Article

Stepping over obstacles challenges stability and is a leading cause
of falls in older adult populations. As walking and Tai Chi (TC) exercise have
been suggested practices for older adults for fall prevention, the purpose of
this study was to evaluate the obstacle-crossing strategies of long-term TC
practitioners and exercise walkers. METHODS: Thirty healthy older women (average
age: 65.7 years) with either TC (n=15) experience (average experience: 8.2 years)
or walking exercise (n=15; average experience: 8.8 years) participated in this
study. We used three trial conditions: (1) normal walking, (2) crossing a 15cm
(20% of leg length) obstacle, and (3) crossing a 23cm (30% of leg length) to
assess obstacle-crossing strategy. Sagittal plane obstacle-crossing kinematic
parameters and plantar pressures were used to evaluate the obstaclecrossing
strategy. A MANOVA assessed differences between groups. RESULTS: Individuals with
a TC background crossed the obstacle significantly faster with a significantly
longer step relative to the exercise walkers. Plantar pressure profiles between
the two groups also differed. Exercise walkers showed greater plantar pressure in
the forefoot; TC practitioners demonstrated greater medial heel plantar pressure
during obstacle-crossing. CONCLUSIONS: Our results suggest that obstacle-crossing
strategies were affected by the type of longterm exercise. The strategies each
group used had important attributes that affect stability during
obstacle-crossing. Future studies are needed to understand how obstacle-crossing
strategies are adopted and how exercise may influence the strategy used.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS