Cosmetic glove stiffness compensation for body-powered hand prostheses: Design of a novel negative stiffness element

The addition of a cosmetic glove to an upper limb prosthesis has an indispensable effect on the cosmetic value, but its viscoelastic behaviour adds a substantial amount of stiffness and hysteresis to the system. Consequently, the overall usability of the prosthesis is degraded. A novel negative stiffness element is designed to compensate for the...

Design and evaluation of a stiffness compensating ankle-foot orthosis

This study proposes an ankle-foot orthosis (AFO) based on a novel concept to compensate increased ankle joint stiffness by adding negative stiffness to the joint. The negative stiffness working principle is a mechanism consisting of a spring generating force around a rotation axis, with a variable moment arm. The spring force is decreasing, when...

The effects of passive stiffness compensation, by negative stiffness, on active RoM and controllability of the ankle joint

Introduction: Paresis in UMND patients leads to immobilization and disuse of the ankle joint. As a result, secondary changes such as increased passive stiffness and plastic CNS rearrangements aggravate the paresis. We propose an intervention that compensates the passive stiffness, enabling the remaining muscle force to initialize movement to...