Bilateral deficit in explosive force production is not caused by changes in agonist neural drive..pdf (397.25 kB)
Bilateral deficit in explosive force production is not caused by changes in agonist neural drive
journal contribution
posted on 2014-10-07, 14:00 authored by Matthew Buckthorpe, Matthew PainMatthew Pain, Jonathan FollandJonathan FollandBilateral deficit (BLD) describes the phenomenon of a reduction in performance during synchronous bilateral (BL)
movements when compared to the sum of identical unilateral (UL) movements. Despite a large body of research
investigating BLD of maximal voluntary force (MVF) there exist a paucity of research examining the BLD for explosive
strength. Therefore, this study investigated the BLD in voluntary and electrically-evoked explosive isometric contractions of
the knee extensors and assessed agonist and antagonist neuromuscular activation and measurement artefacts as potential
mechanisms. Thirteen healthy untrained males performed a series of maximum and explosive voluntary contractions
bilaterally (BL) and unilaterally (UL). UL and BL evoked twitch and octet contractions were also elicited. Two separate load
cells were used to measure MVF and explosive force at 50, 100 and 150 ms after force onset. Surface EMG amplitude was
measured from three superficial agonists and an antagonist. Rate of force development (RFD) and EMG were reported over
consecutive 50 ms periods (0–50, 50–100 and 100–150 ms). Performance during UL contractions was compared to
combined BL performance to measure BLD. Single limb performance during the BL contractions was assessed and potential
measurement artefacts, including synchronisation of force onset from the two limbs, controlled for. MVF showed no BLD
(P = 0.551), but there was a BLD for explosive force at 100 ms (11.2%, P = 0.007). There was a BLD in RFD 50–100 ms (14.9%,
P = 0.004), but not for the other periods. Interestingly, there was a BLD in evoked force measures (6.3–9.0%, P,0.001). There
was no difference in agonist or antagonist EMG for any condition (P$0.233). Measurement artefacts contributed minimally
to the observed BLD. The BLD in volitional explosive force found here could not be explained by measurement issues, or
agonist and antagonist neuromuscular activation. The BLD in voluntary and evoked explosive force might indicate
insufficient stabiliser muscle activation during BL explosive contractions.
History
School
- Sport, Exercise and Health Sciences
Published in
PLOS ONEVolume
8Issue
3Pages
? - ? (8)Citation
BUCKTHORPE,M.W., PAIN, M.T.G., and FOLLAND, J.P., 2013. Bilateral deficit in explosive force production is not caused by changes in agonist neural drive. PLOS ONE, 8 (3), e57549.Publisher
Public Library of Science (© 2013 Buckthorpe et al)Version
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/Publication date
2013Notes
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.ISSN
1932-6203Publisher version
Language
- en