Based on these initial findings, we propose a randomized, controlled clinical trial to rigorously test the efficacy of this modification of CI therapy for rehabilitating arm function in chronic stroke patients with severe upper-extremity impairment. To this end, 40 survivors of stroke with plegic hands will be randomly assigned to receive the intervention described above or a placebo control procedure of the same duration. Control participants will receive either 1) tone management, EMG biofeedback and other procedures in alternating blocks for 6 hr daily for 15 consecutive weekdays or 2) usual & customary care. Measures of arm motor ability (gWMFT; Fugl-Meyer), arm use in daily life (MAL, accelerometry), and quality of life (Stroke Impact Scale) will be administered to all participants before and after treatment and at long-term. If the modified CI therapy participants shows larger improvements in more-impaired arm function than the control group participants, this will suggest it is an efficacious treatment and raise hopes of additional recovery for a large group of healthcare consumers with limited treatment options.