Design, development, and clinical validation of a two degrees of freedom compliant ankle-foot prosthesis based on a 4-4r parallel mechanism

Compared with active prostheses, passive compliant ankle prostheses offer the advantages of reduced energy consumption, a lighter weight, simple structure, and lower costs. However, although various commercial products are available, these designs do not provide adequate degrees freedom (DOFs) for movement. This paper presents ankle–foot prosthesis (CPAF) capable 2-DOF rotation during locomotion. The CPAF uses parallel mechanism to support bodyweight limited movement, it incorporates component facilitate generate torque conform uneven terrains. kinematics mechanism, including workspace singularities, were investigated. Then, prototype was developed, performance evaluations showed that sufficient could be generated an appropriate range motion ankle. Concequently, clinical validations conducted: dynamic analysis indicated provided good gait movement level-ground walking, metabolic tests demonstrated configuration-4 achieve best efficiency walking.