A Two-Degree of Freedom Mobile Ankle Rehabilitation Unit (MARU) to Improve and Track Joint Mobility

Abstract

Rehabilitation for conditions affecting the knee and ankle involve regular mobilization exercises. In order to facilitate the adherence to a rehabilitation plan, we present a mobile and simple to use device consisting of a base and an actuated foot plate. The device can be used for both mobilization and strengthening exercises. Apart from rotation around the ankle, the movement of the foot in the sagittal plane is controlled to imitate walking using a four-bar linkage, potentially expanding the benefits of the exercises to the knee. The trajectory can be fitted to the patient’s individual needs by adjusting the linkage dimensions. Using torque sensors, the exerted forces are monitored and the actuation can be adjusted accordingly. The device can be easily controlled by the patient through a smartphone app, which also supplies additional features such as progress monitoring, with a separate interface for the treating physician.