Feedback-based perturbation balance training during stationary cycling improves reactive and proactive balance among older adults: a single-blinded randomised controlled trial

Abstract

Background: Perturbation balance training (PBT) is an effective regime that reduces fall rates by triggering and improving balance recovery skills. Controlling trunk movements consistently reflects effective reactive stepping, as it enhances proximal stability, providing a stable base for limb movements.

Objective: To demonstrate the effect of PBT during seated hands-free stationery cycling on objective balance parameters of reactive and proactive balance control in standing.

Design: Two-arm parallel-group, single-blinded randomised controlled trial with concealed allocation, blinded assessors and data analysers, with intention-to-treat analyses.

Participants: Fifty-six community-dwelling older adults, 70+ years of age (mean ± standard deviation: 76.43 ± 4.76 years, 39.3% of men and 60.7% of women), walking independently without assistive devices.

Interventions: The two groups performed twenty sessions of seated stationary cycling, 20 minutes each, over 12 weeks, while performing concurrent cognitive tasks: (i) cycling hands free, received perturbations with real-time implicit sensorimotor feedback (PBT during hands-free stationary cycling, n = 29); (ii) standard cycling training (SCT, n = 27) cycled using hands without perturbations.

Outcome measures: The primary outcome measures were the reactive balance measures in standing, e.g. single-step threshold, multiple-step threshold and the probability of stepping. Secondary outcomes were voluntary stepping Test and 6-Minute Walk Test (6MWT). Measures were taken at baseline and immediately postinterventions.

Results: The group-by-time interactions indicate that PBT during hands-free stationary cycling improved balance reactive responses i.e. increased single- and multiple-step thresholds in mediolateral perturbations (P = .001, effect size [ES] = 0.88, and P = .001, ES = 0.64, respectively) and multiple-step threshold in anteroposterior perturbations (P = .022, ES = 0.34) and decreased the probability of stepping compared to standard cycling training. PBT during hands-free stationary cycling also resulted in faster voluntary step reaction (P = .011, ES = -0.84) and foot contact times (P = .037, ES = -0.56). Both groups significantly improved their 6MWT results.

Conclusion: Feedback-based PBT during hands-free stationary cycling has the potential to improve reactive and proactive balance measures in standing.

Registration: clinicaltrials.gov, NCT03636672, https://clinicaltrials.gov/study/NCT03636672.

Keywords: balance control; fall prevention; older adults; perturbation-based balance training; proactive balance; reactive balance.

Figure 1

The Perturbation Stationary Bicycle Robotic (PerStBiRo) system—A feedback-based perturbation device. (a–c) represent a sample of trunk and shoulder lateral angles (c, shoulder angle—dark gray line; head and neck angle—light gray line) and the PerStBiRo system bicycle platforms horizontal angle (c, bicycle angle—black line) by time during perturbation exercises, following a programmed unannounced 15° right and left tilting perturbations (a–c—dotted grey timeline). Note: The ‘sinusoidal’ green line observed before the first perturbation (around second 48) at approximately one cycle per second represents the head and neck angle during voluntary pedalling.

Figure 2

Study flowchart diagram. Note: This study was conducted during the COVID-19 pandemic, and we encountered great difficulties in recruiting and following up subjects. Therefore, we were unable to reach the original sample size of 27 in each group who completed the training programs, as reported in Batcir et al. [45]. Abbreviations: PBT = perturbation balance training.

Figure 3

The probability of stepping (# stepping trials/# trials) by level of perturbation for PBT during hands-free stationary cycling (represented in the legend by PBT) and standard stationary cycling training without perturbations (represented in the legend by SCT), following mediolateral (ML) (a, b) and anteroposterior (AP) (c, d) perturbations at baseline (a, c) and post-intervention (b, d) assessments. Comparisons between groups based on mixed-effects logistic regression models for each perturbation level in the ML and AP directions adjusted for perturbation direction. Abbreviations: PBT = perturbation balance training, SCT = standard cycling training, ML = mediolateral perturbations, AP = antero-posterior perturbations. ^*Significant group-by-time interaction (P < .05).