Limb Loss

Microprocessor-controlled knees (MPKs) automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the prosthesis user during gait. The purpose of this proposed investigation is to determine if there are substantial physical and psychological benefits to fitting lower functioning Veteran ambulators having transfemoral amputations with an MPK compared with a nonmicroprocessor-controlled knee (NMPK). Using a repeated-measures, cross-sectional experimental design, approximately 20 Veterans with unilateral, transfemoral amputations will be evaluated on two separate occasions at the Jesse Brown VA Medical Center or the Edward Hines, Jr. VA Hospital, first with their conventional NMPK and then again after a 2-month accommodation period with the College Park Icon MPK.

Microprocessor-controlled knees (MPKs) do not typically utilize motors to power joint rotation, but they automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the prosthesis user during gait. The Ossur Power Knee is the only commercially-available MPK that uses a motor to provide active power generation during walking and other activities. The purpose of this proposed investigation is to perform and compare biomechanical evaluations of the Power Knee and Ossur Rheo XC, a passive MPK, during walking and other activities by prosthesis users. Furthermore, mobility between male and female subjects will be compared to determine if there are differences in prosthetic knee usage on the basis of sex.

The purpose of this research is to evaluate how people move about in different settings with different assistive devices or components, and to understand how people interact with different assistive technologies. Individuals that have limb weakness, limb paralysis, limb loss, and movement disorders are often provided assistive devices such as prostheses and orthoses to assist with mobility or use assistive technologies for purposes such as to regain muscle strength or retrain movements. It is important to understand the impact of these different assistive technologies on human movement for technology improvement and in preparation for commercialization. Because this research focuses on evaluating how different people move about in different settings with different assistive devices/components, there are different activities that may take place. These activities have been classified as (1) Movement Analysis in the Laboratory, (2) Movement Analysis Outside the Laboratory, (3) Usability Testing, and (4) Focus Groups. Each participant may or may not complete the same activities as the other participants. Each participant may or may not complete all of the activities. Participants may complete the activities more than once.