Microprocessor knee versus non-microprocessor knee for backup device in lower limb prostheses: A qualitative study

Abstract

LAY SUMMARY Current policy in the Canadian Armed Forces (CAF) and Veterans Affairs Canada (VAC) is to provide individuals with an amputation through or above the knee with a prosthesis with a microprocessor knee (MPK) unit for daily use and a backup prosthesis with a non-microprocessor knee (N-MPK) unit. These knee units have significant functional differences. The purpose of this study was to gain an understanding of users’ device preference and the impact of switching between the MPK and N-MPK. To study this, six members participated in semi-structured interviews. Analysis found seven major categories driving prosthetic preference: functionality, physical aspects, mental aspects, activity, maintenance, safety, and health-related quality of life. The MPK was superior in all categories, and immediate switching between devices was problematic. As a result, participants who had an N-MPK backup did not use the device and instead received a loaner MPK from their prosthetist when required. These results suggest that for individuals who do not have ready access to their prosthetist to obtain a loaner knee unit, consideration should be given for a backup prosthesis with the same MPK unit as their daily-use prosthesis. Otherwise, no routine need for a backup N-MPK was identified.