Revisiting the mechanics and energetics of walking in individuals with chronic hemiparesis following stroke: from individual limbs to lower limb joints

Farris, Dominic James, Hampton, Austin, Lewek, Michael D. and Sawicki, Gregory S. (2015) Revisiting the mechanics and energetics of walking in individuals with chronic hemiparesis following stroke: from individual limbs to lower limb joints. Journal of Neuroengineering and Rehabilitation, 12 24: 1-12. doi:10.1186/s12984-015-0012-x


Author Farris, Dominic James
Hampton, Austin
Lewek, Michael D.
Sawicki, Gregory S.
Title Revisiting the mechanics and energetics of walking in individuals with chronic hemiparesis following stroke: from individual limbs to lower limb joints
Journal name Journal of Neuroengineering and Rehabilitation   Check publisher's open access policy
ISSN 1743-0003
Publication date 2015-02-01
Year available 2015
Sub-type Article (original research)
DOI 10.1186/s12984-015-0012-x
Open Access Status DOI
Volume 12
Issue 24
Start page 1
End page 12
Total pages 12
Place of publication London, United Kingdom
Publisher BioMed Central
Collection year 2016
Language eng
Formatted abstract
Background:  Previous reports of the mechanics and energetics of post-stroke hemiparetic walking have either not combined estimates of mechanical and metabolic energy or computed external mechanical work based on the limited combined limbs method. Here we present a comparison of the mechanics and energetics of hemiparetic and unimpaired walking at a matched speed.

Methods:  Mechanical work done on the body centre of mass (COM) was computed by the individual limbs method and work done at individual leg joints was computed with an inverse dynamics analysis. Both estimates were converted to average powers and related to simultaneous estimates of net metabolic power, determined via indirect calorimetry. Efficiency of positive work was calculated as the ratio of average positive mechanical power P¯¯¯+ to net metabolic power.

Results:  Total P¯¯¯+ was 20% greater for the hemiparetic group (H) than for the unimpaired control group (C) (0.49 vs. 0.41 W · kg−1). The greater P¯¯¯+ was partly attributed to the paretic limb of hemiparetic walkers not providing appropriately timed push-off P¯¯¯+ in the step-to-step transition. This led to compensatory non-paretic limb hip and knee P¯¯¯+ which resulted in greater total mechanical work. Efficiency of positive work was not different between H and C.

Conclusions:  
Increased work, not decreased efficiency, explains the greater metabolic cost of hemiparetic walking post-stroke. Our results highlighted the need to target improving paretic ankle push-off via therapy or assistive technology in order to reduce the metabolic cost of hemiparetic walking.
Keyword Locomotion
Individual limbs method
Mechanical power
Metabolic power
Joint power
Inverse dynamics
Stroke
To-step transitions
Energy cost
Work
Ankle
Foot
Poststroke
Muscle
Simulation
Locomotion
Efficiency
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Human Movement and Nutrition Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 5 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 3 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 26 Apr 2015, 11:00:16 EST by System User on behalf of School of Human Movement and Nutrition Sciences