Vi-RABT: A Platform-Based Robot for Ankle and Balance Assessment and Training

Ankle sprain is a significant public health concern that can compromise ambulation and activities of daily living. An effective rehabilitation protocol includes objective range of motion (ROM), strength, and proprioception assessment and training. The virtually interfaced robotic ankle and balance trainer (vi-RABT) is a platform-based robot to streamline the ankle and balance rehabilitation. vi-RABT is a 2-degree of freedom robot about dorsiflexion/plantarflexion and inversion/eversion of ankle joint. It has a compact electromechanical design instrumented with actuators, angle and torque sensors and equipped with an impedance controller. vi-RABT hosts interactive games, which are designed by therapists, to turn the repetitive therapy into a more engaging experience. The system was used in a preliminary study for ankle joint assessment and training of two healthy human subjects. The assessment results were compared with outcomes using standard equipment in which the ankle joint ROM and strength were found close to the benchmark measures. In training blocks, the impedance controller corrected the individuals’ motion in the goal-oriented interactive game, improving the movement speed and accuracy while delivering satisfactory torque and angle tracking performance. The preliminary results shows that vi-RABT can streamline ankle joint assessment and training in the seated posture. The relatively smaller size of vi-RABT may increase the range and frequency of applications in private clinics and hospitals.