<qa>  What is the effect of ischemic nerve block on the forearm of the other handThis study will determine whether impaired hand function due to stroke can be improved by blocking nerve impulses to the unaffected arm. Following a stroke, the unaffected side of the brain might negatively influence the affected side. Studies in healthy volunteers show that function in one hand improves when ischemic nerve block inflating a pressure cuff to block nerve impulses is applied to the forearm of the other hand. This study will examine whether similar improvement also occurs in the affected hand of patients with chronic impairment after stroke. 