Shigeki Kubota

Feasibility of rehabilitation training with a newly developed wearable robot for patients with limited mobility

OBJECTIVE To investigate the feasibility of rehabilitation training with a new wearable robot. DESIGN Before-after clinical intervention. SETTING University hospital and private rehabilitation facilities. PARTICIPANTS A convenience sample of patients (N=38) with limited mobility. The underlying diseases were stroke (n=12), spinal cord injuries (n=8), musculoskeletal diseases (n=4), and other diseases (n=14). INTERVENTIONS The patients received 90-minute training with a wearable robot twice per week for 8 weeks (16 sessions). MAIN OUTCOME MEASURES Functional ambulation was assessed with the 10-m walk test (10MWT) and the Timed Up & Go (TUG) test, and balance ability was assessed with the Berg Balance Scale (BBS). Both assessments were performed at baseline and after rehabilitation. RESULTS Thirty-two patients completed 16 sessions of training with the wearable robot. The results of the 10MWT included significant improvements in gait speed, number of steps, and cadence. Although improvements were observed, as measured with the TUG test and BBS, the results were not statistically significant. No serious adverse events were observed during the training. CONCLUSIONS Eight weeks of rehabilitative training with the wearable robot (16 sessions of 90min) could be performed safely and effectively, even many years after the subjects received their diagnosis.

The voluntary driven exoskeleton Hybrid Assistive Limb (HAL) for postoperative training of thoracic ossification of the posterior longitudinal ligament: a case report

Context: The hybrid assistive limb (HAL) is a wearable robot suit that assists in voluntary control of knee and hip joint motion by detecting bioelectric signals on the surface of the skin with high sensitivity. HAL has been reported to be effective for functional recovery in motor impairments. However, few reports have revealed the utility of HAL for patients who have undergone surgery for thoracic ossification of the posterior longitudinal ligament (thoracic OPLL). Herein, we present a postoperative thoracic OPLL patient who showed remarkable functional recovery after training with HAL. Findings: A 63-year-old woman, who could not walk due to muscle weakness before surgery, underwent posterior decompression and fusion. Paralysis was re-aggravated after the initial postoperative rising. We diagnosed that paralysis was due to residual compression from the anterior lesion and microinstability after posterior fixation, and prescribed bed rest for a further 3 weeks. The incomplete paralysis gradually recovered, and walking training with HAL was started on postoperative day 44 in addition to standard physical therapy. The patient underwent 10 sessions of HAL training until discharge on postoperative day 73. Results of a 10-m walk test were assessed after every session, and the patients speed and cadence markedly improved. At discharge, the patient could walk with 2 crutches and no assistance. Furthermore, no adverse events associated with HAL training occurred. Conclusion: HAL training for postoperative thoracic OPLL patients may enhance improvement in walking ability, even if severe impairment of ambulation and muscle weakness exist preoperatively.

Decrease of spasticity after hybrid assistive limb® training for a patient with C4 quadriplegia due to chronic SCI

Context: Recently, locomotor training with robotic assistance has been found effective in treating spinal cord injury (SCI). Our case report examined locomotor training using the robotic suit hybrid assistive limb (HAL) in a patient with complete C4 quadriplegia due to chronic SCI. This is the first report examining HAL in complete C4 quadriplegia. Findings: The patient was a 19-year-old man who dislocated C3/4 during judo 4 years previously. Following the injury, he underwent C3/4 posterior spinal fusion but remained paralyzed despite rehabilitation. There was muscle atrophy under C5 level and no sensation around the anus, but partial sensation of pressure remained in the limbs. The American Spinal Injury Association impairment scale was Grade A (complete motor C4 lesion). HAL training was administered in 10 sessions (twice per week). The training sessions consisted of treadmill walking with HAL. For safety, 2 physicians and 1 therapist supported the subject for balance and weight-bearing. The devices cybernic autonomous control mode provides autonomic physical support based on predefined walking patterns. We evaluated the adverse events, walking time and distance, and the difference in muscle spasticity before and after HAL-training using a modified Ashworth scale (mAs). No adverse events were observed that required discontinuation of rehabilitation. Walking distance and time increased from 25.2 meters/7.6 minutes to 148.3 meter/15 minutes. The mAs score decreased after HAL training. Conclusion: Our case report indicates that HAL training is feasible and effective for complete C4 quadriplegia in chronic SCI.

Knee-Extension Training with a Single-Joint Hybrid Assistive Limb during the Early Postoperative Period after Total Knee Arthroplasty in a Patient with Osteoarthritis

The knee range of motion is an important outcome of total knee arthroplasty (TKA). According to previous studies, the knee range of motion temporarily decreases for approximately 1 month after TKA due to postoperative pain and quadriceps dysfunction following surgical invasion into the knee extensor mechanism. We describe our experience with a knee-extension training program based on a single-joint hybrid assistive limb (HAL-SJ, Cyberdyne Inc., Tsukuba, Japan) during the acute recovery phase after TKA. HAL-SJ is a wearable robot suit that facilitates the voluntary control of knee joint motion. A 76-year-old man underwent HAL-SJ-based knee-extension training, which enabled him to perform knee function training during the acute phase after TKA without causing increased pain. Thus, he regained the ability to fully extend his knee postoperatively. HAL-SJ-based knee-extension training can be used as a novel post-TKA rehabilitation modality.

Repair of the sciatic nerve defect with a direct gradual lengthening of proximal and distal nerve stumps in rabbits.

Background: The current clinical repair method used for the segmental peripheral nerve defect is autogenous nerve grafting. However, this method has several inherent disadvantages. Therefore, the authors have invented an alternative method for repairing the segmental peripheral nerve defect with a direct gradual lengthening of nerve stumps. In this study, for the clinical application, the authors developed a new external nerve-lengthening device for lengthening peripheral nerve stumps daily without anesthesia. Methods: In this study, a nerve segment 20 mm in length was resected from the rabbit sciatic nerve. In the nerve-lengthening group, direct nerve lengthening was performed in the proximal and distal nerve stumps at a rate of 1 mm/day without anesthesia. After being lengthened for 22 days, both proximal and distal nerve stumps were evaluated by immunohistochemical analysis. When confirming that both nerve stumps were successfully lengthened, a direct end-to-end neurorrhaphy was performed. As a control, 20-mm-long autografting was performed immediately after nerve resection. Nerve regeneration was evaluated by electrophysiologic and histologic examination at 16 weeks after the first operation in both the nerve-lengthening and the control groups. Results: The results of both electrophysiologic evaluation and histologic examination showed that the nerve-lengthening group performed significantly better than the autografting group. Conclusion: The gradual nerve-lengthening procedure can be used as an alternative therapeutic method for repairing segmental peripheral nerve defects, which proved to be advantageous over widely adopted autogenous nerve grafting.

New treatment for peripheral nerve defects: Reconstruction of a 2 cm, monkey median nerve gap by direct lengthening of both nerve stumps

We have developed a new treatment for peripheral nerve defects: nerve‐lengthening method, and confirmed the efficacy and safety of our method using cynomolgus monkeys. A 20‐mm defect in the median nerve of monkeys forearms was repaired through the simultaneous lengthening of both nerve stumps with original nerve‐lengthening device. To evaluate nerve regeneration after neurorrhaphy, electrophysiological, histological, and functional recovery were examined and compared to the standard autografting. Nerve conduction velocity, axon maturation, and the result of functional test were superior in the nerve‐lengthening method than in the autografting. And there were no adverse events associated with our method. We concluded that this method is practical for clinical application.

Application of robot suit HAL to gait rehabilitation of stroke patients: a case study

We have developed the Robot Suit HAL (Hybrid Assistive Limb) to actively support and enhance human motor functions. The HAL provides physical support according to the wearers motion intention. In this paper, we present a case study of the application of the HAL to gait rehabilitation of a stroke patient. We applied the HAL to a male patient who suffered a stroke due to cerebral infarction three years previously. The patient was given walking training with the HAL twice a week for eight weeks. We evaluated his walking speed (10 m walking test) and balance ability (using a functional balance scale) before and after the 8-week rehabilitation with the HAL. The results show an improvement in the gait and balance ability of a patient with chronic paralysis after gait training with the HAL, which is a voluntarily controlled rehabilitation device.

The Hybrid Assistive Limb® intervention for a postoperative patient with spinal dural arteriovenous fistula and chronic spinal cord injury: a case study

Context: The purpose of this report was to describe the improvement in walking ability using the Hybrid Assistive Limb® (HAL®) intervention in the case of a patient with paraplegia after spinal cord injury whose condition deteriorated because of a spinal dural arteriovenous fistula (SDAVF). Findings: A 48-year-old man started the HAL® intervention twice per week (total 10 sessions), after his neurologic improvement had plateaued from 3 to 6 months postoperatively for an SDAVF. During the HAL® intervention, the 10-m walk test (10MWT) without HAL® was performed before and after each session. An electromyography system was used to evaluate muscle activity of both the gluteus maximus (Gmax) and quadriceps femoris (Quad) muscles in synchronization with the Vicon motion capture system. The International Standards for Neurological and Functional Classification of Spinal Cord Injury (ISNCSCI) motor scores of the lower extremities and the Walking Index for Spinal Cord Injury II (WISCI II) score were also assessed to evaluate motor function. The HAL® intervention improved gait speed and cadence during the 10MWT. Before the intervention, both the Gmax and left Quad muscles were not activated. After the intervention, the right Gmax and both Quad muscles were activated in stance phase rhythmically according to the gait cycle. The ISNCSCI motor score also improved from 14 to 16, and the WISCI II scored improved from 7 to 12. Conclusion/clinical relevance: Our experience with this patient suggests that the HAL® can be an effective tool for improving functional ambulation in patients with chronic spinal cord injury.

Improvement of Walking Ability Using Hybrid Assistive Limb Training ina Patient with Severe Thoracic Myelopathy caused by Ossification of thePosterior Longitudinal Ligament - A Case Report

The purpose of this study was to report the improvement of walking ability using Hybrid Assistive Limb (HAL) training in a case of severe thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). The patient received HAL training 2-3 times per week (10 sessions) beginning on the thirteenth postoperative day. The patient’s walking ability and lower muscles strength were significantly improved. It suggests that HAL training in the early postoperative phase has the potential to be an effective rehabilitation tool to improve functional ambulation in surgically-treated thoracic OPLL patients with inability of walk.

Active elbow flexion is possible in C4 quadriplegia using hybrid assistive limb (HAL®) technology: A case study

Context: Patients with complete quadriplegia after high cervical spinal cord injury are fully dependent with activities of daily living. Assistive technology can improve their quality of life. We examined the use of a hybrid assistive limb for single joints (HAL-SJ) in a 19-year-old man with complete C4 quadriplegia due to chronic spinal cord injury to restore function of active elbow flexion. This is the first report on the use of the HAL-SJ in a patient with spinal cord injury. Findings: The HAL-SJ intervention for each elbow was administered in 10 sessions. Clinical assessment using surface EMG was conducted to evaluate muscle activity of the trapezius, biceps brachii, infraspinatus, and triceps brachii muscle before, and during the 2nd, 3rd, 6th, and 9th interventions. Surface electromyography (EMG) before intervention showed no contraction in the upper arms, but in the bilateral trapezius. The HAL-SJ used motion intention from the right trapezius for activation. After the 6th and 7th session, respectively, biceps EMG showed that voluntary contraction and right elbow flexion could be performed by motion intention from the right biceps. After the 10th session, voluntary bicep contraction was possible. HAL-SJ treatment on the left elbow was performed using the same protocol with a similar outcome. After completing treatment on both upper extremities, both biceps contracted voluntarily, and he could operate a standard wheelchair for a short distance independently. Conclusion: HAL-SJ intervention is feasible and effective in restoring elbow flexor function in a patient with C4 chronic spinal cord injury and complete quadriplegia.