외적부하의 방향과 강도변화가 고유감각적 오류보상과정에 미치는 영향 = The Effect of Changes in the Direction and Intensity of External Loads on Proprioceptive Error Compensation

다국어 초록 (Multilingual Abstract)

The purpose of this study was to investigate the precision of proprioceptive information about the property of error occurring in programmed movement trajectory and the proprioceptive error compensation by analyzing the effect of changes in the direction and intensity of external loads on the pattern of agonist and antagonist muscles. Twelve subjects performed elbow flexion movements of 60o in task situation where the direction and intensity of external loads could be altered unexpectedly, and the displacement angle of elbow joint and the activity of biceps brachii and the long head of triceps brachii were measured for each movement. The pattern of agonist and antagonist muscle activities observed in various load conditions was shown to be modulated by the combination of the direction and intensity of external loads. While the activity of agonist muscle measured during the acceleration phase of movement was not sensitive to changes in the intensity of external loads in the assisting load condition, it was shown to increase with increasing intensity of external loads in the opposing load condition. However, the activity of antagonist muscle measured during the same period was found to increase with increasing intensity of external loads regardless of load direction. The activity of agonist muscle measured during the deceleration phase of movement was also shown to increase with increasing intensity of external loads in both load direction conditions, and the amount of change with load intensity was larger in the opposing load condition. The antagonist muscle displayed similar activation patterns, increasing with load intensity regardless of load direction. These results suggest that during goal-directed movements the proprioceptive system provides specific information about the direction and intensity of error occurring in programmed movement trajectory, and the control system can rapidly utilize current proprioceptive input in the on-line modulation of motor commands for the correction of error and the achievement of movement goal.