Learning From Falling
LEARNING FROM FALLING: PERTURBATION-BASED BALANCE TRAINING TO PREVENT FALLS IN OLDER ADULTS
The purpose of our current project is to investigate the difference between Conventional Balance Training (BT) and Perturbation-based Balance training (PBT). It's a parallel-group randomized controlled trial with 6 months follow-up from baseline to determine the effect of PBT program on stepping behavior and fall incidence in community-dwelling older people. Additionally, in order to better understand the social and emotional factors that influence falls and physical activity a questionnaire, that measures factors (FoF, perceptions of physical activity and mental wellness) that have been associated with fall risk, is administered before and after training as well as during the 6-month follow-up.
This project forms the basis of an improved understanding of the effect of balance recovery training methods on balance recovery performance and other factors associated with fall risk such as FOF, perceptions of physical activity and mental wellness and is vital to effectively reducing falls for all Montanans, particularly those living in rural communities.
Balance and Balance Recovery
Over one-third of community dwelling older adults fall each year with about 15% of falls being injurious. Falls are a significant cause of mortality, morbidity, and disability, which adversely affect the individual concerned, as well as the health care system, the economy and the broader community. Falls can cause activity limitation, fear of falling, soft tissue injuries, fractures (e.g. hip and wrist), head injuries, institutionalization and death.
Balance declines with advancing age due a progressive loss of sensorimotor function. Underpinning this loss of function are age-related declines in proprioception, vision, vestibular sense, muscle function and reaction time. While both young and older adults can experience loss of balance, older adults are more likely to fall because they have a markedly reduced capacity to recover from loss of balance.
Currently, older adults in Montana are reported to fall much more often than the rate reported in most other states in the US, this has led to the implementation of the Montana “Stepping-On Fall Prevention Program”. The Stepping-On program addresses several factors related to falls including the need to be physically active, however, the unfortunate problem is that increasing activity can lead to increase incidence of falls. This is in part because of the increased exposure to trips and slips by simply being more active without the prerequisite skill to resist falling following a loss of balance. This strongly suggests that older adults need to develop specific skills to resist falls prior to beginning a general exercise program. This project investigates the relationship between fall incidence and balance training exercises used by older adults by evaluating balance training and its influence on real world falls. Furthermore, as part of this project we are developing methods to make a proposed form of training widely accessible through the development of a balance platform.
Conventional Balance Training
Poor balance is a highly modifiable risk factor for falls, and so exercises that challenge balance are considered a key components of exercise-based fall prevention programs. American College of Sports Medicine Guidelines currently recommend using volitional activities that include (1) progressively difficult postures that gradually reduce the base of support (e.g. two-legged stand, semi-tandem stand, tandem stand, one-legged stand), (2) dynamic movements that perturb the center of gravity (e.g., tandem walk, circle turns), (3) stressing postural muscle groups (e.g., heel stands, toe stands), or (4) reducing sensory input (e.g., standing with eyes closed).
Exercise is a proven intervention to prevent falls in community-dwelling older adults, and has been estimated from a systematic review and meta-analysis of 44 trials with 9603 participants to yield a 17% reduction in fall rates. Pooled data from 25 trials of conventional BT training yielded a 24% reduction in fall rates and was the only mode of exercise that had a significant protective effect on fall rates.
Perturbation-based Balance Training (PBT)
Whereas conventional BT described above involves activities that are volitional, quasi-static, with individuals remaining within their limits of stability, PBT is reactive, dynamic, and imposes a high-challenge to balance. PBT more accurately simulates real- world falls in terms of the type, speed and stability range of the movement and also provides a greater threat to balance and hence a greater stimulus for learning how to avoid a fall. The minimum recommended dose for conventional BT is 50 hours (~2 hours per week for 6 months), whereas adaptations in balance recovery from PBT have been reported following a single training session and as little as a single exposure to a postural disturbance. Importantly, there are no reports in the literature of adverse events arising from participation by healthy and high fall risk older people in PBT, which suggests this type of training can be performed safely in a controlled environment.
A range of PBT programs have been evaluated with respect to their effect on balance-related outcomes. Although the programs differ in terms of the type, dose, intensity and duration of the BT intervention, all studies conducted to date report positive effects on either measures related to stability or speed of movement during balance recovery, or a decreased number of falls during the balance recovery task evaluated.
Taken together, perturbation-based training studies demonstrate efficacy of the approach for improving the ability to recover from loss of balance. Importantly, a study by Bhatt et al also demonstrated significant retention of balance improvements at 6 months following a single PBT session, and that a single trial “booster” perturbation at 3 months led to better balance at 6 months compared to a single session BT group. These authors have therefore speculated that PBT could be a way of “inoculating” older adults against falls with a substantially lower exercise dose that for conventional BT.