Modeling Sport Prostheses Based on the Flat Spring Design Formulas

Abstract

Sports prosthesis for lower extremity amputees has a mechanical structure similar to flat springs, and its elastic energy is expected to improve sports performance. Our research project focuses on a long jump event for track and field, in particular, on the takeoff action. Our previous study established a computer simulation system that derived a comprehensive optimum solution for both the mechanical design parameters of the prosthesis and takeoff action to improve the performance of amputee long jump. The purpose of this study is to improve the mechanical model of the prosthesis based on the flat spring design formulas to represent precise deformation and rolling contact with the ground. The curvature of each element of the prosthesis was modified by the deflection angle of the flat spring model, and the contact point to the ground was calculated by considering deformation and rolling contact. Simulation results showed the deformed shape of the prosthesis and takeoff action qualitatively agreed with the actual phenomena. However, magnitude of the ground reaction force by simulation model were larger than that of measured data.