Translational sports medicine最新文献

{"title":"Evaluation of the Anatomical Cross-Sectional Area of Psoas Major Muscle Using an Ultrasound Imaging System Combined With an Inertial Measurement Unit: Improved Reliability in the US Using IMU-Based Positioning Techniques.","authors":"Kazuhiro Ito, Etsuko Maeshima, Nobuyuki Arai, Koichi Saito, Hiroya Koshiba, Junko Maruyama, Keiji Asada, Takaaki Nakamata, Kazuki Yamaguchi, Yasuhiko Hatanaka","doi":"10.1155/2024/7774612","DOIUrl":"10.1155/2024/7774612","url":null,"abstract":"<p><p><b>Introduction:</b> Recently, ultrasound (US) imaging has been used to estimate the cross-sectional area of skeletal muscle, but the reliability is uncertain. To improve the reliability of the US, we investigated skeletal muscle thickness measurement using an inertial measurement unit (IMU) to determine the direction of US beam incidence based on posture angle information. In addition, we examined whether the anatomical cross-sectional area (ACSA) of muscle can be estimated from the muscle thickness measured using the US with the IMU. <b>Methods:</b> In Experiment 1, two examiners measured the right psoas major at the fourth lumbar vertebra level in 10 university students using the US with and without an IMU. The intraclass correlation coefficient (ICC) was used to examine intra- and inter-rater variability. In Experiment 2, the two examiners measured the muscle thickness of the right psoas major in 31 male subjects using the US with an IMU. In addition, the ACSA of this muscle was measured using MRI. Pearson's correlation coefficient was used to examine the relationship between muscle thickness and ACSA, and a single regression analysis was performed. <b>Results:</b> Both intrarater reliability ICC (1, 2) and inter-rater reliability ICC (2, 2) were higher when US was used with IMU compared to without IMU (Experiment 1). A significant positive correlation (<i>r</i> = 0.84, <i>p</i> < 0.01) was observed between muscle thickness and ACSA (Experiment 2). The regression equation was significant at <i>R</i> ² = 0.71 (<i>p</i> < 0.01). <b>Conclusion:</b> Using an IMU during US measurement of the psoas major improves intra- and interexaminer reliability and can be used to estimate the ACSA of the muscle.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11537743/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142585016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of 1-Week Weight Loss While Maintaining Total Body Water on Jump Performance.","authors":"Hiroyuki Sagayama, Makiko Toguchi, Jun Yasukata, Rie Tomiga-Takae, Yujiro Kose, Masahiro Ikenaga, Takaaki Komiyama, Mamiko Ichikawa, Nemanja Lakicevic, Yasuki Higaki, Hiroaki Tanaka, Hiroyuki Nunome","doi":"10.1155/2024/6458445","DOIUrl":"10.1155/2024/6458445","url":null,"abstract":"<p><p>Jumping performance is influenced by body composition and excess fat mass impairs performance. Maintaining optimal fat mass and fat-free mass (FFM) is crucial for enhancing jump height. However, there is limited evidence on short-term weight loss programs that reduce fat mass without water restriction and their effects on muscle function and jumping performance. This study aimed to clarify the effects of a 1-week weight loss program on jumping height and muscle function of volleyball players. The weight loss group engaged in two 40 min slow-paced jogging sessions in addition to their daily training routine. Energy intake was restricted without limitations on water intake. Total body water and body composition using the deuterium dilution method, muscle strength, and jump height before and after 1 week were evaluated for those in the weight loss and control groups. Body mass was significantly reduced in the weight loss group (-2.7 ± 1.3%, <i>p</i> < 0.05) with a significant reduction in fat mass (-17.7 ± 10.7%, <i>p</i> < 0.05). Meanwhile, there were no significant changes in total body water or FFM. Muscle strength and power tests indicated no significant differences between the groups; no notable differences were observed in handgrip strength or knee extension torque. The height of a single vertical and continuous jump remained consistent pre- and postintervention in the control group. In the weight loss group, although the height of a single vertical jump exhibited a slight decline postintervention, the height of a continuous jump displayed no significant changes. The short-term weight loss program significantly reduced fat mass without compromising muscle function, which is crucial for sports performance. These findings may benefit other athletes who require fat mass reduction while maintaining muscle function and help create new programs during specific training phases.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11527525/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142559591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lower Extremity Asymmetry Values Derived From Multiple Strength Testing Modes Are Associated With Perceived Functional Capabilities Among University Athletes.","authors":"Zachary J McClean, Nathan Boon-van Mossel, Mark McKenzie, Per Aagaard, Walter Herzog, Kati Pasanen, Victor Lun, Matthew J Jordan","doi":"10.1155/2024/5589056","DOIUrl":"10.1155/2024/5589056","url":null,"abstract":"<p><p><b>Background:</b> Muscle strength asymmetry and athlete introspective measures are associated with musculoskeletal (MSK) sport injury and reinjury. However, the interrelationship between mechanical and subjective measures of concentric and eccentric limb function needs further exploration. This includes investigating if an athlete's perception of their overall MSK function influences limb asymmetry across different testing modalities. <b>Objectives:</b> To (i) explore the interrelationship between mechanical and subjective measures of lower limb function in university athletes and (ii) compare the consistency in interlimb strength asymmetries across different strength tests in groups of athletes with good, fair, and poor perceived limb function. <b>Methods:</b> University athletes (<i>n</i> = 175; <i>n</i> = 87 females) from six sports completed four tests of muscle strength, power, and plyometric function along with an assessment of perceived limb function using the Sport Fitness Index (SFI). Participants were categorized into high (GOOD_SFI), fair (FAIR_SFI), and poor (POOR_SFI) perceived overall MSK function (perceived function) groups. Strength asymmetry indexes evaluated interlimb differences in concentric and eccentric maximal strength, countermovement jump (CMJ) impulse, unilateral CMJ height, and reactive strength index in unilateral repeat hop testing. Cumulative link mixed-effects models assessed the relationship between strength asymmetries and perceived limb function. <b>Results:</b> The POOR_SFI group showed increased asymmetry in concentric strength testing (<i>p</i> = 0.022), more consistent interlimb asymmetries (<i>p</i> < 0.001), and reduced overall muscle strength compared to the GOOD_SFI group. <b>Conclusion:</b> Higher interlimb asymmetry in maximal concentric strength measures along with reduced muscle strength was found in the POOR_SFI group compared to the GOOD_SFI group. The POOR_SFI group also showed greater consistency in muscle strength asymmetry derived across different tasks.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11524692/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142549366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Athlete Monitoring Systems in Elite Men's Basketball: Challenges, Recommendations, and Future Perspectives.","authors":"Jakob Burger, Alexander-Stephan Henze, Thomas Voit, Richard Latzel, Othmar Moser","doi":"10.1155/2024/6326566","DOIUrl":"10.1155/2024/6326566","url":null,"abstract":"<p><p>Athlete monitoring systems (AMSs) provide a centralized platform for integrating, processing, analyzing, and graphing various monitoring data to help coaches manage the rigorous demands of elite men's basketball players, who frequently participate in high-stress games with minimal recovery time. This review synthesizes current challenges in deploying AMSs, underscores their role in injury prevention and performance optimization, and discusses technological advances that could enhance their utility. Key challenges include selecting appropriate monitoring methods based on human and financial resources, accuracy of data collection, real-time data processing, and personalization of training regimens. Due to the weaknesses and limitations of each monitoring method, it is recommended that both objective (e.g., external load data, heart rate measures, and biomarkers) and subjective (athlete-reported outcome measures) monitoring data be integrated into an AMS to provide a holistic insight of the athlete's health and readiness. In addition, decision support systems integrated into an AMS can help coaches quickly gain an overview of their players' current condition and make informed decisions about daily load and recovery management. In this context, future perspectives suggest the potential for AMSs to incorporate predictive analytics and artificial intelligence to further enhance decision-making processes in elite men's basketball. Our findings underscore the need for continued innovation and rigorous validation of AMS technologies to ensure they meet the evolving demands of professional sports environments.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511587/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142514397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Injury Prevention Programme in Physical Education Teacher Education Students: Process Evaluation Using the RE-AIM Sports Setting Matrix.","authors":"Lennert Goossens, Greet Cardon, Erik Witvrouw, Evert A L M Verhagen, Dirk De Clercq","doi":"10.1155/2024/5717748","DOIUrl":"https://doi.org/10.1155/2024/5717748","url":null,"abstract":"<p><p>This study aimed to evaluate the feasibility and effectiveness of an injury prevention programme for Physical Education Teacher Education (PETE) students, consisting of an injury awareness module and implementing prevention strategies during intracurricular lessons. Participants from four PETE programmes formed the intervention group (<i>n</i> = 4 programme directors, <i>n</i> = 38 sports lecturers, <i>n</i> = 859 students), while those from four other programmes were the controls (<i>n</i> = 4 programme directors, <i>n</i> = 34 sports lecturers, <i>n</i> = 721 students). Programme directors and sports lecturers received a three-hour workshop on sports injury prevention. The feasibility and effectiveness of the intervention were evaluated following the RE-AIM Sports Setting Matrix. Reach, adoption, and implementation of the prevention strategies were high, but implementation of the awareness module was moderate, ranging from 25% to 75%. Maintenance in terms of intentions ranged from 25% to 75% for aspects of the awareness module and averaged 68% for the prevention strategies. Significantly more static stretching (<i>p</i>=0.029), dynamic stabilisation (<i>p</i> < 0.001), and core stability (<i>p</i>=0.001) were implemented in the intervention group compared to the control group. Injury prevention behaviour and knowledge in students did not increase after the intervention. In conclusion, moderate feasibility of an injury prevention intervention for PETE students was found. Sports lecturers implemented prevention strategies in their lessons frequently, but future interventions should develop more dissemination initiatives.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11412748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142303027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Return to Sport, Reinjury Rate, and Tissue Changes after Muscle Strain Injury: A Narrative Review.","authors":"Mette W Wulff, Abigail L Mackey, Michael Kjær, Monika L Bayer","doi":"10.1155/2024/2336376","DOIUrl":"https://doi.org/10.1155/2024/2336376","url":null,"abstract":"<p><p>A major challenge in sports medicine is to facilitate the fastest possible recovery from injury without increasing the risk of subsequent reruptures, and thus effective rehabilitation programs should balance between these two factors. The present review focuses on examining the role of different resistance training interventions in rehabilitation of acute muscle strain in the time frame from injury until return to sport (RTS), the rate of reinjuries, and tissue changes after injury. Randomized, controlled trials dealing with a component of resistance training in their rehabilitation protocols, as well as observational studies on tissue morphology and tissue changes as a result to muscle strain injuries, were included. The mean time for RTS varied from 15 to 86 days between studies (<i>n</i> = 8), and the mean rate of reinjury spanned from 0 to 70%. Eccentric resistance training at long muscle length and rapid introduction to rehabilitation postinjury led to significant improvement regarding RTS, and core-stabilizing exercises as well as implementing an individualized algorithm for rehabilitation seem to reduce the risk of reinjury in studies with a high rerupture rate. Independent of the rehabilitation program, structural changes appear to persist for a long time, if not permanently, after a strain injury.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11390226/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142303028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Specific Motor Skills through System Wall Bouldering Training: A Pilot Study.","authors":"Nicolay Stien, Kaja Langer, Vidar Andersen, Gunn Helene Engelsrud, Elias Olsen, Atle Hole Saeterbakken","doi":"10.1155/2024/5584962","DOIUrl":"10.1155/2024/5584962","url":null,"abstract":"<p><p>This study evaluated the effects of a five-week period of practicing specific climbing movements using a system wall on motor skills and bouldering performance compared to self-regulated, conventional bouldering. Thirteen advanced female boulderers (age: 24.5 ± 3.6 years, height: 166.9 ± 3.4 cm, and body mass: 63.4 ± 8.0 kg) were divided into an experimental group (<i>n</i> = 7) and a control group (<i>n</i> = 6). Both groups continued their normal training routines during the intervention, but the experimental group dedicated 30 minutes of their climbing time twice per week to practicing specific motor skills on a system climbing wall. Before and after the intervention, the participants attempted two boulder problems on the same wall. The performance was registered as the number of attempts to complete the boulder problems and as the highest hold reached within four attempts. Video recordings of climbers' best attempts, capturing the highest hold reached from a perspective directly behind them, were analyzed by three independent experts. The analysis was conducted using a five-point scale across six categories of movement quality. Modest enhancements in certain motor skills and performance were evident in both groups, revealing no significant distinction between them. The results underscore the efficacy of incorporating system walls into the training routines of advanced female boulder climbers, but the absence of between-group differences highlights the significance of individual preferences when choosing between conventional and system wall bouldering.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11250695/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141629487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Football Was the Most Common Sport among 344 Consecutive Athletes Treated Surgically for Jumper's Knee at an International Tendon Clinic.","authors":"Håkan Alfredson, Christoph Spang, Markus Waldén","doi":"10.1155/2024/5534733","DOIUrl":"10.1155/2024/5534733","url":null,"abstract":"<p><strong>Objectives: </strong>Jumper's knee, or proximal patellar tendinopathy, is commonly seen among athletes in leg explosive sports, and for a subgroup surgical treatment is needed. The aim of this study was to identify what type of sports were most frequent among athletes treated surgically for Jumper's knee at an international tendon clinic during a consecutive 13-year period.</p><p><strong>Methods: </strong>The study included 344 consecutive patients (306 males, mean age 27 years, range 17-58; 38 females, mean age 24 years, range 18-44) from 21 different countries seeking help for therapy-resistant jumper's knee. There were 274 elite athletes, 168 being full-time professionals. All were diagnosed to have tendinopathy in the proximal patellar tendon and were operated on with ultrasound- and Doppler-guided arthroscopic shaving surgery.</p><p><strong>Results: </strong>The single most common sport was football (<i>n</i> = 95, 28%), followed by rugby (<i>n</i> = 37, 11%) and handball (<i>n</i> = 32, 9%), with 117 (34%) playing at a professional level. The rest of the athletes participated in 17 other different elite sports and nine recreational sports (running/jogging, padel, squash, biking, gym training, bowling, cheerleading, dancing, and ultimate frisbee).</p><p><strong>Conclusions: </strong>Football was the most common sport among patients requiring surgical treatment for jumper's knee, constituting 28% of all patients, and together with rugby and handball they constituted almost half of all patients. There was a wide sport distribution with 29 different team and individual sports represented.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11227375/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141556173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is It Time to Step outside the Laboratory? The Feasibility of Field-Based Examination of Exercise-Induced Hypoalgesia in Elite Badminton Athletes with and without Knee Pain.","authors":"Brooke K Coombes, M Dilani Mendis, Felix Leung, Julie A Hides","doi":"10.1155/2024/2953220","DOIUrl":"10.1155/2024/2953220","url":null,"abstract":"<p><strong>Aim: </strong>To investigate the feasibility of testing exercise-induced hypoalgesia (EIH) in a field setting. The effect of knee pain on EIH was also explored.</p><p><strong>Design: </strong>Within-group pre-post design.</p><p><strong>Materials and methods: </strong>Fourteen athletes (8 male, 6 female) competing at an international level in badminton were tested on the sideline during an in-season training session. Participants completed questionnaires and a single leg decline squat to evaluate the presence of knee pain. A blinded examiner measured PPT over the quadriceps muscle before and after two conditions (3-minute quiet rest and 3-minute isometric wall squat).</p><p><strong>Results: </strong>The exercise protocol was completed by 13 (93%) participants. Mean (SD) exertion was 8.4 (1.7), and mean thigh pain was 7.9 (2.0) at 3 minutes. Very high reliability was observed for PPT collected before and after rest (ICC 0.94, 95% CI 0.85, 0.98). PPT significantly increased by 22.4% (95% CI 15.1, 29.7) after wall squat but not after rest. Relative increases in PPT were similar in participants with and without knee pain on single leg decline squat (22.2% versus 22.6%, 7 participants each).</p><p><strong>Conclusion: </strong>Simple, field-based tests of endogenous analgesia are feasible and could provide new opportunities to evaluate an athlete's risk of persistent pain.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11221980/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141499861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Countermovement Depth on the Neuromechanics of a Vertical Jump.","authors":"Malachy P McHugh, Josef Alexander Cohen, Karl F Orishimo, Ian J Kremenic","doi":"10.1155/2024/7113900","DOIUrl":"10.1155/2024/7113900","url":null,"abstract":"<p><p>The purpose of this study was to examine kinematic, kinetic, and muscle activation metrics during countermovement jumps (CMJs) with varying countermovement depths. The hypothesis was that a shallow countermovement depth would compromise jump height by disrupting neuromechanical control. Ten healthy men (age 26 ± 8 yr, height 1.81 ± 0.08 m, mass 83.5 ± 9.0 kg) performed maximal CMJs at self-selected countermovement depth (self-selected CMJ), at reduced countermovement depth (shallow CMJ), and at increased countermovement depth (deep CMJ). Three jumps were performed in each condition on force plates with ankle, knee, and hip motion recorded and electromyograms (EMG) recorded from the gluteus maximus (GM), vastus lateralis (VL), and medial gastrocnemius (MG) muscles. During CMJs, the knee flexion angle was recorded with an electrogoniometer. Jumpers were instructed to flex at least 15% less (shallow CMJ) and at least 15% more (deep CMJ) than the self-selected CMJs. Kinematic, kinetic, and EMG metrics were compared between the different CMJ depths using repeated measures ANOVA. Compared with self-selected CMJs, shallow CMJs had 26% less countermovement depth (<i>P</i> < 0.001, effect size 1.74) and the deep CMJs had 28% greater countermovement depth (<i>P</i> < 0.001, effect size 1.56). Jump height was 8% less for the shallow vs. self-selected CMJs (<i>P</i> = 0.007, effect size 1.09) but not different between self-selected and deep CMJs (<i>P</i> = 0.254). Shallow CMJs differed from self-selected CMJs at the initiation of the countermovement (unweighting). For self-selected CMJs, force dropped to 43% of body weight during unweighting but only to 58% for shallow CMJs (<i>P</i> = 0.015, effect size 0.95). During unweighting, VL EMG averaged 5.5% of MVC during self-selected CMJs versus 8.1% for shallow CMJs (<i>P</i> = 0.014, effect size 0.97). Percent decline in jump height with shallow versus self-selected CMJs was correlated with the difference in VL EMG during unweighting between shallow and self-selected CMJs (<i>r</i> = 0.651, <i>P</i> = 0.041). A deep countermovement prolonged the time to execute the jump by 38% (<i>P</i> < 0.010, effect size 1.04) but did not impair CMJ force metrics. In conclusion, self-selected countermovement depth represents a tradeoff between dropping the center of mass sufficiently far and executing the jump quickly. Unweighting at the initiation of a CMJ appears to be a critical element in the neuromechanics of the CMJ.</p>","PeriodicalId":75247,"journal":{"name":"Translational sports medicine","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11208864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141473366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}