Menstrual Cycle Associated Alteration of Vastus Lateralis Motor Unit Function

Sports Medicine - Open

Table 3 Multilevel model analysis summary determining hormone and motor unit parameter associations at 10 and 25% MVC

	10% MVC			25% MVC
	Beta	95 CI	p value	Beta	95 CI	p value
Firing rate (Hz)
Estrogen	0.001	− 0.001 to 0.002	0.363	0.001	− 0.001 to 0.002	0.185
Progesterone	0.027	− 0.164 to 0.218	0.785	− 0.021	− 0.191 to 0.150	0.813
Firing rate variability
Estrogen	− 0.001	− 0.031 to 0.028	0.923	− 0.011	− 0.035 to 0.012	0.355
Progesterone	− 0.015	− 0.061 to 0.030	0.516	0.035	− 0.002 to 0.072	0.190
MUP area (µV ms)
Estrogen	− 30.04	− 396.24 to 335.56	0.872	− 130.09	− 649..30 to 387.42	0.625
Progesterone	10.04	− 49.26 to 69.35	0.743	60.14	− 19.66 to 139.95	0.154
MUP turns
Estrogen	− 0.046	− 0.101 to 0.009	0.545	0.019	− 0.011 to 0.051	0.785
Progesterone	− 0.100	− 0.347 to 0.127	0.373	0.034	− 0.183 to 0.252	0.758
NMJ transmission instability (%)
Estrogen	0.138	− 0.509 to 0.864	0.718	0.485	− 0.208 to 1.185	0.183
Progesterone	0.430	− 0.706 to 1.567	0.467	0.606	− 0.491 to 1.705	0.291

Model outputs show unstandardised beta, 95% confidence interval and associated p values. Time applied as a fixed factor
MVC Maximum voluntary contraction, MUP Motor unit potential, NMJ Neuromuscular junction