The Use of the Gradual Yielding Mechanism during Downhill Walking in Transfemoral Amputee Gait – a Case Study

To facilitate downhill walking in transfemoral amputees, some prostheses contain knee joints that have a yielding mechanism. The aim of this case study was to investigate 1) at which gradient unilateral transfemoral (UTF) amputees first utilised the yielding mechanism, 2) whether this mechanism is linked to altered spatio-temporal parameters and 3) if the switch occurs at a different gradient when the prosthetic ankle component is altered. Two UTF amputees walked at different slopes (0° to -15°) with an articulating and a rigid prosthetic ankle component. Results showed that the gradient at which the UTFs first used the yielding mechanism is highly individual (UTF1: -6°; UTF2: -12°). UTF2 showed with the switch a decreased speed, step & stride length. The use of an articulating compared to a rigid ankle component did not influence the yielding pattern.