Inertial effects on interface pressure between prosthetic socket and residual limb

A quantitative understanding of interface pressure distribution between prosthetic socket and residual limb is fundamental for an optimal design of prosthesis. Most of traditional finite element (FE) models were static. In this paper a 3-D nonlinear finite element model was developed according to the data of one transtibial amputee. The interface pressures at residual limb were predicted, and the effect of inertial loads was investigated quantitatively. The results show that interface pressures were mainly distributed at patella tendon, lateral tibia, media tibia and popliteal depression regions. Interface pressure had the similar double-peaked waveform in stance phase. The average difference in interface pressure between the two cases with and without consideration of inertial loads was 8.4% in stance phase, while it was up to 20.1% in swing phase with considerably different change trend. It is found that inertial effects during walking can not be ignored.