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Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.

PURPOSE: To examine differences in the electromyographic vs torque (EMG-T) relationship, as well as muscle strength and indicators of muscle mass and quality between young versus postmenopausal females, and explore whether the potential differences in the EMG-T relationships could be explained by di...

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Autores principales: Banks, Nile F., Rogers, Emily M., Jenkins, Nathaniel D.M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9762459/
https://www.ncbi.nlm.nih.gov/pubmed/33123807
http://dx.doi.org/10.1007/s00421-020-04532-0
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author Banks, Nile F.
Rogers, Emily M.
Jenkins, Nathaniel D.M.
author_facet Banks, Nile F.
Rogers, Emily M.
Jenkins, Nathaniel D.M.
author_sort Banks, Nile F.
collection PubMed
description PURPOSE: To examine differences in the electromyographic vs torque (EMG-T) relationship, as well as muscle strength and indicators of muscle mass and quality between young versus postmenopausal females, and explore whether the potential differences in the EMG-T relationships could be explained by differences in muscle mass. METHODS: Thirty young (age = 20.7 ± 2.8 y) and 30 postmenopausal (age = 56.3 ± 4.7 y) females completed maximal isometric strength testing (MVIT) and isometric ramp contractions at 40% and 70% MVIT, during which electromyographic signals were collected to quantify the slopes (Slope(40); Slope(70)) and intercepts (Intercept(40); Intercept(70)) of the EMG-T relationships. Muscle mass and quality measurements were also completed. RESULTS: Postmenopausal females exhibited lower skeletal muscle mass (−2.3 ± 1.5 kg), fat free mass index (−1.1 ± 0.7 kg·m(−2)), MVIT (−17.1 ± 16.3 Nm), phase angle (−0.5 ± 0.0°), muscle cross sectional area (−5.5 ± 1.1 cm(2)), muscle quality (−0.1±0.0 a.u), Slope(40) (−0.0003 ± 0.0002 mV·%MVIT(−1)), Slope(70) (−0.0003 ± 0.0002 mV·%MVIT(−1)), and had a higher echo intensity (+9.8 ± 2.8 a.u), Intercept(40) (+0.001 ± 0.001 mV), and Intercept(70) (+0.004 ± 0.003 mV) (p ≤ 0.001 – 0.04) than the young females. The EMG-T relationship variables were correlated with both muscle mass and quality after controlling for bodyweight. When controlling for muscle mass and bodyweight, group differences in the slopes of the EMG-T relationship and muscle strength were eliminated. CONCLUSION: Muscle mass and quality are primary contributors to the decrements in neuromuscular function observed in postmenopausal versus young females, and the preservation of muscle mass should be prioritized in the years leading up to, during, and immediately after menopause.
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spelling pubmed-97624592022-12-19 Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight. Banks, Nile F. Rogers, Emily M. Jenkins, Nathaniel D.M. Eur J Appl Physiol Article PURPOSE: To examine differences in the electromyographic vs torque (EMG-T) relationship, as well as muscle strength and indicators of muscle mass and quality between young versus postmenopausal females, and explore whether the potential differences in the EMG-T relationships could be explained by differences in muscle mass. METHODS: Thirty young (age = 20.7 ± 2.8 y) and 30 postmenopausal (age = 56.3 ± 4.7 y) females completed maximal isometric strength testing (MVIT) and isometric ramp contractions at 40% and 70% MVIT, during which electromyographic signals were collected to quantify the slopes (Slope(40); Slope(70)) and intercepts (Intercept(40); Intercept(70)) of the EMG-T relationships. Muscle mass and quality measurements were also completed. RESULTS: Postmenopausal females exhibited lower skeletal muscle mass (−2.3 ± 1.5 kg), fat free mass index (−1.1 ± 0.7 kg·m(−2)), MVIT (−17.1 ± 16.3 Nm), phase angle (−0.5 ± 0.0°), muscle cross sectional area (−5.5 ± 1.1 cm(2)), muscle quality (−0.1±0.0 a.u), Slope(40) (−0.0003 ± 0.0002 mV·%MVIT(−1)), Slope(70) (−0.0003 ± 0.0002 mV·%MVIT(−1)), and had a higher echo intensity (+9.8 ± 2.8 a.u), Intercept(40) (+0.001 ± 0.001 mV), and Intercept(70) (+0.004 ± 0.003 mV) (p ≤ 0.001 – 0.04) than the young females. The EMG-T relationship variables were correlated with both muscle mass and quality after controlling for bodyweight. When controlling for muscle mass and bodyweight, group differences in the slopes of the EMG-T relationship and muscle strength were eliminated. CONCLUSION: Muscle mass and quality are primary contributors to the decrements in neuromuscular function observed in postmenopausal versus young females, and the preservation of muscle mass should be prioritized in the years leading up to, during, and immediately after menopause. 2021-02 2020-10-29 /pmc/articles/PMC9762459/ /pubmed/33123807 http://dx.doi.org/10.1007/s00421-020-04532-0 Text en https://creativecommons.org/licenses/by/4.0/Terms of use and reuse: academic research for non-commercial purposes, see here for full terms. https://www.springer.com/aam-terms-v1
spellingShingle Article
Banks, Nile F.
Rogers, Emily M.
Jenkins, Nathaniel D.M.
Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
title Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
title_full Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
title_fullStr Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
title_full_unstemmed Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
title_short Electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
title_sort electromyographic amplitude versus torque relationships are different in young versus postmenopausal females and are related to muscle mass after controlling for bodyweight.
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9762459/
https://www.ncbi.nlm.nih.gov/pubmed/33123807
http://dx.doi.org/10.1007/s00421-020-04532-0
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