Training Independent Muscle Activation From a Common Source

In this study, the investigators are evaluating a new surgical technique that may allow participants to control their muscles in a new way after their amputation or revision surgery. The investigators are looking for people who have limb amputation or require a revision operation to a previous amputation. Participants must be over 18 and younger than 65, willing to begin participation within two weeks of their surgery, and be willing to travel regularly to Boston. In this study, participants will have a modified revision procedure on their amputated limb or a modified amputation procedure, followed by a series of follow up visits in clinic and to a gait lab at Harvard. Participants will also use a wearable device on their limb at home to complete daily training tasks and games.