Journal of Electromyography and Kinesiology最新文献_第5页

Motor performance and aging in males and females 男性和女性的运动表现和衰老

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-18 DOI: 10.1016/j.jelekin.2025.103066

Sandra K. Hunter

Advanced aging is accompanied by marked declines in motor performance in males and females including reductions in strength, speed and power of limb muscles that begin as early as midlife (∼>40 years) and accelerate from ∼65 years of age. Low muscle power and strength is exacerbated by increased fatigability with aging of limb muscles during dynamic contraction tasks and larger performance variability (between and within older adults), especially in older females. Starting in midlife, females exhibit earlier and larger age-related reductions in muscle strength and power and athletic performance than males of the same age and this is paralleled by increased prevalence of poor health, frailty, and loss of independence. This review presents evidence of key neural and muscular mechanisms affecting the motor unit, the age-related reductions in motor performance and the increased variability in healthy old and very old males and females. Muscular atrophy, particularly of fast-twitch (Type II) fibers, contractile slowing, degradation of neuromuscular junctions, and impairments in motor unit activation collectively underpin sarcopenia and impaired motor and functional performance among older adults. This review also briefly highlights approaches to understanding the protective effects of physical activity and high-resistance training on the age-related changes in muscle and neural function, even in the oldest adults. Such interventions delay functional declines and emphasize the adaptability of the aging neuromuscular system. Opportunities abound for future research to focus on understanding the specific mechanisms driving neural and muscular degeneration and optimizing exercise strategies to improve neuromuscular health of old males and females.

老年化伴随着男性和女性运动能力的显著下降，包括肢体肌肉的力量、速度和力量的下降，这种下降早在中年（40岁）就开始了，从65岁开始加速。在动态收缩任务中，肢体肌肉的老化和更大的表现变异性（老年人之间和老年人内部），特别是老年女性，会增加疲劳，从而加剧肌肉力量和力量的低下。从中年开始，与同龄男性相比，女性在肌肉力量、力量和运动表现方面表现出更早、更大的与年龄相关的下降，与此同时，健康状况不佳、身体虚弱和丧失独立性的情况也越来越普遍。这篇综述提供了影响运动单元的关键神经和肌肉机制的证据，在健康的老年和高龄男性和女性中，与年龄相关的运动性能下降和变异性增加。肌肉萎缩，特别是快速抽搐（II型）纤维，收缩减慢，神经肌肉连接退化和运动单元激活损伤共同构成老年人肌肉减少症和运动和功能表现受损的基础。这篇综述还简要地强调了理解体育活动和高阻力训练对肌肉和神经功能的年龄相关变化的保护作用的方法，即使在老年人中也是如此。这样的干预延缓功能衰退，并强调老化的神经肌肉系统的适应性。未来研究的重点是了解驱动神经和肌肉退化的具体机制，优化运动策略，以改善老年男性和女性的神经肌肉健康。

{"title":"Motor performance and aging in males and females","authors":"Sandra K. Hunter","doi":"10.1016/j.jelekin.2025.103066","DOIUrl":"10.1016/j.jelekin.2025.103066","url":null,"abstract":"<div><div>Advanced aging is accompanied by marked declines in motor performance in males and females including reductions in strength, speed and power of limb muscles that begin as early as midlife (∼>40 years) and accelerate from ∼65 years of age. Low muscle power and strength is exacerbated by increased fatigability with aging of limb muscles during dynamic contraction tasks and larger performance variability (between and within older adults), especially in older females. Starting in midlife, females exhibit earlier and larger age-related reductions in muscle strength and power and athletic performance than males of the same age and this is paralleled by increased prevalence of poor health, frailty, and loss of independence. This review presents evidence of key neural and muscular mechanisms affecting the motor unit, the age-related reductions in motor performance and the increased variability in healthy old and very old males and females. Muscular atrophy, particularly of fast-twitch (Type II) fibers, contractile slowing, degradation of neuromuscular junctions, and impairments in motor unit activation collectively underpin sarcopenia and impaired motor and functional performance among older adults. This review also briefly highlights approaches to understanding the protective effects of physical activity and high-resistance training on the age-related changes in muscle and neural function, even in the oldest adults. Such interventions delay functional declines and emphasize the adaptability of the aging neuromuscular system. Opportunities abound for future research to focus on understanding the specific mechanisms driving neural and muscular degeneration and optimizing exercise strategies to improve neuromuscular health of old males and females.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103066"},"PeriodicalIF":2.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The angle-based dynamic control ratio in isokinetic fatiguing knee flexion–extension effort: A study of healthy subjects 基于角度的等运动疲劳膝关节屈伸力动态控制率：健康受试者的研究。

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-11 DOI: 10.1016/j.jelekin.2025.103068

Kodai Suzuki , Takashi Okada , Takayoshi Hakkaku , Shohei Shimowada , Michal Katz-Leurer , Zeevi Dvir

This study examined the angle-based variations in the dynamic control ratio (DCRab), defined as the peak concentric moment of the quadriceps (Qcon) divided by its hamstring counterpart (Hecc) when calculated calculated at 1° intervals, during isokinetic fatiguing conditions. Sixteen men performed 30 maximal concentric knee extensions and eccentric flexions of the right and left knees at speeds of 120°/s and 180°/s. Data were analyzed using ratio values extracted from three repetition segments (4–6, 14–16, and 27–29) and presented graphically. All DCRab curves followed asymmetric second-order patterns, with the values near end-RoM (full extension: 5–7°) significantly higher than at RoM onset (95° of flexion), reflecting increased hamstring moment output. Fatigue reduced the Q and H moment at the equilibrium point [DCRe(M); Hecc = Qcon] and shifted the angle at which the DCRe occurred [DCRe(∠)] rightward, indicating altered muscle balance. DCRe(M) correlated with DCRe(∠): r = 0.84–0.90, while the DCRe(∠) correlated with angle of peak moment (r = 0.63–0.88), especially at 180°/s. Notably, the DCRe(∠) occurred at 20–30° of knee extension and correlated with the angle of peak moment of Hecc at 180°/s, indicating enhanced joint protection. No significant inter-limb differences were found in either Qcon or Hecc strength (p = 0.520). The use of the DCRab and its derivatives, the DCRe(M) and DCRe(∠) indicates that fatigue may affect Q-H balance. Thus, these parameters may aid in assessing the risk of knee injury and design of rehabilitation protocols.

本研究检查了动态控制比（DCRab）的角度变化，DCRab定义为四头肌（Qcon）的峰值同心力矩除以腿筋（Hecc），在等速疲劳条件下以1°间隔计算。16名男性以120°/s和180°/s的速度进行30次最大同心膝关节伸展和左右膝关节偏心屈曲。使用从3个重复片段（4-6、14-16和27-29）中提取的比率值对数据进行分析，并以图表形式呈现。所有DCRab曲线均呈非对称的二阶模式，近踝关节末端（完全伸展：5-7°）的值明显高于踝关节起始（屈曲95°），反映出腘绳肌力矩输出增加。疲劳降低了平衡点处的Q矩和H矩[DCRe(M)]；Hecc = Qcon]并将DCRe发生的角度[DCRe(∠)]向右移动，表明肌肉平衡发生了改变。DCRe(M)与DCRe（∠）的相关系数r = 0.84 ~ 0.90，而DCRe（∠）与峰值弯矩角的相关系数r = 0.63 ~ 0.88，尤其在180°/s处。值得注意的是，DCRe（∠）出现在膝关节伸展20 ~ 30°处，且与Hecc在180°/s处的峰值弯矩角度相关，说明关节保护作用增强。两组间Qcon和Hecc强度均无显著差异（p = 0.520）。DCRab及其衍生物dre (M)和dre（∠）的使用表明，疲劳可能会影响Q-H平衡。因此，这些参数可能有助于评估膝关节损伤的风险和设计康复方案。

{"title":"The angle-based dynamic control ratio in isokinetic fatiguing knee flexion–extension effort: A study of healthy subjects","authors":"Kodai Suzuki , Takashi Okada , Takayoshi Hakkaku , Shohei Shimowada , Michal Katz-Leurer , Zeevi Dvir","doi":"10.1016/j.jelekin.2025.103068","DOIUrl":"10.1016/j.jelekin.2025.103068","url":null,"abstract":"<div><div>This study examined the angle-based variations in the dynamic control ratio (DCRab), defined as the peak concentric moment of the quadriceps (Qcon) divided by its hamstring counterpart (Hecc) when calculated calculated at 1° intervals, during isokinetic fatiguing conditions. Sixteen men performed 30 maximal concentric knee extensions and eccentric flexions of the right and left knees at speeds of 120°/s and 180°/s. Data were analyzed using ratio values extracted from three repetition segments (4–6, 14–16, and 27–29) and presented graphically. All DCRab curves followed asymmetric second-order patterns, with the values near end-RoM (full extension: 5–7°) significantly higher than at RoM onset (95° of flexion), reflecting increased hamstring moment output. Fatigue reduced the Q and H moment at the equilibrium point [DCRe(M); Hecc = Qcon] and shifted the angle at which the DCRe occurred [DCRe(∠)] rightward, indicating altered muscle balance. DCRe(M) correlated with DCRe(∠): r = 0.84–0.90, while the DCRe(∠) correlated with angle of peak moment (r = 0.63–0.88), especially at 180°/s. Notably, the DCRe(∠) occurred at 20–30° of knee extension and correlated with the angle of peak moment of Hecc at 180°/s, indicating enhanced joint protection. No significant inter-limb differences were found in either Qcon or Hecc strength (p = 0.520). The use of the DCRab and its derivatives, the DCRe(M) and DCRe(∠) indicates that fatigue may affect Q-H balance. Thus, these parameters may aid in assessing the risk of knee injury and design of rehabilitation protocols.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103068"},"PeriodicalIF":2.3,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantifying the influence of radiation therapy on functional shoulder health indicators in breast cancer patients: An exploratory study 量化放疗对乳腺癌患者肩功能健康指标的影响：一项探索性研究。

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-10 DOI: 10.1016/j.jelekin.2025.103071

M.C.Herrera Valerio, C.R. Dickerson

Introduction: Radiotherapy is a highly effective treatment for breast cancer, but it is also associated with several complications that can impact quality of life and survivorship, including arm function. This study assessed the influence of radiation therapy on shoulder health indicators of breast cancer patients during their treatment period. Methods: Fourteen breast cancer patients undergoing radiation therapy participated. Shoulder health indicators were assessed at the baseline, midpoint, and endpoint of radiation treatment. The indicators included shoulder muscle activations, arm circumference, shoulder complex range of motion, and arm strength. Repeated measures ANOVAs followed by post-hoc Tukey-Kramer tests were used to identify differences in shoulder indicators between levels (p < 0.05). A multiple linear regression model was created for each dependent measurement including radiation dose and fractions as predictor variables. Results: The activation of the teres major and latissimus dorsi muscles decreased in most of the evaluated movements. Additionally, mean shoulder abduction decreased by 11 deg, and negative correlations existed between shoulder abduction range of motion and radiation dose, and between shoulder abduction strength and radiation fractions. The observed changes may relate to post-treatment inflammation, and lingering effects of radiation on shoulder health indicators may take longer to manifest, hindering identification within the treatment window.

简介：放疗是一种非常有效的乳腺癌治疗方法，但它也与一些影响生活质量和生存率的并发症相关，包括手臂功能。本研究评估放射治疗对乳腺癌患者治疗期间肩部健康指标的影响。方法：对14例接受放射治疗的乳腺癌患者进行研究。在放射治疗的基线、中点和终点评估肩部健康指标。指标包括肩部肌肉激活、手臂围度、肩部复杂活动范围和手臂力量。采用重复测量方差分析和事后Tukey-Kramer检验来确定不同水平之间肩部指标的差异(p)。结果：在大多数评估的运动中，大圆肌和背阔肌的激活减少。肩关节外展活动范围与放射剂量、肩关节外展强度与放射分量呈负相关。观察到的变化可能与治疗后的炎症有关，辐射对肩部健康指标的持续影响可能需要更长的时间才能显现出来，从而阻碍了在治疗窗口内的识别。

{"title":"Quantifying the influence of radiation therapy on functional shoulder health indicators in breast cancer patients: An exploratory study","authors":"M.C.Herrera Valerio, C.R. Dickerson","doi":"10.1016/j.jelekin.2025.103071","DOIUrl":"10.1016/j.jelekin.2025.103071","url":null,"abstract":"<div><div>Introduction: Radiotherapy is a highly effective treatment for breast cancer, but it is also associated with several complications that can impact quality of life and survivorship, including arm function. This study assessed the influence of radiation therapy on shoulder health indicators of breast cancer patients during their treatment period. Methods: Fourteen breast cancer patients undergoing radiation therapy participated. Shoulder health indicators were assessed at the baseline, midpoint, and endpoint of radiation treatment. The indicators included shoulder muscle activations, arm circumference, shoulder complex range of motion, and arm strength. Repeated measures ANOVAs followed by post-hoc Tukey-Kramer tests were used to identify differences in shoulder indicators between levels (p < 0.05). A multiple linear regression model was created for each dependent measurement including radiation dose and fractions as predictor variables. Results: The activation of the teres major and latissimus dorsi muscles decreased in most of the evaluated movements. Additionally, mean shoulder abduction decreased by 11 deg, and negative correlations existed between shoulder abduction range of motion and radiation dose, and between shoulder abduction strength and radiation fractions. The observed changes may relate to post-treatment inflammation, and lingering effects of radiation on shoulder health indicators may take longer to manifest, hindering identification within the treatment window.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103071"},"PeriodicalIF":2.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145082604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimizing passive exoskeleton torque for dynamic overhead work: Phase-specific analysis on muscle activity and perceived exertion 优化被动外骨骼扭矩动态顶工作：肌肉活动和感知消耗的阶段特定分析

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-10 DOI: 10.1016/j.jelekin.2025.103070

Giulia Casu , Alan Barr , Sunwook Kim , Maury A. Nussbaum , David Rempel , Massimiliano Pau , Carisa Harris-Adamson

Purpose: This study investigated how different levels of torque provided by a passive arm-support exoskeleton (ASE) influence upper extremity muscle activity, perceived exertion, and fatigue during arm ascent and descent phases of a Dynamic Overhead (DO) task. Methods: The DO task involved 20 cycles of simulated drilling and was completed by 20 individuals by using a light-duty drill in four conditions: without supporting torque (no ASE) and with three increasing levels of ASE torque (i.e., 50, 75, and 100% of the torque required to support the arm in 90° of flexion). Surface electromyography was measured bilaterally over six shoulder muscles. Moreover, participants indicated torque preference, ratings of perceived exertion (RPE), and fatigue in the shoulder. Results: Increasing torque levels caused significant reductions in shoulder agonist muscle activity (up to 47%) and significant decreases in RPE and fatigue during the ascent phase. In contrast, higher levels of torque increased muscular activity for some antagonist muscles during the descent phase. Conclusions: While torque levels of 75% and 100% received the most positive ratings, we suggest that 75% torque could be an effective supporting condition, by reducing shoulder muscle flexor activity during arm ascent and minimizing antagonist muscle activity during arm descent.

目的：本研究调查了被动臂支撑外骨骼（ASE）提供的不同水平的扭矩如何影响动态架空（DO）任务中上肢肌肉活动、感知劳累和上肢疲劳。方法：DO任务包括20个模拟钻孔循环，由20个人使用轻型钻头在四种条件下完成：无支撑扭矩（无ASE）和三种增加的ASE扭矩（即支持手臂90°弯曲所需的扭矩的50%，75%和100%）。测量两侧六块肩部肌肉的表面肌电图。此外，参与者还指出了扭矩偏好、感知用力等级（RPE）和肩部疲劳。结果：增加扭矩水平导致肩激动剂肌肉活动显著减少（高达47%），在上升阶段RPE和疲劳显著减少。相反，在下降阶段，较高的扭矩水平增加了一些拮抗肌的肌肉活动。结论：虽然75%和100%的扭矩水平得到了最积极的评价，但我们认为75%的扭矩可以是一个有效的支持条件，通过减少手臂上升过程中肩部肌肉屈肌的活动，并减少手臂下降过程中拮抗剂肌肉的活动。

{"title":"Optimizing passive exoskeleton torque for dynamic overhead work: Phase-specific analysis on muscle activity and perceived exertion","authors":"Giulia Casu , Alan Barr , Sunwook Kim , Maury A. Nussbaum , David Rempel , Massimiliano Pau , Carisa Harris-Adamson","doi":"10.1016/j.jelekin.2025.103070","DOIUrl":"10.1016/j.jelekin.2025.103070","url":null,"abstract":"<div><div>Purpose: This study investigated how different levels of torque provided by a passive arm-support exoskeleton (ASE) influence upper extremity muscle activity, perceived exertion, and fatigue during arm ascent and descent phases of a Dynamic Overhead (DO) task. Methods: The DO task involved 20 cycles of simulated drilling and was completed by 20 individuals by using a light-duty drill in four conditions: without supporting torque (no ASE) and with three increasing levels of ASE torque (i.e., 50, 75, and 100% of the torque required to support the arm in 90° of flexion). Surface electromyography was measured bilaterally over six shoulder muscles. Moreover, participants indicated torque preference, ratings of perceived exertion (RPE), and fatigue in the shoulder. Results: Increasing torque levels caused significant reductions in shoulder agonist muscle activity (up to 47%) and significant decreases in RPE and fatigue during the ascent phase. In contrast, higher levels of torque increased muscular activity for some antagonist muscles during the descent phase. Conclusions: While torque levels of 75% and 100% received the most positive ratings, we suggest that 75% torque could be an effective supporting condition, by reducing shoulder muscle flexor activity during arm ascent and minimizing antagonist muscle activity during arm descent.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103070"},"PeriodicalIF":2.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Three-dimensional markerless pose estimation for anatomical landmarks of the shoulder and upper limb 肩部和上肢解剖标志的三维无标记姿态估计

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-10 DOI: 10.1016/j.jelekin.2025.103067

F. Lefebvre , I. Rogowski , N. Long , Y. Blache

This study aimed to develop and validate a 3D markerless pose estimation algorithm for anatomical landmarks of the shoulder and upper limb. Twenty-six healthy participants were asked to hold 21 static positions, while both markerless and marker-based (applied after palpation) images were recorded using eight video cameras. A pre-trained convolutional neural network based on ResNet-50 was fine-tuned on 2612 markerless images to estimate the poses of 20 anatomical landmarks. The model was tested on 1 680 images by calculating the 3D Euclidean distances between predicted coordinates and those labeled from marker-based images. Across all positions, median and 90th percentile Euclidean distances were below 15 mm and 30 mm, respectively for all anatomical landmarks, except for the 8th thoracic vertebra, inferior angle of the scapula and medial epicondyle, which presented the highest Euclidean distances. For most of the anatomical landmarks, loss rates inferior to 6 % were observed for predicted coordinates. The neural network accuracy was similar between movements tested and not influenced by the degree of arm elevation. To conclude, a neural network was developed and validated for estimating shoulder and upper-limb anatomical landmarks poses, demonstrating promising accuracy for future clinical applications.

本研究旨在开发和验证一种用于肩部和上肢解剖标志的三维无标记姿态估计算法。26名健康参与者被要求保持21个静态姿势，同时使用8台摄像机记录无标记和基于标记（触诊后应用）的图像。基于ResNet-50的预训练卷积神经网络对2612张无标记图像进行微调，估计出20个解剖标志的姿态。通过计算预测坐标与基于标记的图像标记坐标之间的三维欧氏距离，在1680幅图像上对该模型进行了测试。在所有体位中，除第8胸椎、肩胛骨下角和内上髁的欧氏距离最大外，所有解剖标志的中位数和第90百分位欧氏距离分别小于15 mm和30 mm。对于大多数解剖标志，预测坐标的损失率低于6%。神经网络的准确性在测试的运动之间是相似的，并且不受手臂抬高程度的影响。综上所述，我们开发并验证了一个神经网络用于估计肩部和上肢解剖标志姿势，为未来的临床应用展示了良好的准确性。

{"title":"Three-dimensional markerless pose estimation for anatomical landmarks of the shoulder and upper limb","authors":"F. Lefebvre , I. Rogowski , N. Long , Y. Blache","doi":"10.1016/j.jelekin.2025.103067","DOIUrl":"10.1016/j.jelekin.2025.103067","url":null,"abstract":"<div><div>This study aimed to develop and validate a 3D markerless pose estimation algorithm for anatomical landmarks of the shoulder and upper limb. Twenty-six healthy participants were asked to hold 21 static positions, while both markerless and marker-based (applied after palpation) images were recorded using eight video cameras. A pre-trained convolutional neural network based on ResNet-50 was fine-tuned on 2612 markerless images to estimate the poses of 20anatomical landmarks. The model was tested on 1680 images by calculating the 3D Euclidean distances between predicted coordinates and those labeled from marker-based images. Across all positions, median and 90th percentile Euclidean distances were below 15 mm and 30 mm, respectively for all anatomical landmarks, except for the 8th thoracic vertebra, inferior angle of the scapula and medial epicondyle, which presented the highest Euclidean distances. For most of the anatomical landmarks, loss rates inferior to 6 % were observed for predicted coordinates. The neural network accuracy was similar between movements tested and not influenced by the degree of arm elevation. To conclude, a neural network was developed and validated for estimating shoulder and upper-limb anatomical landmarks poses, demonstrating promising accuracy for future clinical applications.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103067"},"PeriodicalIF":2.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Establishing a methodological framework for evaluating gait symmetry through muscle synergies: A pilot study 通过肌肉协同作用建立评估步态对称性的方法学框架：一项试点研究

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-10 DOI: 10.1016/j.jelekin.2025.103064

Elham Zargaripour, Farzad Towhidkhah, Farnaz Ghassemi, Otella Shoja

Gait symmetry is vital for stable locomotion, yet conventional metrics often yield inconsistent results. Muscle synergy analysis provides a more precise understanding of neural mechanisms behind symmetric gait. A clear methodology is essential to distinguish true inter-limb differences from natural variability. This study aimed to refine the analysis of muscle synergy symmetry in healthy individuals by incorporating intra-limb similarity as a baseline for comparison, while also including muscle weightings within each synergy to explore muscle synchrony. EMG signals were collected from both lower limbs of healthy subjects during treadmill walking. Muscle synergies were extracted using non-negative matrix factorization (NMF). Intra-limb similarity was used as a baseline to assess inter-limb differences. Muscle activity, number of synergies, muscle weightings within each synergy, and weight (W) and activation coefficients (H) were compared between sides. Normalized scalar products assessed weight coefficients, while Pearson’s correlation was used to compare activation coefficients. No significant differences were found in the number or structure of muscle synergies between limbs, indicating symmetrical coordination. However, significant differences were observed in activation of four of eight muscles and minor variations in muscle weightings. This study underscores the importance of a robust framework for interpreting muscle synergy symmetry.

步态对称对于稳定的运动至关重要，然而传统的指标往往产生不一致的结果。肌肉协同分析为对称步态背后的神经机制提供了更精确的理解。要区分真正的肢间差异和自然变异，明确的方法至关重要。本研究旨在通过将肢体内相似性作为比较基线，同时还包括每个协同作用中的肌肉权重，以探索肌肉同步，从而完善健康个体肌肉协同对称性的分析。采集健康受试者在跑步机上行走时的双下肢肌电信号。使用非负矩阵分解（NMF）提取肌肉协同作用。采用肢内相似性作为评估肢间差异的基线。比较两侧的肌肉活性、协同作用数量、每个协同作用内的肌肉重量、体重(W)和激活系数(H)。归一化标量积评估权重系数，而皮尔逊相关性用于比较激活系数。四肢间肌肉协同作用的数量和结构均无显著差异，说明四肢间肌肉协同作用是对称的。然而，8块肌肉中有4块的激活程度有显著差异，肌肉重量也有细微变化。这项研究强调了解释肌肉协同对称性的强大框架的重要性。

{"title":"Establishing a methodological framework for evaluating gait symmetry through muscle synergies: A pilot study","authors":"Elham Zargaripour, Farzad Towhidkhah, Farnaz Ghassemi, Otella Shoja","doi":"10.1016/j.jelekin.2025.103064","DOIUrl":"10.1016/j.jelekin.2025.103064","url":null,"abstract":"<div><div>Gait symmetry is vital for stable locomotion, yet conventional metrics often yield inconsistent results. Muscle synergy analysis provides a more precise understanding of neural mechanisms behind symmetric gait. A clear methodology is essential to distinguish true inter-limb differences from natural variability. This study aimed to refine the analysis of muscle synergy symmetry in healthy individuals by incorporating intra-limb similarity as a baseline for comparison, while also including muscle weightings within each synergy to explore muscle synchrony. EMG signals were collected from both lower limbs of healthy subjects during treadmill walking. Muscle synergies were extracted using non-negative matrix factorization (NMF). Intra-limb similarity was used as a baseline to assess inter-limb differences. Muscle activity, number of synergies, muscle weightings within each synergy, and weight (W) and activation coefficients (H) were compared between sides. Normalized scalar products assessed weight coefficients, while Pearson’s correlation was used to compare activation coefficients. No significant differences were found in the number or structure of muscle synergies between limbs, indicating symmetrical coordination. However, significant differences were observed in activation of four of eight muscles and minor variations in muscle weightings. This study underscores the importance of a robust framework for interpreting muscle synergy symmetry.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103064"},"PeriodicalIF":2.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sex-specific effects of fatiguing handgrip plus blood flow restriction on upper limb neuromuscular characteristics during a repetitive shoulder height task 重复性肩高任务中疲劳握力加血流限制对上肢神经肌肉特征的性别特异性影响。

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-10 DOI: 10.1016/j.jelekin.2025.103069

Carson Graham, Pruthvi Patel, Julie N. Côté

Blood flow restriction (BFR) aims to accelerate reperfusion post-effort and could provide benefits after shoulder fatiguing work. However, sex-specific effects of localized BFR on whole-limb features are unknown. Ten females and eleven males performed three 30-second repetitive pointing tasks (RPTs) (pre-fatigue, post-fatigue, and recovery). The fatiguing protocol was an intermittent submaximal handgrip task performed until failure to meet the target force (50% of maximum grip strength). Participants completed two sessions: without BFR and with 50% BFR applied to the upper arm during the handgrip task. Electromyography was recorded during the handgrip and each RPT. Muscle thickness (ultrasound), and arm circumferences were recorded after each RPT sequence. Time-to-fatigue was unaffected by condition or sex. Females exhibited greater forearm electromyography amplitude and greater decreases in flexor carpi radialis and brachioradialis median power frequency (MdPF). Post-fatigue, forearm circumference and muscle thickness increased significantly in both sexes. Females demonstrated greater forearm muscle thickness changes, while males showed more consistent increases in biceps brachii thickness under BFR. During the RPTs, males displayed significant increases in MdPF of middle deltoid and pectoralis major, while females showed persistent fatigue effects in forearm muscles. Results suggest that sex differences exist in whole-limb mechanisms of fatigue and BFR adaptations.

血流限制（BFR）旨在加速运动后的再灌注，并可在肩部疲劳工作后提供益处。然而，局部BFR对全肢特征的性别特异性影响尚不清楚。10名女性和11名男性进行了3个30秒的重复性指指任务（rpt）（疲劳前、疲劳后和恢复）。疲劳方案是一个间歇性的次最大握力任务，直到未能达到目标力（最大握力的50%）。参与者完成了两个阶段：在握力任务中，上臂不使用BFR，上臂使用50% BFR。记录握力和每次RPT时的肌电图。每次RPT后记录肌肉厚度（超声）和手臂周长。疲劳时间不受条件或性别的影响。女性表现出更大的前臂肌电振幅和更大的桡侧腕屈肌和肱桡肌中功频率（mpf）的下降。疲劳后，男性和女性的前臂周长和肌肉厚度均显著增加。在BFR下，女性表现出更大的前臂肌肉厚度变化，而男性表现出更一致的肱二头肌厚度增加。在rpt过程中，男性中三角肌和胸大肌的mpf显著增加，而女性前臂肌肉持续疲劳。结果表明，全肢疲劳机制和BFR适应存在性别差异。

{"title":"Sex-specific effects of fatiguing handgrip plus blood flow restriction on upper limb neuromuscular characteristics during a repetitive shoulder height task","authors":"Carson Graham, Pruthvi Patel, Julie N. Côté","doi":"10.1016/j.jelekin.2025.103069","DOIUrl":"10.1016/j.jelekin.2025.103069","url":null,"abstract":"<div><div>Blood flow restriction (BFR) aims to accelerate reperfusion post-effort and could provide benefits after shoulder fatiguing work. However, sex-specific effects of localized BFR on whole-limb features are unknown. Ten females and eleven males performed three 30-second repetitive pointing tasks (RPTs) (pre-fatigue, post-fatigue, and recovery). The fatiguing protocol was an intermittent submaximal handgrip task performed until failure to meet the target force (50% of maximum grip strength). Participants completed two sessions: without BFR and with 50% BFR applied to the upper arm during the handgrip task. Electromyography was recorded during the handgrip and each RPT. Muscle thickness (ultrasound), and arm circumferences were recorded after each RPT sequence. Time-to-fatigue was unaffected by condition or sex. Females exhibited greater forearm electromyography amplitude and greater decreases in flexor carpi radialis and brachioradialis median power frequency (MdPF). Post-fatigue, forearm circumference and muscle thickness increased significantly in both sexes. Females demonstrated greater forearm muscle thickness changes, while males showed more consistent increases in biceps brachii thickness under BFR. During the RPTs, males displayed significant increases in MdPF of middle deltoid and pectoralis major, while females showed persistent fatigue effects in forearm muscles. Results suggest that sex differences exist in whole-limb mechanisms of fatigue and BFR adaptations.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103069"},"PeriodicalIF":2.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Peaks or threshold-crossing: A comparative analysis of neuromuscular jitter measurement methods 峰值或阈值交叉：神经肌肉抖动测量方法的比较分析

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-09 DOI: 10.1016/j.jelekin.2025.103065

César Valle , Armando Malanda , Oscar Garnés-Camarena , Daniel.W. Stashuk , Gurutzi Azkona , Javier Rodríguez-Falces , Javier Navallas

Introduction

Commercial electromyographic recording systems usually include two different methods for jitter measurement, based on peaks or threshold-crossing. There is reported evidence that the measurements obtained with both methods from discharges recorded with concentric needle electrodes offer comparable results, but this evidence is scarce. This study aimed to replicate such studies and extract conclusions related to the use of the two methods.

Methods

129 EMG recordings were obtained from 12 patients using concentric needle electrodes (0.02 mm²), filtered at 1000 Hz and oversampled to 200 kHz. The recordings were aligned using either peak or threshold-crossing methods. Jitter was measured using both methods and obtained as mean consecutive differences (MCD). Statistical analyses included Anderson-Darling, Wilcoxon, and linear regression tests.

Results

Of the 129 recordings, 49 (38 %) were excluded for presenting contaminated waveforms. MCD values were similar in the two methods, with a median difference of −0.92 µs. The Wilcoxon test confirmed this difference (p = 0.0002). The regression yielded a high coefficient of determination (R² = 0.994) and a slope of 0.989.

Conclusion

No significant differences were found between the two jitter measurement methods. Variations were only a few µs, not enough to affect pathological jitter diagnosis. Both methods are valid for clinical use.

商业肌电记录系统通常包括两种不同的抖动测量方法，基于峰值或阈值交叉。有报道的证据表明，用两种方法从同心针电极记录的放电中获得的测量结果可提供可比的结果，但这一证据很少。本研究旨在重复此类研究，并提取与使用这两种方法相关的结论。方法采用同心圆针电极（0.02 mm2）采集12例患者的129张肌电图，1000 Hz滤波，200 kHz过采样。使用峰值或阈值交叉方法对记录进行对齐。用两种方法测量抖动，并获得平均连续差（MCD）。统计分析包括安德森-达林检验、Wilcoxon检验和线性回归检验。结果129份记录中，49份（38%）因出现污染波形而被排除。两种方法的MCD值相似，中位差为- 0.92µs。Wilcoxon检验证实了这一差异（p = 0.0002）。回归的决定系数较高（R2 = 0.994），斜率为0.989。结论两种抖动测量方法无显著差异。变化仅为几µs，不足以影响病理性抖动诊断。两种方法均可用于临床。

{"title":"Peaks or threshold-crossing: A comparative analysis of neuromuscular jitter measurement methods","authors":"César Valle , Armando Malanda , Oscar Garnés-Camarena , Daniel.W. Stashuk , Gurutzi Azkona , Javier Rodríguez-Falces , Javier Navallas","doi":"10.1016/j.jelekin.2025.103065","DOIUrl":"10.1016/j.jelekin.2025.103065","url":null,"abstract":"<div><h3>Introduction</h3><div>Commercial electromyographic recording systems usually include two different methods for jitter measurement, based on peaks or threshold-crossing. There is reported evidence that the measurements obtained with both methods from discharges recorded with concentric needle electrodes offer comparable results, but this evidence is scarce. This study aimed to replicate such studies and extract conclusions related to the use of the two methods.</div></div><div><h3>Methods</h3><div>129 EMG recordings were obtained from 12 patients using concentric needle electrodes (0.02 mm<sup>2</sup>), filtered at 1000 Hz and oversampled to 200 kHz. The recordings were aligned using either peak or threshold-crossing methods. Jitter was measured using both methods and obtained as mean consecutive differences (MCD). Statistical analyses included Anderson-Darling, Wilcoxon, and linear regression tests.</div></div><div><h3>Results</h3><div>Of the 129 recordings, 49 (38 %) were excluded for presenting contaminated waveforms. MCD values were similar in the two methods, with a median difference of −0.92 µs. The Wilcoxon test confirmed this difference (p = 0.0002). The regression yielded a high coefficient of determination (R<sup>2</sup> = 0.994) and a slope of 0.989.</div></div><div><h3>Conclusion</h3><div>No significant differences were found between the two jitter measurement methods. Variations were only a few µs, not enough to affect pathological jitter diagnosis. Both methods are valid for clinical use.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103065"},"PeriodicalIF":2.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of muscle activity between isokinetic and iso-inertial exercise 等速运动和等惯性运动肌肉活动的比较

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-03 DOI: 10.1016/j.jelekin.2025.103052

Timothy H.T. Phillips , Ransi S.S. Subasinghe Arachchige , Roy T.H. Cheung

Background

Resistance training plays a crucial role in musculoskeletal rehabilitation and athletic performance. Traditional resistance training often underloads the eccentric phase, as muscles generate more force while lengthening. Isokinetic and iso-inertial exercises have been used to overcome this limitation, with both showing greater muscle activity compared to traditional methods, potentially leading to enhanced strength and hypertrophy. However, limited research compares the two modalities.

Methods

This randomised crossover study involved healthy adults between the ages of 18–45 years who performed isokinetic knee extensions and iso-inertial squats at fast and slow speeds. Electromyographic activity of the quadriceps was recorded, and the eccentric-to-concentric root-mean-square (RMS) ratio was calculated.

Results

Results showed that iso-inertial exercise at fast speeds led to a significantly greater eccentric-to-concentric RMS ratio in the rectus femoris (95 % CI 0.11 to 0.74; Cohen’s d = 0.89) and vastus lateralis (95 % CI 0.07 to 0.55, Cohen’s d = 0.75) compared to isokinetic exercise, with no difference in vastus medialis or at slow speeds.

Conclusion

Conclusion: These findings indicate that iso-inertial exercise induces greater eccentric muscle activity in key quadriceps muscles at fast speeds, suggesting its potential for enhancing eccentric overload and muscle strength gains.

背景：阻力训练在肌肉骨骼康复和运动表现中起着至关重要的作用。传统的阻力训练通常会使离心阶段负荷不足，因为肌肉在拉伸时产生更多的力量。等速运动和等惯性运动已被用于克服这一限制，与传统方法相比，两者都显示出更大的肌肉活动，潜在地导致力量增强和肥大。然而，比较这两种模式的研究有限。方法：这项随机交叉研究纳入了年龄在18-45岁之间的健康成年人，他们在快、慢速度下进行等速膝关节伸展和等速惯性深蹲。记录股四头肌肌电活动，计算偏心与同心均方根（RMS）比。结果结果显示，与等速运动相比，快速等惯性运动导致股直肌（95% CI 0.11 ~ 0.74, Cohen’s d = 0.89）和股外侧肌（95% CI 0.07 ~ 0.55, Cohen’s d = 0.75）的离心-同轴RMS比显著增大，而股内侧肌和慢速运动无差异。结论：这些结果表明，等惯性运动在快速运动时可诱导关键股四头肌的偏心肌活动，提示其可能增强偏心过载和肌肉力量的增加。

{"title":"Comparison of muscle activity between isokinetic and iso-inertial exercise","authors":"Timothy H.T. Phillips , Ransi S.S. Subasinghe Arachchige , Roy T.H. Cheung","doi":"10.1016/j.jelekin.2025.103052","DOIUrl":"10.1016/j.jelekin.2025.103052","url":null,"abstract":"<div><h3>Background</h3><div>Resistance training plays a crucial role in musculoskeletal rehabilitation and athletic performance. Traditional resistance training often underloads the eccentric phase, as muscles generate more force while lengthening. Isokinetic and iso-inertial exercises have been used to overcome this limitation, with both showing greater muscle activity compared to traditional methods, potentially leading to enhanced strength and hypertrophy. However, limited research compares the two modalities.</div></div><div><h3>Methods</h3><div>This randomised crossover study involved healthy adults between the ages of 18–45 years who performed isokinetic knee extensions and iso-inertial squats at fast and slow speeds. Electromyographic activity of the quadriceps was recorded, and the eccentric-to-concentric root-mean-square (RMS) ratio was calculated.</div></div><div><h3>Results</h3><div>Results showed that iso-inertial exercise at fast speeds led to a significantly greater eccentric-to-concentric RMS ratio in the rectus femoris (95 % CI 0.11 to 0.74; Cohen’s d = 0.89) and vastus lateralis (95 % CI 0.07 to 0.55, Cohen’s d = 0.75) compared to isokinetic exercise, with no difference in vastus medialis or at slow speeds.</div></div><div><h3>Conclusion</h3><div>Conclusion: These findings indicate that iso-inertial exercise induces greater eccentric muscle activity in key quadriceps muscles at fast speeds, suggesting its potential for enhancing eccentric overload and muscle strength gains.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103052"},"PeriodicalIF":2.3,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Shoulder muscle activity magnitude and timing in individuals with specific scapular movement patterns 特定肩胛骨运动模式个体的肩部肌肉活动幅度和时间

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-02 DOI: 10.1016/j.jelekin.2025.103054

Gaura Saini , Madeline Goodson , Paula M. Ludewig

Relationships between specific muscle activity alterations and specific scapular motion patterns have not been well established. The purpose of this study was to identify muscle activation magnitude and timing in two specific scapular movement groups (excessive scapular anterior tilt, scapular lateralization). Surface electromyography (EMG) was captured simultaneously with biplane video radiography and optical motion capture during two repetitions each of shoulder flexion, abduction, and unrestricted overhead reaching in 45 adults with shoulder pain. The following muscle activation magnitudes measured with EMG were assessed individually and in ratios: lower trapezius (LT), serratus anterior (SA), upper trapezius (UT), anterior deltoid (AD), and middle deltoid (MD). The timing of each muscle’s initiation was calculated as a percent of humerothoracic range of motion. For EMG magnitude, significant interactions including group were found for AD, LT/SA, and LT/AD. Findings suggest a relative reduction of SA in both groups in the constrained motions compared to the self-selected motion and a reduction in LT in the lateralization group in early motion. For EMG timing, no group effects were significant, however findings suggest delays in SA and LT activation in both groups. The findings provide evidence that individuals with different scapular movement patterns may have distinct muscle activity patterns which can inform patient-specific rehabilitation interventions.

特定肌肉活动改变与特定肩胛骨运动模式之间的关系尚未得到很好的确立。本研究的目的是确定两种特定肩胛骨运动组（肩胛骨过度前倾和肩胛骨偏侧）的肌肉激活程度和时间。对45例肩关节疼痛的成年人进行两次重复的肩部屈曲、外展和不受限制的头顶伸展运动，同时用双翼视频x线摄影和光学运动捕捉捕捉体表肌电图（EMG）。以下肌电图测量的肌肉激活幅度分别按比例进行评估：下斜方肌（LT）、前锯肌（SA）、上斜方肌（UT）、前三角肌（AD）和中三角肌（MD）。每块肌肉开始运动的时间是用胸骨活动度的百分比来计算的。对于肌电图，AD、LT/SA和LT/AD的显著相互作用包括组。研究结果表明，与自我选择运动相比，两组在受限运动中SA相对减少，而侧化组在早期运动中LT减少。对于肌电时间，没有明显的组效应，但研究结果表明两组的SA和LT激活延迟。研究结果表明，不同肩胛骨运动模式的个体可能有不同的肌肉活动模式，这可以为患者特定的康复干预提供信息。

{"title":"Shoulder muscle activity magnitude and timing in individuals with specific scapular movement patterns","authors":"Gaura Saini , Madeline Goodson , Paula M. Ludewig","doi":"10.1016/j.jelekin.2025.103054","DOIUrl":"10.1016/j.jelekin.2025.103054","url":null,"abstract":"<div><div>Relationships between specific muscle activity alterations and specific scapular motion patterns have not been well established. The purpose of this study was to identify muscle activation magnitude and timing in two specific scapular movement groups (excessive scapular anterior tilt, scapular lateralization). Surface electromyography (EMG) was captured simultaneously with biplane video radiography and optical motion capture during two repetitions each of shoulder flexion, abduction, and unrestricted overhead reaching in 45 adults with shoulder pain. The following muscle activation magnitudes measured with EMG were assessed individually and in ratios: lower trapezius (LT), serratus anterior (SA), upper trapezius (UT), anterior deltoid (AD), and middle deltoid (MD). The timing of each muscle’s initiation was calculated as a percent of humerothoracic range of motion. For EMG magnitude, significant interactions including group were found for AD, LT/SA, and LT/AD. Findings suggest a relative reduction of SA in both groups in the constrained motions compared to the self-selected motion and a reduction in LT in the lateralization group in early motion. For EMG timing, no group effects were significant, however findings suggest delays in SA and LT activation in both groups. The findings provide evidence that individuals with different scapular movement patterns may have distinct muscle activity patterns which can inform patient-specific rehabilitation interventions.</div></div>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"85 ","pages":"Article 103054"},"PeriodicalIF":2.3,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0