High Density EMG Spatial Distribution of the Vastus Lateralis during Isometric Knee Extension in Young and Older Men and Women

Abstract

Multichannel surface electromyography (EMG) or high density EMG (HDsEMG) can be used to study spatial distribution and muscle characteristics in aging muscle. The purpose of this study was to compare spatial EMG potential distribution during isometric knee extension between young and older men and women. Torque and HDsEMG data were recorded from the vastus lateralis during maximal voluntary isometric knee extension (MVC) from 24 young men and women (ages 19 – 25 years) and 25 older men and women (ages 64-78 years). Spatial distribution was estimated using the RMS value for each of the 32 electrode grid locations and 2-Dimensional (2D) maps were developed for each participant. Peak torque, mean EMG RMS, intensity, were compared across age and gender. Analysis of variance indicated statistically significant differences in peak torque, mean RMS and intensity between age and gender groups. Strength, muscle activation and intensity differ due to age and sex during maximal isometric knee extension. Further research that includes a larger range of submaximal and maximal contractions may provide further insight into the impact of age-related changes in muscle morphology on spatial distribution during force development.