A Brake-Based Overground Gait Rehabilitation Device for Altering Propulsion Impulse Symmetry.

Siyao Hu,Krista Fjeld,Erin V Vasudevan,Katherine J Kuchenbecker

doi:10.3390/s21196617

Abstract

This paper introduces a new device for gait rehabilitation, the gait propulsion trainer (GPT). It consists of two main components (a stationary device and a wearable system) that work together to apply periodic stance-phase resistance as the user walks overground. The stationary device provides the resistance forces via a cable that tethers the user’s pelvis to a magnetic-particle brake. The wearable system detects gait events via foot switches to control the timing of the resistance forces. A hardware verification test confirmed that the GPT functions as intended. We conducted a pilot study in which one healthy adult and one stroke survivor walked with the GPT with increasing resistance levels. As hypothesized, the periodic stance-phase resistance caused the healthy participant to walk asymmetrically, with greatly reduced propulsion impulse symmetry; as GPT resistance increased, the walking speed also decreased, and the propulsion impulse appeared to increase for both legs. In contrast, the stroke participant responded to GPT resistance by walking faster and more symmetrically in terms of both propulsion impulse and step length. Thus, this paper shows promising results of short-term training with the GPT, and more studies will follow to explore its long-term effects on hemiparetic gait.

Highlights

Published: 5 October 2021Mobility impairments are a frequent cause of stroke-related disability: among ischemic stroke survivors 65 years and older, half reported hemiparesis persisting six months post-stroke, and 30% were unable to walk without assistance [1].Difficulty with functional movements like gait can lead to physical deconditioning poststroke, which contributes to poor cardiovascular fitness, muscular atrophy, and metabolic syndrome [2]
Propulsion asymmetry between the two legs is negatively correlated with walking speed and functional mobility; improvements in propulsion asymmetry with training are associated with improvements in walking speed [8,11,12]. These findings suggest that targeting propulsion asymmetry during gait training is a promising approach for improving functional mobility after stroke, we note that the reported speed increase is typically in post-intervention conditions and not during intervention [8,10]
The results show that our approach induces greater propulsion impulse contribution from the resisted side for the healthy participant and from the paretic side for the stroke participant, as hypothesized

Summary

Introduction

Difficulty with functional movements like gait can lead to physical deconditioning poststroke, which contributes to poor cardiovascular fitness, muscular atrophy, and metabolic syndrome [2]. These effects can increase the risk of a second stroke or cardiovascular event [2]. There are several training strategies aimed at increasing walking function after stroke [4,5]. Many strategies appear to deliver comparable outcomes and may not result in meaningful gains in walking speed [6]. Propulsion asymmetry after stroke was identified as a functionally limiting gait deficit that is correlated with walking speed [7,8,9,10]

Objectives

Methods

Results

Discussion

Conclusion