Comparison of the performance of the microprocessor knee to a healthy knee during gait

Abstract

Individuals that have undergone a trans-femoral amputation require a prosthetic incorporating an artificial knee joint in order to enable them to walk unassisted. Microprocessor-controlled Prosthetic Knees enable this joint to be controlled by a computer in order to behave more like a natural human knee. The aim of this study was to attempt to identify any limitations in currently available Microprocessor-controlled Prosthetic Knees that may exist when compared to healthy human knees. Two amputees fitted with Microprocessor-controlled Prosthetic Knees were recruited as well as a control subject to represent healthy human knees. Gait studies were conducted at three self-selected speeds along a level walkway. As one of the subjects also owned a non-Microprocessor-controlled Prosthetic Knee, it was included in the study as an additional data point. The resulting data showed some small differences, but the limited data available meant that a few inconsistent results in some data sets made up a significant percentage of the available data. Due to the limitations encountered during this study, chiefly the significantly limited availability of participants fitted with Microprocessor-controlled Prosthetic Knees, the results of this study are limited. As one amputee had a bilateral trans-femoral amputation and the other had a unilateral trans-femoral amputation, it was not even possible to identify if any inconsistencies were due to the individual or the prosthetics. As such, it is not possible to reach any definitive conclusions with the data available, other than that, under the test conditions encountered during the gait studies, Microprocessor controlled Prosthetic Knees are able to enable an amputee to walk with a good approximation of natural human gait on the prosthetic limb. A wider ranging study would be necessary to determine the limitations of that approximation with any certainty.