Estimation of forces at the interface between an artificial limb and an implant directly fixed into the femur in above-knee amputees.

Abstract

This article describes the method used for estimating the forces and moments, acting during locomotion, at the interface between an artificial leg and an implant directly fixed into the femur, in above-knee amputees. Twelve transfemoral amputees completed a predefined gait assessment during which kinetic (ground reaction loads and torque) and kinematic (limb orientation) gait data were recorded. A developed mathematical model enabled the ground reaction forces to be translated to the level of amputation. It is assumed that the loads calculated at the stump-socket interface would approximate those experienced by the proposed implant. The longitudinal force and the moment in the sagittal plane were the two most significant loads at the stump. These data were essential to obtain to facilitate the analysis of stress arising at the implant-bone interface that has been subsequently undertaken.