Real-time foot clearance biofeedback to assist gait rehabilitation following stroke: a randomized controlled trial protocol

Stroke affects > 60,000 Australians every year, with 50% unable to walk one week following the event [1]. Impaired walking impacts independence by reducing the ability to perform everyday activities and limiting community participation [2, 3]. Falls risk is significantly higher in people with chronic stroke [4] and approximately 50% of people living at home after a stroke will fall within 12 months [9], with up to half sustaining multiple falls. Furthermore, in community-dwelling people with stroke, up to 77% of falls occurred during walking. While there has been considerable research investigating falls risk management for older people generally, high-risk groups, such as those who have had a stroke, have not been extensively studied with respect to targeted falls prevention. Traditional exercise-based falls-prevention programs are useful for the general older adult community but are not effective in people with stroke. For example, Batchelor et al. found that a multifactorial intervention including a home-based balance and strength program did not reduce falls in people with stroke [10]. Another study confirmed that a group- and home-based exercise program incorporating balance and strength training did not reduce falls [11]. This suggests that alternative, targeted treatments to reduce falls risk in people with stroke are urgently needed.

Stroke adversely affects sensorimotor function and muscle strength, inhibiting the capacity to activate appropriate muscles and increasing the risk of contact between the foot and either the supporting surface or objects on it. Said et al. [15] found, for example, that stroke participants who had difficulty in stepping over small obstacles (4 cm high) had greater falls rates. The key gait variable for predicting tripping-falls is minimum toe clearance (MTC), an event mid-swing in the walking cycle [5‐8]. Low MTC increases the probability of unanticipated foot-ground contacts [7]. Given that tripping directly results from unsuccessful toe clearance, previous research with both young and older populations has focused on toe trajectory control during walking [6‐8, 12‐14]. Training individuals to increase MTC, therefore, has potential as a falls-prevention intervention.

The primary objective is to determine whether real-time biofeedback of MTC during gait training will significantly increase MTC in people with stroke. We will also determine whether changes in MTC achieved on a treadmill transfer to overground walking. It is hypothesized that, compared to no-biofeedback training, visual biofeedback of foot clearance parameters during gait training will significantly increase toe-ground clearance (MTC) and MTC during biofeedback training will be retained in the longer term. It is also hypothesized that increases in MTC demonstrated in treadmill training will transfer to overground walking, such that tripping-risk in people with stroke is significantly reduced.

This single-blinded parallel group RCT with 1:1 randomization will assess the effects of biofeedback on MTC following gait training. It will conform to CONSORT guidelines and has been registered on the Australian and New Zealand Clinical Trials Registry (ANZCTR): ACTRN12617000250336. Ethics approval for the study was obtained from Austin Health, Melbourne Health, and Victoria University Human Research Ethics Committees. Informed consent procedures include the provision that participants clearly understand that they are free to withdraw at any time without providing a reason. The study design flowchart is shown in Fig. 1.

This innovative study will evaluate the impact of augmented sensory information for improving gait function, specifically foot-ground clearance, via visually presented biofeedback. The research findings will contribute to the broader falls prevention initiative by demonstrating the effectiveness of toe clearance biofeedback in making walking safer. It will also confirm whether faded feedback enhances learning by demonstrating how performance is affected immediately following training and whether it can be retained in the long term. If shown to be effective, there will be opportunities for biofeedback-training applications to other gait-impaired clinical populations. The project’s findings will contribute to understanding how stroke-related changes to sensory and motor processes influence the tripping risks of everyday walking. The protocol is, however, limited to people with chronic stroke capable of walking on a treadmill due to the continuous real-time feedback used for gait training.

Recruitment began on 27 April 2017 with Protocol Version 6 dated 16 September 2016. Protocol Version 8 dated 20 June 2018 is currently in use following minor amendments not affecting the implementation of the project protocol. Recruitment is expected to be completed by 31 December 2020. Any important protocol modifications will be formally communicated to relevant parties by the chief investigator and the Protocol Version updated.