Journal of Electromyography and Kinesiology最新文献_第10页

Acute effects of different muscle fatigue conditions during strength training on localized muscle bioimpedance in women 力量训练中不同肌肉疲劳状态对女性局部肌肉生物阻抗的急性影响

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-08-17 DOI: 10.1016/j.jelekin.2025.103051

Francisco Dalton-Alves , Taisa Menezes de Andrade , Francisco Kássio Menezes da Silva , Carla Bianca Tabosa Oliveira , Alex Soares Marreiros Ferraz

This study aims to compare the localized muscle bioimpedance (ML-BIA) responses under different muscle fatigue conditions during strength training (ST). Twelve women participated in the study, which followed a crossover, counterbalanced, and randomized design. The experimental sessions were conducted using a 45° leg press machine, consisting of two conditions: a session until muscle failure (MF) and a session with no muscle failure (NMF). ML-BIA was assessed before the sessions, immediately after all sets were completed, and 20 and 30 min post-sessions. The ML-BIA measures of resistance (R), reactance (XC), and phase angle (PA) of the quadriceps were obtained. The countermovement Jump (CMJ) was assessed before and after both conditions. Repeated measures analysis of variance was used to compare conditions, with a significance level set at p < 0.05. In the CMJ test, significant reductions in jump height and power were observed only in the MF condition (p < 0.001). PA showed significant reductions compared to rest only in the MF condition (p < 0.001), with reductions maintained up to 30 min after the session. Our data showed that ML-BIA parameters respond differently under varying fatigue conditions, with PA decreasing only in the higher fatigue condition.

本研究旨在比较力量训练（ST）中不同肌肉疲劳状态下的局部肌肉生物阻抗（ML-BIA）反应。12名女性参与了这项研究，该研究遵循交叉、平衡和随机设计。实验使用45°腿压机进行，包括两种情况：一种是直到肌肉衰竭（MF），另一种是没有肌肉衰竭（NMF）。在训练前、所有训练完成后以及训练后20和30分钟分别对ML-BIA进行评估。ML-BIA测量了股四头肌的电阻(R)、电抗（XC）和相位角（PA）。对两种条件前后的反动作跳跃（CMJ）进行评估。采用重复测量方差分析比较条件，显著性水平设置为p <； 0.05。在CMJ测试中，仅在MF条件下观察到跳跃高度和力量的显著降低（p < 0.001）。与仅在MF条件下休息相比，PA表现出显著的减少（p < 0.001），这种减少在会话后持续30分钟。我们的数据表明，ML-BIA参数在不同的疲劳状态下响应不同，只有在高疲劳状态下PA才会下降。

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引用次数: 0

Does hemiparetic dorsiflexion in swing phase depend on spasticity? 摇摆期偏瘫背屈是否与痉挛有关？

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-08-10 DOI: 10.1016/j.jelekin.2025.103047

Maria Vinti , Mathias Blandeau , Hélène Pillet , Wafa Skalli , Philippe Decq , Andrea Merlo , Jean-Michel Gracies , Nicolas Bayle , Mouna Ghédira , Emilie Hutin

Objective

This study quantified dorsiflexor and plantar flexor (PF) spasticity, and agonist and antagonist recruitment (cocontractions) during the swing phase of gait in individuals with hemiparesis with and without prior tibial neurotomy, investigating the role of spastic cocontraction versus spasticity in limiting dorsiflexion (DF).

Methods

Eleven hemiparetic subjects and 11 controls walking at comfortable and slow velocities underwent kinematic and electromyographic (EMG) analysis of PF and DF muscles. Five of the hemiparetic subjects had undergone tibial nerve neurotomy, which eliminates PF spasticity. Key metrics included ankle dorsiflexion, tibialis anterior recruitment, and coefficients of antagonist activation of gastrocnemius medialis and soleus during swing. Spasticity was assessed using the Tardieu scale.

Results

Controls walking at slow speed showed similar velocity as hemiparetic subjects. Hemiparetic subjects showed reduced ankle dorsiflexion despite higher tibialis anterior recruitment, increased plantar flexor cocontraction before any dorsiflexion, even in neurotomy patients without spasticity.

Conclusions

Increased PF cocontraction persists even in the absence of spasticity, limiting dorsiflexion during swing. Spastic cocontraction, not spasticity, is a primary factor impairing active DF.

Significance

These findings emphasize that targeting spastic cocontraction of plantar flexors may be crucial for improving dorsiflexion and gait rehabilitation in hemiparetic patients, instead of addressing spasticity.

目的：本研究量化偏瘫患者在步态摇摆期背屈肌和足底屈肌（PF）的痉挛，以及激动剂和拮抗剂的招募（收缩），研究痉挛性收缩与痉挛性收缩在限制背屈（DF）中的作用。方法对6例偏瘫患者和11例正常人进行慢速舒适步行的运动和肌电图（EMG）分析。5名偏瘫患者接受了胫骨神经切开术，消除了PF痉挛。关键指标包括踝关节背屈，胫骨前肌恢复，以及在摆动过程中腓肠肌内侧肌和比目鱼肌的拮抗剂激活系数。采用Tardieu量表评估痉挛程度。结果对照组慢速行走速度与偏瘫组相近。偏瘫患者表现出踝关节背屈减少，尽管胫骨前肌收缩增加，在任何背屈之前足底屈肌收缩增加，即使在没有痉挛的神经切开术患者中也是如此。结论：即使在没有痉挛的情况下，PF收缩的增加仍然存在，限制了摆动时的背屈。痉挛性收缩，而不是痉挛，是损害活性DF的主要因素。这些发现强调，针对足底屈肌的痉挛性收缩可能对改善偏瘫患者的背屈和步态康复至关重要，而不是解决痉挛问题。

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引用次数: 0

Tendon overuse models have different effects on tissue mechanical properties in ex vivo bovine tendons 肌腱过度使用模型对离体牛肌腱组织力学性能有不同的影响

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-08-07 DOI: 10.1016/j.jelekin.2025.103043

Zoe M. Moore , Grace Wood , Jake Elliott , Julianna C. Simon , Meghan E. Vidt

Tendinopathy is an overuse injury that occurs in high load bearing tendons, causing decreased function and increased pain. Current tendinopathy treatments produce inconsistent outcomes, creating a need for novel treatments. It is unclear whether current tendinopathy models used to develop new treatments replicate the mechanical effects of the injury. We aim to compare the mechanical properties of 2 established tendinopathy models – collagenase injection and mechanical overload − in ex vivo bovine tendons. Eighteen bovine tendons were split into 3 groups, including: uninjured, collagenase injection (0.5 mL collagenase and 0.5 mL fibrin gel), and mechanical overload (5 cycles of tensile loading/unloading). Mechanical testing of samples was performed. Stiffness, maximum force at failure, and ultimate tensile stress (UTS) were computed, then compared across groups using 1-way ANOVA with significance set at p < 0.05. Results showed maximum force and UTS were reduced for the mechanical overload group (402.1 ± 232.3 N; 9.1 ± 5.3 MPa) versus uninjured (1222.9 ± 270.8 N; 28.9 ± 4.6 MPa) and collagenase injection groups (1309.0 ± 242.1 N; 25.0 ± 8.2 MPa) (all p < 0.001). Stiffness was not different across groups (all p > 0.33). Findings suggest that ex vivo mechanical overload better represents the mechanical properties of tendinopathy than collagenase injection.

肌腱病是一种发生在高负荷肌腱的过度使用损伤，导致功能下降和疼痛增加。目前的肌腱病变治疗产生不一致的结果，需要新的治疗方法。目前尚不清楚用于开发新疗法的肌腱病变模型是否能复制损伤的机械效应。我们的目的是比较两种已建立的肌腱病变模型-胶原酶注射和机械过载-在离体牛肌腱中的力学特性。将18根牛肌腱分为3组，分别为未损伤组、胶原酶注射组（0.5 mL胶原酶和0.5 mL纤维蛋白凝胶）组和机械过载组（拉伸加载/卸载5个循环）。对样品进行力学测试。计算刚度、失效时最大力和极限拉应力（UTS），然后使用单因素方差分析（1-way ANOVA）对各组进行比较，显著性设置为p <；0.05. 结果表明：机械过载组最大受力和UTS降低(402.1±232.3 N；9.1±5.3 MPa)与未损伤(1222.9±270.8 N；28.9±4.6 MPa)和胶原酶注射组(1309.0±242.1 N；25.0±8.2 MPa)(均p <；0.001)。各组间硬度无差异(p >；0.33)。结果表明，体外机械负荷比胶原酶注射更能反映肌腱病变的力学特性。

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引用次数: 0

Electromyographic assessment of agonist and antagonist muscles related to the anterior cruciate ligament following surgical Reconstruction: A Cross-Sectional study 手术重建后与前交叉韧带相关的激动剂和拮抗剂肌肉的肌电图评估：一项横断面研究

IF 2.3 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-08-05 DOI: 10.1016/j.jelekin.2025.103044

Ricardo Paredes , Carlos Crasto , António Mesquita Montes , Anabela André , Soraia Pereira , Diana Guedes , Leonel Alves , José L. Arias-Buría

Background

Following anterior cruciate ligament reconstruction (ACLR), neuromuscular control alterations may persist, increasing the risk of reinjury. Objectives: This study aimed to investigate electromyographic (EMG) muscle activation and the co-contraction index (CCI) of ACL-related agonist and antagonist muscles during side-hop tasks in ACLR individuals, offering novel insights into neuromuscular strategies during dynamic tasks. Methods: A cross-sectional study was conducted with 15 ACLR individuals and 15 participants without ACL injury (N-ACLR). Participants performed side-hop tasks while kinematic, kinetic, and EMG data were recorded during the preparatory and loading phases. Statistical analyses were performed at a 95 % confidence level. Results: During ipsilateral side hops, ACLR individuals exhibited higher semitendinosus (ST) activity in the initial contact (IC) and risk phases and increased quadriceps:hamstrings (Q:H) CCI in the risk phase compared to N-ACLR (p < 0.05). In contralateral side hops, ACLR individuals demonstrated higher Q:H CCI in the preparatory phase and higher vastus lateralis:biceps femoris (VL:BF) CCI in the IC and risk phases (p < 0.05). Conclusion: ACLR individuals display altered neuromuscular strategies during side-hop tasks compared to N-ACLR, highlighting adaptations in muscle activation and co-contraction patterns.

背景：前交叉韧带重建（ACLR）后，神经肌肉控制改变可能持续存在，增加再损伤的风险。目的：本研究旨在研究ACLR个体侧跳任务中acl相关激动剂和拮抗剂肌肉的肌电图（EMG）肌肉激活和共收缩指数（CCI），为动态任务中的神经肌肉策略提供新的见解。方法：对15例ACLR患者和15例无ACL损伤（N-ACLR）的参与者进行横断面研究。在准备和加载阶段，参与者进行侧跳任务，同时记录运动学、动力学和肌电图数据。统计分析在95%的置信水平上进行。结果：与N-ACLR相比，在同侧跳跃期间，ACLR个体在初次接触（IC）和危险阶段表现出更高的半腱肌（ST）活性，并且在危险阶段表现出更高的股四头肌：腘绳肌（Q:H） CCI (p <；0.05)。在对侧跳跃中，ACLR个体在准备阶段表现出较高的Q:H CCI，在IC和危险阶段表现出较高的股外侧：股二头肌（VL:BF） CCI (p <；0.05)。结论：与N-ACLR相比，ACLR个体在侧跳任务中表现出改变的神经肌肉策略，突出了肌肉激活和共同收缩模式的适应。

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引用次数: 0

Diagnostic value of EMG of sternocleidomastoid and trapezius in assessing bulbar lower motor neuron involvement in amyotrophic lateral sclerosis patients 胸锁乳突肌和斜方肌肌电图对肌萎缩侧索硬化症患者球下运动神经元受累的诊断价值

IF 2 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-07-23 DOI: 10.1016/j.jelekin.2025.103040

Jiarui Zhao , Jiongming Bai , Hongfen Wang , Ying Zhang , Jinghong Zhang , Yahui Zhu , Xinyuan Pang , Zhaohui Chen , Li Ling , Hongmei Cheng , Mao Li , Xusheng Huang

The diagnostic value of needle electromyography (EMG) of sternocleidomastoid (SCM) and trapezius (TRA) in assessing bulbar lower motor neuron involvement (LMN) remained controversial. 203 sporadic amyotrophic lateral sclerosis (ALS) patients were enrolled to assess the correlation between EMG abnormalities in SCM and TRA and bulbar LMN involvement. Additionally, difference analysis and diagnostic consistency analysis of EMG abnormalities in GEN (genioglossus), SCM, and TRA were compared. Finally, separate effects of EMG abnormalities in GEN, SCM, and TRA on diagnostic gradings were examined according to the Awaji-Shima criteria. 22 (18.2 %) and 65 (53.7 %) patients without bulbar LMN involvement showed EMG abnormalities in SCM and TRA. In contrast, 19 (23.2 %) and 11 (13.4 %) patients with bulbar LMN involvement showed normal EMG results in SCM and TRA. Multivariate logistic regression analyses showed that both EMG abnormalities in SCM and TRA were correlated with bulbar LMN involvement (P < 0.001). SCM showed electrophysiological characteristics similar to GEN when compared to TRA. However, TRA (67.0 %) showed significantly higher rates of EMG abnormalities than SCM (41.9 %) and GEN (40.4 %) in the whole study population. Reclassified diagnostic gradings showed no significant difference when evaluating EMG abnormalities in individual muscles to indicate bulbar LMN involvement (P = 0.072). EMG abnormalities in SCM and TRA could not fully represent bulbar LMN involvement but were correlated with it. It’s advisable to prioritise TRA as a better option when a patient cannot tolerate an EMG examination in the GEN. To enhance the diagnostic evaluation, an EMG examination of GEN could be served as the last choice.

胸锁乳突肌（SCM）和斜方肌（TRA）的针肌电图（EMG）在评估球下运动神经元受累（LMN）中的诊断价值一直存在争议。203例散发性肌萎缩性侧索硬化症（ALS）患者被纳入研究，以评估SCM和TRA肌电图异常与脊髓LMN受累的相关性。此外，比较GEN （genigenogssus）、SCM和TRA的肌电异常的差异分析和诊断一致性分析。最后，根据Awaji-Shima标准，分别检查GEN、SCM和TRA的肌电异常对诊断分级的影响。22例（18.2%）和65例（53.7%）未受累的患者在SCM和TRA表现出肌电异常。相比之下，19例（23.2%）和11例（13.4%）受累于球LMN的患者在SCM和TRA上的肌电图显示正常。多因素logistic回归分析显示，SCM和TRA的肌电图异常与球部LMN受累相关(P <；0.001)。与TRA相比，SCM表现出与GEN相似的电生理特征。然而，在整个研究人群中，TRA（67.0%）的肌电异常率明显高于SCM（41.9%）和GEN（40.4%）。重新分类的诊断分级在评估单个肌肉的肌电图异常以指示球LMN受累时没有显着差异（P = 0.072）。SCM和TRA的肌电异常不能完全代表LMN受累，但与之相关。当患者不能忍受GEN肌电图检查时，建议优先考虑TRA作为更好的选择。为了提高诊断评价，GEN肌电图检查可以作为最后的选择。

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引用次数: 0

Algorithm for jitter measurement in neuromuscular junction disease 神经肌肉交界处疾病的抖动测量算法

IF 2 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-07-17 DOI: 10.1016/j.jelekin.2025.103042

Armando Malanda , Daniel Stashuk , César Valle , Javier Rodríguez-Falces , Javier Navallas , Mamede de Carvalho , José Castro , Oscar Garnés-Camarena

The objective of this work was to extend the evaluation of a recently proposed method for estimating neuromuscular jitter within motor unit potential (MUP) trains extracted from muscles suffering neuromuscular junction disease. The method detects, within the MUP duration, “single-fiber” intervals that have likely been produced by single muscle fibers. Jitter is then estimated between pairs of these “single-fiber” intervals using an algorithm which incorporates the traditional mean consecutive difference (MCD) parameter.

Electromyographic (EMG) recordings from facial muscles of 15 patients with symptoms related to myasthenia gravis were obtained. MUP trains were extracted using DQEMG software and manual jitter measures were obtained using an ad-hoc graphical interface, which emulates single fiber EMG protocols. Automatic measures for two different values of an internal threshold parameter were obtained and compared to manual measures. 5 %, 25 %, 75 % and 95 % percentiles for the differences between the automatic and manual jitter measurements were [−3.74, −1.47, 1.24, 3.47 μs] and [−6.45, −2.07, 1.65, 7.16 μs], for the two threshold values, respectively. Therefore, very small statistical and clinical differences were found between the automatic and manual jitter measures, supporting the method as an accurate tool for jitter assessment or as a guiding aid for manual procedures.

这项工作的目的是扩展评估最近提出的一种方法，用于估计从患有神经肌肉连接疾病的肌肉中提取的运动单位电位（MUP）训练中的神经肌肉抖动。该方法在MUP持续时间内检测可能由单个肌肉纤维产生的“单纤维”间隔。然后使用结合传统平均连续差（MCD）参数的算法估计这些“单光纤”间隔对之间的抖动。本文对15例有重症肌无力相关症状的患者进行了面部肌电图（EMG）记录。使用DQEMG软件提取MUP列车，并使用模拟单光纤肌电信号协议的自组织图形界面获得手动抖动测量。获得了内部阈值参数的两个不同值的自动测量值，并与手动测量值进行了比较。自动抖动测量值与手动抖动测量值差异的5%、25%、75%和95%的百分位数分别为[- 3.74、- 1.47、1.24、3.47 μs]和[- 6.45、- 2.07、1.65、7.16 μs]。因此，自动和手动抖动测量之间的统计和临床差异非常小，支持该方法作为抖动评估的准确工具或作为手动程序的指导辅助。

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引用次数: 0

An articulated ankle foot orthosis with plantarflexion resistance decreased soleus and tibialis anterior muscle activity, and plantarflexion moment of the paretic lower limb of persons with stroke 关节踝关节足矫形器，抗跖屈，降低比目鱼肌和胫骨前肌活动，减少中风患者下肢的跖屈力矩

IF 2 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-07-14 DOI: 10.1016/j.jelekin.2025.103041

Oluwaseye P. Odanye , Emily A. Steffensen , Aaron D. Likens , Elisa S. Arch , Brian A. Knarr

Ankle foot orthoses (AFOs) are important devices for assisting persons with stroke during walking, especially in mediating dorsiflexor weakness. The plantarflexion (PF) resistances of AFOs have been shown to augment dorsiflexor muscle function during the stance and swing phases of gait. However, it is not clear how this translates to the muscle activities of their paretic lower limbs. To further explore this question in stroke rehabilitation, 3D technology was used in designing and fabricating an individual-specific articulated AFO, which we assembled with a mechanical joint that enabled the application of PF resistances. We investigated the impact of regulating two PF resistances (PF1, PF2) on their paretic lower limb muscle activity. At PF2, there was significantly lower mean muscle activity for the Soleus in LR and the Tibialis anterior in the second rocker, pre-swing, and swing phases. The device only impacted the activity of the medial gastrocnemius muscle at the second rocker. The findings corroborated evidence regarding how AFOs with PF resistance impact the muscle activity of stroke survivors following a single session use; however, longitudinal studies are necessary to establish the impacts with long-term use, as most stroke survivors use AFOs long-term.

踝关节足矫形器（AFOs）是辅助中风患者行走的重要装置，特别是在调节背屈肌无力方面。afo的跖屈（PF）阻力已被证明可以增强站立和摇摆步态阶段的背屈肌功能。然而，目前尚不清楚这如何转化为他们的下肢肌肉活动。为了在中风康复中进一步探索这一问题，我们使用3D技术设计和制造了一个个人特定的铰接式AFO，我们将其与一个能够应用PF阻力的机械关节组装在一起。我们研究了调节两种PF阻力（PF1, PF2）对其麻痹性下肢肌肉活动的影响。在PF2时，LR阶段的比目鱼肌和第二摇臂阶段、摇摆前阶段和摇摆阶段的胫骨前肌的平均肌肉活动显著降低。该装置仅影响第二摇杆处内侧腓肠肌的活动。研究结果证实了在单次使用后，具有PF阻力的afo如何影响中风幸存者的肌肉活动；然而，纵向研究是必要的，以确定长期使用的影响，因为大多数中风幸存者长期使用afo。

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引用次数: 0

Comparing motor unit number estimation techniques 比较运动单元数估计技术

IF 2 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-06-29 DOI: 10.1016/j.jelekin.2025.103030

M.I.B. Debenham , O. Roussel , C.J. McNeil , M.J. Berger , B.H. Dalton

It is unclear how comparable motor unit number estimates (MUNEs) are when derived from a non-invasive technique involving repetitive peripheral nerve stimulation vs. one involving volitional contractions and intramuscular recordings of single motor units (MUs). Therefore, this study examined MUNEs from MScanFit (MScan) and Decomposition-Enhanced Spike-Triggered Averaging (DE-STA). Eighteen participants (8 females, 10 males; 29.7 ± 7.1 years) sat with their right leg positioned in an isometric myograph while surface electromyography (EMG) was recorded from the tibialis anterior (TA). The MScan protocol isolated and derived the size of single MUs by repeatedly stimulating the common fibular nerve at progressively weaker currents to model a compound muscle action potential (CMAP) stimulus–response curve. For DE-STA, a concentric needle electrode was inserted into the TA, and participants performed 30-s isometric dorsiflexion contractions at 25 % of maximal voluntary torque to obtain ≥20 individual surface MU potentials (S-MUPs; i.e., single MUs extracted from the surface EMG signal based on needle-detected spikes). Both techniques used the same maximal CMAP to calculate a MUNE, yet MScan used a mathematical model to simulate the recorded CMAP stimulus–response, which was compared to the recorded scan to minimize disagreement; whereas DE-STA compared the size of the maximal CMAP to the average S-MUP. There was no difference between the MUNE calculated via DE-STA (132 ± 26 MUs) and MScan (142 ± 22 MUs; p = 0.11), and the bias (10.0 MUs) and limits of agreement (67.6 vs −47.6 MU difference) suggests that either technique may independently offer a reasonable MU estimate for the TA of young adults.

目前尚不清楚，重复性周围神经刺激的非侵入性技术与意志收缩和单个运动单位（MUs）的肌肉内记录的技术相比，可比性运动单位数估计（MUNEs）的效果如何。因此，本研究检查了MScanFit （MScan）和分解增强峰值触发平均（DE-STA）的MUNEs。18名参与者(女性8人，男性10人；29.7±7.1岁)坐下，右腿定位于等长肌图，记录胫骨前肌（TA）的肌表电图（EMG）。MScan方案通过以逐渐变弱的电流反复刺激腓骨总神经来模拟复合肌肉动作电位（CMAP）刺激-反应曲线，从而分离并推导出单个MUs的大小。对于DE-STA，将一个同心针电极插入TA，参与者以最大自主扭矩的25%进行30秒的等长背屈收缩，以获得≥20个个体表面MU电位（S-MUPs）；即，根据针检测到的尖峰从表面肌电信号中提取单个mu)。两种技术都使用相同的最大CMAP来计算MUNE，但MScan使用数学模型来模拟记录的CMAP刺激反应，并将其与记录的扫描进行比较，以尽量减少差异；而DE-STA将最大CMAP的大小与平均S-MUP进行比较。通过DE-STA计算的MUNE（132±26 MUs）与MScan计算的MUNE（142±22 MUs）无差异；p = 0.11)，偏差（10.0 MU）和一致性限制（67.6 vs - 47.6 MU差异）表明，这两种技术都可以独立地为年轻人的TA提供合理的MU估计。

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引用次数: 0

Shoulder load during wheelchair-related activities of daily life 日常生活中与轮椅有关的活动中的肩部负荷

IF 2 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-06-20 DOI: 10.1016/j.jelekin.2025.103027

Ursina Arnet , Dirkjan (H. E. J.) Veeger , Wiebe H.K. de Vries

Manual wheelchair users experience significant upper extremity strain, leading to a high prevalence of shoulder pain. Identifying modifiable risk factors for shoulder complaints is crucial for developing effective interventions. Consequently, it’s important to quantify shoulder load (magnitude, frequency and duration) experienced by manual wheelchair users throughout the day.

This study aims to quantify the magnitude of shoulder load during various daily activities, including wheelchair propulsion at different speeds and inclines, ascending and descending ramps, weight relief lift, material handling and desk work. Ten able-bodied participants performed these activities while their upper extremity kinematics and exerted forces were measured. The analysis focused on glenohumeral contact force and rotator cuff muscle forces using the Delft Shoulder and Elbow Model.

Highest mean glenohumeral contact forces were found during weight relief lift (1363 ± 1204 N), followed by descending a ramp (997 ± 1043 N) and fast propulsion (802 ± 742 N). The supraspinatus muscle generated the greatest force during weight relief lift (327 ± 490 N) and fast propulsion (184 ± 205 N). These findings provide a first reference for estimating joint load in daily activities. By combining these data with the individual activity frequency and duration, personalized shoulder load exposure can be assessed, informing the development of targeted interventions to reduce shoulder pain in manual wheelchair users.

手动轮椅使用者会经历明显的上肢劳损，导致肩部疼痛的高发。确定可改变的肩部疾病风险因素对于制定有效的干预措施至关重要。因此，量化手动轮椅使用者全天所经历的肩部负荷（强度、频率和持续时间）是很重要的。本研究旨在量化各种日常活动中肩负荷的大小，包括轮椅在不同速度和倾斜度下的推进，上升和下降的斜坡，减轻重量的升降机，物料搬运和案头工作。10名身体健全的参与者在进行这些活动的同时，测量了他们的上肢运动学和施加的力。使用Delft肩肘模型分析肩关节接触力和肩袖肌肉力。平均肩关节接触力在卸重提升（1363±1204 N）时最高，其次是下降坡道（997±1043 N）和快速推进（802±742 N）。在负重提升（327±490 N）和快速推进（184±205 N）时冈上肌产生的力最大。这些发现为估计日常活动中的关节负荷提供了第一个参考。通过将这些数据与个人活动频率和持续时间相结合，可以评估个性化的肩部负荷暴露，为制定有针对性的干预措施提供信息，以减少手动轮椅使用者的肩部疼痛。

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引用次数: 0

The Probability Density Function (PDF) of surface EMG with increasing force: a comparison between the tibialis anterior and the vastus lateralis 增加力的表面肌电的概率密度函数：胫骨前肌和股外侧肌的比较

IF 2 4区医学 Q3 NEUROSCIENCES

Journal of Electromyography and Kinesiology

Pub Date : 2025-06-20 DOI: 10.1016/j.jelekin.2025.103029

Silvia Recalde-Villamayor , Javier Navallas , Cristina Mariscal , Armando Malanda , Javier Rodriguez-Falces

Objectives

The process by which the surface EMG signal is progressively filled up with motor unit potentials has so far been investigated only in the quadriceps muscles. However, the sEMG filling process is influenced by anatomical, physiological, and neural factors, and thus may be different for each muscle. Here, we sought to characterize the sEMG filling process of the tibialis anterior (TA) and compare it to that of the vastus lateralis (VL).

Methods

Surface EMG signals were recorded from the TA and VL muscles of healthy subjects as force was gradually increased from 0 to 80% MVC. The sEMG filling process was analyzed by measuring the EMG filling factor (FF), an index determined by the shape of the probability density function (PDF) of the sEMG signal.

Results

(1) The sEMG filling process showed significant differences between the TA and VL muscles (p < 0.05).

(2) In the TA, the degree of sEMG filling at the onset of the contraction was low (FF < 0.45) for 72 % of male subjects and 53 % of female subjects, whereas, in the VL, the degree of initial sEMG filling was low for 89 % of male subjects, but only in 12 % of female subjects.

(3) In the TA, the sEMG at high forces (>40 % MVC) contained spikes with largely different amplitudes (FF ∼ 0.5), whereas, in the VL, the sEMG contained spikes with comparable amplitudes (FF ∼ 0.63).

Conclusions

(1) At high forces, the TA PDF was close to Laplacian, whilst the VL PDF was nearly Gaussian; (2) The sEMG filling curves are more informative in the TA than in the VL; (3) The sEMG filling process is muscle and gender specific.

目的：表面肌电信号逐渐充满运动单位电位的过程迄今为止仅在股四头肌中进行了研究。然而，肌电信号填充过程受解剖、生理和神经因素的影响，因此每块肌肉的肌电信号填充过程可能是不同的。在这里，我们试图描述胫骨前肌（TA）的肌电信号填充过程，并将其与股外侧肌（VL）的肌电信号填充过程进行比较。方法记录健康受试者从0 ~ 80% MVC逐渐增加时TA肌和VL肌的表面肌电信号。通过测量表面肌电信号概率密度函数（PDF）的形状决定的表面肌电信号填充因子（FF）来分析表面肌电信号填充过程。结果(1)表面肌和VL肌的表面肌电信号填充过程存在显著差异(p <；(2)在TA区，收缩开始时肌表肌电信号充盈程度较低(FF <；0.45), 72%的男性和53%的女性主题,然而,六世,初始表填写很低程度的男性受试者的89%,但只有12%的女性主题。(3)在助教,面肌电信号在高力量(MVC)在40%包含峰值很大程度上不同的振幅(FF∼0.5),然而,六世,面肌电信号包含峰值与可比振幅(FF∼0.63).Conclusions(1)在高力量,助教PDF接近拉普拉斯算子,而六世PDF近高斯分布;(2)表面肌电信号填充曲线在TA区比在VL区更具信息量；(3)表面肌电信号填充过程具有肌肉和性别特异性。

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引用次数: 0