Is the firing rate of motor units in different vastus medialis regions modulated similarly during isometric contractions?: Local Modulation of VM MUs

Hélio da Veiga Cabral; Leonardo M.L. de Souza; Roger G.T. Mello; Alessio Gallina; Liliam F. de Oliveira; Taian M. Vieira

doi:10.1002/mus.25688

Is the firing rate of motor units in different vastus medialis regions modulated similarly during isometric contractions? Local Modulation of VM MUs

Hélio da Veiga Cabral, Leonardo M.L. de Souza, Roger G.T. Mello, Alessio Gallina, Liliam F. de Oliveira, Taian M. Vieira

Sport, Exercise and Rehabilitation Sciences

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

190 Downloads (Pure)

Abstract

Introduction: Previous evidence suggests the fibers of different motor units reside within distinct vastus medialis (VM) regions. It remains unknown whether the activity of these motor units may be modulated differently. Herein we assess the discharge rate of motor units detected proximodistally from the VM to address this issue.

Methods: Surface electromyograms (EMGs) were recorded proximally and distally from the VM while 10 healthy subjects performed isometric contractions. Single motor units were decomposed from surface EMGs. The smoothed discharge rates of motor units identified from the same and from different VM regions were then cross‐correlated.

Results: During low‐level contractions, the discharge rate varied more similarly for distal (cross‐correlation peak; interquartile interval: 0.27–0.40) and proximal (0.28–0.52) than for proximodistal pairs of VM motor units (0.20–0.33; P = 0.006).

Discussion: The discharge rates of motor units from different proximodistal VM regions show less similarity in their variations than those of pairs of units either distally or proximally.

Original language	English
Pages (from-to)	279-286
Number of pages	8
Journal	Muscle & Nerve
Volume	57
Issue number	2
Early online date	29 May 2017
DOIs	https://doi.org/10.1002/mus.25688
Publication status	Published - 13 Jan 2018

Keywords

compartmentalization
knee
motor unit
quadriceps
surface electromyography
vastus medialis

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Cabral_et_al_Is_the_firing_rate_of_motor_units_in_different_vastus_medialis_regions_Muscle_&_Nerve_2017
Checked for eligibility: 19/09/2019 This is the peer reviewed version of the following article: Cabral, H. V., de Souza, L. M., Mello, R. G., Gallina, A. , de Oliveira, L. F. and Vieira, T. M. (2018), Is the firing rate of motor units in different vastus medialis regions modulated similarly during isometric contractions?. Muscle Nerve, 57: 279-286. doi:10.1002/mus.25688, which has been published in final form at: https://doi.org/10.1002/mus.25688. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
Accepted author manuscript, 590 KBLicence: Other (please specify with Rights Statement)

Cite this

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title = "Is the firing rate of motor units in different vastus medialis regions modulated similarly during isometric contractions?: Local Modulation of VM MUs",

abstract = "Introduction: Previous evidence suggests the fibers of different motor units reside within distinct vastus medialis (VM) regions. It remains unknown whether the activity of these motor units may be modulated differently. Herein we assess the discharge rate of motor units detected proximodistally from the VM to address this issue. Methods: Surface electromyograms (EMGs) were recorded proximally and distally from the VM while 10 healthy subjects performed isometric contractions. Single motor units were decomposed from surface EMGs. The smoothed discharge rates of motor units identified from the same and from different VM regions were then cross‐correlated. Results: During low‐level contractions, the discharge rate varied more similarly for distal (cross‐correlation peak; interquartile interval: 0.27–0.40) and proximal (0.28–0.52) than for proximodistal pairs of VM motor units (0.20–0.33; P = 0.006). Discussion: The discharge rates of motor units from different proximodistal VM regions show less similarity in their variations than those of pairs of units either distally or proximally.",

keywords = "compartmentalization, knee, motor unit, quadriceps, surface electromyography, vastus medialis",

author = "{da Veiga Cabral}, H{\'e}lio and Souza, {Leonardo M.L. de} and Mello, {Roger G.T.} and Alessio Gallina and Oliveira, {Liliam F. de} and Vieira, {Taian M.}",

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T1 - Is the firing rate of motor units in different vastus medialis regions modulated similarly during isometric contractions?

T2 - Local Modulation of VM MUs

AU - da Veiga Cabral, Hélio

AU - Souza, Leonardo M.L. de

AU - Mello, Roger G.T.

AU - Gallina, Alessio

AU - Oliveira, Liliam F. de

AU - Vieira, Taian M.

PY - 2018/1/13

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N2 - Introduction: Previous evidence suggests the fibers of different motor units reside within distinct vastus medialis (VM) regions. It remains unknown whether the activity of these motor units may be modulated differently. Herein we assess the discharge rate of motor units detected proximodistally from the VM to address this issue. Methods: Surface electromyograms (EMGs) were recorded proximally and distally from the VM while 10 healthy subjects performed isometric contractions. Single motor units were decomposed from surface EMGs. The smoothed discharge rates of motor units identified from the same and from different VM regions were then cross‐correlated. Results: During low‐level contractions, the discharge rate varied more similarly for distal (cross‐correlation peak; interquartile interval: 0.27–0.40) and proximal (0.28–0.52) than for proximodistal pairs of VM motor units (0.20–0.33; P = 0.006). Discussion: The discharge rates of motor units from different proximodistal VM regions show less similarity in their variations than those of pairs of units either distally or proximally.

AB - Introduction: Previous evidence suggests the fibers of different motor units reside within distinct vastus medialis (VM) regions. It remains unknown whether the activity of these motor units may be modulated differently. Herein we assess the discharge rate of motor units detected proximodistally from the VM to address this issue. Methods: Surface electromyograms (EMGs) were recorded proximally and distally from the VM while 10 healthy subjects performed isometric contractions. Single motor units were decomposed from surface EMGs. The smoothed discharge rates of motor units identified from the same and from different VM regions were then cross‐correlated. Results: During low‐level contractions, the discharge rate varied more similarly for distal (cross‐correlation peak; interquartile interval: 0.27–0.40) and proximal (0.28–0.52) than for proximodistal pairs of VM motor units (0.20–0.33; P = 0.006). Discussion: The discharge rates of motor units from different proximodistal VM regions show less similarity in their variations than those of pairs of units either distally or proximally.

KW - compartmentalization

KW - knee

KW - motor unit

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KW - surface electromyography

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M3 - Article

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ER -

Is the firing rate of motor units in different vastus medialis regions modulated similarly during isometric contractions? Local Modulation of VM MUs

Abstract

Keywords

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