髌股疼痛综合征患者股四头肌失衡程度评估及其与Q角的相关分析

目的:利用表面肌电图对髌股疼痛综合征(PFPS)患者股四头肌失衡程度进行评估,并对其与Q角的关系进行分析.方法:PFPS病例组及正常对照组各30人,分别进行Q角测量,同时在双足半蹲动作时检测股外侧肌(VL)及股内斜肌(VMO)表面肌电图(sEMG),分析股内、外侧肌时域指标,对Q角与VL/VMO肌电比值进行相关分析.结果:病例组VL、VMP时域指标ZCR、RMS、IEMG差异有统计学意义(P＜0.05),且VL较VMO高.Q角与VL/VMO肌电比值之间进行线性相关分析,Pearson相关系数为0.149(P＞ 0.05).结论:PFPS患者VL运动单位募集数量、活化程度要高于VMO.股四头肌失衡程度与Q角大小无明显相关.     

双足半蹲伴髋内收对髌股疼痛综合征股内斜肌的强化作用

目的采用表面肌电图(sEMG)评估髌股疼痛综合征（PFPS）患者的股四头肌失衡程度,观察PFPS患者各种表面肌电的特征及变化规律,并探讨髋内收对股内斜肌的针对性强化作用机制。 方法将PFPS患者60例按随机数字表法分为病例组和对照组,每组患者30例,分别在双足半蹲伴或不伴髋内收动作时检测股外侧肌(VL)及股内斜肌（VMO）表面肌电图,分析股内、外侧肌时域指标,比较其平衡关系。 结果双足半蹲不伴髋内收动作时,病例组VL的均方根振幅（RMS）和积分肌电值（IEMG）分别为（103.31±44.54）μV和（8.02±3.45）μVs,分别与组内VMO RMS的（85.02±41.19）μV和IEMG的（6.72±3.20）μVs比较,差异均有统计学意义（P<0.05）。病例组不伴髋内收时VMO的RMS、IEMG与组内伴髋内收时VMO的RMS、IEMG比较,差异均有统计学意义（P<0.05）。 结论双足半蹲伴髋内收的动作可以优先强化VMO,使VL与VMO之间达到更好的平衡状态。     

膝骨关节炎患者股内侧肌、股直肌和股外侧肌间的协调性

目的应用表面肌电图和等速肌力测定方法比较膝骨关节炎患者与正常人股内侧肌、股直肌和股外侧肌间的协调性改变。方法34例膝骨关节炎患者和34名膝关节健康者在膝关节屈曲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(VM)、股直肌(RF)和股外侧肌(VL)的表面肌电图和股四头肌肌力的评测,包括肌肉激活启动顺序和VM/VL神经肌电比值。结果与正常人对比,膝骨关节炎患者在等速180°/s伸膝运动时VM相对于VL启动延迟（P＜0.05）;在膝屈10°等长伸膝运动时,VM/VL神经肌电比值降低（P＜0.05）。结论膝骨关节炎患者患侧股四头肌的协调性减退。     

太极拳特定动作下股内侧肌和股外侧肌表面肌电特征的研究

目的 研究太极拳特定动作中股内侧肌(VMO)和股外侧肌(VL)的肌纤维募集情况.方法 收集15名健康志愿者在维持5个太极拳定势(白鹤亮翅、金鸡独立、搂膝拗步、十字手、仆步)时VL、VMO的表面肌电信号,比较平均肌电值(AEMG)、平均功率频率(MPF)、中位频率(MF)、零点通过率(ZCR).结果 维持白鹤亮翅、金鸡独立时,其支撑脚VMO、VL的所有指标均无显著性差异;维持搂膝拗步、十字手、仆步时,其支撑脚VL的AEMG、MFC、ZCR、MF均小于VMO(P<0.05);与股四头肌的最大随意收缩负荷相比,所测试的动作下,肌肉负荷属于中小负荷,并且能募集到更多的慢肌纤维.结论 进行太极拳运动时,肌肉负荷较小,并且能募集到更多的慢肌纤维;某些太极拳动作下,VMO可以较多地募集到肌纤维.     

髌股疼痛综合征患者神经肌电活动比率与Merchant匹配角的相关性

目的:研究应用肌电生物反馈仪测量的髌股疼痛综合征(PFPS)患者的神经肌电活动比率与CT测量PFPS患者的髌骨倾斜角、Merchant匹配角的相关关系。方法:本实验收集山西大医院髌股疼痛综合征患者32例(其中女22例,男10例),应用肌电生物反馈治疗仪评定神经肌电活动比率[股内侧斜肌(VMO)/股外侧斜肌(VL)],行膝关节CT检查,测量患者髌骨倾斜角和Merchant匹配角。患者经肌电生物反馈疗法治疗5周后再次测量上述3个数值,并对数据进行统计分析。结果:32例PFPS患者治疗前CT图像Merchant匹配角和治疗前VMO/VL基线值之间的相关系数为-0.470(P<0.05),为中度相关关系,治疗前CT图像Merchant匹配角和治疗前VMO/VL动态值之间的相关系数为-0.447(P<0.05),为中度相关关系;治疗后CT图像Merchant匹配角与治疗后VMO/VL基线值之间的相关系数为-0.51(P<0.05),为中度相关关系,治疗后CT图像Merchant匹配角与治疗后VMO/VL动态值之间的相关系数为-0.604(P<0.05),为中度相关关系。32例PFPS患者治疗前、后CT髌骨倾斜角与治疗前、后VMO/VL基线值和动态值之间均无相关关系(P>0.05)。结论:应用肌电生物反馈仪测得的神经肌电活动比率可以反映髌骨移位的程度,但不能反映髌骨倾斜的程度,可以间接作为PFPS的诊断和疗效评价指标之一。     

表面肌电图在评定髌股疼痛综合征患者髌骨动态稳定中的应用

目的利用自建表面肌电图的标准化测试分析髌股疼痛综合征（PFPS）患者股内侧肌（VM）与股外侧肌(VL)在控制髌骨运动中的变化特征。 方法选取PFPS患者7例（13个膝）作为病例组,另选健康志愿者10例（20个膝）作为对照组,并分别进行表面肌电图检查,测量蹲起运动VM和VL的平均波幅和峰值时限（TBP)。 结果PFPS组和对照组VM∶VL平均振幅比值分别为（0.97±0.31）和（1.09±0.36）,2组差异无统计学意义（P&rt;0.05）,2组下蹲时的平均比值（1.00±0.16）明显高于起立时的平均比值（0.83±0.15）（P<0.05）。在蹲起时PFPS组的TBPVM较TBPVL延迟（8.77%±5.12%）与对照组（-1.45%±4.02%）的比较有统计学意义（P<0.01）。 结论所用表面肌电图的标准化测试能发现本组PFPS患者下蹲时VM的峰值时限明显滞后于VL,可用于评定局部型PFPS患者术后或康复治疗前后的变化。     

基于表面肌电图检查技术的脑卒中患者下肢肌肉痉挛的定量分析

目的探讨脑卒中偏瘫患者股四头肌表面肌电图（sEMG)信号和改良Ashworth分级（MAS）之间的相关性,研究表面肌电图指标是否可作为评估痉挛的量化指标。 方法选择符合标准的脑卒中患者60例,由同一测试人员对脑卒中偏瘫患者患侧股四头肌进行MAS评估,并记录股四头肌被动牵伸时股四头肌内侧头（VM)、股直肌(RF)、股四头肌外侧头(VL)处表面肌电信号的均方根值（RMS）值和平均肌电值（AEMG）值,对不同表面肌电图指标与MAS进行相关性分析。 结果被动牵伸股四头肌时,VM、RF、VL的表面肌电信号都与MAS分级呈正相关;经Spearman相关统计分析,被动活动时,VM（r=0.751）、VL（r=0.563）、RF（r=0.800）的均方根值（RMS）均与MAS相关（P<0.001）;VM（r=0.767）、VL（r=0.646）、RF（r=0.834）的平均肌电值（AEMG）均与MAS相关（P<0.001）。 结论脑卒中偏瘫患者被动牵伸股四头肌(VM、VL、RF) 时,表面肌电信号的RMS指标及AEMG指标与MAS分级呈正相关;sEMG检查股四头肌被动牵伸时的幅度指标可为临床肌张力评估和痉挛的治疗提供量化的参考。     

膝关节角度对屈伸肌共同收缩及伸膝力矩的影响

目的 应用表面电极肌电图（EMG）测量膝关节在不同角度做开放链最大等长伸膝时屈膝肌的共同兴奋能力，比较不同角度膝屈伸肌的共同兴奋水平。方法 12名健康在校大学生参与测试。每名受试者在Cybex测试仪上髋关节屈曲90°，单侧膝关节分别于屈膝10，60和90°时各做1组开放链的最大等长伸膝动作。使用表面电极EMG测量每次膝关节伸展时股四头肌与胭绳肌的电信号。在每次伸膝的同时用cy—bex测量股四头肌的最大伸膝力矩。结果所有角度下股四头肌的最大等长收缩均伴胭绳肌的共同兴奋。平均最大伸膝力矩出现在屈膝60°（P〈0．05）。结论膝关节在屈膝60°时可产生最大等长伸膝力矩，开放链的伸膝肌等长收缩伴有屈膝肌的共同兴奋。     

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。     

髋等张和等长内收时股内斜肌的肌电图分析

<正> 髋关节功能障碍的保守治疗要点在于恢复股内斜肌(Vastus medialis oblique muscle,VMO)的功能。股内收肌收缩可以促进VMO收缩。Malone等认为增加VMO肌力的最简单方法是等长收缩。作者让受试者在坐位和侧卧位作膝伸直、髋内收动作,分析VMO自由等张和最大等长收缩时的肌电图。 资料与方法 无肌病史的正常志愿者15名(男10,女5),年龄19～33岁(24.2±4.1)。用8道     

Vastus medialis obliquus and vastus lateralis activity in open and closed kinetic chain exercises in patients with patellofemoral pain syndrome: an electromyographic study

OBJECTIVES: To evaluate the electromyographic activities of vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles in open and closed kinetic chain exercises in subjects with patellofemoral pain syndrome (PFPS). DESIGN: Case-controlled study. SETTING: Rehabilitation science center in a tertiary medical center. PARTICIPANTS: Ten patients with bilateral knee pain diagnosed with PFPS and 10 healthy volunteers. INTERVENTIONS: Subjects performed open kinetic chain exercise on an isokinetic dynamometer and closed kinetic chain exercise by squat-to-stand and stand-to-squat tasks. Surface electromyography was done for the VMO and VL muscles. MAIN OUTCOME MEASURES: VMO/VL ratios were calculated after normalization of muscle activities. RESULTS: The VMO/VL ratios of PFPS subjects were significantly lower than were those of unimpaired subjects during knee isokinetic closed kinetic chain exercises (p = .047). However, there was no statistical difference in VMO/VL ratio between subjects with and without PFPS during closed kinetic chain exercises (p = .623). Maximum VMO/VL ratio was obtained at 60 degrees knee flexion in closed kinetic chain exercise. CONCLUSION: In closed kinetic chain exercises, more selective VMO activation can be obtained at 60 degrees knee flexion. Maximal VMO/VL ratio was observed at this knee flexion angle, and muscle contraction intensity was also greatest.     

表面肌电仪对髌股疼痛综合征患者膝关节肌电活动的分析

目的利用表面肌电仪分析髌股疼痛综合征患者康复训练前后股内侧斜肌（VMO）和股外侧肌（VL）肌电活动的变化。方法26例髌股疼痛综合征患者随机分为神经肌电生物反馈训练组（A组）和单纯训练组（B组）各13例，均接受相同的家庭训练，但A组患者在神经肌电生物反馈仪配合下进行训练。所有患者在开始训练前和训练8周后，利用表面肌电仪对VMO和VL的神经肌肉电活动进行连续6h评定，同时对膝关节疼痛程度进行评定。结果治疗后，B组患者的VMO／VL神经肌电比率与治疗前比较差异无显著性意义（P〉0．05），而A组患者的VMO／VL神经肌电比率与治疗前比较差异有显著性意义（P〈0．05）。结论采用神经肌电生物反馈仪配合髌股疼痛综合征患者的康复训练可促进股内侧斜肌的募集。     

Electromyographic fatigue characteristics of the quadriceps in patellofemoral pain syndrome

This study compared the fatigue characteristics of the vastus medialis oblique (VMO), vastus lateralis (VL) and rectus femoris (RF) muscles. Ten healthy subjects with 10 patients with patellofemoral pain syndrome (PFPS) performed an isometric leg press for 60 seconds at 60% MVIC with data collected using surface EMG. The power spectrum was analyzed and the extracted median frequency normalised to calculate a linear regression slope for each muscle. A repeated measures ANOVA revealed no significant differences, neither between the groups (P=0.592) nor the muscles (P=0.434). However, the slopes for the VMO and VL were different between the two groups with similar slopes for the RF. There was much larger variability of MF values in the PFPS group. The VMO:VL ratio calculated from these slopes for the healthy subjects was 1.17 and for the PFPS group was 1.78. These results may indicate unusual features in the fatigue indices of the quadriceps in PFPS.     

Comparison of vastus medialis obliquus: vastus lateralis muscle integrated electromyographic ratios between healthy subjects and patients with patellofemoral pain

The purpose of this study was to compare vastus medialis obliquus:vastus lateralis muscle (VMO:VL) integrated electromyographic (IEMG) ratios of healthy subjects and patients with unilateral patellofemoral pain (PFP) under isotonic and isometric quadriceps femoris muscle contraction conditions. Subjects ranging in age from 18 to 35 years (mean = 28.06, SD = 5.97) were assigned to one of three groups on the basis of type of knee condition. In group 1, which consisted of seven healthy control subjects with no history of knee pathology, both knees were tested. In group 2, which consisted of nine patients with unilateral PFP, only the painful knee was tested. In group 3, which consisted of the same nine patients who comprised group 2, only the nonpainful knee was tested. Nonnormalized and normalized VMO:VL IEMG ratios were computed for ascending stairs, descending stairs, submaximal isometric contraction, and maximal isometric contraction (nonnormalized only). A two-way analysis of variance for repeated measures indicated VMO:VL ratios for isotonic stair-climbing activities were significantly greater than VMO:VL ratios for isometric contractions. Nonnormalized VMO:VL ratios in group 1 were significantly greater than nonnormalized VMO:VL ratios in the other two groups. Patients with PFP may have abnormal VMO:VL activation patterns, and isotonic quadriceps femoris muscle exercise may elicit more favorable muscle activation patterns than isometric exercise for patients with PFP.     

Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome

OBJECTIVE: To determine whether electromyographic (EMG) onsets of vastus medialis obliquus (VMO) and vastus lateralis (VL) are altered in the presence of patellofemoral pain syndrome (PFPS) during the functional task of stair stepping. DESIGN: Cross-sectional. SETTING: University laboratory. PATIENTS: Thirty-three subjects with PFPS and 33 asymptomatic controls. INTERVENTIONS: Subjects ascended and descended a set of stairs-2 steps, each 20-cm high-at usual stair-stepping pace. EMG readings of VMO and VL taken on middle stair during step up (concentric contraction) and step down (eccentric contraction). MAIN OUTCOME MEASURES: Relative difference in onset of surface EMG activity of VMO compared with VL during a stair-stepping task. EMG onsets were determined by using a computer algorithm and were verified visually. RESULTS: In the PFPS population, the EMG onset of VL occurred before that of VMO in both the step up and step down phases of the stair-stepping task (p <.05). In contrast, no such differences occurred in the onsets of EMG activity of VMO and VL in either phase of the task for the control subjects. CONCLUSION: This finding supports the hypothesized relationship between changes in the timing of activity of the vastimuscles and PFPS. This finding provides theoretical rationale to support physiotherapy treatment commonly used in the management of PFPS.     

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.     

Altered vastii recruitment when people with patellofemoral pain syndrome complete a postural task

OBJECTIVE: To investigate the recruitment of the vastus medialis obliquus (VMO) and vastus lateralis during voluntary tasks that challenge the stability of the knee and to evaluate whether there is a change in the coordination of the postural response by the central nervous system in subjects with patellofemoral pain syndrome (PFPS). DESIGN: Cross-sectional. SETTING: University laboratory in Australia. PARTICIPANTS: Thirty-seven subjects with PFPS and 37 asymptomatic sex-matched controls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Recordings of electromyographic activity of the VMO, vastus lateralis, tibialis anterior, and soleus were made by using surface electrodes. Subjects rose onto their toes (rise task) or rocked back on their heels (rock task) in a visual choice-reaction time task. Electromyographic onsets were determined by using a computer algorithm and were verified visually. RESULTS: Our results confirm that, in asymptomatic subjects, contraction of the VMO and vastus lateralis occurs as part of the feed-forward postural response associated with ankle movements in standing, and the contraction of these separate heads of the quadriceps group occurs simultaneously. However, when subjects with PFPS perform identical tasks, the electromyographic onset of the vastus lateralis occurs before that of the VMO. CONCLUSION: These findings indicate a difference in motor control in subjects with PFPS. They also support the hypothesized relation between changes in the timing of activity of the vastii and PFPS and provide the theoretic rationale to support physiotherapy treatment commonly used in the management of PFPS.     

Activation of vastus medialis oblique is not delayed in patients with osteoarthritis of the knee compared to asymptomatic participants during open kinetic chain activities

This study investigated whether the onset of electromyographic (EMG) activity of vastus medialis oblique (VMO) was delayed relative to that of vastus lateralis (VL) in patients with osteoarthritis (OA) of the knee compared to asymptomatic participants during open kinetic chain activities. An exploratory observational cross sectional study was carried out. Two groups were tested, symptomatic OA knee patients, diagnosed by an orthopaedic surgeon, (n=17), mean (SD) age 66.0 (7.6) years, and asymptomatic participants (n=17), 56.7 (8.6) years. Surface EMG activity of VMO and VL was measured, during concentric contractions extending the knee from 90 degrees flexion, and during maximal voluntary isometric contractions at 60 degrees knee flexion. The EMG onset times of VMO and VL were determined visually and by algorithm. The onset timing difference (OTD) between the two muscles was calculated for each subject, by subtracting the onset time of VL from VMO. Mann-Whitney U-tests revealed that the OTD between VMO and VL was not significantly different between the groups during either contraction type (both p>0.05). The results of this exploratory study may have implications for rehabilitation programmes aimed at developing preferential activation of VMO compared to VL in OA knee patients.     

Outcomes of a weight-bearing rehabilitation program for patients diagnosed with patellofemoral pain syndrome

OBJECTIVE: To determine the effects of a weight-bearing rehabilitation program on quadriceps and gluteus medius electromyographic activity, pain, and function in subjects diagnosed with patellofemoral pain syndrome (PFPS). DESIGN: Pretest and posttest 6-week intervention study. SETTING: Musculoskeletal research laboratory. PARTICIPANTS: Fourteen subjects diagnosed with PFPS and 14 healthy control subjects volunteered to participate in this study. No subjects withdrew from the study because of adverse effects. INTERVENTION: Subjects diagnosed with PFPS participated in a 6-week rehabilitation program. The rehabilitation program consisted of weight-bearing exercises that focused on strengthening the quadriceps and hip abductor musculature. MAIN OUTCOME MEASURES: Electromyographic onsets of the vastus medialis oblique (VMO) and vastus lateralis and onset and duration of the gluteus medius were collected during a stair-stepping task that was performed during the pretest and posttest. A visual analog scale (VAS) and Functional Index Questionnaire (FIQ) were administered at pretest and posttest and each week of the intervention. RESULTS: Vastus lateralis and VMO onset timing differences (vastus lateralis electromyographic onset minus VMO electromyographic onset) and VAS and FIQ scores significantly improved for patients diagnosed with PFPS. Vastus lateralis and VMO onset timing in the PFPS group were significantly different from those in the control group at baseline and were not significantly different from the control group after the intervention. We did not find differences in gluteus medius onsets or duration of activity. CONCLUSIONS: Subjects diagnosed with PFPS responded favorably and quickly to a therapeutic exercise program that incorporated quadriceps and hip musculature strengthening. The efficacy of the therapeutic exercise program used in this study should be further investigated in a larger subject population.     

Motor unit synchronization is reduced in anterior knee pain.

Anterior knee pain (AKP) is common and has been argued to be related to poor patellofemoral joint control due to impaired coordination of the vasti muscles. However, there are conflicting data. Changes in motor unit firing may provide more definitive evidence. Synchronization of motor unit action potentials (MUAPs) in vastus medialis obliquus (VMO) and vastus lateralis (VL) may contribute to coordination in patellofemoral joint control. We hypothesized that synchronization may be reduced in AKP. Recordings of single MUAPs were made from VMO and multiunit electromyograph (EMG) recordings were made from VL. Averages of VL EMG recordings were triggered from the single MUAPs in VMO. Motor units in VL firing in association with the VMO motor units would appear as a peak in the VL EMG average. Data were compared to previous normative data. The proportion of trials in which a peak was identified in the triggered averages of VL EMG was reduced in people with AKP (38%) compared to controls (90%). Notably, although 80% of subjects had values less than controls, 20% were within normal limits. These results provide new evidence that motor unit synchronization is modified in the presence of pain and provide evidence for motor control dysfunction in AKP. PERSPECTIVE: This study shows that coordination of motor units between the medial and lateral vasti muscles in people with anterior knee pain is reduced compared to people without knee pain. It confirms that motor control dysfunction is a factor in this condition and has implications for selection of rehabilitation strategies.