Older but not younger adults rely on multijoint coordination to stabilize the swinging limb when performing a novel cued walking task

authored by

Noah J. Rosenblatt, Nils Eckardt, Daniel Kuhman, Christopher P. Hurt

Abstract

Motor flexibility, the ability to employ multiple motor strategies to meet task demands, may facilitate ambulation in complex environments that constrain movements; loss of motor flexibility may impair mobility. The purpose of this study was to determine the effects of obesity (a specific model of mobility impairment) and advanced age on motor flexibility during a task that constrained foot placement while walking. Twenty-one community-dwelling obese (OB) and 25 normal weight (NW) older adults (46 total older adults—OA) and 10 younger adults (YA) walked normally on a treadmill (baseline) then walked while stepping on lighted cues projected onto the treadmill at locations corresponding to average foot placement during normal walking (cued). The uncontrolled manifold (UCM) analysis was used to partition total variance in a set of seven lower-limb segment angles into components that did (“bad” variance) and did not (“good” variance) affect step-to-step variance in the trajectory of the swing foot. Motor flexibility was operationalized as an increase (baseline to cued) in total variance with an increase in good variance that exceeded the change in bad variance. There was no significant group × walking task interaction for total and good variance for OB vs NW, but there was a strong and significant interaction effect for OA vs YA (p < 0.01; Cohen’s d > 1.0). Whereas YA reduced both good and bad variance, OA increased good variance beyond the change in bad variance. In OA, these changes were associated with several functional measures of mobility. Cued walking may place greater demands on OA requiring greater reliance on motor flexibility, although otherwise healthy older obese adults may be able to compensate for functional and cognitive declines associated with obesity by increasing motor flexibility under such tasks. The extent to which motor flexibility is employed during novel or constrained tasks may be a biomarker of healthy aging and a target for (re)habilitation.

Organisation(s)

Institute of Sports Science

External Organisation(s)

Rosalind Franklin University of Medicine and Science
Carl von Ossietzky University of Oldenburg
University of Alabama at Birmingham

Type

Article

Journal

Experimental brain research

Volume

238

Pages

1441-1454

No. of pages

14

ISSN

0014-4819

Publication date

06.2020

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Neuroscience(all)

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1007/s00221-020-05822-x (Access: Closed)