Rehabilitation clinic sessions - These will occur up to twice per week for the first 3 weeks and once per week for the second 3 weeks of the 6 week treatment. They are therapist-guided and last up to 90 min consisting of 45 minutes of contralaterally-controlled functional electrical stimulation (CCFES)-mediated video games and up to 45 minutes of CCFES-mediated functional task practice. Early sessions will focus on training the patient and caregiver to self-administer play of a CCFES-mediated video game at home. As proficiency with one game develops, more games will be introduced. The functional task practice part of the session will engage the participant in using the CCFES system to assist them in practicing using their hand in activities such as lacing beads, throwing balls, eating finger foods, and other play and activities of daily living. Prior to the start of lab treatment, the investigators will assess hand extensor and flexor muscle co-activation (see below).