Quadratic spring design for variable stiffness prostheses

Allowing amputees to have direct control of joint stiffness in a prosthesis can significantly reduce energy expenditure Jar interactive tasks. The traditional method for implementation of variable stiffness is by active feedback. Mechanical modulation of the stiffness through antagonistic actuation can further decrease energy requirements. Decoupling joint stiffness from deflection requires quadratic springs. Such springs are impossible To produce by conventional techniques. Proposed here is a method of producing quadratic springs through the Else of rolamites, Analysis shows that there are limitations on joint torque.