A Prosthetic Foot Test-Drive Strategy for Improving Stability in Veterans With Leg Amputations

Self-report: perceived stability,Biomechanical measures: Medial/Lateral Margin of Stability (MOS),Performance-based outcomes: Narrowing Beam Walking Test,Performance-based outcomes: Narrowing Beam Walking Test,Performance-based outcomes: Four Square Step Test,Performance-based outcomes: Four Square Step Test,Self-report: balance confidence Activities-specific Balance Confidence,Self-report: Activity Restriction PROMIS Ability to Participate in Social Roles and Activities (APSRA),Self-report: Activity Restriction PROMIS Ability to Participate in Social Roles and Activities (APSRA),Self-report: perceived stability with emulated feet and commercial feet,Self-report: perceived stability with emulated feet and balance confidence using corresponding commercial feet,Self-report: perceived stability with emulated feet and balance confidence using corresponding commercial feet,Self-report: perceived stability with emulated feet and performance-based measures of stability (NBWT and FSST) using corresponding commercial feet,Self-report: perceived stability with emulated feet and performance-based measures of stability (NBWT and FSST) using corresponding commercial feet,Self-report: initial perceived stability and follow-up perceived stability,Self-report: initial perceived stability and follow-up perceived stability,Self-report: initial perceived stability and follow-up performance-based based measures of stability,Self-report: initial perceived stability and follow-up performance-based based measures of stability

Objective/Hypotheses and Specific Aims: The first aim of this proposal is to determine the
 effects of commercial prosthetic feet of varying stiffness on stability and falls-related
 outcomes in Veterans with TTA. The second aim is to determine whether a PFE can be used to
 predict stability and balance-confidence outcomes with corresponding commercial prosthetic
 feet. The third and final aim is to determine whether a brief trial of commercial prosthetic
 feet can predict longer-term stability and balance-confidence outcomes in Veterans with TTA.
 
 Study Design: The investigators will use a participant blinded cross-over study with repeated
 measurements in Veterans and Service members with TTA. Up to 50 participants will be enrolled
 at each of the two study sites VA Puget Sound and VA Minneapolis. 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 on difference surfaces in the laboratory (cross-slopes, inclines, even,
 and uneven ground). During visit 3 participants will repeat the procedures in the other
 condition (e.g., PFE if visit 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 approximately one week. At visit 4 participants will be fit with the next actual foot and
 repeat the 1 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.