BIOMECHANICAL STUDY OF GAIT REHABILITATION ROBOT
Hsiao-Ju Cheng1, Pavithra Thangavel2, Gong Chen1, Vidhya S2, Haoyong Yu1
1National University of Singapore, Singapore; 2VIT University, India
Walking is the most significant act of locomotion by humans. This ability can be compromised due to various diseases’ such as spinal cord injuries, stroke, neurodegenerative diseases or brain injury. Patients with gait impairment are advised to undergo intensive rehabilitation therapy to restore their normal gait and improve their quality of life. Since manual therapy can be physically demanding for both the patient and the physiotherapist, a prototype of the gait rehabilitation robot was designed to provide assistance while walking and also be used for rehabilitation therapy to restore an individual’s normal gait pattern. The Gait Rehabilitation Robot uses gait event based synchronization, which enables the exoskeleton to provide synchronous assistance during walking. The study performed deals with the evaluation of the robot’s performance so it can further be tested in clinical trials. This evaluation was done by performing experiments on healthy subjects where they were asked to walk under the following conditions: Free Walk (FW, without robot), Zero Force (ZF, with the robot in no assist mode), and Assisted condition (AS, assistive torque provided by the robot). During the experiment the knee joint angles, the torque provided and the EMG pattern were recorded. EMG signals from Tibialis Anterior (TA), Gastrocnemius Lateralis (GL), Rectus Femoris (RF) and Semitendinosus (SM) were recorded. EMG showed overall decrease in muscle activity of the four muscles with the provision of assistive torque as the human will reduce their muscle activity to fully utilize the assistive torque provided. A significant improvement in the knee joint angles was also seen with the increase in the assistive torque. With higher torque the knee joint angle was closer to the knee joint angle in normal walking. The study found that the robot provided effective torque and it is further suitable for clinical trials.