Medicine and Science in Sports and Exercise最新文献

{"title":"Frequency Matters: The Influence of Stimulation Frequency on Force Loss for Human Females and Males.","authors":"Alexander D Paish, Neil D Eves, Chris J McNeil","doi":"10.1249/MSS.0000000000003724","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003724","url":null,"abstract":"<p><strong>Purpose: </strong>Most studies applying repeated neuromuscular electrical stimulation (NMES) to assess intrinsic contractile properties employ frequencies considerably greater than the mean motor unit discharge rate (MUDR) for a given force level. It is hypothesized that force loss increases with stimulation frequency, but this has not been evaluated in the same pool of participants when other parameters are unchanged. Furthermore, there is a paucity of research investigating possible sex-based differences for force loss during an NMES protocol, with the presence or absence of a group difference seemingly dependent on stimulation frequency. To address these limitations, we compared force loss of electrically-evoked contractions at (10 Hz), slightly above (15 Hz), and well above (30 Hz) the expected mean MUDR of the quadriceps at 25% maximal voluntary force.</p><p><strong>Methods: </strong>On three separate occasions, 24 participants (12 females) received 3 minutes of intermittent NMES (10, 15 or 30 Hz) over the quadriceps of the dominant leg.</p><p><strong>Results: </strong>Force impairment increased with NMES frequency (19.8 ± 14.5%, 42.6 ± 8.1%, and 52.9 ± 4.7% for 10, 15, and 30 Hz, respectively), with no significant differences between sexes. Relative to the start of each task, the rates of force development (RFD) and relaxation (RFR) slowed markedly during the 10, 15, 30 Hz fatiguing protocols (RFD: 42.1 ± 13.5, 61.6 ± 13.2, and 75.9 ± 9.8%; RFR: 38.0 ± 13.9, 64.2 ± 9.1, and 80.4 ± 5.0%, respectively). RFD impairment was less at 10 compared to 15 and 30 Hz, whereas the slowing of RFR increased with NMES frequency. Post-hoc analysis revealed no sex-based differences at any time point for RFD or RFR.</p><p><strong>Conclusions: </strong>These findings underscore the impact of stimulus frequency on muscle fatigability and highlight a lack of sex-based differences for electrically-evoked force loss, emphasizing the need for appropriate frequency selection in NMES protocols.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achilles Subtendons Stiffness Differ in People with and without Achilles Tendinopathy.","authors":"Marion Crouzier, Stéphane Baudry, Benedicte Vanwanseele","doi":"10.1249/MSS.0000000000003717","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003717","url":null,"abstract":"<p><strong>Purpose: </strong>Previous work showed altered mechanical properties of the Achilles tendon in the presence of tendinopathy, considering the Achilles tendon as a homogeneous structure with the gastrocnemius medialis (GM) subtendon representative of it. However, the Achilles tendon consists of three semi-independent structures: the GM, gastrocnemius lateralis (GL) and soleus (SOL) subtendons, each independently pulled by their respective muscle. The aim of this study was (i) to compare the mechanical properties of the different Achilles subtendons in humans in vivo by considering the force of each muscle within the triceps surae group and (ii) to determine whether the loss of stiffness in the presence of tendinopathy is specific to individual subtendons. We hypothesized that (i) stiffness would differ between subtendons in healthy participants and that (ii) the loss of stiffness in people with Achilles tendinopathy compared to healthy controls would not affect the three subtendons identically.</p><p><strong>Methods: </strong>Fourteen participants with tendinopathy and 14 controls performed ramped isometric plantarflexions. Simultaneously, the elongation of the three subtendons was recorded, and an estimate of the force pulling on each was made (from muscle activation and volume). Stiffness was calculated from the individual muscle index of force-subtendon elongation relationships.</p><p><strong>Results: </strong>Results showed that regardless of the group, SOL stiffness was significantly higher than stiffness of both gastrocnemii (muscle effect: p < 0.001). A muscle x group interaction showed specific loss of stiffness of GL in Achilles tendinopathy compared to controls (p = 0.029, d = 1.3), with no between-group difference for GM or SOL (both p > 0.925, d = 0.3).</p><p><strong>Conclusions: </strong>This study supports the hypothesis that the biomechanical properties of the Achilles tendon differ between subtendons and further shows that the loss of stiffness in Achilles tendinopathy is specific to the GL subtendon.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical Activity and Sedentary Behavior Differ by Sex During the First Six Months after Anterior Cruciate Ligament Reconstruction.","authors":"Elizabeth Wellsandt, David Werner, Matthew Tao, Kaleb Michaud, Christopher Wichman, Yvonne M Golightly","doi":"10.1249/MSS.0000000000003714","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003714","url":null,"abstract":"<p><strong>Methods: </strong>PA and sedentary behavior were measured in an observational cohort of 30 participants (19.6 ± 4.9 years old, 66.7% female) using a 3-axis accelerometer before (Pre-Op) and at two, four and six months after ACL reconstruction. Daily steps, daily minutes of moderate to vigorous PA (MVPA) and percentage of wake time in sedentary behavior (%SED) were measured. Two-by-four (sex-by-time) repeated measures analyses of variance were used to test changes in PA and %SED.</p><p><strong>Results: </strong>In females and males, daily steps and MVPA increased from two to four months after ACL reconstruction (all p < 0.05) but not between other consecutive time points. %SED did not change between any consecutive time points. At six months, females walked fewer daily steps (p = 0.002; females: 7003 ± 2068; males: 10,406 ± 3277), spent fewer minutes in MVPA (p = 0.010; females: 31.3 ± 14.6; males: 54.9 ± 32.4) and spent more time in %SED (p = 0.003; females: 67.9 ± 7.4; males: 57.5 ± 9.5).</p><p><strong>Conclusions: </strong>PA levels increased in females and males from two to four months after ACL reconstruction but not between other consecutive time points from before through six months after surgery. Females completed less PA and spent more time in sedentary behavior than males and may require greater monitoring to improve PA after ACL reconstruction. The disparity in PA and sedentary behavior across sex follows consistent previous findings that outcomes after ACL reconstruction are poorer in females compared to males.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bone Health of Female Elite Cyclists Is Characterized by Impaired Cortical and Trabecular Microarchitecture.","authors":"Luuk Hilkens, Melissa S A M Bevers, Caroline E Wyers, Luc J C van Loon, Joop P van den Bergh, Jan-Willem van Dijk","doi":"10.1249/MSS.0000000000003718","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003718","url":null,"abstract":"<p><strong>Purpose: </strong>Many elite road-race cyclists have low areal bone mineral density (aBMD) as previously shown by dual-energy X-ray absorptiometry (DXA). However, aBMD provides limited insight into bone quality. Therefore, this cross-sectional study aimed to assess volumetric BMD (vBMD), bone microarchitecture, and bone strength in elite road-race cyclists using high-resolution peripheral computed tomography (HR-pQCT), along with aBMD measured by DXA.</p><p><strong>Methods: </strong>Twenty female elite (Tier 3/ 4) road-race cyclists (21 ± 2 y; BMI 20.8 ± 1.6 kg/m2) had DXA scans at the hip, lumbar spine, and total body to assess aBMD, and HR-pQCT scans at the distal radius and tibia to assess vBMD, bone microarchitecture, and failure load. Z-scores were calculated for all outcomes, with Z-scores <-1 considered as low or impaired. The risk of low energy availability was assessed using the Low Energy Availability in Females Questionnaire (LEAF-Q).</p><p><strong>Results: </strong>Low aBMD was observed in 20%, 25%, 35%, and 10% of the participants at the hip, femoral neck, lumbar spine, and total body, respectively. Low total vBMD was present in 45% and 40% at the distal radius and tibia, respectively. With regard to bone microarchitecture, the tibial cortical area and tibial cortical thickness were low in 40% and 60% of the participants, respectively, and number and thickness of trabeculae at the tibia were low in 40% and 30% of the participants. The impairments were less pronounced at the distal radius. Failure load was low in 15% (radius) and 20% (tibia) of the participants.</p><p><strong>Conclusions: </strong>Along with low aBMD, a substantial proportion of female elite cyclists had impaired bone microarchitecture, mainly characterized by a low cortical area and thickness and low trabecular number and thickness, especially at the distal tibia.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Dynamics of Locomotor Neuromuscular Fatigue during Ramp-Incremental Cycling to Intolerance.","authors":"Molly M Baldwin, Matt R Chadwick, Alan P Benson, Harry B Rossiter, Carrie Ferguson","doi":"10.1249/MSS.0000000000003414","DOIUrl":"10.1249/MSS.0000000000003414","url":null,"abstract":"<p><strong>Introduction: </strong>Traditional neuromuscular fatigue assessments are not task-specific and are unable to characterize neuromuscular performance decline during dynamic whole-body exercise. This study used interleaved maximal isokinetic cycling efforts to characterize the dynamics of the decline in neuromuscular performance during ramp-incremental (RI) cycle ergometry exercise to intolerance.</p><p><strong>Methods: </strong>Eleven young healthy participants (10 male/1 female) performed two RI cycle ergometry exercise tests to intolerance: 1) RI exercise with peak isokinetic power (Piso) at 80 rpm measured at baseline and immediately at intolerance from a maximal ~6 s effort, and 2) RI exercise where additional Piso measurements were interleaved every 90 s to characterize the decline in neuromuscular performance during the RI test. Muscle excitation was measured using EMG during all Piso assessments, and pulmonary gas exchange was measured throughout.</p><p><strong>Results: </strong>Baseline Piso was 832 ± 140 W and RI exercise reduced Piso to 349 ± 96 W at intolerance ( P = 0.001), which was not different from flywheel power at intolerance (303 ± 96 W; P = 0.292). There was no reduction in Piso between baseline cycling and gas exchange threshold (GET; baseline Piso vs mean Piso below GET: 828 ± 146 vs 815 ± 149 W; P = 1.00). Piso fell progressively above GET until intolerance (Piso every 90 s above GET: 759 ± 139, 684 ± 141, 535 ± 144, 374 ± 117 W; each P < 0.05 vs baseline and mean Piso below GET). Peak muscle excitation (EMG) was also reduced only above GET (73% ± 14% of baseline, at intolerance; P < 0.05). However, the reduction in peak Piso preceded the reduction in peak muscle excitation.</p><p><strong>Conclusions: </strong>The dynamics of the decline in neuromuscular performance (reduction in Piso and EMG) during RI exercise are consistent with known intensity-dependent metabolic and traditional pre-post neuromuscular fatigue responses to discrete bouts of constant-power exercise.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"700-709"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11878584/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140094369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing Step Counting Algorithms for High-Resolution Wrist Accelerometry Data in NHANES 2011-2014.","authors":"Lily Koffman, Ciprian Crainiceanu, John Muschelli","doi":"10.1249/MSS.0000000000003616","DOIUrl":"10.1249/MSS.0000000000003616","url":null,"abstract":"<p><strong>Purpose: </strong>To quantify the relative performance of step counting algorithms in studies that collect free-living high-resolution wrist accelerometry data and to highlight the implications of using these algorithms in translational research.</p><p><strong>Methods: </strong>Five step counting algorithms (four open source and one proprietary) were applied to the publicly available, free-living, high-resolution wrist accelerometry data collected by the National Health and Nutrition Examination Survey (NHANES) in 2011-2014. The mean daily total step counts were compared in terms of correlation, predictive performance, and estimated hazard ratios of mortality.</p><p><strong>Results: </strong>The estimated number of steps were highly correlated (median, 0.91; range, 0.77-0.98), had high and comparable predictive performance of mortality (median concordance, 0.72; range, 0.70-0.73). The distributions of the number of steps in the population varied widely (mean step counts range from 2453 to 12,169). Hazard ratios of mortality associated with a 500-step increase per day varied among step counting algorithms between HR = 0.88 and 0.96, corresponding to a 300% difference in mortality risk reduction ([1-0.88] / [1-0.96] = 3).</p><p><strong>Conclusions: </strong>Different step counting algorithms provide correlated step estimates and have similar predictive performance that is better than traditional predictors of mortality. However, they provide widely different distributions of step counts and estimated reductions in mortality risk for a 500-step increase.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"746-755"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142716588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is the Force-Velocity Profile for Free Jumping a Sound Basis for Individualized Jump Training Prescriptions?","authors":"Maarten F Bobbert, Kolbjørn Lindberg, Gøran Paulsen","doi":"10.1249/MSS.0000000000003612","DOIUrl":"10.1249/MSS.0000000000003612","url":null,"abstract":"<p><strong>Introduction: </strong>Formulating individualized optimized jump training prescriptions based on the force-velocity profile has become popular, but its effectiveness has been contested. Such training programs have opposite effects on \"maximal average force\" and \"maximal average shortening velocity,\" and we set out to investigate which training-induced changes in the neuromuscular system could cause such effects.</p><p><strong>Methods: </strong>We used a musculoskeletal simulation model with four body segments and six muscle-tendon actuators to simulate vertical squat jumps with different loads. Independent input was muscle stimulation over time, which was optimized for maximal jump height. We determined the force-velocity profile for a reference model and investigated how it changed when we modified muscle properties and initial postures.</p><p><strong>Results: </strong>We could not reproduce the reported training effects by realistically improving muscle properties (maximal force, shortening velocity, and rate of force development) or modifying initial postures of the model. However, the profile was very sensitive to gains in jump height at low loads but not high loads, or vice versa. Reaching maximal height in force-velocity profile jumps requires skill. We argued that submaximal performance in low-load or high-load jumps caused by lack of skill could be responsible for large imbalances in profiles before training. Differential skill training promoted by the individualized optimized approach could explain quick changes toward a balanced profile.</p><p><strong>Conclusions: </strong>If the success of individualized optimized training studies is explained by selective skill improvements, training effects are unlikely to transfer to other tasks, and individualized optimized training will not be superior to other types of training.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"727-737"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142739894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Single Night in Hypoxia Either with or without Ketone Ester Ingestion Reduces Sleep Quality without Impacting Next-Day Exercise Performance.","authors":"Myrthe Stalmans, Domen Tominec, Ruben Robberechts, Wout Lauriks, Monique Ramaekers, Tadej Debevec, Chiel Poffé","doi":"10.1249/MSS.0000000000003604","DOIUrl":"10.1249/MSS.0000000000003604","url":null,"abstract":"<p><strong>Background: </strong>Sleeping at altitude is highly common in athletes as an integral part of altitude training camps or sport competitions. However, concerns have been raised because of expected negative effects on sleep quality, thereby potentially hampering exercise recovery and next-day exercise performance. We recently showed that ketone ester (KE) ingestion beneficially impacted sleep after strenuous, late evening exercise in normoxia, and alleviated hypoxemia. Therefore, we hypothesized that KE ingestion may be an effective strategy to attenuate hypox(em)ia-induced sleep dysregulations.</p><p><strong>Methods: </strong>Eleven healthy male participants completed three experimental sessions including normoxic training and subsequent sleep in normoxia or at a simulated altitude of 3000 m while receiving either KE or placebo postexercise and presleep. Sleep was evaluated using polysomnography, whereas next-day exercise performance was assessed through a 30-min all-out time trial (TT 30' ). Physiological measurements included oxygen status, heart rate variability, ventilatory parameters, blood acid-base balance, and capillary blood gases.</p><p><strong>Results: </strong>Hypoxia caused a ~3% drop in sleep efficiency, established through a doubled wakefulness after sleep onset and a ~22% reduction in slow wave sleep. KE ingestion alleviated the gradual drop in SpO 2 throughout the first part of the night, but did not alter hypoxia-induced sleep dysregulations. Neither KE nor nocturnal hypoxia affected TT 30' performance, but nocturnal hypoxia hampered heart rate recovery after TT 30' .</p><p><strong>Conclusions: </strong>We observed that sleeping at a 3000 m altitude impairs sleep efficiency. Although this hypoxia-induced sleep disruption was too subtle to limit exercise performance, we for the first time indicate that sleeping at altitude might impair next-day exercise recovery. KE alleviated nocturnal hypoxemia only when SpO 2 values dropped below ~85%, but this did not translate into improved sleep or next-day exercise performance.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"807-819"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11878631/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cigarette Smoking Impairs Cardiorespiratory and Metabolic Response at Peak Incremental Exercise and during Recovery in Young, Physically Active Adults.","authors":"Marta Borrelli, Christian Doria, Nicholas Toninelli, Stefano Longo, Giuseppe Coratella, Emiliano Cè, Susanna Rampichini, Fabio Esposito","doi":"10.1249/MSS.0000000000003602","DOIUrl":"10.1249/MSS.0000000000003602","url":null,"abstract":"<p><strong>Purpose: </strong>Cigarette smoking (CS) induces systemic changes that impair cardiorespiratory and muscular function both at rest and during exercise. Although these abnormalities are reported in sedentary, middle-aged smokers (SM) with pulmonary disease, few and controversial studies focused on young, physically active SM at the early stage of smoking history. This study aimed at assessing the effect of CS on cardiorespiratory and metabolic response during an incremental test and the subsequent recovery in young, physically active SM without known lung or cardiovascular disease.</p><p><strong>Methods: </strong>After pulmonary function evaluation, 12 SM (age: 22±2 yr; body mass: 75±8 kg; stature: 1.78±0.06 m; 12±4 cigarette per day for 6±2 yr; mean ± SD) and 12 non-SM (control group; age: 23±1 yr; body mass: 76±8 kg; stature: 1.79±0.08 m) matched for age and exercise habits underwent an exhaustive incremental step test (25 W/2 min) on a cycle ergometer. Pulmonary O 2 uptake (V̇O 2 ), expiratory ventilation (V̇ E ), heart rate ( fH ) responses and lactate concentration were assessed during the test and subsequent recovery.</p><p><strong>Results: </strong>Despite similar static lung volumes, SM reported lower peak expiratory flow (-23%; P = 0.003) and maximal voluntary ventilation (-10%; P = 0.003). At submaximal exercise, no differences in the cardiorespiratory and metabolic were noted between the two groups. However, SM exhibited ventilatory ( P < 0.01) and lactate thresholds at lower work rates ( P = 0.01). At peak exercise, SM exhibited lower V̇O 2 (-8%; P = 0.02), mechanical power (-11%; P = 0.02), and V̇ E (-9%; P = 0.01). During recovery, SM showed longer time constants (τ) in V̇O 2 (+52%; P = 0.002), V̇ E (+19%; P = 0.027) and fH (+21%; P = 0.022) and smaller fH at 30 s of recovery (HRR30; -31%; P = 0.032).</p><p><strong>Conclusions: </strong>These results are compatible with an early CS-related impairment of the cardiorespiratory and metabolic function even in young individuals with relatively short smoking history.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"680-690"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11878581/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Varus Strength of the Medial Elbow Musculature for Stress Shielding of the Ulnar Collateral Ligament in Competitive Baseball Pitchers.","authors":"Toshimasa Yanai, Kengo Onuma, Tomoyuki Nagami","doi":"10.1249/MSS.0000000000003614","DOIUrl":"10.1249/MSS.0000000000003614","url":null,"abstract":"<p><strong>Purpose: </strong>Valgus load opens the medial elbow compartment, causing elongation of the ulnar collateral ligament (UCL) that can eventually lead to attenuation and failure. Ideally, the muscles surrounding the medial aspect of elbow joint should coordinate medial elbow compression to prevent the medial elbow compartment from opening and loading the UCL. This study aimed to determine whether baseball pitchers have sufficient elbow varus strength to unload the UCL during pitching.</p><p><strong>Methods: </strong>Using an electromagnetic tracking device, we measured the peak elbow varus moment during pitches (fastball, slider, curveball, and changeup) by 14 professional and 8 collegiate pitchers. Elbow varus strength was measured with an isokinetic dynamometer system while the medial elbow joint space was monitored using ultrasonography. A paired t -test was used to compare the peak varus moment generated during pitching with the varus strength, and the relative intensity of muscular output required to unload the UCL was determined.</p><p><strong>Results: </strong>Except for curveballs, the muscular varus strength (57.5 ± 9.2 N·m) was not significantly larger ( P = 0.165-0.853) than the peak varus moments during pitching (55.4 ± 13.0 N·m). Ten participants did not have sufficient muscular varus strength to completely unload the UCL from valgus loading when throwing fastballs and other pitch types. The relative intensity of muscular torque output required for stress shielding of the UCL ranged from 89.1% ±21.7% maximum voluntary isometric varus strength (MVIVS) for curveballs to 103.1% ±26.5% MVIVS for fastballs.</p><p><strong>Conclusions: </strong>Our findings demonstrate that most of the valgus load on the elbow joint during pitching can be counteracted by the muscular varus moment, but valgus loading on the UCL is likely unavoidable in baseball pitching.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"791-799"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11878578/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142710554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}