Passive Prosthesis of Human Foot With Spring System of Bending Parts

This paper sets the task of modeling a below-knee prosthetic foot with a spring system for bending individual parts: tarsal, metatarsal, and phalanges. The design of a below-knee prosthesis with a spring assisted system is considered, allowing the user to walk identical to a human gait and smoothing the transitions between the movements of the tarsal, metatarsal, and phalanges. The prosthesis has the ability to bend in the area of the phalangeal joint, which allows the user to get used to the product faster. The results of computer modeling of the prosthesis structure in Solidworks CAD showed that the stiffness of the structure when loaded with a static vertical force of 488 H will be equal to 65 kN/m. According to the results of calculation of the kinematic model of the foot, the limiting value of the axial stiffness of the springs is 70 kN/m. Steel 35G2, 40G2, etc. can be used as one of the possible materials for manufacturing the tarsal and phalangeal springs of the prosthesis. These materials ensure stable operation of the prosthetic foot. The obtained foot model can be used in the design of medical bioprostheses.