Development, modeling and control of an adjustable stiffness-based supination-pronation forearm physical rehabilitator

Abstract

Wrist and forearm therapy exercises, which include bending (flexion and extension), turning the forearm over (supination and pronation), hand gripping exercises, and forearm strengthening with a dumbbell, these exercises are important to build strength and operation for the wrist, hand, elbow, and shoulder. Assisted motor therapy as continuous passive motion devices is used during the first phase of rehabilitation and plays a critical role in improving passive motion in a specific plane of movement, and protecting the healing process of the tissue, however, current devices are unable to recreate these exercises well. The current thesis is aimed to design and examine the viability of a wrist-forearm exercise device that reproduces pronation-supination range of motion (ROM) therapy and improves the strength of the associated muscles, by adopting an adjustable stiffness system. The device incorporates a handle that will serve as a guide for the required movements linked with two springs to provide stiffness and a smooth return, and four non-elastic cables actuated for two linear actuators that provide linear motion.