Application of a newly developed upper limb single-joint hybrid assistive limb for postoperative C5 paralysis: An initial case report indicating its safety and feasibility.

Postoperative C5 paralysis is a serious complication of cervical spine surgery, with no established method for effective rehabilitation. A 67-year-old man presented with postoperative bilateral C5 paralysis following cervicothoracic surgery for ossification of the posterior longitudinal ligament (OPLL). Starting 15 days after surgery, left elbow joint training was performed 2-3 times weekly, for a total of 10 sessions, using an upper limb single-joint hybrid assistive limb (upper limb HAL-SJ). Right elbow joint training was also performed 5 times weekly starting 38 days after surgery, for a total of 10 sessions, using the upper limb HAL-SJ. No serious adverse events were noted during treatment with the upper limb HAL-SJ. Manual muscle testing showed no apparent change in deltoid and biceps strength on either side during use of the upper limb HAL-SJ; however, hand-held dynamometer testing showed improvement over time in both muscles. At 12 months after surgery, the patient was able to elevate both arms. The present case indicates initial safety and feasibility of treatment for postoperative C5 paralysis with an upper limb HAL-SJ.