Menstrual Cycle Associated Alteration of Vastus Lateralis Motor Unit Function

Sports Medicine - Open

Table 2 Multilevel model analysis summary comparing motor unit parameters from 10 to 25% MVC, at 3 timepoints of the menstrual cycle

	Beta	95 CI	p value
Firing rate (Hz)
Early follicular	− 0.266	− 0.654 to 0.121	0.179
Ovulation	0.380	− 0.010 to 0.770	0.047
Mid luteal	0.434	0.085 to 0.784	0.015
Firing rate variability
Early follicular	0.010	0.003 to 0.017	0.004
Ovulation	0.004	− 0.003 to 0.010	0.290
Mid luteal	0.013	0.007 to 0.019	< 0.001
MUP area (µV ms)
Early follicular	135.21	56.47 to 213.95	0.001
Ovulation	202.84	136.48 to 269.21	< 0.001
Mid luteal	202.65	131.92 to 273.38	< 0.001
MUP turns
Early follicular	− 0.003	− 0.253 to 0.246	0.980
Ovulation	− 0.093	− 0.346 to − 0.716	0.474
Mid luteal	− 0.266	− 0.560 to − 1.769	0.077
NMJ transmission instability (%)
Early follicular	2.114	0.064 to 4.164	0.045
Ovulation	2.005	− 0.087 to 4.096	0.049
Mid luteal	2.221	0.096 to 4.345	0.043

Model outputs show unstandardised beta, 95% confidence interval and associated p values
MVC Maximum voluntary contraction, MUP Motor unit potential, NMJ Neuromuscular junction
Bold indicates significantly different