גיא שני

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