Effects of Perturbation-Based Balance Training on Reactive Postural Control in Community-Dwelling Older Adults

Background
Perturbation-based balance training (PBT) is a promising intervention for preventing falls among community-dwelling older adults. Effective reactive postural control is essential to maintain stability when encountering unexpected perturbations. However, the immediate and sustained effects of short-term PBT on reactive postural control in older adults remain inconsistent across existing research. Additionally, the influence of lower limb dominance on PBT training responses remains unclear.

Methods
In this assessor-blinded, randomized controlled trial, 48 community-dwelling older adults were allocated to receive two sessions of either treadmill walking without perturbation (controls, n=24) or treadmill-based PBT (PBT, n=24) experiencing 112 forward or backward perturbations each session, simulating tripping and slipping, while walking. The primary outcome was the margin of stability (MoS) at the first recovery step. Secondary outcomes included grasping reactions and clinical assessments of physical, cognitive and sociopsychological factors at post-intervention and 4-month follow-up.

Results
The PBT group demonstrated both immediate and sustained improvements in reactive postural adjustments compared to controls. Significant improvements in MoS during dominant-leg slips [Mean difference (MD)=1.17, p=0.004] and reduced the total number of handrail grasping reactions (MD=-1.25, p<0.001) post-intervention and at follow-up (MoS: MD=1.00, p=0.043; handrail use: MD=-0.68, p=0.013) were revealed in PBT but not in controls. European Quality of Life 5 Dimensions 5 Levels (EQ-5D-5L) also improved significantly in the PBT group at follow-up (MD=0.05, p<0.001). However, no significant differences were observed in other physical capacity or cognitive function measures.

Conclusion
This study demonstrated that a two-session PBT protocol effectively improved reactive postural adjustments and health-related quality of life in older adults for a duration of at least four months. Effects were more marked in preventing backward slips triggered on the dominant leg. These findings suggest that short-term PBT may offer a time-efficient solution for fall prevention in community-dwelling older adults.