One vs. Two Hand Use After Stroke: Role of Task Requirements

To further develop interventions, the investigators need a better understanding of which task requirements (i.e. size or weight of object, location in workspace, etc.) drive a person after stroke to use 2 hands (as opposed to 1), and how the severity of their injury impacts this relationship and compare this to reaching in age-matched healthy controls subjects. A better understanding of this relationship will promote more informed development of rehabilitative interventions. This study proposes to explore in people after stroke and healthy controls: i.) how specific functional tasks requirements relate to 1 vs. 2 handed use, and ii.) how stroke severity impacts this arm use. We are proposing to study 15 individuals more than 6 months after stroke in the CSU Motor Behavior Lab for a two x 3 hour session of task-related reaching in sitting and 33 age matched (double sample size) healthy controls. The investigators will systematically vary task requirements (i.e. object size or weight, location in workspace, etc.), and record use of 1 versus 2 hands using videotaping as well as recording of quality of arm movement (kinematics) and muscle activity (EMG) in both arms.