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Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials

It has recently been shown that motor units in human medial gastrocnemius (MG), activated during standing, occupy relatively small territories along the muscle’s longitudinal axis. Such organisation provides potential for different motor tasks to produce differing regional patterns of activity. Here...

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Detalles Bibliográficos
Autores principales: Hodson-Tole, Emma F., Loram, Ian D., Vieira, Taian M.M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566583/
https://www.ncbi.nlm.nih.gov/pubmed/22967836
http://dx.doi.org/10.1016/j.jelekin.2012.08.003
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author Hodson-Tole, Emma F.
Loram, Ian D.
Vieira, Taian M.M.
author_facet Hodson-Tole, Emma F.
Loram, Ian D.
Vieira, Taian M.M.
author_sort Hodson-Tole, Emma F.
collection PubMed
description It has recently been shown that motor units in human medial gastrocnemius (MG), activated during standing, occupy relatively small territories along the muscle’s longitudinal axis. Such organisation provides potential for different motor tasks to produce differing regional patterns of activity. Here, we investigate whether postural control and nerve electrical stimulation produce equal longitudinal activation patterns in MG. Myoelectric activity, at different proximal–distal locations of MG, was recorded using a linear electrode array. To ensure differences in signal amplitude between channels did not result from local, morphological factors two experimental protocols were completed: (i) quiet standing; (ii) electrical stimulation of the tibial nerve. Averaged, rectified values (ARVs) were calculated for each channel in each condition. The distribution of signals along electrode channels was described using linear regression and differences between protocols at each channel determined as the ratio between mean ARV from standing: stimulation protocols. Ratio values changed systematically across electrode channels in seven (of eight) participants, with larger values in distal channels. The distribution of ARV along MG therefore differed between experimental conditions. Compared to fibres of units activated during MG nerve stimulation, units activated during standing may have a tendency to be more highly represented in the distal muscle portion.
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spelling pubmed-35665832013-02-07 Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials Hodson-Tole, Emma F. Loram, Ian D. Vieira, Taian M.M. J Electromyogr Kinesiol Article It has recently been shown that motor units in human medial gastrocnemius (MG), activated during standing, occupy relatively small territories along the muscle’s longitudinal axis. Such organisation provides potential for different motor tasks to produce differing regional patterns of activity. Here, we investigate whether postural control and nerve electrical stimulation produce equal longitudinal activation patterns in MG. Myoelectric activity, at different proximal–distal locations of MG, was recorded using a linear electrode array. To ensure differences in signal amplitude between channels did not result from local, morphological factors two experimental protocols were completed: (i) quiet standing; (ii) electrical stimulation of the tibial nerve. Averaged, rectified values (ARVs) were calculated for each channel in each condition. The distribution of signals along electrode channels was described using linear regression and differences between protocols at each channel determined as the ratio between mean ARV from standing: stimulation protocols. Ratio values changed systematically across electrode channels in seven (of eight) participants, with larger values in distal channels. The distribution of ARV along MG therefore differed between experimental conditions. Compared to fibres of units activated during MG nerve stimulation, units activated during standing may have a tendency to be more highly represented in the distal muscle portion. Elsevier 2013-02 /pmc/articles/PMC3566583/ /pubmed/22967836 http://dx.doi.org/10.1016/j.jelekin.2012.08.003 Text en © 2013 Elsevier Ltd. https://creativecommons.org/licenses/by/3.0/ Open Access under CC BY 3.0 (https://creativecommons.org/licenses/by/3.0/) license
spellingShingle Article
Hodson-Tole, Emma F.
Loram, Ian D.
Vieira, Taian M.M.
Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials
title Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials
title_full Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials
title_fullStr Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials
title_full_unstemmed Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials
title_short Myoelectric activity along human gastrocnemius medialis: Different spatial distributions of postural and electrically elicited surface potentials
title_sort myoelectric activity along human gastrocnemius medialis: different spatial distributions of postural and electrically elicited surface potentials
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566583/
https://www.ncbi.nlm.nih.gov/pubmed/22967836
http://dx.doi.org/10.1016/j.jelekin.2012.08.003
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