Measurement of force and pressure distribution in walking for prosthesis design

Abstract

This work deals with measurement of the force and pressure distribution during walking of a patient with both feet not fully formed. Patient' legs are completely formed down to the heels and the beginning of one midfoot. Since the forefoot is missing, the subject has a difficult propulsion during the boost phase and an excessive rotation at the ankle due to an absent malleolar stability. Design of a customized prosthesis, conceived to ease the subject movement, required the measurement of the forces and pressure distributions during movement. In fact, existing trans-tibial and trans-femoral prostheses studies cannot be applied given that the patient has a limited ankle mobility that shall be preserved during the movement. The force and pressure distributions, measured by means of a commercial measurement system based on capacitive sensors, have been used as input for the finite elements based design. Models of the prostheses have been developed and the performed finite element analyses validated the preliminary design, allowing the manufacturing of prosthetic prototypes.