Sherwood D E, Schmidt R A, Walter C B
Department of Kinesiology, University of California, Los Angeles 90024.
Exp Brain Res. 1988;69(2):355-67. doi: 10.1007/BF00247580.
Transformations of the underlying movement control of rapid sequential (reversal) responses were examined as the movement amplitude (Experiment 1) and moment of inertia (Experiment 2) were altered, with constant movement time. Increases in amplitude and inertia were both met by sharply increased joint torques with a constant temporal structure, suggesting that the alterations may have been governed by a single gain parameter. The durations of various EMG bursts were essentially constant across changes in inertia, supporting a model in which the output of a fixed temporal representation is amplified to alter joint torques. The EMG amplitudes increased greatly with both amplitude and load. However, the fact that the EMG durations increased systematically with increases in distance provided difficulties for this model of amplitude control. The data suggest an economy in motor control in simple agravitational movements, whereby relatively simple transformations of an underlying representation can accommodate large changes in movement amplitude and moment of inertia.
在运动时间恒定的情况下，当改变运动幅度（实验1）和转动惯量（实验2）时，研究了快速连续（反转）反应的潜在运动控制的转变。幅度和惯量的增加均伴随着关节扭矩急剧增加，且具有恒定的时间结构，这表明这些改变可能受单一增益参数的控制。各种肌电爆发的持续时间在惯量变化过程中基本保持恒定，这支持了一个模型，即固定时间表示的输出被放大以改变关节扭矩。肌电幅度随幅度和负荷的增加而大幅增加。然而，肌电持续时间随着距离增加而系统增加这一事实给这种幅度控制模型带来了困难。数据表明，在简单的失重运动中，运动控制存在经济性，即潜在表征的相对简单转变能够适应运动幅度和转动惯量的大幅变化。
