The Effect of Sex and Menstrual Cycle Phase on Neuromuscular Control of Trunk Musculature

Abstract

Women have higher rates of noncontact musculoskeletal injuries compared to men, as well as at certain times in their menstrual cycles compared to others. The purpose of this study was two-fold: i) to examine the neuromuscular activation patterns of trunk musculature between men and women and ii) within women at different times in their menstrual cycle, during the trunk stability test (TST). The TST is a dynamic lower limb exercise that challenged the trunk musculature to maintain lumbopelvic stability. Surface electromyograms for 24 muscle sites and three-dimensional pelvic motion data were collected during the TST for 18 male and 19 female subjects, as well as for nine female subjects at different times in their menstrual cycles. Through analysis of amplitude and temporal characteristics of the EMG waveforms it was determined that women respond to the TST task with a less coordinated response than men, mainly relying on more co-activation. It was further determined that women have differences in their neuromuscular control patterns during the TST at different points in their menstrual cycle.