The recovery from a stroke is often incomplete. It is the leading cause of acquired permanent disability in the adult population. Persistent functional loss of the hand and arm contributes significantly to disability. However, the current standard of care to treat hand and arm movements are inadequate. There is an urgent need for innovative and effective therapies for recovery of the upper limb after stroke. Growing evidence shows that electrical spinal cord stimulation, combined with activity-dependent rehabilitation, enables voluntary movement of paralyzed muscles in some neurologic disorders, such as spinal cord injury. The investigators hypothesize that spinal networks that lost control after stroke can be activated by non-invasive electrical stimulation of the spinal cord to improve functional recovery. The aims of the study are: 1. to determine the improvements in hand and arm function that result from the combined application of non-invasive spinal stimulation and activity-based rehabilitation. Surface electrodes placed over the skin of the neck will be used for non-invasive electrical stimulation of the spinal cord. Functional task practice will be used for activity-dependent rehabilitation, 2. to evaluate long-lasting benefits to hand and arm function that persist beyond the period of spinal stimulation.