Sarcolemmal excitability, M-Wave changes, and conduction velocity during a sustained low-force contraction

Rodríguez Falces, Javier; Place, Nicolas

Sarcolemmal excitability, M-Wave changes, and conduction velocity during a sustained low-force contraction

dc.contributor.author	Rodríguez Falces, Javier
dc.contributor.author	Place, Nicolas
dc.contributor.department	Ingeniería Eléctrica, Electrónica y de Comunicación	es_ES
dc.contributor.department	Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren	eu
dc.date.accessioned	2022-04-12T06:27:08Z
dc.date.available	2022-04-12T06:27:08Z
dc.date.issued	2021
dc.description.abstract	This study was undertaken to investigate whether sarcolemmal excitability is impaired during a sustained low-force contraction [10% maximal voluntary contraction (MVC)] by assessing muscle conduction velocity and also by analyzing separately the first and second phases of the muscle compound action potential (M wave). Twenty-one participants sustained an isometric knee extension of 10% MVC for 3min. M waves were evoked by supramaximal single shocks to the femoral nerve given at 10-s intervals. The amplitude, duration, and area of the first and second M-wave phases were computed. Muscle fiber conduction velocity, voluntary surface electromyographic (EMG), perceived effort, MVC force, peak twitch force, and temperature were also recorded. The main findings were: (1) during the sustained contraction, conduction velocity remained unchanged. (2) The amplitude of the M-wave first phase decreased for the first ~30s (−7%, p<0.05) and stabilized thereafter, whereas the second phase amplitude increased for the initial ~30s (+7%, p<0.05), before stabilizing. (3) Both duration and area decreased steeply during the first ~30s, and then more gradually for the rest of the contraction. (4) During the sustained contraction, perceived effort increased fivefold, whereas knee extension EMG increased by ~10%. (5) Maximal voluntary force and peak twitch force decreased (respectively, −9% and −10%, p<0.05) after the low-force contraction. Collectively, the present results indicate that sarcolemmal excitability is well preserved during a sustained 10% MVC task. A depression of the M-wave first phase during a low-force contraction can occur even in the absence of changes in membrane excitability. The development of fatigue during a low-force contraction can occur without alteration of membrane excitability.	en
dc.description.sponsorship	This work has been supported by the Spanish Ministry of Science and Innovation under the project PID2019-109062RB-I00.	en
dc.format.extent	13 p.
dc.format.mimetype	application/pdf	en
dc.format.mimetype	image/tiff	en
dc.identifier.doi	10.3389/fphys.2021.732624
dc.identifier.issn	1664-042X
dc.identifier.uri	https://academica-e.unavarra.es/handle/2454/42718
dc.language.iso	eng	en
dc.publisher	Frontiers Media	en
dc.relation.ispartof	Frontiers in Physiology, 12, 2021	en
dc.relation.projectID	info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-109062RB-I00/ES/
dc.relation.publisherversion	https://doi.org/10.3389/fphys.2021.732624
dc.rights	© 2021 Rodriguez-Falces and Place. Creative Commons Attribution 4.0 International	en
dc.rights.accessRights	info:eu-repo/semantics/openAccess
dc.rights.uri	https://creativecommons.org/licenses/by/4.0/
dc.subject	Conduction velocity	en
dc.subject	Low-level contraction	en
dc.subject	Membrane excitability	en
dc.subject	Neuromuscular propagation	en
dc.subject	Peripheral fatigue	en
dc.subject	Submaximal contraction	en
dc.subject	Sustained contraction	en
dc.title	Sarcolemmal excitability, M-Wave changes, and conduction velocity during a sustained low-force contraction	en
dc.type	info:eu-repo/semantics/article
dc.type.version	info:eu-repo/semantics/publishedVersion
dspace.entity.type	Publication
relation.isAuthorOfPublication	8ebfa8e7-2a2b-41eb-a0c2-f82e9b6f39dc
relation.isAuthorOfPublication.latestForDiscovery	8ebfa8e7-2a2b-41eb-a0c2-f82e9b6f39dc