2 Clinical Trials for Various Conditions
In older adults, poor circulation in the lower extremities leads to serious health complications including limb loss. In addition, individuals with dysvascular disease also suffer from other co-morbidities like diabetes, coronary and cerebrovascular disease. An individual with a transfemoral (TF) amputation is usually fitted with a prosthetic limb to assist with function, including a prosthetic knee and a prosthetic foot. Currently, dysvascular amputees are given a prosthetic knee based on the basic expectation that they will be functionally stable. This consideration does not address higher levels of function like walking at multiple speeds and over uneven ground. Also, dysvascular amputees are not able to counteract their co-morbidities with a more active lifestyle. Walking is less energy efficient; their traditional prostheses may cause early onset of fatigue and induce a fear of falling. Newer microprocessor knees enable patients with transfemoral amputations to walk on different surfaces and at multiple cadences through better control in swing and stance phases of gait. The impact of the functional differences in the prostheses is not clear and requires additional investigation to clarify the choice of the most appropriate functional prosthesis. The purpose of this study is to compare the functional outcomes with the traditional mechanical knee versus the microprocessor knee (C-leg) in transfemoral amputees.
Amputees wearing a conventional prosthesis require 20-30% more metabolic energy to walk at the same speeds as non-amputees and this discrepancy is more apparent at faster walking speeds. Amputees choose to walk at speeds 30-40% slower than non-amputees. Preferred walking speed is likely influenced by elevated metabolic energy, but the underlying reason for slower preferred walking speeds is not fully understood. Unilateral amputees exhibit highly asymmetrical gait patterns that likely require more metabolic energy and impair functional mobility, increasing the risk of degenerative joint disease, osteo-arthritis and lower back pain. Improvements in prosthetic devices could enhance mobility in amputees, thus positively effecting rehabilitation and ambulation in veterans. A prosthesis that allows amputees to reduce metabolic energy would be especially useful for rehabilitation in older, ill individuals with reduced exercise capacities and could literally restore walking ability in people that are currently non-ambulatory. Hypotheses. Amputees wearing the Massachusetts Institute of Technology (MIT) Powered Ankle-Foot (PAF) prosthesis will have a lower metabolic cost, faster preferred walking speed, and improved gait symmetry during walking than amputees wearing a conventional prosthesis and will have nearly the same metabolic cost, preferred walking speed, and gait symmetry during walking as age, gender, height, and weight matched non-amputees.