Campus Units

Kinesiology

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

10-2016

Journal or Book Title

Gait and Posture

Volume

50

First Page

131

Last Page

136

DOI

10.1016/j.gaitpost.2016.08.034

Abstract

During walking older adults rely less on ankle and more on hip work than young adults. Disproportionate declines in plantarflexor strength may be a mechanism underlying this proximal work redistribution. We tested the hypothesis that proximal redistribution is more apparent in older compared to young adults and in sedentary compared to active individuals over multiple walking speeds. We recruited 18 young (18-35 yrs) and 17 older (65-80 yrs) physically active and sedentary adults. Participants completed five trials at four walking speeds as marker positions and ground reaction forces were collected. Sagittal plane net joint moments were computed using inverse dynamics. Instantaneous joint powers for the ankle, knee, and hip were computed as products of net joint moments and joint angular velocities. Positive joint work was computed by integrating hip, knee, and ankle joint powers over time in early, mid, and late stance, respectively. Relative joint work was expressed as a percentage of total work. Isokinetic strength of lower limb flexor and extensor muscles was measured. Older adults had lower relative ankle (p=0.005) and higher relative hip (p=0.007) work than young adults for multiple speeds. Non-significant trends (p<0.10) indicating sedentary participants had lower relative ankle (p=0.068) and higher relative hip work (p=0.087) than active adults were observed. Age-related differences in plantarflexor strength were not disproportionate compared to strength differences in knee and hip musculature. Age influenced proximal work redistribution over multiple walking speeds. Physical activity status showed a similar trend for proximal work redistribution, but failed to reach statistical significance.

Comments

This accepted article is published as Buddhadev HH, Martin PE. Effects of age and physical activity status on redistribution of joint work during walking. Gait and Posture. 2016;50:131–136. doi:10.1016/j.gaitpost.2016.08.034. Posted with permission

Copyright Owner

Elsevier B.V.

Language

en

File Format

application/pdf

Published Version

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