Finite element analysis of a model of a therapeutic shoe: effect of material selection for the outsole.

The finite element analysis method was used to perform a sensitivity study of the effect of the materials used for the two layers of the outsole (high-density polyethylene, HDPE, and polyurethane, PU) of a "solid rocker-bottom" design of a therapeutic shoe on the responses (stresses and displacements) of a model of the shoe. It was found that the aforementioned materials choice affected the model responses in a noticeable manner. For example, when HDPE was used for the top layer of the outsole, the von Mises stress at the interface between the bottom of the foot and the top layer of the insole ranged from being about 8% lower to being about 62% higher compared to when PU was used. The implications of this finding are discussed.