摘要：This study was designed to examine the reaction time (RT) of the upper extremity agonist during shift motions among contact boards by using electromyogram, and to analyze the effects of the frequency of stimuli, disorders subjects suffered, and dominancy of the hand examined on RT. The premotor time of the elderly subjects was found to approximately 130 ms, which was unchanged in spite of variation of the frequency from 0.2 to 1.2 Hz. This suggests that the elderly persons may respond to different stimuli by the fixed movement pattern. To any stimuli, there was no difference in the ratio of RT to the required time for finishing the motion between Spino-cerebellar degenerations (SCD) and Parkinsonism (PS) patients. It was assumed from this fact that either abnormal muscle tonus or reciprocal, synchronous disorder in muscle contraction may play an important role in inducing disability of motor ”switching mechanism”.
关键词：EMG-RT; shift motions of upper extremities; Spino-cerebellar Degeneration (SCD); Parkinsonism(PS)
