Development of a Lower Extremity Exoskeleton as an Individualized Auxiliary Tool for Sit-to-Stand-to-Sit Movements

This paper presents a lower extremity exoskeleton as a rehabilitation tool that involves electronics, biomedicine and mechanism design. Using the rehabilitation tool, the paralyzed lower limb muscles and impaired neurons of a stroke patient can be well revitalized during repeated stand-to-sit-to-stand movements. The body of an exoskeleton user can be well stabilized using a zero-torque theory. As compared with a “without” exoskeleton counterpart, an average of 66.98% reduction was observed in the RMS value of electromyography signals across the vastus intermedius muscle among a group of 5 healthy subjects with the exoskeleton (p <;.05), and a 47.248% reduction in the case of a female with an impaired lower limb. Ideally, the exoskeleton was designed to make a disabled user move in the same way as a healthy one, and the sit-to-stand-to-sit movement pattern of the female was improved, as evidenced by joint angle curves captured using a Kinect. Hence, the exoskeleton serves as an effective auxiliary sit-to-stand-to-sit tool not only for the elderly but also for those with mild lower limb motor impairment.