The experiment will be conducted with 15 chronic stroke survivors and 15 control subjects. Subjects will perform extension movements of the index finger of their more-impaired (stroke) or nondominant (control) hand under two different assistance types: end-effector assistance and exotendon assistance. For each assistance type, unassisted movements will be performed before and after the assistance. Subjects will be randomly assigned into two groups (A and B), who will receive the assistance in a different order. The finger movements and muscle activation patterns will be recorded during movements.