Table 2. The median and interquartile intervals (Q1–Q3) and peak amplitudes of the muscles analyzed.

Muscles#	C group**	CLBP group**
ROI	1.84 (0.78–2.18)	1.23 (1.00–2.44)*
LOI	1.53 (1.00–2.08)	1.28 (1.05–1.80)*
RLES	1.11 (0.99–1.32)	1.52 (1.05–8.07)*
LLES	1.13 (0.64–2.00)	1.36 (1.09–5.28)*
RGM	1.60 (1.00–2.10)	1.25 (1.00–2.16)*
LGM	1.81 (1.02–2.11)	1.19 (1.04–2.31)*

^#Right and left (R, L) obliquus internus abdominis (OI), the lumbar erector spinae (LES) and the gluteus medius (GM). **C group= asymptomatic subjects, CLBP group= chronic low back pain patients. * p<0.05