A Prosthetic Foot Emulator To Optimize Prescription Of Prosthetic Feet In Veterans And Service Members With Leg Amputations

Severe injury to a foot or leg may necessitate amputation of the limb. Using a prosthesis allows many who experience lower leg amputation to regain functional abilities, but walking may be more difficult, and a sub-optimal prosthesis can substantially restrict participation in desired activities. Selecting an optimal prosthetic foot is an important aspect of maximizing mobility and the achievement of functional goals for people with lower leg amputation, however there is limited evidence to guide this process. The current prosthetic prescription process relies on clinician experience and typically does not allow people with a leg amputation to easily try out different prosthetic feet. We have developed a customizable robotic prosthetic foot that mimics the mechanical properties of commercially available prosthetic feet without physically changing feet. This prosthetic foot emulator (PFE) can be attached to the prescribed prosthetic socket and worn like a regular prosthetic foot within the laboratory or clinic, providing people with leg amputations the opportunity to quickly test-drive many prosthetic foot designs within a single test session. Trial and error with actual commercial prosthetic feet can be inefficient given the time and expense required for the purchasing and fitting of prosthetic feet. The PFE could provide a means to explore a range of feet in a very short period of time. This study will evaluate the ability of the emulator to accurately reproduce the experience of wearing several commercially available (actual) prosthetic feet. We will test whether brief in-laboratory experiences with emulated or actual feet can accurately predict longer-term foot preference, satisfaction, and walking ability in the community. We will use a participant blinded cross-over study with repeated measurements in individuals with TTA. Up to 50 participants will be enrolled at each of the three study sites: two VA sites (Puget Sound and Minneapolis), and one DoD site (Center for the Intrepid). Participants will complete up to 6 visits. After an initial assessment visit, participants will be assigned to the high or low mobility group, and then during visit 2 they will be randomized to use the PFE in three foot modes or the three corresponding actual (commercially available) feet during walking tests in the laboratory. During visit 3 participants will repeat the procedures in the other condition (e.g., PFE if Day 2 included actual feet testing). At the end of visit 3 participants will be fit with one of the actual feet and wear it at home and in the community for at least two weeks. At visit 4 participants will be fit with the next actual foot and repeat the 2 week use window. The same process will be followed for the final foot at visit 5, and the study foot will be returned at visit 6. Participants preference, satisfaction and perceived mobility, and functional mobility will be measured and compared across all foot conditions (emulated and actual). Results from this study may provide evidence to support a new approach to prosthesis prescription and could resolve longstanding uncertainty in the prescription process for prosthetic feet.