Table 2.

Comparison of nerve cross-sectional area measurements (mm²) among different age and gender groups.

	Age ≥ 20 and < 40		Age ≥ 40 and < 60		Age ≥ 60
	Men	Women	Men	Women	Men	Women	p-value (overall)
CSA (C5, IE)	8.37 ± 1.59a	6.38 ± 1.04adef	8.40 ± 1.30d	7.95 ± 0.72e	8.19 ± 1.59f	7.51 ± 0.91	<0.001
CSA (C6, IE)	9.14 ± 2.06	8.18 ± 1.54d	10.09 ± 1.44dgh	8.53 ± 0.89g	9.21 ± 1.27	8.33 ± 1.14h	<0.001
CSA (SNBP, IE)	2.04 ± 0.54abc	1.58 ± 0.32adf	2.10 ± 0.43dgh	1.52 ± 0.23bgi	2.14 ± 0.38fij	1.37 ± 0.36chj	<0.001
CSA (SNMC, IE)	2.07 ± 0.47bc	1.73 ± 0.61	2.03 ± 0.36h	1.63 ± 0.37bi	2.09 ± 0.43ij	1.42 ± 0.33chj	<0.001
CSA (C5, OE)	15.63 ± 3.40ac	11.67 ± 1.76adef	16.17 ± 3.21dh	14.27 ± 2.38e	14.92 ± 2.77f	12.97 ± 1.76ch	<0.001
CSA (C6, OE)	16.87 ± 3.10	14.90 ± 2.49d	18.11 ± 3.09d	15.68 ± 2.36	16.97 ± 2.13	16.45 ± 2.16	0.004
CSA (SNBP, OE)	4.98 ± 1.89c	4.20 ± 1.20	4.78 ± 1.07h	4.05 ± 0.99	4.99 ± 0.96j	3.55 ± 0.86chj	<0.001
CSA (SNMC, OE)	4.38 ± 0.66c	4.12 ± 1.40k	4.59 ± 069h	4.07 ± 0.98l	4.97 ± 0.82j	2.58 ± 1.48ckhlj	<0.001
CSA (SNSS, OE)	10.18 ± 2.29	9.34 ± 2.18	11.07 ± 2.80	9.31 ± 1.87	10.56 ± 1.31	9.73 ± 1.08	0.038
CSA (SNIS, OE)	10.99 ± 2.52	9.41 ± 9.62	9.62 ± 1.95	9.80 ± 1.67	9.35 ± 1.35	10.42 ± 1.40	0.048

CSA, cross-sectional area; IE, inside-epineurium method; OE, outside-epineurium method; SNBP, suprascapular nerve departing from the brachial plexus; SNMC, suprascapular nerve at the mid-clavicular level; SNSS, suprascapular nerve at the floor of the supraspinatus fossa; SNIS, suprascapular nerve at the spinoglenoid notch of the infraspinatus fossa.

Annotation for post-hoc analysis of between-group difference:

^a indicates significant between men (age ≥ 20 and < 40) and women (age ≥ 20 and < 40);

^b indicates significant between men (age ≥ 20 and < 40) and women (age ≥ 40 and < 60);

^c indicates significant between men (age ≥ 20 and < 40) and women (age ≥ 60);

^d indicates significant between women (age ≥ 20 and < 40) and men (age ≥ 40 and < 60);

^e indicates significant between women (age ≥ 20 and < 40) and women (age ≥ 40 and < 60);

^f indicates significant between women (age ≥ 20 and < 40) and men (age ≥ 60);

^g indicates significant between (age ≥ 40 and < 60)and women (age ≥ 40 and < 60);

^h indicates significant between men (age ≥ 40 and < 60) and women (age ≥ 60);

ⁱ indicates significant between women (age ≥ 40 and < 60) and men (age ≥ 60);

^j indicates significant between women (age ≥ 60) and men (age ≥ 60);

^k indicates significant between women (age ≥ 20 and < 40) and women (age ≥ 60);

^l indicates significant between women (age ≥ 40 and < 60) and women (age ≥ 60).