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.

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 wearer's 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.

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.

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 wearer's 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.

Effect of Visuo-Motor Co-location on 3D Fitts' Task Performance in Physical and Virtual Environments.

Given the ease that humans have with using a keyboard and mouse in typical, non-colocated computer interaction, many studies have investigated the value of co-locating the visual field and motor workspaces using immersive display modalities. Significant understanding has been gained by previous work comparing physical tasks against virtual tasks, visuo-motor co-location versus non-colocation, and even visuo-motor rotational misalignments in virtual environments (VEs). However, few studies have explored all of these paradigms in context with each other and it is difficult to perform inter-study comparisons because of the variation in tested motor tasks. Therefore, using a stereoscopic fish tank display setup, the goal for the current study was to characterize human performance of a 3D Fitts' point-to-point reaching task using a stylus-based haptic interface in the physical, co-located/non-colocated, and rotated VE visualization conditions.Five performance measures - throughput, initial movement error, corrective movements, and peak velocity - were measured and used to evaluate task performance. These measures were studied in 22 subjects (11 male, 11 female, ages 20-32) performing a 3D variant of Fitts' serial task under 10 task conditions: physical, co-located VE, non-colocated VE, and rotated VEs from 45-315° in 45° increments. HYPOTHESES: All performance measures in the co-located VE were expected to reflect significantly reduced task performance over the real condition, but also reflect increased performance over the non-colocated VE condition. For rotational misalignments, all performance measures were expected to reflect highest performance at 0°, reduce to lowest performance at 90° and rise again to a local maximum at 180° (symmetric about 0°). RESULTS: All performance measures showed that the co-located VE condition resulted in significantly lower task performance than the physical condition and higher mean performance than the non-colocated VE condition, but the difference was not statistically significant. Also, rotation misalignments showed that task performance were mostly reduced to minimums at 90°, 135°, and 225°. We conclude that co-located VEs may not significantly improve point-to-point reaching performance over non-colocated VEs. Also, visual rotations of ±45° affected throughput, efficiency, peak velocity, and initial movement error, but the number of corrective movements were not affected until ±90°.

Effect of Visuo-Haptic Co-location on 3D Fitts' Task Performance.

Given the ease that humans have with using a keyboard and mouse in typical, non-colocated computer interaction, many studies have investigated the value of colocating the visual field and haptic workspaces using immersive virtual reality (VR) modalities. Significant understanding has been gained by previous work comparing physical tasks against VR tasks, visuo-haptic co-location versus non-colocation, and even visuo-haptic rotational misalignments in VR. However, few studies have explored all of these paradigms in context with each other and it is difficult to do inter-study comparisons because of the variation in tested motor tasks. Therefore, the goal for the current study was to characterize human performance of Fitts' point-to-point reaching task - an established test of manual performance - in the physical, co-located/non-colocated VR, and rotated VR visualization conditions. A key finding was the significant decrease observed in end-point error for tasks performed in a co-located virtual reality environment. The results also showed cyclic performance degradations due to rotational visuo-haptic misalignments that were consistent with trends reported by the literature.