Article

Several studies have quantified and compared balance recovery between healthy
younger and older adults, using a variety of large postural perturbations and
loss of balance directions. However, to the best of our knowledge, no studies at
the threshold of balance recovery, where avoiding a fall is not always possible,
have included middle-aged adults. We thus determined the maximum lean angle from
which 20 younger, 16 middle-aged and 16 older healthy adults could be suddenly
released and still recover balance using a single step for forward, sideways and
backward leans. Results showed that the maximum lean angles of younger adults
were 23% greater than middle-aged adults and 48% greater than older adults. The
maximum lean angles for forward leans were 23% greater than sideways leans and
22% greater than backward leans. These declines with age and lean direction were
associated with declines in response initiation, execution and geometry. Finally
exponential regressions showed that the critical ages at which the ability to
recover balance and avoid a fall significantly decreases were 51.0, 60.6 and 69.9
yrs for forward, sideways and backward leans, respectively. Therefore, we have
demonstrated that age affects the ability to recover balance nearly a decade
earlier than the rate of falls. Future studies should thus not only include older
adults over 65 yrs, but also middle-aged adults under 65 yrs, or recruit all ages
from 18 to 85 yrs. Finally, the critical ages identified in this study may
justify an earlier screening of aging adults to prevent future falls, especially the first fall.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS