Article

This study investigated age-related and fall-risk-related differences in the
ability to make visually guided reactive stepping adjustments during locomotion.
Participants were asked to walk towards and step accurately onto a visual target
which, during the step towards it, moved to an unpredictable location at an
unpredictable time. We measured lower limb kinematics and eye movement
characteristics of young adults and two groups of older adults deemed to be
either at a low- or high-risk of falling. High-risk older adults produced
significant deviations in foot trajectory with latencies of approximately 300 ms,
compared to 280 ms in low-risk older adults and approximately 200 ms in young
adults. Furthermore, high-risk older adults were unable to generate adjustments
with the same magnitude and consistency as low-risk older adults and young
adults. Saccadic reaction latencies also were doubled in high-risk older adults
compared to young. Analysis of covariance showed that the significant between
group differences in final foot placement error could be accounted for by
differences in saccadic response times. We propose that age-related delays in
visuomotor processing times may disrupt the timing and magnitude of stepping
adjustments, possibly contributing to an increased likelihood of falls.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS