Effects of task instructions and target location on reaching kinematics in people with and without cerebrovascular accident: a study of the less-affected limb.

OBJECTIVE We investigated how verbal instructions and target location interacted to influence reaching movement of the less-affected limb in participants with and without unilateral cerebrovascular accidents (CVAs). METHOD Using a counterbalanced repeated-measures design, 26 people with CVA and 24 age-matched healthy people performed the reaching tasks under 4 conditions formed by the crossing of verbal instructions (speed and accuracy emphasis) and target locations (ipsilateral and contralateral to the performing hand). RESULTS In the control groups, speeded instructions and ipsilateral reaches elicited significantly more preprogrammed movements than did accuracy instruction and contralateral reaches, respectively. Similar patterns of performance in response to task constraints were found in the CVA groups except for movement initiation in the right CVA group. CONCLUSION Instruction and locations interacted to constrain reaching movements in both control and CVA groups. The combination of speeded instruction and ipsilateral reach may optimize movement performance of the less-affected limb in stroke patients.