Vital for a strong foundation for walking, the ankle is essential for forward motion, balance and gait. Post-stroke or a neurological condition, foot drop is a common lower limb impairment caused by weakness in the dorsiflexor muscles in the ankle region responsible for motion and flexing the foot upwards. When experiencing foot drop the front of the foot drags on the ground while walking. Another complication that can cause lateral instability while walking is weakness in ankle eversion and inversion. This occurs when ankle joints are stretched excessively from side-to-side causing the foot to roll inwards or outwards. These ankle impairments are a result of neurological, muscular or anatomical complications.
Developed to assist ankle neruorehabilitation by MIT’s Department of Mechanical Engineering, the Anklebot is an exoskeletal robotic system designed around improving four types of ankle motion: plantar flexion, dorsiflexion, inversion and eversion. During robotic therapy, the Anklebot is securely mounted to a cushioned chair and gently attached to the lower limb undergoing therapy with a knee brace and a custom fitted shoe. Using gamification, the Anklebot allows one to play a computer game using the ankle to move a cursor on a computer screen while the movement of the goal-oriented task is tracked and recorded. As the ankle moves in the four types of motion, the robotic device sensors make guided adjustments to the ankle muscles coaching the performance of the goal-oriented tasks. As ankle movement, function and control improves the amount of guided robotic assistance decreases. Through repetition of the ankle robotic therapy the primary neruorehabilitation goal of building strength, engaging muscle memory and awakening neuro-plasticity, the healing of brain nerves, becomes viable.