A research group led by Director Etsuo Chosa, and Chief Shigeaki Miyazaki of the Rehabilitation Unit at University of Miyazaki Hospital, Associate Professor Go Yamako of Mechanical Engineering Program, the Faculty of Engineering, the University of Miyazaki, and their collaborators demonstrated through a clinical study that the weight-shifting-based robot control system 'LOCOBOT,' developed through a medical-engineering collaboration, is effective in improving the motor functions of patients.
Patients with hip osteoarthritis who underwent unilateral (hip joint replacement using hip prosthesis) used the LOCOBOT for 10 min from the day following their surgery. The weight-bearing ratio (WBR) of the legs in the standing position recovered to the normal range within 12 days after surgery, significantly improving the impairment compared to that under standard rehabilitation. Postural balance improved significantly after the surgery. The research group continues to study the LOCOBOT to gain approval for its use as a medical device. The LOCOBOT is expected to help patients swiftly resume their daily activities and decrease their rehabilitation period. These results were published in PeerJ.
Japan's super-aging society and polar exercise habits among children (over exercise or under exercise) have resulted in increased occurrence of locomotive syndrome (a condition of reduced mobility), which can potentially shorten healthy lifespans of people. Approximately 47 million people in Japan are estimated to be either diagnosed with or exposed to the risk of the syndrome.
The research group developed the robot system 'LOCOBOT' through a medical-engineering collaboration to prevent and minimize the effects of the locomotive syndrome in a fun and enjoyable manner. In July 2021, the group initiated foundational research to investigate the effectiveness of the 'LOCOBOT.' In November 2021, a rental and sales business was initiated through a university-affiliated venture company, LOCOBOT. Since then, the developed robot system has found potential applications in the academic, sports, and health fields.
The effect of the LOCOBOT-based postoperative rehabilitation on improving the postoperative standing position compared to that of traditional rehabilitation methods was investigated for 20 patients with hip osteoarthritis who underwent total hip arthroplasty (THA).
Specifically, all patients underwent 40 minutes (min) of rehabilitation sessions after THA. Patients in the LOCOBOT group were subjected to rehabilitation using the LOCOBOT for the last 10 min during the rehabilitation session, whereas patients in the control group underwent traditional rehabilitation with exercise to control their body weight, with weight loading in the final 10 min of the session. The WBR and postural balance ability on postoperative day 12 were compared between the groups to assess recovery.
Each group contained 10 patients allocated equally based on their age and sex. Before THA, the WBRs were 0.85 and 0.77 in the LOCOBOT and control groups, respectively. Although the WBR for healthy individuals is usually 1.0, patients with impairment on one foot have a WBR of less than 1.0 owing to an imbalance in the weight-load distribution. In both groups, rehabilitation was initiated 2 days after surgery.
The WBRs on postoperative day 12 were 1.07 and 0.85 in the LOCOBOT and control groups, respectively. The gait ability levels on postoperative day 12 for patients who used a crutch or a T-handle cane or those who walked independently were one, five, and four in the LOCOBOT group and three, six, and one in the control group, respectively.
Comparing the results of both groups revealed that they presented different improvements. The balance ability in the control group declined temporarily after THA and recovered during follow up, whereas in the LOCOBOT group, it recovered and remained stable without a decline after THA.
The average length of rehabilitation was approximately 7 days over the 12 postoperative days in the LOCOBOT group, which confirmed that rehabilitation based on the LOCOBOT could recover the motor function in a short time.
In Japan, THA is performed in 47,000 cases annually, and the postoperative hospital stay is generally two-week long. After being discharged, patients undergo rehabilitation at local hospitals for approximately three months.
The LOCOBOT comprises a spherical robot, control personal computer, and force board. Because the spherical robot can be controlled easily as an avatar, the patient does not feel exhausted and may even experience a favorable psychological impact.
The research group plans to further investigate the effectiveness of the LOCOBOT in improving gait ability and muscle strength.
Yamako said, "We will continue clinical research to extend the applications of the LOCOBOT for additional rehabilitation purposes. Further, we plan to develop measurement functions, e.g., center of gravity oscillations with a database, and aim to seek approval to recognize the LOCOBOT as a medical device."
Journal Information
Publication: PeerJ
Title: Weight-shifting-based robot control system improves the weight-bearing rate and balance ability of the static standing position in hip osteoarthritis patients: a randomized controlled trial focusing on outcomes after total hip arthroplasty
DOI: 10.7717/peerj.15397
This article has been translated by JST with permission from The Science News Ltd. (https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.