Abstract
Objective
To investigate the effect of timing and magnitude of horizontally directed propulsive
forces to the center of mass (COM) on the metabolic cost of walking (COW) for individuals
poststroke.
Design
Repeated-measures, within-subject design.
Setting
Research laboratory.
Participants
A total of 9 individuals with chronic hemiparesis poststroke and 7 unimpaired similarly
aged controls (N=16).
Intervention
Individuals walked on a treadmill in 2 separate studies. First, we compared the metabolic
COW with an anterior force applied to the COM that (1) coincided with paretic propulsion
or (2) was applied throughout the gait cycle. Next, we compared the metabolic COW
with anterior (assistive) or posterior (resistive) forces applied during paretic propulsion.
Main Outcome Measure
Metabolic COW.
Results
The COW was significantly greater in the Stroke group. Anterior (propulsive) assistance
reduced the COW differently based on group. The Stroke group exhibited a 12% reduction
in COW when assistance was provided only during paretic propulsion, but not when assistance
was provided throughout the gait cycle. In contrast, the Control group demonstrated
reduced COW during both anterior assistance conditions. In addition, we observed that
resistance during paretic propulsion (simulated hemiparesis for Control group) significantly
increased the COW.
Conclusions
Systematically manipulating propulsive forces at the body’s COM had a profound influence
on metabolic cost. The timing of propulsive forces to the COM is important and needs
to coincide with paretic terminal stance. Additional internally or externally generated
propulsive forces applied to the body’s COM poststroke may produce a lower metabolic
COW.
Keywords
List of abbreviations:
BW (body weight), COM (center of mass), COW (cost of walking)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: November 01, 2018
Footnotes
Supported by the National Center for Advancing Translational Sciences, National Institutes of Health (grant no. UL1TR002489). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Disclosures: none.
Identification
Copyright
© 2018 by the American Congress of Rehabilitation Medicine
