Upper extremity control in adults post stroke with mild residual impairment.

Motor control deficits in the upper extremity (UE) ipsilateral to the side of brain damage persist after stroke, but it is not known if the presence of these deficits is related to impairment of the contralateral UE. The purpose of this study was to investigate whether motor deficits are present in the ipsilateral UE when contralateral UE impairment is mild in adults with chronic stroke. Right-handed adults (10 controls, 10 right stroke, 10 left stroke) performed rapid continuous aiming movements to small and large targets. Using kinematic analysis, temporal measures of the movement were defined, including movement time (MT) and the three components of MT: acceleration, deceleration, and dwell time (i.e., time on target). Participants with right stroke had prolonged MT only with the left UE, primarily due to longer dwell times. Participants with left stroke had prolonged MT with both UEs as a result of longer dwell times. The results indicate that control deficits of the ipsilateral UE are evident in individuals with left but not right brain damage who have minimal impairment of the contralateral UE. These findings are consistent with the role of the left hemisphere in the control of both UEs.