膝骨关节炎患者膝关节置换后下肢肌的表面肌电图变化

背景：膝骨关节炎患者膝关节置换后下肢肌功能恢复一直存在着争议。目的：评价膝骨关节炎患者膝关节置换手术后下肢肌肉功能。方法：应用TELEMYO2400RG2表面肌电图遥测仪对25例双膝骨关节炎单膝关节置换后患者在平常自然步态下进行双下肢股直肌、胫前肌、股二头肌和腓肠肌内侧的表面肌电信号测试。在肌电图测试前,对患者双膝关节功能进行美国特种外科医院膝关节评分。结果与结论：患者置换后美国特种外科医院膝关节评置换侧平均分91．44,其优良率达100％;未置换侧平均分54．52。置换侧在疼痛、关节功能方面有明显改善;膝关节置换后置换侧股直肌、胫前肌、股二头肌的肌电振幅、肌电积分、平均频率、中位频率的（平均值、最小值、最大值）与未置换侧相比差异无显著性意义（P〉0．05）;置换侧腓肠肌内侧肌电振幅值及肌电积分值显著大于未置换侧（P〈0．05）;置换侧腓肠肌内侧平均频率、中位频率与未置换侧相比差异无显著性意义（P〉0．05）。提示膝关节置换后置换侧的下肢肌没有恢复到正常的功能活动水平,因此膝关节置换后康复要特别重视患者的肌肉锻炼。     

脑卒中患者步态周期各时相中下肢肌肉的表面肌电特点

目的探讨脑卒中患者下肢前后肌群在步态周期及其各分相中表面肌电(sEMG)信号的变化,以便有针对性地对脑卒中患者进行步态康复训练。方法 2018年1月至6月,采用Noraxon表面肌电无线采集系统记录20例脑卒中患者和20例健康对照者在自然行走过程中双下肢胫骨前肌(TA)、股直肌(RF)、腓肠肌内侧头(GM)和股二头肌(BF)的sEMG信号。结果健康受试者双下肢TA、RF、GM和BF的肌电活动随步态周期呈活动与静止周期性变化、双侧同名肌肉交替活动,而脑卒中患者双下肢相关肌肉肌电活动发生明显改变,且失去规律性。结论 sEMG能反映脑卒中患者步态相关肌肉受损情况,可用于指导步态康复训练。     

日常生活活动中人体下肢肌肉的表面肌电特性

目的探讨个体完成日常生活活动时下肢主要肌肉群肌电信号特征。方法30 名正常成年人完成7 个基本动作,同步检测双侧股直肌、股内侧肌、股外侧肌、腓肠肌外侧、胫前肌和比目鱼肌的表面肌电平均肌电值(AEMG)。结果和结论在日常生活活动中,左右下肢肌肉的发力有显著性差异,下肢各肌肉发力有显著性差异,男、女性在完成日常生活活动时下肢发力方式不同     

穿戴塑料踝足矫形器对下肢肌肉疲劳性的影响

背景：目前尚未见到系统研究踝足矫形器对下肢肌肉影响的文献。目的：提取正常人穿戴固定踝足矫形器时的下肢肌电信号,分析固定踝足矫形器对下肢肌肉疲劳性的影响。方法：选择5名健康男性受试者参加试验,每名受试者分别进行3组试验：①第1组,在不穿戴任何矫形器的情况下以自然步态行走。②第2组,受试者穿戴平跟踝足矫形器以自然步态行走（此时矫形器踝部包裹超过踝中心1 cm,记1.0 cm）,穿戴同一矫形器但在踝部去掉1.0 cm、踝部塑料边缘刚好通过踝中心时采集（记0 cm）,在踝部再去掉1.0 cm后以自然步态行走（记-1.0 cm）。③第3组,受试者穿戴1.5 cm正常跟高踝足矫形器以自然步态行走,穿戴同一矫形器,但跟高分别改为1.0,2.0 cm后以自然步态行走。行走中采用肌电采集仪检测受试者下肢股二头肌、股直肌、胫骨前肌、腓肠肌的表面肌电信号。结果与结论：①正常不穿戴任何矫形器时,4块肌肉的肌电信号是最弱的。②对于任何一块肌肉,正常不穿戴矫形器时所对应肌电值比穿戴不同硬度矫形器时所对应的肌电值要小。③对于股二头肌,正常不穿戴矫形器时所对应的积分肌电值与穿戴正常跟高矫形器时所对应的值很接近,同时这两个值要比穿戴不正常跟高矫形器时所对应的积分肌电值小。表明固定塑料踝足矫形器会引起股二头肌、股直肌、胫骨前肌、腓肠肌的疲劳,当固定塑料踝足矫形器的跟高不合适时会进一步增加股二头肌的疲劳程度。     

步行训练中偏瘫患者步速对下肢肌肉活动及能量消耗的影响

目的：探讨偏瘫患者行走时的步速与能量消耗及下肢肌肉活动的关系。方法：２４例能行走的偏瘫患者系安全带，下肢不负重，在走步机上分别以自然步速、慢速（自然步速减去２５％）及快速（自然步速加上２５％）行走。主要结果评定包括基础评定、步态周期参数、下肢肌肉活动、能量消耗。结果：步频、跨距、双支撑期及偏瘫侧胫前肌、腓肠肌、股外侧肌、股直肌、股二头肌肌肉活动与步速呈正相关，平均最高心率是１３１次／min，能量消耗和心肌负荷与步速呈负相关。肌肉活动方式定性分析显示下肢肌肉激活越早越好。结论：患者在走步机上应尽量快…     

表面肌电结合三维步态分析观察脑卒中患者步行支撑相期下肢肌肉激活时序的研究

目的 应用表面肌电技术结合三维步态分析研究卒中患者康复中步行支撑相期下肢肌肉激活时序的变化规律。 方法 采用分层随机化分组方式，按随机数字表法随机选取在院或门诊的Brunnstrom III期、IV期、V期脑卒中患者各20例，共60例患者分为III期组、IV期组及V期组。采用三维步态分析同步表面肌电图测试3组受试者步行支撑相期健患两侧下肢股直肌、股二头肌、胫前肌及腓肠肌各肌肉在步行支撑相期的激活开始时间和激活持续时间，比较各组受试者健、患两侧及组间对应下肢相关肌肉激活开始时间及持续时间（完整步态周期百分比）。 结果 III期组患侧股直肌激活开始时间显著迟于健侧，而患侧腓肠肌激活开始时间显著早于健侧，患侧股二头肌及腓肠肌激活持续时间均显著低于健侧，差异均有统计学意义（P<0.05）；IV期组患侧胫前肌、腓肠肌的激活开始时间均显著早于健侧，差异均有统计学意义（P<0.05）；V期组患侧胫前肌激活开始时间显著早于健侧，差异均有统计学意义（P<0.05）。IV期组患侧股直肌、患侧股二头肌激活开始时间分别为（-12.39±8.75）%和（-15.30±11.08）%，均显著早于III期组，差异均有统计学意义（P<0.05）；V期组健侧胫前肌和患侧腓肠肌的激活开始时间分别为（-5.01±7.51）%和（10.40±10.45）%，均显著迟于IV期组，差异均有统计学意义（P<0.05）；V期组健侧股直肌、健侧胫前肌、患侧腓肠肌激活开始时间分别为（-8.31±3.33）%、（-5.01±7.51）%和（10.40±10.45）%，显著迟于III期组，而其患侧股二头肌和胫前肌激活开始时间分别为（-12.7±11.88）%、（-25.11±14.60）%，显著早于III期组，差异均有统计学意义（P<0.05）；IV期组健侧股二头肌激活持续时间为（44.51±16.60）%，显著低于III期组，差异有统计学意义（P<0.05）；V期组健侧胫前肌激活持续时间为（46.32±13.77）%，显著低于IV期组，差异有统计学意义（P<0.05）；V期组患侧股直肌及健侧股直肌、股二头肌、胫前肌和腓肠肌的激活持续时间分别为（45.30±6.13）、（50.85±11.86）%、（37.74±18.24）%、（46.32±13.77）%和（46.72±25.06）%，均显著低于III期组，差异均有统计学意义（P<0.05）。 结论 不同恢复阶段的脑卒中患者在步行中健患两侧下肢肌肉的激活时序存在较大的差异，各阶段均存在患侧下肢部分肌肉的提前激活及健侧下肢部分肌肉的过度激活现象，随着下肢运动功能的恢复，其健侧下肢部分肌肉的过度激活逐渐得到改善。     

先天性马蹄内翻足表面肌电信号研究

摘要 目的：探讨表面肌电（sEMG）检测技术在先天性马蹄内翻足患儿中的临床应用。 方法：采用十通道生物机能实验系统采集32例单侧先天性马蹄内翻足患儿的下肢表面肌电信号。患儿取仰卧位,在自然放松位、踝被动背伸至中立位、踝被动跖屈45度时检测双侧股直肌、胫前肌、腓肠肌的表面肌电信号,经信号处理得到股直肌、胫前肌、腓肠肌的平均均方根（RMS）值,并分析健侧与患侧相关肌肉平均RMS值的差异。 结果：患侧的小腿肌肉受累,健侧与患侧胫前肌、腓肠肌在背伸位、跖屈位平均RMS值差异有统计学意义（P＜0.05）,且患侧胫前肌、腓肠肌肌电信号均较健侧低。 结论：先天性马蹄内翻足患儿存在神经、肌肉功能异常,表面肌电图检测可以无创地了解患儿的神经及肌肉功能。     

正常步态10m自由步行胫前后肌群的SEMG研究

目的:利用表面肌电图(SEMG)进行步态分析评定,为拓展表面肌电图的临床应用建立可靠的依据.方法:5例青年健康受试者进行10m自由步行测试,同步记录双下肢胫前肌及腓肠肌内侧头肌群的表面肌电信号,分析在正常步态周期中受试肌SEMG的变化规律.结果:正常步态周期中,胫前肌近乎呈持续活动状态,并有两个活动高峰;腓肠肌在摆动期除表现为电静息状态外,在中末期也可有一个较小的梭形波存在.健康人步行时胫前肌的肌电活动,优势与非优势侧存在差异(P＜0.05),但总体两侧胫前后肌群的收缩负荷比均等.结论:步行周期中胫前肌和腓肠肌的表面肌电信号特征明显不同,胫前肌较腓肠肌更易发生疲劳;摆动中期的小腿后部伸肌肌群的轻度肌电活动可能是哺乳类动物步行时共有的规律.     

基于表面肌电的步态分析

背景:步态分析在人体运动系统和神经系统疾病的病因分析,诊断,功能、疗效与残疾评定中是重要的评价手段,其中肌肉活动是影响步行动力的基础因素.目的:分析人体自然行走过程中下肢前后肌群的表面肌电变化,分析对应于步态周期不同时相前后肌群的表面肌电特征和机制.方法:采用德国zebris FDM 步态分析系统(6 m)配套的同步肌电仪采集7例健康人正常步态过程中下肢胫骨前肌和腓肠肌外侧表面肌电信号,利用Matlab软件进行消噪和归一化,得到完整步态周期不同时相对应的表面肌电信号图,观察其峰值变化.采用芬兰ME6000肌电仪测试15 m自由行走人体左右侧下肢胫骨前肌和腓肠肌外侧表面肌电信号,提取时域和频域特征参数.结果与结论:下肢胫骨前肌和腓肠肌外侧表面肌电信号在一个完整步态周期中呈特征性变化,即胫骨前肌表面肌电的峰值发生在后跟着地处,而腓肠肌外侧其峰值发生在中后支撑相处.进一步分析发现,人体在自由行走时其下肢肌肉优势侧与非优势侧差异有显著性意义(P＜0.05),且不同肌肉其差异趋势不同.     

半月板损伤患者膝周肌肉的表面肌电图分析

目的探讨半月板损伤对膝周肌肉功能的影响。方法 2017年2月至2018年2月,单侧半月板损伤患者22例,记录下蹲、站起和屈膝70°最大等长收缩时,健、患侧股外侧肌、股直肌、股内侧肌和股二头肌的表面肌电图。结果下蹲和站起时,患侧股外侧肌和股二头肌的平均肌电值显著低于健侧(t 3.945, Z 3.847, P 0.001),腘绳肌共同活动比率明显高于健侧(t 3.650, P 0.01)。在70°最大等长收缩时,患侧股外侧肌、股直肌、股内侧肌和股二头肌平均肌电值均明显小于健侧(t 2.907, Z=4.107, P 0.01)。结论 sEMG能定量评价半月板损伤患者不同运动状态下膝屈伸肌功能。半月板损伤患者患肢膝周肌肉功能下降,协调性异常,应在康复治疗过程中加以纠正。     

Comparison of toe grip strength and muscle activities during maximal toe grip strength exertion according to the presence/absence of an ankle immobilization belt

[Purpose] The aim of this study was to compare toe grip strength and muscle activity during toe grip strength exertion according to the presence/absence of an ankle immobilization belt and to examine the relationship between the differences in muscle activity and toe grip strength. [Subjects] The Subjects were 13 healthy young women. [Methods] We measured toe grip strength and muscle activity during toe grip strength exertion in the presence and absence of an ankle immobilization belt using electromyography. Activity in the following leg muscles was recorded: rectus femoris, biceps femoris, medial head of the gastrocnemius, and tibialis anterior. We then calculated the percent integrated electromyography during toe gripping. [Results] Toe grip strength and percent integrated electromyography of the medial head of the gastrocnemius muscle were significantly higher with ankle belt immobilization compared with without ankle belt immobilization. In addition, in the presence of ankle belt immobilization, the percent integrated electromyography of the tibialis anterior muscle and medial head of the gastrocnemius muscle demonstrated a positive correlation with toe grip strength (r = 0.75 and r = 0.65, respectively). [Conclusion] These findings suggest that greater toe grip strength could be exerted in the presence of ankle belt immobilization. The measured values reflect the percent integrated electromyography of the crural muscles. Therefore, it was shown that toe grip strength should be measured in the presence of an immobilization belt.Key words: Toe gripping strength, Muscle activity, Immobilization belt     

Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

ABSTRACT: BACKGROUND: Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user's nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. METHODS: We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step intersubject variability of these profiles by calculating variance-to-signal ratios. RESULTS: We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. CONCLUSION: Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee's nervous system.     

Responses to whole head-and-body tilts with and without passive ankle dorsiflexion in the absence of visual feedback

OBJECTIVES: We have investigated lower limb responses in seven blindfolded healthy subjects to well controlled tilts in the standing position. Our aims were (1) to determine the effect of head acceleration magnitude on responses evoked by whole head-and-body tilts, and (2) to establish whether tilt-evoked responses are modifiable by passive ankle dorsiflexion. Whole head-and-body tilts evoked responses in the biceps femoris, medial gastrocnemius and tibialis anterior muscles. METHODS: Seven young healthy subjects stood on a spring-activated tilting apparatus and underwent sudden whole head-and-body tilts of about 15 degrees from the vertical position, with or without passive ankle dorsiflexion. Head acceleration was recorded with a linear accelerometer and ankle angular displacement with a potentiometer. Surface EMG signals were recorded in the right biceps femoris, medial gastrocnemius and tibialis anterior muscles. RESULTS: As the peak of head acceleration was increased from 0.5 g to 1.8 g, the frequency of occurrence of tilt-evoked responses increased from 7% to 60% of trials in the biceps femoris muscle during whole head-and-body tilts. In general, the more proximal muscle (biceps femoris) was activated before the more distal muscle (medial gastrocnemius) during whole head-and-body tilts, while the opposite pattern was found during tilt with dorsiflexion. CONCLUSIONS: Our results indicate that the occurrence of tilt-evoked responses increases with an increase in the amplitude of tilting acceleration. This suggests that tilt-evoked responses are dependent, at least in part, on vestibular stimulation. In addition, the spatio-temporal pattern of biceps femoris and medial gastrocnemius muscle activation was opposite during whole head-and-body tilts and tilts with dorsiflexion. This finding suggests that foot/ankle somatosensory inputs can modify tilt-evoked responses.     

Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system.     

Quantified electromyography of lower-limb muscles during level walking

The electromyography (EMG) of eleven different lower limb muscles of ten healthy subjects was quantified during normal level walking. The surface EMGs obtained were normalized, in percentage, to the activity obtained during an isometric maximum voluntary test contraction of each subject. The mean peak activities of the gluteus maximus, gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris and medial hamstring muscles occurred at heel-strike and were between 5 and 15% of max isometric EMG. The magnitudes of tibialis anterior and triceps surae muscular activity were higher than those of the other muscles investigated. Mean peak activity in tibialis anterior was 27%, in gastrocnemius medialis 42%, in gastrocnemius lateralis 19% and in soleus 40%. The important role of the triceps surae during walking was reflected in comparatively high muscular activity at push-off.     

Muscular activity during ergometer cycling

The aim of the study was to quantify the activity as recorded by electromyography during ergometer cycling in eleven different muscles of the lower extremity. Eleven healthy subjects rode in twelve different ways at different work-load, pedalling rate, saddle height and pedal foot position. Vastus medialis and lateralis, gastrocnemius medialis and lateralis and the soleus muscle were the most activated muscles. Changes in muscle activity during different calibrations were studied in eight of the eleven muscles. An increase in work-load significantly increased the mean maximum activity in all the eight muscles investigated. An increase of the pedalling rate increased the activity in the gluteus maximus, gluteus medius, vastus medialis, medial hamstring, gastrocnemius medialis and soleus muscles. An increase of the saddle height increased the muscle activity in the gluteus medius, medial hamstring and gastrocnemius medialis muscles. Use of a posterior pedal foot position increased the activity in the gluteus medius and rectus femoris muscles, and decreased the activity in the soleus muscle.     

Do Fitflops™ increase lower limb muscle activity?

Background

Fitness toning shoes are becoming increasingly popular, they aim to increase muscle activity, raise energy expenditure and improve overall health while wearing them. Yet there is a lack of consensus in the literature regarding their effectiveness. One such shoe on the market is the Fitflop™ designed to activate leg muscles through density shifts in the shoe's sole. The purpose of this study was to investigate the effect of wearing Fitflops^TM on the muscle activity of the lower limb.

Methods

Twenty three females (age 20.8 (1.3)years, mass 62.9 (11.9)kg, height 165.4 (5.6)cm) participated in the study. Muscle activity of the medial gastrocnemius, biceps femoris, rectus femoris and gluteus maximus of the participants' right limb were recorded using surface electromyography during participation in three different tasks to simulate daily living activities. These were a) treadmill walking b) stair climbing and c) zigzag walking around cones. The participants completed the tasks barefoot, while wearing Fitflops™ and while wearing regular flip flops so that comparisons between muscle activity in the different shoe conditions could be made.

Findings

The results show that there was no significant difference in the activity of the medial gastrocnemius, biceps femoris, rectus femoris and gluteus maximus muscles across all shoe conditions and simulated daily activities (P > 0.05).

Interpretation

Based on these results, the use of Fitflops™ is not recommended as a means of increasing muscle activity of the medial gastrocnemius, biceps femoris, rectus femoris and gluteus maximus during activities of daily living in a healthy recreationally active female population.