A compliant prosthetic foot is designed and fabricated by combining a compliant mechanism optimization technique with a calculation of low leg trajectory error under a reference loading condition. The compliant mechanism optimization technique includes a set of determinants for the compliant prosthetic foot. An optimized set of determinants of the compliant prosthetic foot is formed that minimizes the lower leg trajectory error relative to a target kinematic data set. The compliant prosthetic foot is then fabricated in conformance with the optimized set of determinants.