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

Eur J Appl Physiol

Kinesiology, Applied Health and Recreation, Department of Nutritional Sciences, Applied Neuromuscular Physiology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA.

Published: February 2021

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; Slope) and intercepts (Intercept; Intercept) 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), MVIT (- 17.1 ± 16.3 Nm), phase angle (- 0.5 ± 0.0°), muscle cross-sectional area (- 5.5 ± 1.1 cm), muscle quality (- 0.1 ± 0.0 a.u), Slope (- 0.0003 ± 0.0002 mV·%MVIT), Slope (- 0.0003 ± 0.0002 mV·%MVIT), and had a higher echo intensity (+ 9.8 ± 2.8 a.u), Intercept (+ 0.001 ± 0.001 mV), and Intercept (+ 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.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9762459PMC
http://dx.doi.org/10.1007/s00421-020-04532-0DOI Listing

Publication Analysis

Top Keywords

muscle mass
32
mass quality
16
muscle
13
postmenopausal females
12
emg-t relationship
12
mass
9
young versus
8
versus postmenopausal
8
controlling bodyweight
8
muscle strength
8

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!