Active 2-Axis Ankle-Foot Exoskeleton Using Single Actuator for Physiotherapy

Stroke patients perform resistance training during the recovery phase to regain muscle strength and neuromuscular functioning. The active ankle-foot exoskeletons (AAFE) available in the market, used for leg muscle training, have multiple actuators to facilitate multiple ankle movements. This increases the complexity, weight and makes the device less portable. In this paper, we propose an AAFE having a spatial mechanism that can facilitate variable resistance training during plantarflexion/dorsiflexion and inversion/ eversion using a single actuator. Based on the focus on the group of muscles to be trained, an independent motion is achieved by arresting the redundant joints. The paper presents the design and analysis of the AAFE, and the performance of the fabricated exoskeleton is demonstrated for three different training modes.