Practice effects on the less-affected upper extremity after stroke

Objective: To test the hypotheses that (1) adults who have had a stroke, using the less affected upper extremity (UE), improve performance of an aiming task with practice, and (2) compared with control subjects, stroke patients show less improvement in a complex condition. Design: Movement time (MT) and kinematic data were collected over practice. Comparisons were made between the less-affected UE of stroke patients and the same hand of controls. Setting: A human performance laboratory. Participants: A matched sample of right-handed adults, 10 with unilateral stroke and 10 nondisabled controls. Intervention: Practice of an aiming task in an easy and complex condition as defined by target width and distance between two targets. Main Outcome Measures: MT, peak velocity, and temporal phases of the trajectory. Results: Adults who had experienced a stroke had persistently longer MTs than control subjects; however, all participants achieved faster MTs with practice in both conditions. The absolute amount of time in each temporal phase decreased without a change in the relative times. Peak velocity increased only in the easy condition. Conclusions: Adults with stroke damage can improve motor performance of the less-affected UE with practice. Further study is needed to see if practice effects are permanent and generalizable.