Fast Arm Motor Skill Training in Chronic Stroke Survivors

About 65% of stroke survivors experience long-term limitations in upper extremity (UE) functions. In particular, limitations in arm reaching movements are prominent and correlate strongly with patients' impairment levels. Because activities of daily living often involve the UEs, retraining reach and grasp skills is critical for return to a full quality-of-life. Yet, the training parameters required for effective rehabilitation of UE function are not known. Recent evidence suggests that high-speed movements during training are effective at improving arm movements in individuals with chronic stroke. Hence, fast movements generating large errors, would promote the restoration of the feedforward controllers and therefore improves arm movements and UE functions in individuals with chronic stroke. Because the cerebellum is involved in learning feedforward controllers from motor errors, the improvements would be proportional to the integrity of the cerebellar-cortical networks. A double-blind quasi-randomized controlled study will be carried out in chronic post-stroke survivors. Participants will be assigned to either the speed-bias training group or a dose equivalent accuracy-bias training group (control) and will receive 4 days of training over a 1week period by a trained Occupational or physical therapist. Behavioral, EMG, and MRI data will be acquired within two weeks before, 3 days post, and one month after intervention.