Inclusion Criteria:  Unilateral upper limb amputation above or below the elbow with fully healed and healthy surgical sites Viable peripheral nerve function in the residual limb Volitional activity of the residual muscles in the amputated limb Medically fit to undergo general anesthesia Fitted with a prosthesis by a certified prosthetic and orthotic specialist (CPO) and at least one month of experience using a prosthesis Willingness and availability to follow the study protocol Recommendation of a psychologist that the subject is mentally competent and capable of completing the study-related activities  Exclusion Criteria:  Bilateral upper limb amputation Inability to speak English Medically unfit to undergo surgery Pregnancy, or those who are of childbearing potential, unwilling to prevent pregnancy during the trial Uncontrolled diabetes Active infection or open sores on the residual limb History of frequent infection or sores with unknown cause Inability to provide informed consent or follow experimental protocols Severe pain that would prevent the subject from completing study-related activities