Comparing the Effects of Two Perturbation-based Balance Training Paradigms in Fall-prone Older Adults: A Randomized Controlled Trial.

Introduction There is increasing evidence that perturbation-based balance training (PBT) is highly effective in preventing falls at older age. Different PBT paradigms have been presented so far, yet a systematic comparison of PBT approaches with respect to feasibility and effectiveness is missing. Two different paradigms of PBT seem to be promising for clinical implementation: 1. Technology-supported training on a perturbation treadmill (PBTtreadmill); 2. Training of dynamic stability mechanisms in the presence of perturbations induced by unstable surfaces (PBTstability). This study aimed to compare both program's feasibility and effectiveness in fall-prone older adults. Methods In this three-armed randomized controlled trial, seventy-one older adults (74.9 ± 6.0 years) with a verified fall risk were randomly assigned into three groups: PBTtreadmill on a motorized treadmill, PBTstability using unstable conditions such as balance pads and a passive control group (CG). In both intervention groups, participants conducted a 6-weeks intervention with 3 sessions per week. Effects were assessed in fall risk (Brief-BEST), balance ability (Stepping Threshold Test, Center of Pressure, Limits of Stability), leg strength capacity, functional performance (Timed Up and Go Test, Chair-Stand), gait (preferred walking speed) and fear of falling (Short-FES-I). Results Fifty-one participants completed the study. Training adherence was 91% for PBTtreadmill and 87% for PBTstability, while no severe adverse events occurred. An ANCOVA with an intention-to-treat approach revealed statistically significant group effects in favor of PBTstability in the Brief-BEST (p=.009, η²=.131) and the Limits of Stability (p=.020, η²=.110), and in favor of PBTtreadmill in the Stepping Threshold Test (p<.001, η²=.395). The other outcomes demonstrated no significant group effects. Discussion/Conclusion Both training paradigms demonstrated high feasibility and were effective in improving specific motor performances in the fall-prone population and these effects were task-specific. PBTtreadmill showed higher improvements in reactive balance, which might have been promoted by the unpredictable nature of the included perturbations and the similarity to the tested surface perturbation paradigm. PBTstability showed more wide-ranging effects on balance ability. Consequently, both paradigms improved fall-risk-associated measures. The advantages of both formats should be evaluated in the light of individual needs and preferences. Larger studies are needed to investigate the effects of these paradigms on real-life fall rates.