Feng C J, Mak A F
Rehabilitation Engineering Centre, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Electromyogr Clin Neurophysiol. 1998 Oct-Nov;38(7):393-404.
Surface electromyography (EMG) signals were measured from the biceps brachii (BIC), the brachioradialis (BRD) and the triceps brachii (TRI) of seven young adults with pure spastic quadriplegia and eight normal individuals. The signals were analyzed in both the time domain and the frequency domain. The subjects sat in an adjustable chair and were asked to perform two voluntary tasks involving the elbow joint. For task A, the subjects moved the hand from the proximal target plate to the distal target plate and then back to the proximal one along the table plane. For task B, the subject followed the sound of a metronome (0.5 Hz), perform 5 elbow flexion/extension cycles in the vertical plane. Certain quantitative parameters were identified as statistically significant in describing quantitatively the condition of spasticity. Compared to the normal subjects, the spastic subjects showed significantly higher EMG activities for both the elbow flexors and extensor. The stretch/shortening (S/S) ratios for BRD and TRI were significantly different from those of the normal subjects. The power spectra analysis showed higher mean power frequency (MPF). MPF of BIC and TRI were uncorrelated for normal subjects, but correlated for the spastic subjects. It is speculated that low motor unit discharge rate and fiber type abnormalities may account for these differences.
对7名患有单纯痉挛性四肢瘫痪的年轻成年人以及8名正常人的肱二头肌（BIC）、肱桡肌（BRD）和肱三头肌（TRI）进行表面肌电图（EMG）信号测量。对信号进行时域和频域分析。受试者坐在可调节椅子上，被要求执行两项涉及肘关节的自主任务。对于任务A，受试者将手沿着桌面从近端目标板移动到远端目标板，然后再回到近端目标板。对于任务B，受试者跟随节拍器（0.5Hz）的声音，在垂直平面上进行5次肘关节屈伸循环。确定了某些定量参数在定量描述痉挛状态方面具有统计学意义。与正常受试者相比，痉挛受试者的肘关节屈肌和伸肌的肌电图活动均显著更高。BRD和TRI的拉伸/缩短（S/S）比率与正常受试者的显著不同。功率谱分析显示平均功率频率（MPF）更高。正常受试者中，BIC和TRI的MPF不相关，但痉挛受试者中相关。据推测，运动单位放电率低和纤维类型异常可能是造成这些差异的原因。
