Intense skill practice with the affected arm after stroke has the potential to improve upper extremity (UE) function resulting from neuroplastic changes in the motor cortex. However, the necessary and sufficient parameters of this therapy in humans have not been fully investigated. Delineation of the most efficacious and efficient therapy for promoting UE recovery post-stroke is necessary before effective clinical implementation of this therapy. In this study, using parallel group design methodology, we will test the effect of 2 practice parameter (i.e. spacing of practice and number of repetitions per task practiced per session) modifications on UE function following skill practice.