膝骨关节炎患者与正常人股内侧肌、股直肌和股外侧肌收缩特征的对照研究

目的 应用表面肌电图和等速肌力评测方法比较膝骨关节炎患者与正常人股内侧肌、股直肌、股外侧肌肌肉收缩特征,包括收缩速度、收缩力量和抗疲劳性.方法 34例膝骨关节炎患者参与观察组;34名健康人参与对照组.两组的年龄、身高、体重、性别、左右侧、Q角相匹配.所有受试者均在膝关节屈曲10°、60°、100°等长伸膝和等速60°/s、180°/s伸膝运动测试模式下,进行股内侧肌、股直肌和股外侧肌的表面肌电图和股四头肌肌力的评测.采用独立样本 t检验对两组评定指标包括募集速率、平均振幅、峰力矩/体重比、疲劳指数分别进行对比分析.结果 ①观察组股内侧肌在膝屈60°等长伸膝测试和等速60°/s、180°/s伸膝测试中募集速率较对照组减小;股直肌在膝屈60°等长伸膝测试和等速60°/s伸膝测试中募集速率较对照组减小;股外侧肌在等长膝屈10°和100°伸膝测试和等速60°/s伸膝测试中募集速率较对照组减小( P＜0.05).②观察组股内侧肌、股直肌在等速60°/s、180°/s伸膝测试中平均振幅较对照组增大;观察组股直肌、股外侧肌在等长膝屈10°伸膝测试中平均振幅较对照组增大( P＜0.05).③观察组股内侧肌、股直肌和股外侧肌在膝屈10°、60°、100°等长伸膝和等速60°/s、180°/s伸膝运动测试模式中峰力矩/体重比均小于对照组( P＜0.05).④观察组在等速180°/s伸膝测试中股四头肌耐疲劳能力较对照组增强( P＜0.05).结论 膝骨关节炎患者患侧股内侧肌、股直肌和股外侧肌的收缩速度减慢、收缩力量减小、抗疲劳性增加.     

基于多通道表面肌电探讨不同角速度下膝骨关节炎患者生物力学基础的研究

目的：应用表面肌电图观察和分析膝骨关节炎（knee osteoarthritis,KOA）患者股四头肌表面肌电活动。方法：采用全无线肌电测试系统评测30例KOA患者（KOA组）和30例健康受试者（CON组）在不同角速度（60°/s、90°/s、180°/s）膝关节屈伸运动等速肌力测试下,股内侧肌、股直肌和股外侧肌的表面肌电图,并记录KOA组受试者股内侧肌、股直肌和股外侧肌肌肉厚度与膝痛程度,以评估肌电数据和临床指标的相关性。结果：KOA患者和健康受试者在各不同角速度60°/s(P<0.001)、90°/s(P<0.01)、180°/s(P<0.01)膝关节屈伸运动中屈膝最大力矩与伸膝最大力矩均具有显著性意义,且KOA组膝关节屈伸最大力矩平均值均低于CON组。在角速度为60°/s等速肌力测试时,KOA组股外侧肌的中值频率差值率（P<0.05）、股直肌的均方根值（P<0.01）与相应对照组具有显著性意义;在角速度为90°/s等速肌力测试时,两组受试者的股直肌均方根值存在显著性差异（P<0.05）;在角速度为180°/s时,两组的股直肌中值频率差值率（P&...     

运动疗法对膝关节骨关节炎患者肌发电量的影响

目的：研究肌发电量在膝关节骨关节炎患者股四头肌肌力训练中的变化情况及股四头肌的详细变化情况。方法：采用股四头肌的等长收缩运动训练方法和其他疗法进行比较,用肌电图进行股直肌、股内侧肌、股外侧肌的肌发电量测定,同时用“膝关节功能评定表”进行功能的辅助评定。结果：两种方法治疗后,股直肌、股内侧肌的肌发电量都有显著的变化,尤其以股内侧肌的变化极显著,股外侧的肌发电量无显著变化。两种方法中肌力训练较其他治疗方法在提高肌发电量方面更为有效。结论：股内侧肌在膝关节肌力锻炼中的变化最大,说明股内侧肌比股直肌和股外侧肌在稳定膝关节方面更重要。股外侧肌在训练中的变化最小,在维护膝关节的稳定性方面起的作用比股内侧肌和股直肌小;肌力训练比其他方法在增加肌发电量方面更有效,更能提高膝关节的稳定性。     

膝关节骨关节炎患者膝屈伸肌的表面肌电信号研究

目的 评价单侧膝关节骨关节炎（OA）患者在不同运动状态下的健、患侧膝屈伸肌的肌肉功能和协调活动差异，为临床制定康复方案提供依据。方法 用Noraxon Myosystem1200型表面肌电图仪对26例单侧膝关节骨关节炎患者的等长肌肉收缩功能和下蹲运动进行表面肌电信号的测试。结果 患侧股外侧肌和股二头肌在最大等长收缩和下蹲运动时的肌电振幅均值小于健侧（P〈0．05）。在最大等长收缩过程中，患侧的拮抗肌协同收缩率较健侧增高（P〈0．05）；在下蹲运动过程中，患侧的胭绳肌共同活动比率高于检测（P〈0．05）。结论 表面肌电图测试可用于量化评价膝OA患者在不同运动过程中肌肉功能。膝OA患肢在不同运动状态下均可能存在肌肉功能降低和肌力平衡异常。康复治疗不仅应重视股四头肌肌力增强而且应重视改善膝关节的肌力平衡。     

髌腱末端病运动员膝关节屈伸峰力矩和表面肌电图的特征(英文)

背景:髌腱末端病是腱止点部位的微细损伤,股四头肌群中的股内侧肌与股外侧肌之间的力量平衡发生变化,可直接导致髌骨产生异常运动从而对腱止点部位产生影响。目的:分析髌腱末端病发生机制和髌腱末端病对膝关节及其周围肌肉活动产生的影响。方法:选择10名患有髌骨肌腱病的男运动员及10名运动项目、身高和年龄匹配的正常男运动员,采用瑞士CON-TREX等速肌力测试与训练系统,分别进行膝关节力量和表面肌电图的测试,比较与分析膝关节屈肌力矩、伸肌力矩和股四头肌表面肌电图的变化。结果与结论:发现在等长运动时,末端病组的伸肌伸肌峰力矩明显小于对照组、峰值转矩比比值明显大于对照组;在等速运动时,末端病组的伸肌伸肌峰力矩明显小于对照组,并随着运动角速度增加而变化显著,而峰值转矩比比值均不同程高于对照组;末端病组的股内侧肌/股外侧肌的整合肌电图比值在等长运动和等速运动时,均明显低于对照组。提示髌腱末端病运动员膝关节屈肌与伸肌的力量差距较为突出,存在股内侧肌活动低下和股内侧肌与股外侧肌之间不平衡的现象。     

髌腱末端病运动员膝关节屈伸峰力矩和表面肌电图的特征（英文）

背景：髌腱末端病是腱止点部位的微细损伤,股四头肌群中的股内侧肌与股外侧肌之间的力量平衡发生变化,可直接导致髌骨产生异常运动从而对腱止点部位产生影响。目的：分析髌腱末端病发生机制和髌腱末端病对膝关节及其周围肌肉活动产生的影响。方法：选择10名患有髌骨肌腱病的男运动员及10名运动项目、身高和年龄匹配的正常男运动员,采用瑞士CON-TREX等速肌力测试与训练系统,分别进行膝关节力量和表面肌电图的测试,比较与分析膝关节屈肌力矩、伸肌力矩和股四头肌表面肌电图的变化。结果与结论：发现在等长运动时,末端病组的伸肌伸肌峰力矩明显小于对照组、峰值转矩比比值明显大于对照组;在等速运动时,末端病组的伸肌伸肌峰力矩明显小于对照组,并随着运动角速度增加而变化显著,而峰值转矩比比值均不同程高于对照组;末端病组的股内侧肌/股外侧肌的整合肌电图比值在等长运动和等速运动时,均明显低于对照组。提示髌腱末端病运动员膝关节屈肌与伸肌的力量差距较为突出,存在股内侧肌活动低下和股内侧肌与股外侧肌之间不平衡的现象。     

膝骨关节炎患者股四头肌功能水平及髋关节步态运动学特征分析

目的:观察中老年膝骨关节炎(KOA)患者股四头肌功能水平及步行过程中髋关节的运动学特征。方法:选取18例KOA患者为KOA组,8例无KOA者为对照组,2组的年龄、身高、体重和身体质量指数(BMI值)相匹配。2组受试者均进行等速肌力测试、无线表面肌电测试及步态测试,测试及比较2组股四头肌峰力矩(PT值)、股内侧肌(VM)、股外侧肌(VL)和股直肌(RF)的积分肌电值(iEMG)、均方根值(RMS)、平均功率频率(MPF)及峰值髋内收、外展角度等和步行中髋关节的运动学特征,将股四头肌肌力与髋关节运动学特征进行相关性分析。结果:KOA组股四头肌等长和等速运动时PT值较对照组显著下降(P<0.01),VL在60°/s等速收缩时表面肌电信号RMS值显著高于对照组(P<0.05),RF在180°/s等速收缩时表面肌电信号RMS值显著高于对照组(P<0.01),步行时峰值髋关节内收及外展角度显著低于对照组(P<0.05),股四头肌肌力与髋关节运动学特征无相关。结论:KOA组较对照组股四头肌肌力显著降低,活动时神经支配效率显著下降,且步行过程中峰值髋内收、外展角度显著减少,股四...     

膝部损伤后膝关节功能障碍患者股四头肌的表面肌电信号研究

目的 探讨膝部损伤后膝关节功能障碍对股四头肌功能的影响.方法 对23例单侧膝部损伤后膝关节功能障碍患者,膝屈曲30°,记录最大伸展等长收缩(MIVC)时的力矩,股外侧肌、股内侧肌和股直肌的表面肌电信号.结果 在患侧膝屈曲30°膝最大伸展MIVC时的力矩,股外侧肌、股内侧肌和股直肌的平均肌电值(AEMG)、平均功率频率(MPF)、中位频率(MF)均低于健侧(P＜0.01);健侧股外侧肌的AEMG、MPF大于股内侧肌、股直肌(P＜0.01或P＜0.05), 股直肌大于股内侧肌(P＜0.05);患侧股直肌的AEMG、MPF大于股外侧肌、股内侧肌(P＜0.01或P＜0.05);股外侧肌大于股内侧肌(P＜0.05).结论 sEMG能够定量评价膝部损伤后膝关节功能障碍患者的肌肉功能.膝关节功能障碍患者患肢肌力及股四头肌受累肌肉活动水平显著降低,股直肌可能受影响程度较轻.     

髌股关节炎患者膝周肌群表面肌电信号特征研究

目的:观察髌股关节炎患者膝周肌群肌肉功能和协调活动差异,及其与膝关节疼痛的关系.方法:选择20例髌股关节炎患者,记录屈膝90°最大等长收缩(MVIC)、下蹲和站起时,双侧股外侧肌、股内侧肌、股二头肌和半腱肌的表面肌电图.计算均方根值(RMS)和协同收缩率(CCR),并观察CCR与疼痛的关系.将单膝患病患者健侧及双膝患病...     

闭链与开链运动对髌股疼痛综合征股四头肌作用的表面肌电图研究

摘要 目的：利用表面肌电图(sEMG)对髌股疼痛综合征（patellofemoral pain syndrome, PFPS）患者双足半蹲伴或坐位伸膝动作下股四头肌进行评估,比较不同开链与闭链动作对股四头肌的作用差异。 方法：PFPS病例组及正常对照组各30例,分别在双足半蹲以及坐位伸膝动作时检测股外侧肌(vastus lateralis, VL)及股内斜肌（vastus medialis oblique, VMO）表面肌电图,分析时域、频域指标,比较其平衡关系。 结果：病例组双足半蹲动作与坐位伸膝动作时各肌电指标的VL/VMO比值在时域、频域指标均有显著性差异,在坐位单侧完全伸膝动作时VL/VMO肌电比值大于双足半蹲动作且>1。 结论：VL、VMO表面肌电指标在双足半蹲动作时较坐位单侧完全伸膝动作时更接近平衡,提示适当屈膝时的闭链运动能够更有选择性地激发VMO,这为PFPS的康复治疗的动作选择提供参考。     

Electromyographic activity of the quadriceps components during the final degrees of knee extension

An imbalance in the recruitment patterns of the quadriceps muscle has been implicated in patellofemoral knee pain; however ambiguity remains in the normal recruitment patterns of this muscle. We investigated the activity of the quadriceps muscle during the final degrees of knee extension, specifically in the medial and lateral components. Sixteen healthy subjects (age; 22.5 (± 3.4) years, body mass; 67.5 (± 12.1) kg and height; 173.9 (± 10.4) cm) participated.Torque and electromyographic (EMG) activity of the quadriceps muscle were measured during isokinetic and isometric knee extensions. Torque and EMG activity reduced in all component muscles during the final degrees of isokinetic extension, but this did not occur during isometric contractions at similar angles. Normalised activity of rectus femoris (RF) was greater than that of vastus lateralis (VL) and vastus medialis obliquus (VMO) during the final degrees of isokinetic knee extension at 30°/sec; there were no differences between any component muscles at the higher velocities. VMO:VL and vastus medialis longus (VML):VL ratios were unchanged during knee extensions, except that VML:VL ratio increased significantly during the final degrees of extension at 30°/sec. Future work should compare these results with people with anterior knee pain, and explore this further during activities of daily living.     

Neuromuscular and architectural alterations of the vastus lateralis muscle in elderly patients with unilateral knee osteoarthritis]

AIM: The aim of this study was to determine the mechanisms involved in muscle weakness in elderly patients with unilateral knee osteoarthritis. SUBJECTS: We investigated 7 patients with unilateral knee osteoarthritis. METHOD: We measured knee position sense and isometric maximal voluntary contraction (MVC) of the knee extensors. Electromyographic (EMG) measurement of biceps femoris (BF), rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) involved different levels of contraction (25, 50, 75 and 100% MVC). Neuromuscular efficiency of quadriceps was also calculated (MVC/EMG). Ultrasonography was used to investigate the VL architectural parameters at the median part of the VL for different levels of contraction (25, 50, and 75% MVC). All tests were performed on the osteoarthritic and healthy knees. RESULTS: The quadriceps MVC of the affected knee was reduced by 30%. The VL thickness of the affected knee was 10% smaller than that of the unaffected knee. VL activity seen on EMG did not differ between knees, but RF, VM and BF activity was greater in the unaffected than affected knee. Neuromuscular efficiency was higher (26%) in the unaffected knee. Knee position sense was reduced by 33% in the affected knee. CONCLUSION: Quadriceps weakness associated with knee osteoarthritis seems to be related to changes in muscle rather than pennation angle and changes in fascicule length.     

Relationship between knee alignment and the electromyographic activity of quadriceps muscles in patients with knee osteoarthritis

[Purpose] We evaluated the relationship between knee alignment and the electromyographic (EMG) activity of the vastus medialis (VM) to the vastus lateralis (VL) muscles in patients with knee osteoarthritis (OA) in a cross-sectional study. [Subjects and Methods] Forty subjects with knee OA were assessed by anatomic radiographic knee alignment and the VM/VL ratio was calculated. Surface EMG from both the VM and VL muscles were evaluated during maximal isometric contraction at 60° knee flexion. Simultaneously, peak quadriceps torque was assessed using an isokinetic dynamometer. Subjects were categorized into low, moderate, and high varus groups according to knee malalignment. The peak quadriceps torque and VM/VL ratio across groups, and their relationships with varus malalignment were analyzed. [Results] All subjects had medial compartment OA and the VM/VL ratio of all subjects was 1.31 ± 0.28 (mean ± SD). There were no significant differences in the peak quadriceps torque or VM/VL ratios across the groups nor were there any significant relationships with varus malalignment. [Conclusion] The VM/VL ratio and peak quadriceps torque were not associated with the severity of knee varus malalignment.Key words: Malalignment, Knee, Quadriceps     

A Study on the Differences of Quadriceps Femoris Activities by Knee Alignment during Isometric Contraction

[Purpose] This study attempted to identify how genu varum or valgum affects the electromyographic activities of the vastus medialis, vastus lateralis, and rectus femoris during knee isometric contraction. [Subjects] Fifty-two healthy young adults were enrolled in this study. They were enrolled and classified into three groups by knee alignment conditions: the genu varum, genu valgum, and control groups. [Methods] The electromyographic activity ratio of the vastus medialis to the vastus lateralis and rectus femoris were calculated using the percentage of maximum voluntary contraction. The participants contracted their quadriceps during isometric contraction at 30 and 60° of knee flexion. [Results] The genu varum group had more activity in the vastus medialis than in the vastus lateralis and rectus femoris, whereas the genu valgum group had more activity in the vastus lateralis and rectus femoris than in the vastus medialis. There was a significant difference in the muscle activity ratio between the vastus medialis and vastus lateralis by angle of knee flexion degree only in the genu valgum. There were no significant differences in any of the three groups in terms of the muscle activity ratio of the vastus medialis to the rectus femoris by angle of knee flexion. [Conclusion] The quadriceps femoris was used for different strategies according to knee alignment during isometric contraction at 30 and 60°. This study suggests that rehabilitation training programs used to strengthen the quadriceps should consider the knee alignment conditions of the target subjects.Key words: Electromyography, Quadriceps muscle, Isometric contraction     

The association between muscle EMG and perfusion in knee extensor muscles

The relationships between electromyographic (EMG) activity and force as well as muscle blood flow and work have been well established. However, the association between muscle blood flow and EMG activity remains unsolved. Thus, to test the hypothesis that muscle EMG activity relates to muscle perfusion in different compartments of the quadriceps femoris (QF) muscle, 12 healthy male subjects were studied. During two very submaximal exercise bouts, at different exercise intensities, oxygen labelled radiowater and positron emission tomography were used to measure muscle perfusion. In addition, produced force of knee extensors and muscle EMG activity in the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles were recorded during both exercise bouts. Although the exercise intensity and average force production was higher during the second exercise bout (38 +/- 15 versus 51 +/- 17 N; P = 0.007), the mean EMG activity was lower (RF; P<0.001) or unchanged (VL; P = 0.722 and VM; P = 0.640). During the second exercise period, perfusion also remained unchanged in the entire QF muscle (P = 0.223) and in its separate muscles (VL, P = 0.703; VM, P = 0.141; RF, P = 0.113) in a group level. However, the individual changes in muscle perfusion were tightly related to changes in muscle EMG activity in VL (r = 0.84; P = 0.002) and VM (r = 0.68; P = 0.015) but poorly in the RF muscle (r = 0.40; P = 0.257). In conclusion, the different associations between muscle perfusion and EMG activity in different QF muscles suggests specific functional role of the vasti muscles and the RF muscle.     

Contribution of components of the quadriceps femoris muscle for producing external torque in patients with patellofemoral pain syndrome

IntroductionDifferent muscular activities of the quadriceps components for producing necessary torque may change in patients with patellofemoral pain syndrome (PFPS). The aim of the current study, therefore, was to assess the contribution of each component of the quadriceps femoris muscle for producing external torque in patients with PFPS.MethodTwelve females with PFPS (24.7 ± 2.3 years) and twelve healthy matched females (25.4 ± 2.4 years) performed three consecutive knee flexion and extension movements with maximum effort at 45°/s and 300°/s using a Biodex system 3 dynamometer. Simultaneously, electromyographic (EMG) activities of the vastus medialis oblique (VMO), RF (rectus femoris) and vastus lateralis (VL) muscles were recorded using a DataLog instrument. Standard multiple regressions were used to assess the ability of EMG activities of the VMO, RF and VL muscles to predict normalized quadriceps femoris isokinetic concentric and eccentric torques at 45°/s and 300°/s in the normal and patient groups.ResultsIn the normal group, the VL and the VMO were the good predictors of quadriceps concentric torque at 45°/s and 300°/s, respectively. The VL and the RF were the good predictors of quadriceps eccentric torque at 300°/s in the patient group. No other conditions showed a considerable prediction for quadriceps torque in the normal or patient group.ConclusionFemales with PFPS differ with normal females in terms of the contribution of each component of the quadriceps femoris for producing external torque. Training the VMO for concentric contraction at both high and low velocities should be included in the management of the patients with PFPS.     

Influence of angular velocity on vastus lateralis and rectus femoris oxygenation dynamics during knee extension exercises

The purpose of this study was to investigate whether changes in angular velocity would alter vastus lateralis (VL) and rectus femoris (RF) oxygenation status during maximal isokinetic knee extension exercises. Eleven recreationally active male participants randomly performed ten maximal knee extensions at 30, 60, 120 and 240° s(-1). Tissue oxygenation index (TOI) and total haemoglobin concentration ([tHb]) were acquired from the VL and RF muscles by means of near-infrared spectroscopy (NIRS). Breath-by-breath pulmonary oxygen consumption (VO(2p)) was recorded throughout the tests. Peak torque and VO(2p) significantly decreased as a function of velocity (P<0·05). Interestingly, RF and VL TOI significantly increased as a function of velocity (P<0·05), whereas [tHb] significantly decreased as a function of velocity (P<0·05). A greater number of muscle fibre recruited at slow velocity, where the torque and VO(2p) were the highest, might explain the lower VL and RF TOI observed herein. Furthermore, the increase in local blood flow (suggested by [tHb] changes) during isokinetic knee extension exercises performed at slow angular velocity might have been induced by a higher intramuscular pressure during the contraction phases as well as a greater microcirculatory vasodilatation during relaxation phases. Implementing slow-velocity isokinetic exercises in rehabilitation or other training programmes could delay the short-term anoxia generated by such exercises and result in muscle metabolism enhancement.     

MUSCLE ACTIVITY DURING KNEE‐EXTENSION STRENGTHENING EXERCISE PERFORMED WITH ELASTIC TUBING AND ISOTONIC RESISTANCE

Background/Purpose:

While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG‐angle relationship of the quadriceps muscle during 10‐RM knee‐extensions performed with elastic tubing and an isotonic strength training machine.

Methods:

7 women and 9 men aged 28‐67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric contraction phase of a knee extension exercise performed with elastic tubing and in training machine and normalized to maximal voluntary isometric contraction (MVC) EMG (nEMG). Knee joint angle was measured during the exercises using electronic inclinometers (range of motion 0‐90°).

Results:

When comparing the machine and elastic resistance exercises there were no significant differences in peak EMG of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) during the concentric contraction phase. However, during the eccentric phase, peak EMG was significantly higher (p<0.01) in RF and VM when performing knee extensions using the training machine. In VL and VM the EMG‐angle pattern was different between the two training modalities (significant angle by exercise interaction). When using elastic resistance, the EMG‐angle pattern peaked towards full knee extension (0°), whereas angle at peak EMG occurred closer to knee flexion position (90°) during the machine exercise. Perceived loading (Borg CR10) was similar during knee extensions performed with elastic tubing (5.7±0.6) compared with knee extensions performed in training machine (5.9±0.5).

Conclusion:

Knee extensions performed with elastic tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions displayed reciprocal EMG‐angle patterns during the range of motion.

Level of Evidence:

5