Numerical Study of a Customized Transtibial Prosthesis Based on an Analytical Design under a Flex-Foot® Variflex® Architecture

This work addresses the design, analysis, and validation of a transtibial custom prosthesis. The methodology consists of the usage of videometry to analyze angular relationships between joints, moments, and reaction forces in the human gait cycle. The customized geometric model of the proposed prosthesis was defined by considering healthy feet for the initial design. The prosthesis model was developed by considering the Flex-Foot® Variflex® architecture on a design basis. By means of the analytical method, the size and material of the final model were calculated. The behavior of the prosthesis was evaluated analytically by a curved elements analysis and the Castigliano theorem, and numerically by the Finite Element Method (FEM). The outcome shows the differences between the analytical and numerical methods for the final prosthesis design, with an error rate no greater than 6.5%.