Learning From Falling: Perturbation-based Training to Prevent Falls in Older Adults

The investigators will evaluate the difference between a commonly accepted paradigm of balance training (BT) and a more dynamic and task specific form of balance training, perturbation-based training (PBT) in older adults. BT is a key evidenced based strategy for preventing falls in older adults, however it needs to be regular (2hours/week) and long term (>6moths) while the average effect is only moderate (24%). The reason for the moderate effect on falls is like to be the non-specific stimulus presented during BT. That is, training tends to be quasi-static and slow and largely based on movements described as strength training. However, when an individual loses balance, they are most often required to implement a rapid and dynamic response. Furthermore, while older adults who are unable to recover balance well have generally lower strength, our recent work has demonstrated that it is not their force producing capability that limits them. Rather it is the ability to access moderate levels of muscular force very rapidly and early in the recovery step that differentiates successful versus unsuccessful recovery of balance. Importantly, the ability to produce an effective and rapid recovery step is predicative of avoiding future real world falls.

An emerging fall prevention training regimen is perturbation-based training (PBT). PBT involves rapidly disrupting balance requiring the participant to take rapid steps to recover balance. This is commonly achieved on a laboratory treadmill equipped with a safety harness to prevent actual falls during training. By simulating "real-world" balance challenges such as slips and trips, PBT provides a direct means for learning how to recover balance and avoid falls. It has been demonstrated that with only a few PBT sessions, older adults make rapid and dramatic improvements in balance recovery performance, retain the skills long-term and potentially suffer fewer falls over extended periods. This study builds on the previous published work of the PI that describes the key factors related to differences in balance recovery performance, the neuro-motor coordination strategies used during successful and unsuccessful recovery, and currently unpublished pilot studies indicating the efficacy of PBT. To date studies have not directly compared BT regimes recommended by the American College of Sports Medicine (ACSM) against PBT, nor have they evaluated the influence of training on the incidence of real-world falls. In part this may be because PBT currently requires the use of expensive, laboratory treadmills and as such is not accessible by the average independent, community dwelling older adults. A specific randomized study is required and our overall purpose for this study is to compare the balance recovery performance of older adults following either BT or PBT, evaluate differences in the incidence of real-world falls, and develop a safe, effective and portable device for use in future community PBT training studies. The short-term goals are to determine the effect of PBT versus BT and the neuro-motor mechanism of improved recovery behavior.

Aim 1: To evaluate differences in balance recovery behavior in older adults following either balance training (BT) and perturbation-based training (PBT) and the incidence on real-world falls.

H1: Balance recovery performance will improve in both BT and PBT groups but will be significantly better in those completing PBT when compared to BT.

H2: Improvements in balance recovery behavior will be related to improved coordination and neuro-motor control strategies.

H3: Real world loss of balance events will be similar in both BT and PBT but incidence of resulting falls will be lower in the PBT group.