Oxygen Consumption During Machine-Assisted and Unassisted Walking: A Pilot Study in Hemiplegic and Healthy Humans
Abstract
David D, Regnaux J-P, Lejaille M, Louis A, Bussel B, Lofaso F. Oxygen consumption during machine-assisted and unassisted walking: a pilot study in hemiplegic and healthy humans.
Objective
To determine whether a gait-training (GT) machine influenced walking time duration and oxygen consumption in hemiplegic patients.
Design
Repeated measures with comparison of 2 groups.
Setting
Physiology laboratories in a rehabilitation hospital.
Participants
Seven patients with stroke-related hemiplegia (2 men, 5 women; age, 46±11y; time since stroke, 12±9wk) and 7 healthy subjects (3 men, 4 women; age, 30±7y).
Interventions
Floor walking (FW) and GT-assisted walking with and without 50% body-weight support (BWS).
Main Outcome Measures
Walking time duration, oxygen consumption (V̇o2), minute ventilation (V̇e), and heart rate.
Results
When the condition effect was analyzed independently from the group, mean V̇o2 was higher during FW than during the GT tests (post hoc analysis: FW vs GT, P=.017; FW vs GT+BWS, P<.002). When the groups were compared independently of the condition, the group with hemiplegia had a significantly shorter walking time duration (analysis of variance [ANOVA], P<.001) and a significantly higher V̇o2 as a percentage of baseline (ANOVA, P=.03), compared with the controls. Walking time duration was influenced by walking condition (ANOVA, P<.001; post hoc analysis: FW vs GT, P<.001; FW vs GT+BWS, P<.001). V̇e was influenced by walking condition (ANOVA, P=.043; not significant in the post hoc analysis) and was higher in the group with hemiplegia (ANOVA, P=.02). Heart rate was not influenced by walking condition (P=.11). A group effect was found with heart rate in cycles per minute (P=.035) but not as a percentage of baseline. No interaction was found between the ANOVA group-effect factor and the ANOVA walking-condition effect factor.
Conclusions
Compared with FW, GT assistance increased walking time duration and reduced V̇o2 in patients with severe hemiplegia.
Correspondence to Frédéric Lofaso, MD, PhD, Service de Physiologie-Explorations Fonctionnelles, Hôpital Raymond Poincaré, 92380 Garches, France. Reprints are not available from the author.
Supported by the Garches Foundation.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated.
ABSTRACT