SJMSS_Accepted_Lanza et al 2018 Mmax normalisation_adiposity & location.pdf (631.91 kB)

Does normalization of voluntary EMG amplitude to MMAX account for the influence of electrode location and adiposity?

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journal contribution
posted on 06.08.2018, 08:24 by Marcel Bahia Lanza, Tom Balshaw, Garry J. Massey, Jonathan Folland
Voluntary surface electromyography (sEMG) amplitude is known to be influenced by both electrode position and subcutaneous adipose tissue thickness, and these factors likely compromise both between- and within-individual comparisons. Normalization of voluntary sEMG amplitude to evoked maximum M-wave parameters [MMAX peak-to-peak (P-P) and Area] may remove the influence of electrode position and subcutaneous tissue thickness. The purpose of this study was to: (i) assess the influence of electrode position on voluntary, evoked (MMAX P-P and Area) and normalized sEMG measurements across the surface of the vastus lateralis (VL; experiment 1: n=10); and (ii) investigate if MMAX normalization removes the confounding influence of subcutaneous tissue thickness [muscle-electrode distance (MED) from ultrasound imaging] on sEMG amplitude (experiment 2; n=41). Healthy young men performed maximum voluntary contractions (MVCs) and evoked twitch contractions during both experiments. Experiment 1: voluntary sEMG during MVCs was influenced by electrode location (P≤0.046, ES≥1.49 "large"), but when normalized to MMAX P-P showed no differences between VL sites (P=0.929) which was not the case when normalized to MMAX Area (P<0.004). Experiment 2: voluntary sEMG amplitude was related to MED, which explained 31-38% of the variance. Normalization of voluntary sEMG amplitude to MMAX P-P or MMAX Area reduced but did not consistently remove the influence of MED which still explained up to 16% (MMAX P-P) and 23% (MMAX Area) of the variance. In conclusion, MMAX P-P was the better normalization parameter for removing the influence of electrode location and substantially reduced but did not consistently remove the influence of subcutaneous adiposity.

History

School

  • Sport, Exercise and Health Sciences

Published in

Scand J Med Sci Sports

Citation

LANZA, M.B. ... et al, 2018. Does normalization of voluntary EMG amplitude to MMAX account for the influence of electrode location and adiposity?. Scandinavian Journal of Medicine & Science in Sports, 28(12), pp. 2558-2566.

Publisher

© Wiley

Version

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/

Publication date

2018

Notes

This is the peer reviewed version of the following article: LANZA, M.B. ... et al, 2018. Does normalization of voluntary EMG amplitude to MMAX account for the influence of electrode location and adiposity?. Scandinavian Journal of Medicine & Science in Sports, 28(12), pp. 2558-2566, which has been published in final form at https://doi.org/10.1111/sms.13270. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

ISSN

0905-7188

eISSN

1600-0838

Language

en

Location

Denmark

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