The Effect of Perturbation-Based Balance Training and Conventional Intensive Balance Training on Reactive Stepping Ability in Individuals With Incomplete Spinal Cord Injury or Disease: A Randomized Clinical Trial

Abstract

Introduction: Impaired balance leads to falls in individuals with motor incomplete spinal cord injury or disease (iSCI/D). Reactive stepping is a strategy used to prevent falls and Perturbation-based Balance Training (PBT) can improve this ability. Objective: The objective of this study was to determine if PBT results in greater improvements in reactive stepping ability than frequency-matched Conventional Intensive Balance Training (CIBT) in adults with iSCI/D. Design: Randomized clinical trial. Setting: Tertiary SCI/D rehabilitation center. Participants: Twenty-one adults with chronic (>1 year) iSCI/D were randomized. Due to one drop out 20 participants completed the study. Methods: Participants were randomly allocated to complete either PBT or CIBT three times per week for 8 weeks. Both programs included challenging static and dynamic balance tasks, but the PBT group also experienced manual external balance perturbations. Main Outcome Measures: Assessments of reactive stepping ability using the Lean-and-Release test were completed at baseline, and after 4 and 8 weeks of training, and 3 and 6 months after training completion. A blinded assessor evaluated secondary outcomes. Results: Twenty-five participants were screened and 21 consented; one withdrew. Ten PBT and 10 CIBT participants were included in analyses. Across all participants there were improvements in reactive stepping ability (p = 0.049), with retention of improvements at follow up assessments. There were no differences in reactive stepping ability between groups [median (interquartile range): PBT 0.08 (0.68); CIBT 0.00 (0.22)]. One participant in the PBT group experienced a non-injurious fall during training. Conclusions: Balance training is beneficial for individuals with iSCI/D, but the addition of manual perturbations (i.e., PBT) did not prove advantageous for performance on a measure of reactive stepping ability. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT02960178.

Keywords: balance; fall prevention; postural control; randomized clinical trial; rehabilitation; spinal cord injury.

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2021 Unger, Chan, Lee, Craven, Mansfield, Alavinia, Masani and Musselman.

Figures

Figure 1

CONSORT flow diagram depicting the flow of participants through the study.

Figure 2

Balance reactions during training. The mean (standard deviation) number of balance reactions that occurred during training for both the PBT and CIBT groups. According to independent t-tests, the number of single step and multi-step reactions were different between the two groups, but there were no differences in the number of trials where assistance was needed to recover. *p < 0.05.

Figure 3

Gardner-Altman estimation plots for the clinical measures. (A) Behavioral Responses of the Lean-and-Release test and (B) Mini-BESTest. The median differences between the PBT and CIBT groups are represented in the Gardner-Altman estimation plots. Both groups' scores are plotted on the left axis and the median difference is plotted on the right axis as a bootstrap sampling distribution. The median difference and 95% confidence intervals are represented by the bold black dot and line, respectively. Figure developed from (50).

Figure 4

Gardner-Altman estimation plots for self-report measures (A) ABC Scale and (B) FES-I. The mean differences between the PBT and CIBT groups are shown in the Gardner-Altman estimation plots. Both groups' scores are plotted on the left axis and the mean difference is plotted on the right axis as a bootstrap sampling distribution. The mean difference and 95% confidence intervals are represented by the bold black dot and line, respectively. Figure developed from (50).

Figure 5

Kaplan-Meier Curve. This Kaplan-Meier curve represents the time to first fall for both the CIBT and PBT groups, participants who did not experience any falls during the 6 month follow up period are labeled as censored events. Although the p-value of 0.13 indicates there is no difference between groups, this curve shows the CIBT group experienced, on average, their first fall sooner than the PBT group.