Table 3.

Mean and standard deviation of muscle volume and Muscle Fatty Infiltrate (MFI) values for left and right side rectus abdominis (RA), psoas (PS), multifidus (M) and erector spinae (ES) in the young and mature group. Pairs of matching superscripts indicate within-group left and right significant differences (^a,b p<0.05, ^c–j p<0.001).

Muscle		Volume (cm3)				MFI (%)
		young		mature		young		mature
		mean	stdev	mean	stdev	mean	stdev	mean	stdev
RA	left	13.78	3.85	12.43a	2.87	37.88c	3.59	39.35g	2.21
	right	13.39	4.05	11.70a	2.25	42.99c	4.51	43.64g	3.11
PS	left	16.67	6.35	14.47	5.38	39.62d	3.71	41.25h	3.89
	right	15.82	5.33	14.11	5.10	31.87d	2.90	32.91h	1.84
M	left	10.89	3.53	9.97	1.68	44.63e	3.41	47.30i	4.00
	right	11.00	3.32	10.25	1.57	36.79e	3.83	40.41i	3.73
ES	left	29.00	10.03	29.17b	6.76	44.65f	3.33	45.52j	3.59
	right	28.24	9.41	28.19b	6.51	34.52f	2.80	37.99j	1.92