Perturbation-based gait training to improve daily life gait stability in older adults at risk of falling: protocol for the REACT randomized controlled trial

Abstract

Background: The European population is rapidly ageing. There is an urgent need for innovative solutions to reduce fall risk in older adults. Perturbation-based gait training is a promising new method to improve reactive balance responses. Whereas positive effects on task-specific dynamic balance recovery during gait have been shown in clinical or laboratory settings, translation of these effects to daily life gait function and fall risk is limited. We aim to evaluate the effect of a 4-week perturbation-based treadmill training on daily-life dynamic gait stability, assessed with inertial sensor data. Secondary outcomes are balance recovery performance, clinical balance and gait assessment scores, the amount of physical activity in daily life and falls incidence during 6 months follow-up. Methods: The study is a monocenter assessor-blinded randomized controlled trial. The target study sample consists of 70 older adults of 65 years and older, living in the community and with an elevated risk of falling. A blockrandomization to avoid seasonal effects will be used to allocate the participants into two groups. The experimental group receives a 4-week, two times per week perturbation-based gait training programme on a treadmill, with simulated slips and trips, in combination with cognitive dual tasks. The control group receives a 4-week, two times per week treadmill training programme under cognitive dual-task conditions without perturbations. Participants will be assessed at baseline and after the 4-weeks intervention period on their daily-life gait stability by wearing an inertial sensor on the lower back for seven consecutive days. In addition, clinical balance and gait assessments as well as questionnaires on falls-and gait-efficacy will be taken. Daily life falls will be followed up over 6 months by a fall calendar. Discussion: Whereas perturbation-based training has shown positive effects in improving balance recovery strategies and in reducing laboratory falls, this study will contribute to investigate the translation of perturbationbased treadmill training effects in a clinical setting towards improving daily life gait stability and reducing fall risk and falls.

Promoting Generalized Learning in Balance Recovery Interventions

“…In PBT, the notion of a ‘challenge’ can be framed in several ways. This includes manipulating training factors such as (a) the parameters of the perturbation, (b) the complexity of the environment in which responses must be made, and (c) multi-tasking (both motor and cognitive) [ 33 , 65 , 66 ]. From these factors, the challenge can be increased, for example, by gradually imposing a larger perturbation over time.…”

“…In this case, one could imagine graduating from a small perturbation to a more forceful perturbation, where the former is manageable via a feet-in-place reaction and the latter requires a change of support to prevent a fall [ 7 , 25 ]. Alternatively, the direction and/or predictability of the perturbation could be adjusted [ 66 ]. Beyond the issue of how the perturbation is delivered, features of the environment can be altered to make conditions more or less difficult to regain balance.…”

“…To illustrate, forcing someone to walk faster than their preferred pace can challenge their capacity to recover balance in the event of a postural disturbance [ 70 ]. Lastly, the introduction of a secondary cognitive task [ 66 ], distracting sensory stimuli [ 71 ], reduced lighting [ 72 ], or concurrent engagement in a separate motor task (e.g., carrying groceries) [ 73 ], are all factors that influence gait and posture, and can all be used to increase task-specific transfer [ 74 ]. It is notable that such manipulations also tend to amplify cognitive burden [ 66 , 75 ].…”

“…Lastly, the introduction of a secondary cognitive task [ 66 ], distracting sensory stimuli [ 71 ], reduced lighting [ 72 ], or concurrent engagement in a separate motor task (e.g., carrying groceries) [ 73 ], are all factors that influence gait and posture, and can all be used to increase task-specific transfer [ 74 ]. It is notable that such manipulations also tend to amplify cognitive burden [ 66 , 75 ]. In broad terms, when we discuss the idea of task variation in PBT, it could involve introducing any of these elements alone or in combination.…”

“…Similar to any motor skill training program, there are key elements that contribute to outcome success. The initial level of PBT challenge should be tailored to the individual through baseline assessment, and then challenge of the task can be adjusted to keep pace with an individual’s progress [ 33 , 65 , 66 ]. To maximize participant adherence and engagement, training must be challenging, but also motivating and enjoyable [ 76 , 77 , 78 , 79 ].…”