Table 2.

The results of the non-parametric Mann-Whitney U test

	MCG	FM	p level
CV initial values (m/s)	4.07 ± 0.45	4.32 ± 0.36	NS
CV rate of change (m/s2)	-0.02 ± 0.01	-0.02 ± 0.01	NS
CV norm. rate of change (%/s)	-0.50 ± 0.29	-0.46 ± 0.23	NS
MNF initial values (Hz)	62.28 ± 17.22	57.63 ± 13.26	NS
MNF rate of change (Hz/s)	-0.43 ± 0.29	-0.44 ± 0.19	NS
MNF norm. rate of change (%/s)	-0.64 ± 0.31	-0.74 ± 0.20	NS
ARV initial values (μV)	28.53 ± 13.12	21.24 ± 9.44	NS
ARV rate of change (μV/s)	0.17 ± 0.22	0.16 ± 0.15	NS
ARV norm. rate of change (%/s)	0.58 ± 0.72	0.78 ± 0.64	NS

Mean values ( ± SD) of EMG variables during electrically elicited contractions in the two groups. The results of the non parametric Mann-Whitney U test are reported.

MCG = Matched Control Group, FM = Fibromyalgic group, MVC = maximal voluntary contraction, CV = conduction velocity, MNF = mean spectral frequency, ARV = average rectified value; NS = non significative