Assessment of deteriorated muscle function using interrelationship among electromyogram, acoustic myogram and force.

为了保持身体健康和提高肢体残障人士的身体素质，应考虑使用有助于发展潜在能力的残存身体功能的适当运动疗法。本研究主要针对肢体残疾患者的肌肉功能进行研究。本实验旨在比较痉挛型脑性瘫痪(CP)患者的二臂肌电(EMG)和声学肌电(AMG)的记录。经肌肉横截面积(CSA)归一化后，CP组的最大自主收缩(MVC)约为正常组的一半。CP组和正常组的肌电(RMS_lt；EMG&gt；/CsA)和AMG(RMS_&lt；AMG&gt；/CSA)的单位肌肉CSA的均方根值均呈递增趋势，增加幅度达50%MVC，两组受试者的RMS&lt；EMG&gt；/CSA随力的增加幅度无显著差异。然而，所有水平的力量导致CP组的RMS；AMG；/CSA明显小于正常组。在30%MVC以上的力量水平下，CP组的RMS&lt；AMG&gt；/RMS&lt；EMG&gt；比值明显小于正常组。提示CP患者的运动障碍不仅是由原发神经损害引起的，而且是肌肉收缩特性的继发性恶化，可能是肌纤维萎缩所致。这似乎在快速抽动纤维中更具选择性。

In order to maintain good health and to improve physical fitness in persons with physical disabilities, someappropriate exercise therapy using residual physical functions which contribute to development of latent abilities should be considered. The present study focused on the muscle function for patients with physical disabilities. The experimental study was designed to compare electromyogram (EMG) and acoustic myogram (AMG) recordings of bicepsbrachii muscles in patients with spastic cerebral palsy (CP). The maximal voluntary contraction (MVC) in the CP group was approximately one-half of that of the normal group even after being normalized by the muscle cross-sectional area (CSA). Both CP and normal groups demonstrated a progressive increase in the root mean squared values per unit muscle CSA in the EMG (RMS_<EMG>/CSA) as well as in the AMG (RMS_<AMG>/CSA) with increasing force up to 50% MVC.The increasing magnitude of the RMS_<EMG>/CSA with force was not significantly different between two subject groups. However, all the levels of forces resulted in significantly smaller RMS_<AMG>/CSA in the CP group compared to the normal group. The ratios of RMS_<AMG> to RMS_<EMG> in the CP group were significantly smaller than that in the normal group at force levels above 30% MVC.These results suggest that motor disabilities in CP patients are caused not only by primary neural impairment but also secondary deterioration in muscular contractile properties, probably resulting from muscle fiber atrophy. This appears to be more selective in fast twitch fibers.