Effects of walking speed, strength and range of motion on gait stability in healthy older adults

JOURNAL OF BIOMECHANICS

卷:41

Article

Kang, Hyun G.^2,3,4,5  Dingwell, Jonathan B.¹ 

[1] Univ Texas Austin, Dept Kinesiol & Hlth Educ, Austin, TX 78712 USA

[2] Inst Aging Res, Boston, MA 02131 USA

[3] Beth Israel Deaconess Med Ctr, Gerontol Div, Boston, MA 02215 USA

[4] Harvard Univ, Sch Med, Boston, MA 02215 USA

[5] Boston Univ, Dept Biomed Engn, Boston, MA 02215 USA

关键词: Falls;    Aging;    Gait;    Stability;    Speed;   

DOI  :  10.1016/j.jbiomech.2008.08.002

来源: Elsevier

【 摘 要 】

Falls pose a tremendous risk to those over 65 and most falls occur during locomotion. Older adults commonly walk slower, which many believe helps improve walking stability. While increased gait variability predicts future fall risk, increased variability is also caused by walking slower. Thus, we need to better understand how differences in age and walking speed independently affect dynamic stability during walking. We investigated if older adults improved their dynamic stability by walking slower, and how leg strength and flexibility (passive range of motion (ROM)) affected this relationship. Eighteen active healthy older and 17 healthy younger adults walked on a treadmill for 5 min each at each of 5 speeds (80-120% of preferred). Local divergence exponents and maximum Floquet multipliers (FM) were calculated to quantify each subject's inherent local dynamic stability. The older subjects walked with the same preferred walking speeds as the younger subjects (p = 0.860). However, these older adults still exhibited greater local divergence exponents (p < 0.0001) and higher maximum FM (p < 0.007) than the younger adults at all walking speeds. These older adults remained more locally unstable (p < 0.04) even after adjusting for declines in both strength and ROM. In both age groups, local divergence exponents decreased at slower speeds and increased at faster speeds (p < 0.0001). Maximum FM showed similar changes with speed (p < 0.02). Both younger and older adults exhibited decreased instability by walking slower, in spite of increased variability. These increases in dynamic instability might be more sensitive indicators of future fall risk than changes in gait variability. (c) 2008 Elsevier Ltd. All rights reserved.

【 授权许可】

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