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

为了保持身体健康，提高肢体残疾者的体质，应考虑利用残馀身体功能进行适当的运动治疗，以促进潜在能力的发展。本研究的重点是肢体残疾患者的肌肉功能。本实验旨在比较痉挛性脑瘫（CP）患者肱二头肌肌电图（EMG）和肌声图（AMG）记录。肌横截面积（CSA）归一化后，CP组的最大随意收缩（MVC）约为正常组的一半。CP组和正常组均表现出肌电图（RMS_<EMG>/CSA）和肌电图（RMS_<AMG>/CSA）的单位肌肉CSA均方根值随着力的增加而逐渐增加至50% MVC。两组间RMS_<EMG>/CSA随用力的增加幅度无显著差异。然而，与正常组相比，所有水平的力导致CP组的RMS_<AMG>/CSA明显更小。在30% MVC以上时，CP组RMS_<AMG>与RMS_<EMG>的比值显著小于正常组。这些结果表明，CP患者的运动障碍不仅是由原发性神经损伤引起的，还可能是由肌纤维萎缩引起的肌肉收缩性能的继发性恶化引起的。这似乎在快速抽搐纤维中更具选择性。

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.