Improved stability in lower extremity exoskeletons using foot extensions

Existing lower extremity exoskeletons lack sufficient foot support area to guarantee safe operation for rehabilitation of patients, and normal posture/gait for users carrying heavy loads on backpack. In order to enhance the stability of lower extremity exoskeletons, an adaptive foot system is presented. It consists of two foot extensions, one extending behind the toe and another on the heel side that extends the support area behind the heel when the foot is flat and retracts when the heel is off the ground. Such a system has an important application in rehabilitation for enhancing stability where safety of patients is critical. We present a detailed description of the adaptive foot system and analyze the stability in sagittal plane.