Dynamic coupling: intrinsic and extrinsic influences on reaching and grasping in children with hemiplegic cerebral palsy

Abstract

The purpose of the present study was to investigate the influence of task and organismic constraints on the dynamic coupling, during reaching and touching, and reaching and grasping tasks in individuals with hemiplegic cerebral palsy. Executions with a hand and with both hands were compared. Thus, three different studies were acomplished: 1) envolving reaching and touching; and reaching and grasping; 2) envolving the same tasks, with under speed pressure; 3) envolving the same tasks, but with a change in the angle of the table upon which the object rested. In generally, the results showed a coupling between the body sides during the bimanual movement. The influence of the constraints introduced in the task was different among the subjects. The results of this study were discussed in the light of the dynamic systems approach, which emphasizes the role of organismic, task and environment constraint upon behavior