Cybernic treatment with wearable cyborg Hybrid Assistive Limb (HAL) improves ambulatory function in patients with slowly progressive rare neuromuscular diseases: a multicentre, randomised, controlled crossover trial for efficacy and safety (NCY-3001)

Abstract

Background: Rare neuromuscular diseases such as spinal muscular atrophy, spinal bulbar muscular atrophy, muscular dystrophy, Charcot-Marie-Tooth disease, distal myopathy, sporadic inclusion body myositis, congenital myopathy, and amyotrophic lateral sclerosis lead to incurable amyotrophy and consequent loss of ambulation. Thus far, no therapeutic approaches have been successful in recovering the ambulatory ability. Thus, the aim of this trial was to evaluate the efficacy and safety of cybernic treatment with a wearable cyborg Hybrid Assistive Limb (HAL, Lower Limb Type) in improving the ambulatory function in those patients.

Results: We conducted an open-label, randomised, controlled crossover trial to test HAL at nine hospitals between March 6, 2013 and August 8, 2014. Eligible patients were older than 18 years and had a diagnosis of neuromuscular disease as specified above. They were unable to walk for 10 m independently and had neither respiratory failure nor rapid deterioration in gait. The primary endpoint was the distance passed during a two-minute walk test (2MWT). The secondary endpoints were walking speed, cadence, and step length during the 10-m walk test (10MWT), muscle strength by manual muscle testing (MMT), and a series of functional measures. Adverse events and failures/problems/errors with HAL were also evaluated. Thirty patients were randomly assigned to groups A or B, with each group of 15 receiving both treatments in a crossover design. The efficacy of a 40-min walking program performed nine times was compared between HAL plus a hoist and a hoist only. The final analysis included 13 and 11 patients in groups A and B, respectively. Cybernic treatment with HAL resulted in a 10.066% significantly improved distance in 2MWT (95% confidence interval, 0.667-19.464; p = 0.0369) compared with the hoist only treatment. Among the secondary endpoints, the total scores of MMT and cadence at 10MWT were the only ones that showed significant improvement. The only adverse effects were slight to mild myalgia, back pain, and contact skin troubles, which were easily remedied.

Conclusions: HAL is a new treatment device for walking exercise, proven to be more effective than the conventional method in patients with incurable neuromuscular diseases.

Trial registration: JMACTR, JMA-IIA00156.

Keywords: Cybernics; Gait exercise; Hybrid Assistive Limb (HAL); Neuromuscular disease.

Fig. 1

Trial schedule used to test the effectiveness of the Hybrid Assistive Limb (HAL). V, visit

Fig. 2

Photographs showing the use of mobile hoist and HAL-HN01 in control and cybernic treatments. A Control treatment (treatment 1), patient in hoist only. B Cybernic treatment (treatment 2), patient in hoist + wearing HAL

Fig. 3

Overview of the trial for the efficacy and safety of the Hybrid Assistive Limb (HAL)

Fig. 4

Rate of change for the two-minute walk test (2MWT) for all participants. This figure shows the rate of change (%) in the primary endpoint, the 2MWT, between the treatment 1 (control, white bars) and treatment 2 (HAL, black bars), as well as the therapeutic positive effect (stripe bar) of cybernic treatment (black bar- white bar: -d_A or d_B) for group A or B. Group (A or B) and patient number are also shown. Asterisks (*) indicate the outpatient status during the study period. The order of treatments 1 and 2 was randomly determined by crossover design. Patients in the graph are displayed in order of the magnitude of the effect of treatment 2