AJP Accepted Version (in press).pdf (2.33 MB)
Localized and systemic variations in central motor drive at different local skin and muscle temperatures
journal contribution
posted on 2017-06-14, 13:48 authored by Alex LloydAlex Lloyd, Lewis Picton, Margherita Raccuglia, Simon HodderSimon Hodder, George HavenithGeorge HavenithThis study investigated the ability to sustain quadriceps central motor drive while subjected to localized heat and metaboreceptive feedback from the contralateral leg. Eight active males each completed two counter-balanced trials, in which muscle temperature (Tm) of a single-leg (TEMP-LEG) was altered to 29.4 (COOL) or 37.6°C (WARM), while the contralateral leg (CL-LEG) remained thermoneutral; 35.3 and 35.2°C Tm in COOL and WARM respectively. To activate metaboreceptive feedback, participants first performed one 120-s isometric maximal voluntary contraction (MVC) of the knee extensors in the TEMP-LEG, immediately followed by post-exercise muscle ischemia (PEMI) via femoral blood flow occlusion. To assess central motor drive of a remote muscle group immediately following PEMI, another 120-s MVC was subsequently performed in the CL-LEG. Voluntary muscle activation (VA) was assessed using the twitch interpolation method. Perceived mental effort and limb discomfort were also recorded. In a cooled muscle, a significant increase in mean force output and mean VA (force, p<0.001; VA, p<0.05) as well as a significant decrease in limb discomfort (p<0.05) occurred during the sustained MVC in the TEMP-LEG. However, no differences between Tm were observed in mean force output, mean VA or limb discomfort during the sustained MVC in the CL-LEG (Force, p=0.33; VA, p>0.68, limb discomfort, p=0.73). The present findings suggest that elevated local Tsk and Tm can increase limb discomfort and decrease central motor drive, but this does not limit systemic motor activation of a thermoneutral muscle group.
History
School
- Design
Published in
American Journal of Physiology: Regulatory, Integrative and Comparative PhysiologyVolume
313Issue
3Pages
R219-228Citation
LLOYD, A. ... et al., 2017. Localized and systemic variations in central motor drive at different local skin and muscle temperatures. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 313(3), pp.R219-228.Publisher
© American Journal of Physiology-Regulatory, Integrative and Comparative PhysiologyVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2017-06-05Publication date
2017-09-01Copyright date
2017Notes
This article was published in the AJP - Regulatory, Integrative and Comparative Physiology [© APS] and the definitive version is available at: https://doi.org/10.1152/ajpregu.00055.2017ISSN
0363-6119Publisher version
Language
- en