Energy storage ankle joint

How does ankle joint rotation affect a cantilever spring?

Rotation of the ankle joint deflects the cantilever spring, allowing energy to be stored and released. The shape of the cam profile governs the amount of elastic energy stored in the spring for a given ankle joint rotation. Higher energy storage in the spring results in a larger normal force between the cam profile and cam follower.

How do ankle prosthetics work?

The desired ankle mechanics can be encoded in the shape of each cam profile, and by interchanging the cam profiles at specific points during the stance phase of gait (i.e., points in the torque–angle relationship), the ankle prosthesis can produce multiple energy storage and return profiles.

Does the energy storage mechanism enhance the assistance of the exoskeleton?

Results: Level ground studies indicate that the energy-storage mechanism enhances the assistance by increasing the output torque of the exoskeleton. Reductions in metabolic cost (6.4 ± 1.3%, p < 0.05) were observed.

How is energy stored during foot loading phase of stance?

During the foot loading phase of stance energy is stored and locked through a one-way clutch. The potential energy level of the spring is sustained by the clutch mechanism during the mid-stance aspect of gait cycle.

What is the role of the ankle joint in gait?

Published by Cambridge University Press The ankle joint plays a critical role during gait, absorbing energy during collision with the ground, contributing to overall stability, and providing the majority of net positive work for the forward propulsion of the body (Winter, 1991; Farris and Sawicki, 2011; Zelik et al., 2015 ).

What are energy storage and return feet?

Energy storage and return (ESR) feet are passive prostheses capable of storing elastic energy during midstance and returning it during late stance to help transition the center of mass over the leading limb (Casillas et al., 1995; Hafner, 2006; Versluys et al., 2009 ).