The word prosthesis comes from Ancient Greek, meaning addition, application, or attachment. Prostheses are intended to restore the normal functions of a missing body part, lost either through trauma, disease, or a condition present at birth.

A person’s prosthesis should be designed and assembled according to the person’s appearance and functional needs. For instance, a person may need a certain type of prosthesis but will need to choose between an aesthetic functional device, a myoelectric device, a body-powered device, or an activity specific device. The person’s future goals and economical capabilities may help them choose between one or more devices.