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

Vigorous physical activity enhances intermuscular coordination between ankle muscles during gait. 剧烈的体力活动增强了步态中踝关节肌肉间的肌肉协调。

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-10-01 Epub Date: 2025-08-05 DOI: 10.1016/j.jelekin.2025.103045

Carlos Cruz-Montecinos, Camila Barraza-Viluñir, Luis Acuña-Cancino, Jean Arias, Cristina Olivares, Rodrigo Nuñez-Cortés, Joaquín Calatayud, Xavier Garcia-Masso, Carlos De la Fuente, Claudio Tapia, Felipe P Carpes

Intermuscular coordination (IMC) refers to the nervous system's ability to synchronise muscle activity. While regular physical activity is thought to enhance IMC, the nature of this relationship remains poorly understood. Here we investigate whether high and low IMC between ankle muscles during gait differs based on physical activity levels and individuals' weekly engagement in vigorous activities among young adults. Twenty-five participants (10 females) aged 20-34 years were evaluated. Surface electromyography (EMG) recorded activity of the tibialis anterior (TA), soleus (SOL), and medial gastrocnemius (GM) at 1000 Hz during 10 walking trials at 1 m/s (90 m total). Each EMG epoch included 200 ms before to 600 ms after heel contact and was analysed using causal empirical mode decomposition to identify intrinsic mode functions (IMFs) with stronger causal relationships among muscle pairs. Coordination between selected IMFs of the SOL-TA and SOL-MG muscle pairs was assessed using cross-approximate entropy (XApEn). K-means clustering of XApEn values identified low and high IMC groups (p < 0.001). Proportion of physically active individuals was 83 % in high IMC group, compared to 23 % in low IMC group (p = 0.003). Weekly vigorous activity was greater in the active group (240 vs. 0 min, p = 0.010) and showed a significant moderate correlation with IMC between antagonistic muscles. Physical activity enhances intermuscular coordination among ankle muscles during gait. This emphasizes the role of physical activity, particularly vigorous activity, in enhancing neuromuscular function and counteracting the negative effects of sedentary behaviour on the neuromuscular system.

肌间协调（IMC）是指神经系统同步肌肉活动的能力。虽然人们认为有规律的体育活动可以增强IMC，但人们对这种关系的本质仍知之甚少。在这里，我们研究了步态中踝关节肌肉之间的高IMC和低IMC是否会根据身体活动水平和年轻人每周的剧烈活动而有所不同。25名参与者（10名女性），年龄20-34岁。表面肌电图（EMG）记录了10次以1米/秒（共90米）的速度行走试验中胫骨前肌（TA）、比目鱼肌（SOL）和腓肠肌内侧肌（GM）在1000赫兹下的活动。每个EMG epoch包括与足跟接触前200 ms至接触后600 ms，并使用因果经验模式分解进行分析，以识别肌肉对之间具有较强因果关系的内在模式函数（IMFs）。采用交叉近似熵（cross-approximate entropy, XApEn）评估SOL-TA和SOL-MG肌肉对所选imf之间的协调性。XApEn值的K-means聚类确定了低和高IMC组(p

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引用次数: 0

Muscle coactivation during knee joint-position sense assessments: the effect of muscle fatigue and implications for the magnitude of errors and directional bias 膝关节位置感评估中的肌肉协同激活：肌肉疲劳的影响和误差和方向偏差的大小的含义

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-09-23 DOI: 10.1016/j.jelekin.2025.103072

Joana Azevedo , Pedro Fonseca , Adérito Seixas , José Oliveira , João Paulo Vilas-Boas

Purpose

This study aimed to describe muscle coactivation during knee joint-position sense (KJPS) assessments in healthy individuals, before and after muscle fatigue, and to analyse the implications for the magnitude of errors and directional bias.

Methods

The KJPS of 21 healthy males was assessed in the sitting position through concentric (SIT_CC) and eccentric repositionings (SIT_ECC) to 45° of knee flexion. Two fatigue protocols were tested, consisting of concentric contractions of the knee extensors or flexors. Muscle coactivation indices were calculated based on the normalized mean activation of the vastus lateralis and biceps femoris muscles. Absolute and relative errors were calculated to group participants by magnitude of errors (lower vs. higher errors) and directional bias (extension vs. flexion).

Results

Coactivation indices ranged between 74.92 % - 98.43 %. Significant overall decrease in coactivation indices after both fatigue protocols (p < 0.05). No significant differences in coactivation were found between magnitude of errors groups (p > 0.05), but significant higher coactivation were observed in participants failing the target position into flexion, only in the SIT_CC test (0.001 < p < 0.042).

Conclusion

Muscle coactivation between knee extensors and flexors was high in the assessed JPS tests, and decreased after fatigue. Muscle coactivation does not appear to explain the magnitude of errors, while it seems to influence directional bias.

目的本研究旨在描述健康个体在肌肉疲劳前后膝关节位置感（KJPS）评估过程中的肌肉协同激活，并分析误差大小和方向偏差的影响。方法21例健康男性，采用同心式（SIT_CC）和偏心式（SIT_ECC）膝关节屈曲45°的坐姿，评估KJPS。测试了两种疲劳方案，包括膝关节伸肌或屈肌的同心收缩。根据股外侧肌和股二头肌的归一化平均激活值计算肌肉共激活指数。计算绝对误差和相对误差，根据误差的大小（低误差vs高误差）和方向偏差（伸展vs屈曲）对参与者进行分组。结果活化指数在74.92% ~ 98.43%之间。两种疲劳方案后共活化指数总体显著下降（p < 0.05）。误差大小组之间的共激活没有显著差异（p > 0.05），但在未能完成目标体位屈曲的参与者中观察到显著更高的共激活，只有在SIT_CC测试中（0.001 < p < 0.042）。结论在JPS试验中，膝关节伸屈肌之间的肌肉协同激活程度较高，疲劳后肌肉协同激活程度降低。肌肉共激活似乎不能解释误差的大小，但它似乎影响方向偏差。

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引用次数: 0

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。

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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。

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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。

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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。

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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。

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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。

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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。

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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。

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