Kenichi Yoshikawa

Gait training of subacute stroke patients using a hybrid assistive limb: a pilot study

Abstract Purpose To determine whether gait training with a hybrid assistive limb (HAL) as an exoskeleton robotic device was safe and could increase functional mobility and gait ability in subacute stroke patients. Methods The participants were eight patients with post-stroke hemiparesis whose walking impairment and gait recovery curves had plateaued. The intervention program was gait training using HAL and a walker for 20 min daily 5 days a week for 5 weeks. The 10-m maximum walking speed (MWS), self-selected walking speed (SWS) and 2-min-walk test (2MT) without HAL were used as primary outcome measures to determine the effects of training. The Berg Balance Scale (BBS), Fugl-Meyer Assessment of Motor Recovery after Stroke (FMA) and functional ambulation category (FAC) were assessed as secondary outcomes. These measures were assessed before and after the 5-week intervention program and were analyzed statistically using a paired t-test. Results All eight participants completed the intervention program with no adverse events. There were significant increases in MWS, SWS and 2MT. BBS, FMA and FAC also increased, but not significantly. Conclusion The new HAL exoskeleton robotic device was efficient and safe for improving motor function and gait in patients in the subacute stage after stroke. Implications for Rehabilitation Gait training using HAL will improve gait ability of individuals with post stroke. The HAL achieve intensive gait training without increase spasticity and abnormal gait pattern.

Gait training with Hybrid Assistive Limb enhances the gait functions in subacute stroke patients: A pilot study

BACKGROUND The robotic Hybrid Assistive Limb (HAL) provides motion according to the wearers voluntary activity. HAL training effects on walking speed and capacity have not been clarified in subacute stroke. OBJECTIVES To determine improvement in walking ability by HAL and the most effective improvement measure for use in future large-scale trials. METHODS Sixteen first-ever hemiplegic stroke patients completed at least 20 sessions over 5 weeks. Per session, the experimental group received no more than 20 min of gait training with HAL (HT) and 40 min of conventional physiotherapy, whereas the control group received at least 60 min of conventional physiotherapy. Primary outcome was maximum walking speed (MWS). RESULTS The change in MWS from baseline at week 5 was 11.6±10.6 m/min (HAL group) and 2.2±4.1 m/min (control group) (adjusted mean difference = 9.24 m/min, 95% confidence interval 0.48-18.01, P = 0.040). In HAL subjects there were significant increases in Self-selected walking speed (SWS; a secondary outcome) and in step length (a secondary outcome) at MWS and SWS compared with controls. CONCLUSIONS HT improved walking speed in hemiplegic sub-acute stroke patients. In future, randomized controlled trials are needed to confirm the utility of HT.

Immediate effects of a single session of robot-assisted gait training using Hybrid Assistive Limb (HAL) for cerebral palsy

[Purpose] Robot-assisted gait training (RAGT) using Hybrid Assistive Limb (HAL, CYBERDYNE) was previously reported beneficial for stroke and spinal cord injury patients. Here, we investigate the immediate effect of a single session of RAGT using HAL on gait function for cerebral palsy (CP) patients. [Subjects and Methods] Twelve patients (average age: 16.2 ± 7.3 years) with CP received a single session of RAGT using HAL. Gait speed, step length, cadence, single-leg support per gait cycle, hip and knee joint angle in stance, and swing phase per gait cycle were assessed before, during, and immediately after HAL intervention. [Results] Compared to baseline values, single-leg support per gait cycle (64.5 ± 15.8% to 69.3 ± 12.1%), hip extension angle in mid-stance (149.2 ± 19.0° to 155.5 ± 20.1°), and knee extension angle in mid-stance (137.6 ± 20.2° to 143.1 ± 19.5°) were significantly increased immediately after intervention. Further, the knee flexion angle in mid-swing was significantly decreased immediately after treatment (112.0 ± 15.5° to 105.2 ± 17.1°). Hip flexion angle in mid-swing also decreased following intervention (137.2 ± 14.6° to 129.7 ± 16.6°), but not significantly. Conversely, gait speed, step length, and cadence were unchanged after intervention. [Conclusion] A single-time RAGT with HAL improved single-leg support per gait cycle and hip and knee joint angle during gait, therapeutically improving gait function in CP patients.

The Training Effect of Early Intervention with a Hybrid Assistive Limb after Total Knee Arthroplasty

After total knee arthroplasty (TKA), it is important for patients to show early improvements in knee joint function and walking to regain independence in performing the activities of daily life. We conducted for 4 weeks an intervention one week after TKA using a hybrid assistive limb (HAL: unilateral leg type) as an exoskeleton robotic device to facilitate knee joint function and walking. The intervention improved the range of knee extension movement safely and without pain compared to preoperation. In addition, we found that training with the HAL improved walking ability, speed, and rate, as well as the time taken to perform the timed up and go (TUG) test compared to preoperation. The strength of the quadriceps muscle did not improve with training; however, the patient was able to induce a knee extensor moment during the initial stance phase, as measured by kinetics and kinematics, and these actions could be performed without pain. HAL training soon after TKA improved knee joint function in a 76-year-old patient who presented with OA of the knee. The improvements in knee extension lag and knee extensor moment allowed the patient to walk without pain and regain ADL in comparison with preoperation.

Proposal of bioinstrumentation using shape deformation of amputated upper limb

Some upper limb amputees have been annually supplied with myoelectric prostheses by social rehabilitation promotion services. However, the persons supplied with the prostheses have been limited because a supply system has not been established yet. Accordingly, we propose a new bioinstrumentation using the shape deformation of the amputated upper limbs without using the myoelectricity generated on the skin of the upper limbs. The repeatability is superior to the myoelectricity because the shape deformation is directly measured by strain gages and also the cost is much superior to the myoelectricity.

Proposal of bioinstrumentation using flex sensor for amputated upper limb

We previously proposed a new bioinstrumentation using the shape deformation of the amputated upper limbs without using the myoelectricity generated on the skin of the upper limbs. However many electronic parts were required owing to a bridge circuit and multi-amplifier circuits so as to amplify a tiny voltage of strain gages. Moreover, the surplus heat might occur by the overcurrent owing to low resistance value of strain gages. Therefore, in this study, we apply a flex sensor to this system instead of strain gages to solve the above problems.

Safety and immediate effect of gait training using a Hybrid Assistive Limb in patients with cerebral palsy

[Purpose] This study aimed to determine the safety and immediate effect of a single training session with the Hybrid Assistive Limb (CYBERDYNE) on walking ability in patients with cerebral palsy. [Participants and Methods] This study included 20 patients with cerebral palsy (15 males, 5 females, mean age 15.0 ± 6.3 years; 19 with spastic cerebral palsy, 1 with athetoid cerebral palsy; Gross Motor Function Classification System level I: 4, II: 3, III: 9, and IV: 4). Participants completed a single 20-minute gait training session using the Hybrid Assistive Limb. The safety and immediate effect were evaluated. The immediate outcomes were gait speed and mean step length, and cadence before and after training. [Results] Two participants were excluded because they were not tall enough to use the Hybrid Assistive Limb. Eighteen participants performed the training. There were no serious adverse events during the training. Since 14 participants were able to walk on their own, walking evaluations were performed before and after training. Statistically significant improvements were observed in gait speed and mean step length. [Conclusion] Gait training using the Hybrid Assistive Limb is safe for patients with cerebral palsy and can produce immediate effects on walking ability in ambulatory patients with cerebral palsy.

Long-term sustained effect of gait training using a hybrid assistive limb on gait stability via prevention of knee collapse in a patient with cerebral palsy: a case report

[Purpose] The hybrid assistive limb was developed to improve the kinematics and muscle activity in patients with neurological and orthopedic conditions. The purpose of the present study was to examine the long-term sustained effect of gait training using a hybrid assistive limb on gait stability, kinematics, and muscle activity by preventing knee collapse in a patient with cerebral palsy. [Participant and Methods] A 17 year-old male with cerebral palsy performed gait training with a hybrid assistive limb 12 times in 4 weeks. After completion of 12 sessions of hybrid assistive limb training, monthly follow-up was conducted for 8 months. The improvement was assessed on the basis of joint angle and muscle activity during gait. [Results] The degree of knee collapse observed at baseline was improved at 8-month follow-up. Regarding muscle activity, electromyography revealed increased activation of the vastus lateralis at 8-month follow-up. Moreover, the hip and knee angles were expanded during gait. In particular, the knee extension angle at heel contact was increased at 8 months after follow-up. [Conclusion] Gait training with a hybrid assistive limb provided improvement of gait stability such as kinematics and muscle activity in a patient with cerebral palsy. The improved gait stability through prevention of knee collapse achieved with hybrid assistive limb training sustained for 8 months.

Robot-assisted training using Hybrid Assistive Limb® for cerebral palsy

PURPOSE The Hybrid Assistive Limb® (HAL®, CYBERDYNE) is a wearable robot that provides assistance to a patient while they are walking, standing, and performing leg movements based on the wearers intended movement. The effect of robot-assisted training using HAL® for cerebral palsy (CP) is unknown. Therefore, we assessed the effect of robot-assisted training using HAL® on patients with CP, and compared walking and gross motor abilities between pre-intervention and post-intervention. METHODS Six subjects with CP were included (mean age: 16.8 years; range: 13-24 years; Gross Motor Function Classification System levels II-IV: n = 1, 4, 1). Robot-assisted training using HAL® were performed 2-4 sessions per week, 20 min per session, within a 4 weeks period, 12 times in total. Outcome measures included gait speed, step length, cadence, single-leg support per gait cycle, hip and knee joint angle in stance, and swing phase per gait cycle, 6-minute walking distance (6 MD), physiological cost index (PCI), knee-extension strength, and Gross Motor Function Measure (GMFM). RESULTS There were significant increases in self-selected walking speed (SWS), cadence during SWS and maximum walking speed (MWS), single-leg support per gait cycle, hip joint angle in the swing phase, 6 MD, and GMFM. In contrast, gait speed during MWS, step length during SWS and MWS, hip and knee joint angle in the stance phase, knee joint angle in the swing phase, PCI, and knee-extension strength generally improved, but not significantly. CONCLUSION Robot-assisted training using HAL® may improve walking and gross motor abilities of patients with CP.

Use of Hybrid Assistive Limb (HAL ® ) for a postoperative patient with cerebral palsy: a case report

BackgroundThe Hybrid Assistive Limb (HAL®) is an exoskeleton wearable robot suit that assists in voluntary control of knee and hip joint motion. There have been several studies on HAL intervention effects in stroke, spinal cord injury, and cerebral palsy. However, no study has investigated HAL intervention for patients with cerebral palsy after surgery.Case presentationWe report a case of using HAL in a postoperative patient with cerebral palsy. A 15-year-old boy was diagnosed with spastic diplegia cerebral palsy Gross Motor Function Classification System level IV, with knee flection contracture, equinus foot, and paralysis of the right upper extremity with adduction contracture. He underwent tendon lengthening of the bilateral hamstrings and Achilles tendons. Although the flexion contractures of the bilateral knees and equinus foot improved, muscle strength decreased after the soft tissue surgery. HAL intervention was performed twice during postoperative months 10 and 11. Walking speed, stride, and cadence were increased after HAL intervention. Post HAL intervention, extension angles of the knee in stance phase and hip in the pre-swing phase were improved. In the gait cycle, the proportion of terminal stance in the stance and swing phase was increased.ConclusionsHybrid Assistive Limb intervention for postoperative patients with cerebral palsy whose muscle strength decreases can enhance improvement in walking ability. Further studies are needed to examine the safety and potential application of HAL in this setting.