This is a pilot randomized controlled trial of an intervention to improve arm function in children ages 6 to 17 with cerebral palsy and upper limb hemiparesis. Twenty participants will be randomized to either a group treated with neuromuscular electrical stimulation and video games or video games alone. Both groups will receive 6 wks of treatment consisting of home and lab sessions. Both the experiment group and control group interventions consist of therapist-guided sessions in the rehabilitation clinic and self-administered or caregiver-assisted sessions at home. While both groups will receive the same task practice and video game training, only the experiment group will receive an electrical stimulation device to assist with hand opening during practice. Changes in upper extremity motor impairment and function will be assessed for each participant at baseline, mid treatment, end of treatment and at 3 mo follow-up.