# Gait Rehabilitation Using Hybrid Assistive Limb in Patients With Lower Limb Amputation: Protocol for a Single-Arm Clinical Trial

## TL;DR

This study tests a new rehabilitation protocol using a robotic exoskeleton to help lower limb amputees regain walking ability faster.

## Contribution

This is the first study to evaluate early gait training with the Hybrid Assistive Limb (HAL) in lower limb amputation patients.

## Key findings

- HAL-assisted gait training may improve walking ability and daily living activities in amputees.
- Early use of HAL could shorten recovery time and reduce medical costs.
- Results will be compared at baseline, post-intervention, and 6-month follow-up.

## Abstract

Lower limb amputation rates are increasing owing to aging and vascular diseases. However, no standardized rehabilitation protocol has been established for regaining walking ability. Conventional rehabilitation delays prosthetic gait training until 6-8 weeks post amputation, prolonging recovery and increasing medical expenses.

This study aims to evaluate the impact of neurorehabilitation using the Hybrid Assistive Limb (HAL) for Medical Use Lower Limb Type, developed by Japan's Tsukuba University and the robotics company Cyberdyne, on gait acquisition, improvement in activities of daily living (ADL), and enhancement of quality of life (QOL) in patients with lower limb amputation, and assess the effectiveness of early HAL-assisted gait training before and after amputation.

This single-arm trial will include 20 patients undergoing unilateral transfemoral or transtibial amputations. HAL-assisted gait training will be performed 5 days per week (30 minutes per session) until postoperative week 8. The primary outcome is a 2-minute walking distance, while secondary outcomes include muscle strength, balance, gait parameters, and ADL/QOL measures. Statistical analyses will be conducted using SPSS (IBM Corp), and results obtained at the following time points will be compared: preoperative, postintervention, and 6-month follow-up.

The planned sample size is 20 patients, calculated using JMP version 12 (SAS Institute) based on an expected 1.5-fold improvement in 6-minute walk distance (effect size 0.8, α=.05, power=0.8). Analyses will be performed using SPSS version 15.0 (IBM Corp). The 2-minute walk test (primary outcome) and secondary outcomes will be compared at baseline, post intervention, and 6-month follow-up using 1-way analysis of variance or Kruskal-Wallis test, and P values <.05 and 95% CIs will be reported.

This is the first study to apply HAL-assisted neurorehabilitation to patients with lower limb amputations. Early gait training may increase prosthetic gait acquisition rates, shorten rehabilitation and hospitalization periods, and reduce medical costs. If effective, this study may contribute to the development of a Japan-originated rehabilitation program and provide clinical evidence supporting broader HAL implementation for patients with lower limb amputations.

Japan Registry of Clinical Trials jRCTs062200031; https://jrct.mhlw.go.jp/latest-detail/jRCTs062200031

PRR1-10.2196/76509