Citation

Sherwood DE, Schmidt RA, Walter CB. Exp. Brain Res. 1988; 69(2): 355-367.

Affiliation

Department of Kinesiology, University of California, Los Angeles 90024.

Copyright

(Copyright © 1988, Holtzbrinck Springer Nature Publishing Group)

DOI

unavailable

PMID

3345812

Abstract

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.

Language: en