to maximum voluntary contraction (MVC). A linear mixed model was used to evaluate the effects of experience level, limb dominance, and their interaction while accounting for repeated measures within participants. No significant differences were observed between dominant and non-dominant limbs for any variable. Significant differences between experience/age groups were identified mainly in the triceps brachii, particularly for activation time in the lateral head and %MA in the long head. In general, more experienced/aged athletes demonstrated higher levels of neuromuscular activation and shorter activation times, suggesting different motor control strategies. A significant positive association was found between years of practice and %MA of the long head of the triceps brachii. These findings provide novel insights into neuromuscular recruitment during both the execution and reception phases of the basketball chest pass and may inform training strategies aimed at enhancing technical efficiency across developmental stages. Full article

Introduction: Vertical jump performance is linked to key performance indicators in rugby, including tackling success and ruck involvement. Although plyometric jump training (PJT) is known to enhance explosive qualities in various sports, its specific effects in rugby remain unclear. Objective: To synthesise evidence on the effects of PJT on vertical jump ability and other physical fitness components in adult rugby players. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, EBSCO (SPORTDiscus), WoS, and Scopus were searched up to December 2025. Experimental and quasi-experimental studies involving rugby players undertaking PJT programmes of at least two weeks, with at least one vertical jump outcome, were included. Two reviewers independently performed study selection and data extraction. Risk of bias was assessed using the RoB 2.0 tool. Results: Seven studies involving 178 male players were included. PJT improved sprint speed, change of direction, anaerobic power, reactive strength, lower-limb stiffness, and isometric plantar flexion strength. Gains in countermovement jump power were noted in some conditions, such as training on softer surfaces. However, improvements in jump height were inconsistent. Conclusion: PJT enhances several important physical qualities in rugby players but shows variable effects on vertical jump height. Further high-quality research is needed. Full article

Understanding the interaction forces between climbers and climbing holds is important for motion analysis and performance evaluation in sport climbing. In particular, force measurement during speed climbing can provide valuable insights into explosive movements and athlete performance. However, many existing measurement systems require modifications to the climbing wall structure or sensors installed behind the wall, which limits their applicability to existing speed climbing facilities. This study proposes a wireless instrumented climbing hold for speed climbing that enables force-related measurement without modifying the wall structure. The proposed system integrates a six-axis force sensor, a microcomputer, a wireless communication module, and a battery inside the climbing hold. This self-contained configuration allows the hold to wirelessly transmit force and moment data during climbing while maintaining compatibility with standard speed climbing walls and competition environments. In addition, the system enables an estimation of the point of force application on the hold surface by combining measured force and moment data with the three-dimensional hold geometry. Experimental evaluations were conducted to verify the feasibility and performance of the system. External load tests using a digital force gauge confirmed that the embedded sensor can measure static loads and respond to rapidly changing loads with sufficient temporal responsiveness, and the estimated point of force application corresponded closely to the actual loading point. Furthermore, measurements on an actual speed climbing wall demonstrated that the proposed system can successfully capture interaction forces during climbing movements. These results indicate that the proposed system is a practical tool for force-based motion analysis in speed climbing. Full article

Drag-reducing coating technology is a core approach to enhancing the performance of ice and snow sports equipment. By regulating the interfacial characteristics between the equipment surface and the ice or snow medium, it significantly reduces frictional resistance during motion, thereby optimizing athletes’ speed performance and control precision. This paper aims to review the current research status and challenges in this technological field. The review first elaborates on the fundamental principles of applying drag-reducing coatings to key equipment such as skis, sleds, and ice skates, covering current mainstream coating material systems, key preparation processes, and comprehensive performance evaluation methods. Furthermore, integrating multidisciplinary advances in surface engineering, fluid dynamics, and materials science, this review specifically examines how these disciplines can be harnessed to address the unique tribological challenges of snow/ice interfaces. It focuses on cutting-edge research directions such as micro-nano-structured coatings driven by biomimetic design concepts and smart coatings with environmental responsiveness. By synthesizing existing research achievements and potential technological bottlenecks, this paper aims to provide a systematic, theoretical basis and innovative ideas for the future development of a new generation of high-performance, intelligent ice and snow sports equipment. Full article

Background/Objectives: Adolescent mental health problems emerge early, remain undertreated, and are shaped by diverse contextual stressors. In response to calls for more youth-centered prevention, school-based health promotion, and participatory intervention design, this study explored which mental health-related problems internationally mobile adolescents prioritize and which solution ideas they generate in a structured co-creation setting, including where movement- and sport-related elements are embedded. Methods: A qualitative, participatory study was conducted during a 24 h social hackathon embedded in the Youth Empowerment Seminar for exchange students. Hackathon materials from 43 projects were analyzed using content-structuring qualitative content analysis following Kuckartz. Results: Adolescents most frequently framed problems in terms of self-image, stress and anxiety, belonging, and harassment. Solutions clustered around low-threshold group formats, while implementation segments focused strongly on staffing, funding, barriers, and feasibility. Cross-domain analyses suggested recurring problem-solution matches, such as loneliness with hobby or interest groups. Conclusions: Social hackathons can surface adolescent-prioritized mental health concerns and translate them into context-sensitive prevention ideas. The findings mainly point to social and psychosocial solution pathways, while some proposals additionally positioned shared activity or movement contexts as potentially supportive for well-being. These results provide a starting point for subsequent school-based prototyping and feasibility work. Full article

BACKGROUND: Overhead athletes are at increased risk of shoulder dysfunction due to repetitive, high-velocity movements that can disrupt scapular muscle activation patterns. Whole-body vibration (WBV) has been proposed as a training modality to enhance neuromuscular activation, but its effects on scapular muscle activity and activation timing remain unclear. METHODS: This randomized controlled trial investigated the effects of WBV-assisted push-up training on scapular muscle activation and onset latency in university-level overhead athletes. Forty participants were randomly assigned to a WBV group or a control group performing identical push-up exercises without vibration for four weeks. Surface electromyography was used to assess normalized muscle activation (%MVIC) and activation latency of the upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) before and after the intervention. A 2 × 2 mixed-model ANOVA was applied for statistical analysis. RESULTS: Significant time × group interactions were found for muscle activation in LT and SA (p < 0.01). The WBV group demonstrated substantially greater increases in activations in these muscles compared with the control group, with the largest improvements observed in the serratus anterior. No statistically significant between-group differences were identified for muscle onset latency (p > 0.05). CONCLUSIONS: Adding WBV to push-up training significantly enhances key scapular muscle activation in overhead athletes but does not significantly affect muscle onset latency. WBV-assisted push-ups may act as a practical, low-load strategy to improve scapular muscle recruitment and potentially reduce the risk of sports-related shoulder injuries and pain in overhead athletes. Full article

A novel procedure is proposed in this paper to investigate the capacity of parking structures to resist additional live loads that could come from many cars, potentially from heavier or driverless cars. In recent decades, the typical operating weight of passenger vehicles has risen significantly. The anticipated widespread adoption of electric vehicles (EVs), which contain heavy battery systems, may further increase live load demands. As a result, a new robust procedure is needed to assess the live load effects on parking structures. Hence, using the proposed innovative approach based on 3D influence surfaces, tributary areas (AT) and three-dimensional influence surfaces (AI) were calculated (for the first time) to examine the equivalent uniformly distributed load corresponding to selected column axial loads and beam midspan moments that are expected to be experienced during the lifetime of parking structures. As case studies, the responses of two existing multistory parking garages on the Ohio State University campus were investigated under different arrangements of two car types—standard cars and sports utility vehicles (SUVs)—and the calculated maximum live loads were compared with the current code requirements. The results show that the maximum live load for the midspan moment is conservative; however, the maximum axial column loading in the extreme scenarios presented in this paper can be larger than the specified (original) design limit of the selected parking garages. The novel methodology proposed in this paper is based on 3D influence line analysis and can be applied for any vehicle configuration and weight, and different parking arrangements or loading scenarios to investigate the performance of parking garages. Full article

Knee joint moment is an important biomechanical parameter for sports assessment, rehabilitation monitoring, and human–machine interaction. However, direct measurement is often restricted to laboratory-based settings. Surface electromyography (sEMG) offers a non-invasive alternative for indirect joint moment estimation, but many existing deep learning models remain too computationally demanding for potential wearable edge deployment. To address this gap, this study proposes Topo2DCNN-LSTM, a lightweight two-dimensional (2D) convolutional neural network model, designed for sagittal-plane knee flexion moment estimation. The model used a feature-based sequential representation, transforming raw sEMG signals into compact Root Mean Square (RMS) feature frames. The input was processed by a lightweight 2D convolutional neural network (CNN) encoder and paired with long short-term memory (LSTM) units. The model was trained on a public walking dataset of healthy subjects with synchronized sEMG and joint kinetics at two treadmill speeds. When compared with selected deep learning baselines, the quantized model achieved a mean RMS Error of 0.088 ± 0.020 Nm/kg at 1.2 m/s and 0.114 ± 0.034 Nm/kg at 1.8 m/s. On a SparkFun Thing Plus–SAMD51, it achieved an average inference latency of 28 ms using 71,316 bytes of random-access memory (RAM) and 257,172 bytes of flash. These results support its use as a proof of concept for personalized unilateral knee moment estimation with isolated on-device inference feasibility under resource-constrained and limited walking conditions. Full article

This study proposes a unified multimodal temporal motion state perception framework for optical imaging-oriented biomedical applications, integrating visual skeleton sequences, inertial measurement unit (IMU) signals, and surface electromyography (EMG) signals. The framework utilizes modality-specific encoders and a cross-modal temporal alignment attention mechanism to explicitly model temporal offsets from heterogeneous sensing streams. A multimodal temporal Transformer backbone is introduced to capture long-range motion dependencies and cross-modal interactions, while an uncertainty-aware fusion module dynamically allocates weights based on modality confidence. Experimental results demonstrate that the proposed approach achieves an accuracy of 94.37%, an F1-score of 93.95%, and a mean average precision of 96.02%, outperforming mainstream baseline models. Robustness evaluations further confirm stable performance under visual occlusion and sensor noise. These results indicate that the framework provides a highly accurate and robust solution for rehabilitation assessment, sports training monitoring, and wearable intelligent interaction systems. Full article

A warm-up is a critical procedure in sports science for enhancing muscular performance and optimizing subsequent athletic activities. However, the physiological and athletic performance effects of a warm-up are often transient, diminishing rapidly during the period of inactivity after the warm-up, which is known as the warm-up transition phase. In this study, a multi-functional thermoregulation wearable composite film of graphene–MXene–bacterial cellulose/polyethylene glycol (G-M-BC/PEG) was developed by integrating MXene (a two-dimensional material with good photothermal conversion performance) and graphene into a bacterial cellulose aerogel framework, subsequently impregnated with polyethylene glycol (PEG-2000). The film showed stable structure, efficient solar photothermal conversion and storage (SPCS), and improved mechanical properties. Under 1 sun irradiation, the optimized G-M-BC/PEG wearable film showed excellent SPCS performance, sustaining a temperature plateau of 38–40 °C for 10 min after the xenon lamp was switched off under 1 sun irradiation, with a leakage rate of only 5.32% after five cycles. By constructing a biomimetic sports human body model, the composite aerogel was shown to significantly elevate muscle surface temperature and effectively mitigate heat loss during the transition phase. In the warm-up effectiveness and sports performance tests, the wearable film improved 200 m sprint performance by 0.8% ± 0.4% (p = 0.039). It also maintained subjective thermal sensation during the warm-up transition phase, with no significant decline at 5 or 10 min after the warm-up and a significant decrease only at 15 min (p = 0.02), while thermal comfort remained stable, suggesting improved neuromuscular readiness. This research provided a novel strategy for the fabrication of advanced aerogel-based wearable devices aimed at precision thermal management and athletic performance optimization. Full article

Sports-related injuries present challenges across training, acute care, and rehabilitation, and largely rely on episodic, subjective, and delayed assessment methods. Wearable sensor technologies have emerged as powerful tools for objective monitoring of biomechanical and physiological parameters, offering new opportunities to enhance the entire sports injury management continuum. While prior research has explored the function for sports monitoring and injury prevention, the potential role of wearable sensors in the entire clinical pathway covering acute injury assessment, emergency clinical decision-making and rehabilitation guidance remains insufficiently integrated. This review synthesizes current advances in wearable sensor technologies, including inertial measurement units, pressure sensors, surface electromyography, cardiovascular monitoring, biochemical sweat sensing, and emerging self-powered and textile-integrated systems. Another main part of this review is the proposal of a wearable sensor–driven emergency clinical decision framework that integrates multimodal sensor data with clinically interpretable indicators to support risk assessment, early triage, treatment suggestions, and rehabilitation management. We also analyze the key challenges related to data integration and interpretation barriers, clinical implementation, ethical, privacy, and regulatory considerations. In the end, we look forward to the future of wearable sensors in data-driven, timely, and personalized sports injury care at the intersection of sports and emergency medicine. Full article