Changes in timing of muscle contractions and running economy with altered stride pattern during running

Connick, Mark J. and Li, Francois-Xavier (2014) Changes in timing of muscle contractions and running economy with altered stride pattern during running. Gait and Posture, 39 1: 634-637. doi:10.1016/j.gaitpost.2013.07.112

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads

Author Connick, Mark J.
Li, Francois-Xavier
Title Changes in timing of muscle contractions and running economy with altered stride pattern during running
Journal name Gait and Posture   Check publisher's open access policy
ISSN 0966-6362
1879-2219
Publication date 2014-01
Year available 2013
Sub-type Article (original research)
DOI 10.1016/j.gaitpost.2013.07.112
Open Access Status
Volume 39
Issue 1
Start page 634
End page 637
Total pages 4
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2014
Language eng
Formatted abstract
Highlights
• The effect of altered stride pattern on running economy and muscle coordination.
• Identified timing of muscle activation and eccentric contractions during running.
• A quadratic fit to economy data was optimised at a shorter than preferred stride.
• Timing of muscle contractions changed at shorter than preferred strides.
• We detected no changes to the timing of muscle contractions with longer strides.

Large alterations to the preferred running stride decrease running economy, and shorter strides increase leg muscle activity. However, the effect of altered strides on the timing of leg muscle activation is not known. The aim of this study was to evaluate the impact of moderate alterations to the running stride on running economy and the timing of biceps femoris (BF), vastus lateralis (VL) and gastrocnemius (GAST) muscle contractions. The preferred stride pattern for eleven trained male runners was measured prior to a separate visit where participants ran for bouts of 5 min whilst synchronising foot contacts to a metronome signal which was tuned to (1) the preferred stride, and (2) frequencies which related to ±8% and ±4% of the preferred stride length. Running economy was measured at each stride pattern along with electromyography and three-dimensional kinematics to estimate onset and offset of muscle contractions for each muscle. Running economy was greatest at the preferred stride length. However, a quadratic fit to the data was optimised at a stride which was 2.9% shorter than preferred. Onset and offset of BF and VL muscle contractions occurred earlier with shorter than preferred strides. We detected no changes to the timing of muscle contractions with longer than preferred strides and no changes to GAST muscle contractions. The results suggest that runners optimise running economy with a stride length that is close to, but shorter than, the preferred stride, and that timing of BF and VL muscle contractions change with shorter than preferred strides.
Keyword Stride frequency
Stride length
Eccentric contraction
EMG
Electromechanical delay
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Available online: 12 August 2013.

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 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 6 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Mon, 02 Sep 2013, 16:40:46 EST by Dr Mark Connick on behalf of School of Human Movement and Nutrition Sciences