Portable Design and Range of Motion Control for an Ankle Rehabilitation Mechanism Capable of Adjusting to Changes in Joint Axis

This paper proposes improvements to a simple spatial rehabilitation mechanism for the human ankle, aiming to prevent exertion of forces on the joint, and control the range of flexion it experiences. Such functions would additionally provide information on recovery status in terms of degree of mobility regained, and the force and torque on the affected joint. This information would both provide support for physiotherapists in their work and help to establish self-rehabilitation on the part of the patients themselves. The mechanism presented is built upon previous research of an extended Oldham's coupling mechanism combined with a driving four-bar linkage. A complete rehabilitation device is designed and produced to be lightweight, affixed only to the patient's leg with no additional supporting structure, and able to drive motion along a variety of total flexion angles by changing link lengths using a removable 10 mm pin and pre-drilled holes.