Characteristics of the soft tissue hardness of the residual limb on transfemoral amputees

Abstract

To increase the femoral prosthesis socket fitting, it is necessary to fix the residual limb soft tissue moderately. The hardness of the residual limb soft tissue is one of factors for the fabrication of a transfemoral prosthetic socket, but there is no quantitative evidence of the factor working. In this study, we tried to quantify the hardness of the soft tissue on the thighs of six non-amputee subjects and on the residual limb of fourteen transfemoral (TF) amputee subjects. An indentation test was carried out on the soft tissue of both subject groups. There are four measurement points (A proximal and distal point on each thigh and residual or sound limb). The elasticity model coefficient (index of the hardness) and its average were calculated on each point. As result, there was no significant difference in the index of the hardness of the soft tissue of the thigh in the dominant leg and the non-dominant leg on the non-amputee subjects. However, the index of the hardness on the residual limb of TF amputee subjects was significantly smaller than that of the non-amputee subjects and sound leg of amputee subjects. In addition, the index of the proximal points of the residual limb tended to have a different hardness from the distal points.