Bench Testing of a Tunable Ankle-Foot Orthosis

Abstract

Cerebral palsy (CP) is the most common childhood motor disability and affects about 0.31% of children in the US. An ankle-foot orthosis (AFO) is commonly prescribed for children with CP to restore gait pattern and function. The properties of an AFO are primarily determined by two parameters: the neutral angle and the stiffness. There is no standard guidance for clinicians to determine what combination of parameters would maximize the function of an AFO. The Human/Machine Design Lab at the University of Minnesota is developing a tunable AFO emulator to help clinicians determine the effect of AFO with certain parameters immediately and the make more objective prescriptions of AFO. This project conducted a bench test on the latest design of this tool, and evaluated if the mechanisms to control the stiffness and the neutral angle of the emulator would work as intended. The mechanism for controlling the neutral angle worked as intended while the mechanism for stiffness was affected by the compliance of the AFO structure and the material of the prototype. A computer control system for the device all functions required.