Orthosis and Rehabilitation Robots for improvement of gait disorder

Abstract

The most unique part of Japanese physiotherapy for stroke is the frequent use of orthosis. For example, many stroke patients stand and walk with Knee-Ankle-Foot-Orthosis (KAFO) during early acute phase. Especially, gait training with KAFO in early phase is conducted by one therapist assist. Although this training is an only passive walking, obvious muscle activity is shown in EMG measurement during walking even when they cannot generate the voluntary contraction. This is the rationale of KAFO training, patients maintain the activity on the paretic side and prevent the disuse atrophy.

However, patients with KAFO training loss the opportunity of the limb control during gait. Therefore, when the knee lock of the KAFO is removed, patients cannot walk independently and must be regained the independent gait by adding training. Thus, we must develop the way that patients could learn the adequate limb control during gait.

According to previous studies, rehabilitation robot can improve the gait for the patient who cannot walk. They reported that the rate to regain the independent walk was increased due to many repetitions provide by the robot. However, because these robots are large and costly, uses in clinical situation are limited. Thus, usability in clinical setting is one of the most important point in concept of robot.

We have developed some types of rehabilitation robots for gait training. Wearable robot“Orthobot” is one of them, and was developed to improve the utility and usability of rehabilitation robot. This robot can change the ordinary KAFO to wearable rehabilitation robot, only attaching the robot unit. This robot assists the limb motion at adequate timing during overground walking. Knee actuator assists the knee extension from late swing to initial contact, and the knee flexion from pre-swing to early swing phase. These movement improve the foot clearance and trajectory during swing phase. In fact, gait performance of chronic stroke patients improved by using this robot in our previous study. Interestingly, improvement of gait pattern by wearable robot assist was well remained after turning off the robot. According to this hypothesis, rehabilitation robots may facilitate the recovery of gait function and change the clinical situation for patient after stroke.

Wearable robot “Honda Walking Assist” is also one of the robots that we joined the development team. This robot induces the adequate hip motion, improves the gait asymmetry. In many previous studies, the effect of this robot was already shown. It is worth mentioning that this device is very simple and easy towear. It means that this robot can be used for outpatients at home. We are now conducting the clinical trial for effect of home use of this robot for children with cerebral palsy.

The advantage of Japanese neurological physiotherapy is availability of the new technology, such as device and orthosis. It is likely that we can provide a reliable recovery regardless of the therapist’s competence and policy.

 

Biology

Dr. Ohata is a Senior Lecturer in Department of Human Health Sciences, Graduate School of Medicine Kyoto University. He earned his Ph.D. degrees in Medicine from Graduate School of Medicine Kyoto University, his M.S., from Osaka Kyoiku University Graduate School Health Sciences. He started to work in Rehabilitation Center for Children with Physical Disabilities as a Physical therapist. His main research interests include rehabilitation robotics and rehabilitation for children with cerebral palsy and adult after stroke. Currently, many hospitals have been utilizing some rehabilitation robotics to improve the gait function for individuals after stroke in Japan；“HONDA walking assist device” is one of the most popular one.

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