Athletic Movements Research Articles

Neural network and layer-wise relevance propagation reveal how ice hockey protective equipment restricts players' motion.

Understanding the athlete's movements and the restrictions incurred by protective equipment is crucial for improving the equipment and subsequently, the athlete's performance. The task of equipment improvement is especially challenging in sports including advanced manoeuvres such as ice hockey and requires a holistic approach guiding the researcher's attention toward the right variables. The purposes of this study were (a) to quantify the effects of protective equipment in ice hockey on player's performance and (b) to identify the restrictions incurred by it. Twenty male hockey players performed four different drills with and without protective equipment while their performance was quantified. A neural network accompanied by layer-wise relevance propagation was applied to the 3D kinematic data to identify variables and time points that were most relevant for the neural network to distinguish between the equipment and no equipment condition, and therefore presumable result from restrictions incurred by the protective equipment. The study indicated that wearing the protective equipment, significantly reduced performance. Further, using the 3D kinematics, an artificial neural network could accurately distinguish between the movements performed with and without the equipment. The variables contributing the most to distinguishing between the equipment conditions were related to the upper extremities and movements in the sagittal plane. The presented methodology consisting of artificial neural networks and layer-wise relevance propagation contributed to insights without prior knowledge of how and to which extent joint angles are affected in complex maneuvers in ice hockey in the presence of protective equipment. It was shown that changes to the equipment should support the flexion movements of the knee and hip and should allow players to keep their upper extremities closer to the torso.

The role of innovations in the development of modern sports games and its impact on physical activity and sports achievements

Scientific and technical progress is rapidly accelerating, therefore innovative technologies penetrate into all aspects of human life, in particular, into the sports sphere. They open new horizons, allow you to achieve positive results and offer high-tech equipment and equipment. The purpose of the article was to analyze the impact of innovations on physical activity in modern society and sports achievements. In the course of the study, it was found that innovations are innovative methods, technologies and approaches that are implemented to achieve new results, improve processes or solve problems in a certain field. Technological innovations such as virtual reality, innovative materials for sports equipment, artificial intelligence, digital technologies have affected all sports. The main examples of these technologies and their advantages of implementation in the sports industry were analyzed. So, for example, it is determined that the use of synthetic materials in poles for athletics increases their catapulting properties and sports achievements of athletes. Virtual reality technologies contribute to the effective training of cyclists, providing the opportunity to reproduce different weather conditions and types of routes, to test different strategies of speed and intensity of riding without any risks. Modern technologies, which allow to objectively evaluate the biomechanical parameters of the athlete's movements and to correct and improve them, contribute to a significant increase in the effectiveness of the athlete training system. The main groups of modern biomechanical technologies implemented in sports are analyzed. Significant technological updates in the field of sports are caused by the active implementation of digital technologies. Digital technologies help improve the national health care system by facilitating the collection, analysis and dissemination of data on health and physical activity. A key innovation in sports is also the use of fitness trackers and mobile applications that provide personalized training programs and nutritional recommendations.

Early Functional Outcomes and Complications of Tibial and/or Peroneal Sesamoidectomy Utilizing a Burr Through a Medial Approach.

Sesamoid pathology can lead to significant pain and disability both with activities of daily living and high-impact athletic movements. Sesamoidectomy is a widely used procedure for patients who fail conservative treatment measures. Traditional dorsal or plantar approaches for sesamoidectomy have shown to successfully alleviate pain, but complications were reported. A proposed alternative medial approach using a burr may provide many advantages compared with traditional approaches. This study presents patient outcomes and complications for this technique. This was a retrospective chart review of patients undergoing sesamoidectomy (tibial, peroneal, or both) using a burr through a medial approach to the sesamoid metatarsal articulation. Data collected included patient demographics, radiographic analysis, and outcomes: Veterans Rand 12 Item Health Survey (VR-12), Foot and Ankle Ability Measure (FAAM), visual analog scale (VAS), patient satisfaction, and complications. Twenty-seven patients (29 feet) were included. The mean age was 38.4 years followed up for a mean of 30.9 months. VR-12 physical component improved from 35.98 ± 7.86 to 51.34 ± 8.01 (P < .001), FAAM ADL and sport improved from 58.33 ± 16.61 to 83.27 ± 18.28 (P < .001) and 26.37 ± 20.31 to 63.75 ± 29.74 (P < .001), respectively. Patient satisfaction with the treatment was 80.59% ± 27.06%. The overall complication rate was 11 (37.9%) whereas the overall reoperation rate was 4 (13.7%) of 29 feet. Complications included 1 arthrofibrosis, 1 flexor hallucis longus subacute rupture, and 1 asymptomatic hallux valgus. There were no sesamoid excision revisions. Sesamoidectomy using a medial approach with a burr provided significantly improved short-term functional outcomes, 80% patient satisfaction rate, with a relatively acceptable complications rate including 20% persistent pain. The medial approach is familiar to orthopaedic foot and ankle surgeons, provides adequate exposure, and eliminates the possibility of a painful plantar scar while avoiding disruption of the plantar plate, flexor hallucis brevis tendon, and ligamentous structures attached to the sesamoids. Larger studies with long-term follow-up from other centers are needed.

Volleyball training video classification description using the BiLSTM fusion attention mechanism

This study aims to explore methods for classifying and describing volleyball training videos using deep learning techniques. By developing an innovative model that integrates Bi-directional Long Short-Term Memory (BiLSTM) and attention mechanisms, referred to BiLSTM-Multimodal Attention Fusion Temporal Classification (BiLSTM-MAFTC), the study enhances the accuracy and efficiency of volleyball video content analysis. Initially, the model encodes features from various modalities into feature vectors, capturing different types of information such as positional and modal data. The BiLSTM network is then used to model multi-modal temporal information, while spatial and channel attention mechanisms are incorporated to form a dual-attention module. This module establishes correlations between different modality features, extracting valuable information from each modality and uncovering complementary information across modalities. Extensive experiments validate the method's effectiveness and state-of-the-art performance. Compared to conventional recurrent neural network algorithms, the model achieves recognition accuracies exceeding 95 % under Top-1 and Top-5 metrics for action recognition, with a recognition speed of 0.04 s per video. The study demonstrates that the model can effectively process and analyze multimodal temporal information, including athlete movements, positional relationships on the court, and ball trajectories. Consequently, precise classification and description of volleyball training videos are achieved. This advancement significantly enhances the efficiency of coaches and athletes in volleyball training and provides valuable insights for broader sports video analysis research.

Analyzing the Impact of Accumulated Training Shots on Electromyography Parameters in Trained Archery Athletes: Exploring Fatigue and Its Association with Training Practices

Background: Accumulated training shots throughout a session may induce changes in electromyography (EMG) parameters of the primary muscles involved in movement in archery athletes. Thus, the aim of this study was two-fold: (i) analyze the impact of 50 and 100 archery shots on a single session on the EMG parameters of trained archery athletes; and (ii) explore the effects of training routines of the athletes to cope with fatigue induced by the accumulated shots on the EMG parameters. Methods: They were divided into two groups: those who regularly performed ≤100 shots per training session (n = 13) and those who performed &gt;100 shots per session (n = 7). The participants were exposed to a condition involving 100 archery shots, with measurements taken at baseline, after 50, and after 100 shots. EMG was used to measure the electric potential of the deltoid (middle and posterior), trapezius (upper, middle, and lower), and infraspinatus during isometric contraction. The collected outcomes included the mean and maximal amplitude of EMG root mean square (EMGRMS, µV) and the median frequency of the raw surface EMG signal power spectrum (EMGMED, Hz). Results: The results showed significant differences for most of the analyzed muscles analyzed, specifically in the deltoid, infraspinatus, and trapezius (p &lt; 0.05). Conclusions: Our study suggests that in most of the muscles analyzed, EMG parameters—particularly mean and maximal EMGRMS—tend to increase from baseline to 50 shots, with significant declines observed after 100 shots, indicating muscle fatigue. The training routines of the athletes do not appear to significantly influence their response to fatigue conditions.

Innovative pressure sensing with amorphous silicon nanostructures: Exploring applications in sports training supervision

This study introduces an innovative approach to pressure sensing in sports training using amorphous silicon nanostructure-based sensors. These sensors demonstrated high sensitivity (0.75 Ω/kPa) and a broad pressure detection range (1–100 kPa), making them ideal for capturing the nuances of athletic movements. Their compact size (5 mm×5 mm) and superior durability (over 5000 cycles with minimal performance variation) allowed for seamless integration into athletic shoes and attire. The sensors effectively captured pressure patterns in running, such as heel strikes peaking at 300 kPa, and cycling, revealing a 200 kPa increase in the perineal region during posture shifts. Comparative analysis highlighted the advantages of amorphous silicon nanostructure sensors over existing technologies, including higher sensitivity, wider pressure range, smaller size, and better durability. The integration of these sensors provided invaluable data for optimizing training regimes and preventing injuries. The study also delved into the physical and chemical characterization of the nanostructures, confirming their uniform size distribution, surface morphology, and amorphous nature, which contributed to their exceptional sensing performance. The findings underscore the immense potential of amorphous silicon nanostructure sensors in revolutionizing athletic performance analysis and injury prevention, offering a significant upgrade over current technologies in terms of accuracy, adaptability, and user-friendliness. This research paves the way for more sophisticated, precise, and athlete-centric pressure sensing solutions, transforming the landscape of sports technology and biomechanical assessment.

Benefits of Training on the SHREDmill, a Non-motorized Resistance Treadmill

The SHREDmill, a non-motorized, non-curved resistance treadmill, offers significant benefits for sports training, particularly in activities requiring high speed and agility, such as football. Its design promotes natural running mechanics, crucial for performance enhancement and injury prevention. Customizable incline and resistance settings allow for tailored training to simulate specific athletic movements, enhancing both safety and effectiveness. Advanced software provides real-time feedback on performance metrics, enabling immediate adjustments and continuous improvement. The SHREDmill’s compact design supports high-intensity sprint training in confined spaces, making it ideal for gyms and training facilities. Athletes, such as football players benefit from the SHREDmill’s ability to replicate short sprints and explosive power, essential to their training regimen.

A multifunctional triboelectric nanogenerator based on PDMS/MXene for bio-mechanical energy harvesting and volleyball training monitoring

Within the domain of wearable devices that are self-powered and sensory, triboelectric nanogenerators (TENGs) have surfaced as a notable solution to meet the growing needs for energy harvesting. This study unveils an innovative wearable and stretchable multifunctional double-layered TENG, based on PDMS/MXene, known as PM-TENG. Furthermore, PM-TENG can also be used as a joint sensor to monitor the movement of athletes' joints during volleyball training. By augmenting the matrix with PDMS/MXene, which possesses dual capabilities—namely, charge capture and charge movement—the intermediary layer is integrated. This leads to a two fold increase in the ability to trap charges and the overall triboelectric performance. With a power density reaching 11.27 mW, it notably exceeds the performance of its counterparts that solely utilize PDMS, by nearly 11 times. This academic effort elucidates the important role of PM-TENG in biomechanical energy capture and autonomous wearable sports motion sensing.

Inclusion of a skeletal model partly improves the reliability of lower limb joint angles derived from a markerless depth camera

A single depth camera provides a fast and easy approach to performing biomechanical assessments in a clinical setting; however, there are currently no established methods to reliably determine joint angles from these devices. The primary aim of this study was to compare joint angles as well as the between-day reliability of direct kinematics to model-constrained inverse kinematics recorded using a single markerless depth camera during a range of clinical and athletic movement assessments.A secondary aim was to determine the minimum number of trials required to maximize reliability. Eighteen healthy participants attended two testing sessions one week apart. Tasks included treadmill walking, treadmill running, single-leg squats, single-leg countermovement jumps, bilateral countermovement jumps, and drop vertical jumps. Keypoint data were processed using direct kinematics as well as in OpenSim using a full-body musculoskeletal model and inverse kinematics. Kinematic methods were compared using statistical parametric mapping and between-day reliability was calculated using intraclass correlation coefficients, mean absolute error, and minimal detectable change. Keypoint-derived inverse kinematics resulted in significantly smaller hip flexion (range = −9 to −2°), hip abduction (range = −3 to −2°), knee flexion (range = −5° to −2°), and greater dorsiflexion angles (range = 6–15°) than direct kinematics. Both markerless kinematic methods had high between-day reliability (inverse kinematics ICC 95 %CI = 0.83–0.90; direct kinematics ICC 95 %CI = 0.80–0.93). For certain tasks and joints, keypoint-derived inverse kinematics resulted in greater reliability (up to 0.47 ICC) and smaller minimal detectable changes (up to 13°) than direct kinematics. Performing 2–4 trials was sufficient to maximize reliability for most tasks. A single markerless depth camera can reliably measure lower limb joint angles, and skeletal model-constrained inverse kinematics improves lower limb joint angle reliability for certain tasks and joints.

Application of VR motion intelligent capture based on DLPMA algorithm in sports training

With the rapid development of Virtual Reality (VR) technology, its application in the field of sports training is also receiving increasing attention. This study applies the Distance Likelihood Based Probabilistic Model Averaging (DLPMA) algorithm to the VR motion intelligent capture system, aiming to provide an efficient and accurate motion data collection method to improve existing sports training methods. Introduced the design and implementation of a VR motion intelligent capture system based on DLPMA algorithm, and applied it to sports training. By conducting comparative experiments with traditional training methods, the advantages of the system in motion capture accuracy, real-time performance, and user experience are verified. The research results indicate that the system can accurately capture the movements of athletes and provide timely feedback to users, providing an effective auxiliary means for sports training. Although the system has shown good performance in sports training, there are still some limitations. Future research can further optimize algorithms, enhance system stability and flexibility, to meet a wider range of sports training needs.

Biomechanics of athlete movement: kinematic analysis and injury prevention

Biomechanics of athlete movement: kinematic analysis and injury prevention

SCB-YOLOv5: a lightweight intelligent detection model for athletes’ normative movements

Intelligent detection of athlete behavior is beneficial for guiding sports instruction. Existing mature target detection algorithms provide significant support for this task. However, large-scale target detection algorithms often encounter more challenges in practical application scenarios. We propose SCB-YOLOv5, to detect standardized movements of gymnasts. First, the movements of aerobics athletes were captured, labeled using the labelImg software, and utilized to establish the athlete normative behavior dataset, which was then enhanced by the dataset augmentation using Mosaic9. Then, we improved the YOLOv5 by (1) incorporating the structures of ShuffleNet V2 and convolutional block attention module to reconstruct the Backbone, effectively reducing the parameter size while maintaining network feature extraction capability; (2) adding a weighted bidirectional feature pyramid network into the multiscale feature fusion, to acquire precise channel and positional information through the global receptive field of feature maps. Finally, SCB-YOLOv5 was lighter by 56.9% than YOLOv5. The detection precision is 93.7%, with a recall of 99% and mAP value of 94.23%. This represents a 3.53% improvement compared to the original algorithm. Extensive experiments have verified that our method. SCB-YOLOv5 can meet the requirements for on-site athlete action detection. Our code and models are available at https://github.com/qingDu1/SCB-YOLOv5.

Judging athletic movement in moving images: a critique of agonic reason in representations of alpine sport, seen through the Paltrow v. Sanderson ski crash trial

ABSTRACT This paper concerns the judgement and critique of athletic movement in moving images. Inspired by the ski crash trial case of Paltrow v. Sanderson, and by comparing different media representations of downhill skiing, the essay outlines a framework that discerns as well as connects elements of movement and images, developing the concept of the ‘diorama’ in relation to Deleuze’s notion of the diagram and Kant’s idea of critique. Thus, moving images featuring elite alpine skier Mikaela Shiffrin, fictional character James Bond, and an official skiing game for the international ski federation (World Cup Ski Racing, FIS) figure as comparative material to the animation that played a central role in the celebrity trial. Diorama and diagram are posited on a continuum to assess when and how judgement takes place in each of the exhibits. The essay concludes by discussing how the judging of athletic movement in moving images contributed to Paltrow winning the case, and theoretically by connecting this finding to dioramas and diagrams as tools apt for a framework aiming at the critique of athletic movement in moving images.

Accuracy and feasibility of 3D virtual dynamic fit technology

PurposeThe research evaluated the feasibility of 3D dynamic fit utilizing female compression tops by comparatively analyzing the virtual and actual dynamic fit.Design/methodology/approachSix female participants were 3D body-scanned and photographed in compression tops in four types of athletic movements (pull-up, kettlebell swing, circle-crunch and sit-up). Fit measurements, waist cross-sectional areas, waist width, waist depth, numerical simulation of clothing pressure (kPa) and objective pressure measurements (kPa) were collected from 3D virtual animation, 3D fit scan data and actual photos with the four types of athletic motions. The data were comparatively investigated between virtual and actual dynamic fit.FindingsThe 3D-animated body was not reflected with human body deformation because only bone structure was changed while maintaining the constant forms of muscle and body surface in athletic movements. Due to this consistency of virtual dynamic fit, there were significant differences with the actual dynamic fit at the top length, shoulder width and waist cross-sectional areas. Also, the virtual dynamic pressure indicated significantly higher levels than the objective dynamic pressure while presenting no significant correlations at the front neckline, breast, lateral waist, upper back, back armhole and back waist.Originality/valueThis study is the first to verify multiple aspects of virtual dynamic fit using 3D digital technology. This study provided useful information about which aspects of the current virtual animation need to be improved to apply in the dynamic fit evaluation.

Factors associated with the Single Leg Squat test in female soccer players: a cross-sectional study

BackgroundThe Single Leg Squat (SLS) test is widely used in the clinical setting to examine and evaluate rehabilitation goals. It is simple to perform and is proposed to have biomechanical and neuromuscular similarities to athletic movements. The aim of the present study was to investigate whether demographics, previous injuries, and biomechanical and psychosocial factors are associated with the outcome of the SLS, assessed as a total score for all segments and as a separate knee segment in elite and sub-elite female soccer players.MethodsWe conducted a cross-sectional study involving 254 female soccer players (22 yrs; SD ± 4, height 1.69 m; SD ± 0.1, weight 64 kg; SD ± 6) from divisions 1–3 of the Swedish Soccer League. During the preseason, we assessed the participants using the SLS and tested their hip strength and ankle mobility. Demographics, previous injury, sleep quality, fear of movement, anxiety, and perceived stress were assessed with questionnaires. Logistic regression models were built to analyse the association between the outcome of the SLS and the independent variables for the dominant and non-dominant leg.ResultsSignificantly more participants failed the SLS on the dominant leg compared with the non-dominant leg (p < 0.001). The outcome of the SLS associated with various biopsychosocial factors depending on if the dominant or non-dominant leg was tested. The total score associated with hip strength for the dominant (OR 0.99, 95% CI 0.98–0.99, p = 0.04) and the non-dominant leg (OR 0.99, 95% CI 0.97–0.99, p = 0.03). The knee segment associated with division level for the dominant (div 2; OR 2.34, 95% CI 1.01–5.12, p = 0.033. div 3; OR 3.07, 95% CI 1.61–5.85, p = 0.001) and non-dominant leg (div 2; OR 3.30, 95% CI 1.33-8.00, p = 0.01. div 3; OR 3.05, 95% CI 1.44–6.43, p = 0.003).ConclusionsThis study identified that leg dominance, division level, hip strength, and psychosocial factors were associated with the outcome of the SLS when assessed as a total score and as a separate knee segment. This indicates that clinicians need to understand that movement control is associated with factors from several domains. Whether these factors and, the results of the SLS are related to injury need to be studied prospectively.Trial registrationClinical Trials Gov, date of registration 2022-03-01. Clinical trials identifier: NCT05289284A.

Kinematic criteria determining swing movement of world class dancesport athletes

PurposeThe aim of the study was to identify the distinguishing characteristics of the swing movement of the world’s top dancesport couples through kinematic variables.MethodsThe study involved six world-class and six intermediate dance couples. The couples were asked to execute three identical series of three natural turns of the figure in a Viennese Waltz, all being filmed as they danced to music. Six international experts evaluated all the trials of each couple from the point of view of the technical quality component based on the Absolute Judging System. A triaxial rotational angular velocity measurement (gyroscope) device was placed on the dorsal part of the pelvic girdle and on the posterior part of the thorax of each competitor.ResultsAn analysis of covariance demonstrated that regardless of the sports level, the maximum hip girdle angular rotation velocity in the forward swing movement performed by men was significantly related to the judging score achieved (F1,9 = 11.5; p &lt; 0.05; ηp2 = 0.45).ConclusionsThe mean squares of the differences of the hip and thoracic spine angular rotation velocity signals were found to be a good criterion for evaluating the swing movement, which is related to the judges’ evaluation. The descriptions of the performance of complex rotational movements obtained in this study can find their application in the analysis, teaching, and evaluation of dance couples. This is one of the first studies in the literature that deals in detail with swing movement in sports dance.

Gaze Behavior and Cognitive Performance on Tasks of Multiple Object Tracking and Multiple Identity Tracking by Handball Players and Non-Athletes.

Multiple object tracking (MOT) and multiple identity tracking (MIT) each measure the ability to track moving objects visually. While prior investigators have mainly compared athletes and non-athletes on MOT, MIT more closely resembles dynamic real-life environments. Here we compared the performance and gaze behavior of handball players with non-athletes on both MOT and MIT. Since previous researchers have shown that MOT and MIT engage different eye movement strategies, we had participants track 3-5 targets among 10 moving objects. In MOT, the objects were identical, while in MIT they differed in shape and color. Although we observed no group differences for tracking accuracy, the eye movements of athletes were more target-oriented than those of non-athletes. We concluded that tasks and stimuli intended by researchers to demonstrate that athletes' show better object tracking than non-athletes should be specific to the athletes' type of sport and should use more perception-action coupled measures. An implication of this conclusion is that the differences in object tracking skills between athletes and non-athletes is highly specific to the skills demanded by the athletes' sport.

Knee Biomechanics During Neurocognitively Challenged Drop Landings in Male Elite Soccer Players with Anterior Cruciate Ligament Reconstruction.

Reactive decision-making during athletic movement has been demonstrated to evoke unfavorable biomechanics associated with anterior cruciate ligament (ACL) rupture. However, the current evidence is based on assessments of healthy individuals. We aimed to investigate unplanned jump landing kinetics and knee kinematics in ACL-reconstructed (ACLR) and non-injured athletes. A total of 30 male professional soccer players (n = 15 ACLR after return to play, n = 15 matched controls) performed six drop landings onto a force plate. As a neurocognitive challenge requiring decision-making, a diode flashing in randomly selected colors indicated the requested landing location. Knee joint kinematics (flexion, valgus and tibial rotation angles) assessed with a 10-camera motion capture system, vertical ground reaction force (vGRF), time to stabilization (TTS) and length of the center of pressure (COP) trace (all analyzed from force plate data) were calculated. Cognitive function was assessed using the CNS Vital Signs battery. The ACLR group produced lower knee flexion angles than the control group (median [interquartile range] 50.00° [6.60] vs. 55.20° [4.45], p = .02). In addition, path length of the center of pressure (379mm [56.20] vs. 344mm [37.00], p = .04) and ground reaction force (3.21 N/kg [0.66] vs. 2.87 N/kg [0.48], p = .01) were higher for the ACLR group. No differences were found for knee valgus (p = .96), tibial rotation (p = .83) and TTS (p = .82). ACLR participants scored lower for reaction time (p = .02) and processing speed (p = .01). Unfavorable knee biomechanics were more often related to cognitive function in the ACLR group than in the control group (p < .05). Impaired reactive decision-making during athletic movement may contribute to the high re-injury risk in individuals with ACLR. Prospective studies confirming potential cause-effect relationships are warranted.

Аналіз ланок тіла боксерів під час нанесення ударів за допомогою сучасних технологій

Purpose: to evaluate the effectiveness of using modern computer vision technologies to determine the body parts of boxers during a punch. Material and methods. During the research, the following methods were used: analysis of scientific and methodological literature and Internet resources, analysis of videos and images using machine learning technologies (in particular, computer vision technologies), as well as the application of mathematical statistics methods. The final boxing match in the weight category up to 91 kg at the Olympic Games (Tokyo, 2021) was chosen for analysis. The total number of images for analysis was 1025. In the study, YOLO machine learning models were used to detect the persons who were in the images and MediaPipe to determine the body parts of each of the athletes. Results: as part of a scientific study of detecting the YOLO pattern during a boxing match, fairly high results were obtained. The first athlete in a red uniform was detected with high accuracy - he was not detected on only 1,4% of images; the second athlete in the blue uniform was detected in 98,7 % of all images. The probability of correctly identifying the athlete by the model was 89,5 % and 91,2 %, respectively, for the first and second athlete. Analysis of the results indicates that the MediaPipe model has limitations in identifying certain body parts of athletes during martial arts competitions. In particular, the percentage of images in which body parts could not be identified varies from 21,7 % to 31,7 %. The overall picture shows that the model successfully identifies key body parts such as shoulders, elbows, wrists, palms, and fingers, with a probability of results ranging from 61,5 % to 74,5 %. But visual direct analysis shows certain problems with determining the movements of athletes. Conclusions. An analysis of the results of the use of modern computer vision technologies to determine the body parts of boxers during striking in competitive activities was carried out. The results indicate the high efficiency and accuracy of the YOLO model in the task of detecting athletes during sports events. But at the same time, opposite data were obtained using the MediaPipe model to determine the body parts of athletes. Visual direct analysis shows certain problems with determining the movements of athletes. The general trend is that in the conditions of boxing competitions, the MediaPipe model may face challenges related to the specifics of this sport and require further optimizations to achieve the highest accuracy and reliability in the identification of boxers' body parts. But at the same time, the integration of computer vision technologies into sports events opens up new opportunities for objective analysis and improvement of the technical skills of martial artists. Keywords: boxing, competitive activity, impact, modern technologies, detection, modeling, body parts.

The influence of jump-landing direction on dynamic postural stability following anterior cruciate ligament reconstruction

BackgroundTraditional testing prior to return to sport following anterior cruciate ligament reconstruction typically involves jump-landing tasks in the forward direction. As injury is most likely the result of multiplanar neuromuscular control deficits, assessment of dynamic postural stability using landing tasks that require multiplanar stabilization may be more appropriate. The purpose of this study was to examine how dynamic postural stability is affected when performing jump-landing tasks in three different directions. MethodsFifteen athletes [11 females (18.0 ± 3.0 years) and 4 males (18.5 ± 3.1 years)] following anterior cruciate ligament reconstruction performed a series of single-limb jump-landing tasks in 3 directions. Individual directional stability indices and a composite dynamic postural stability index were calculated using ground reaction force data and were compared using separate one-way repeated measures ANOVAs. FindingsAll directional stability indices demonstrated a significant main effect for jump-landing direction (medial-lateral P < 0.001, η2p = 0.95; anterior-posterior P < 0.001, η2p = 0.97; vertical P = 0.021, η2p = 0.24). The diagonal jump-landing direction produced increased medial-lateral stability and vertical stability scores, while the forward and diagonal jump-landing directions produced increased anterior-posterior stability scores. There was no significant effect for the composite dynamic stability index score. InterpretationJump-landing direction affects dynamic postural stability in all 3 planes of movement in athletes following anterior cruciate ligament reconstruction. Results indicate the potential need to incorporate multiple jump-landing directions to better assess dynamic postural stability prior to return to sport.