Table 3.
Overview of CSA with based on age and gender.
| Age | Gender | |||||||
| Nerve | Site | <40 y (n = 40) | 40–59 y (n = 40) | ≥60 y (n = 27) | P∗ | Male (n = 51) | Female (n = 56) | P† |
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | ||||
| Median | Wrist‡ | 8.70 (1.41) | 9.64 (1.33) | 9.8 (1.76) | .003 | 9.73 (1.42) | 8.98 (1.57) | .008 |
| Forearm | 6.25 (1.51) | 6.13 (1.30) | 6.69 (1.69 | .397 | 7 (1.47) | 5.70 (1.22) | <.001 | |
| Below-elbow | 6.55 (1.62) | 7 (1.78) | 7.07 (1.41) | .219 | 7.49 (1.65) | 6.27 (1.39) | <.001 | |
| Antecubital fossa | 8.58 (2.54) | 9.18 (2.55) | 9.22 (1.99) | .303 | 10.20 (2.45) | 7.84 (1.76) | <.001 | |
| Mid-arm | 9.03 (2.11) | 9.53 (2.86) | 9.52 (1.99) | .597 | 10.39 (2.6) | 8.38 (1.68) | <.001 | |
| Axilla | 9.53 (2.65) | 10.03 (2.72) | 10.19 (1.96) | .284 | 11.2 (2.5)) | 8.68 (1.86) | <.001 | |
| WFR | 1.49 (0.4) | 1.66 (0.35) | 1.58 (0.4) | .083 | 1.47 (0.33) | 1.66 (0.41) | .033 | |
| Ulnar | Wrist | 4.85 (1.14) | 5.38 (1.43) | 5.04 (1.26) | .178 | 5.73 (1.22) | 4.52 (1.08) | <.001 |
| Arterial split | 5.28 (1.36) | 6 (1.38) | 6.04 (1.43) | .022 | 6.35 (1.41) | 5.18 (1.18) | <.001 | |
| CT outlet | 6.55 (1.85) | 7.10 (1.57) | 7.26 (1.95) | .143 | 7.88 (1.84) | 6.07 (1.22) | <.001 | |
| ME | 6.78 (1.46) | 7.58 (1.71) | 7.73 (1.85) | .031 | 8 (1.77) | 6.7 (1.36) | <.001 | |
| Proximal 2 cm to ME | 6.75 (1.45) | 7.28 (1.83) | 7.41 (1.58) | .252 | 7.53 (1.64) | 6.73 (1.55) | .008 | |
| Mid-arm | 6.25 (1.46) | 6.53 (1.72) | 6.33 (1.49) | .813 | 7.08 (1.7) | 5.73 (1.09) | <.001 | |
| Axilla | 6.68 (2.25) | 7.1 (1.88) | 7.11 (1.67) | .213 | 7.9 (2.08) | 6.07 (1.39) | <.001 | |
| Radial | Above SG | 6.63 (1.79) | 6.95 (1.71) | 7.7 (2.07) | .122 | 7.49 (1.75) | 6.59 (1.89) | .005 |
| Spiral groove | 6.33 (1.59) | 6.88 (1.54) | 7.41 (2.08) | .063 | 7.16 (1.69) | 6.5 (1.75) | .03 | |
| Antecubital fossa | 6.8 (1.36) | 7.33 (1.87) | 7.85 (1.75) | .037 | 7.41 (1.9) | 7.13 (1.5) | .521 | |
| SRS | Proximal forearm | 2.2 (0.79) | 2.73 (0.96) | 2.59 (0.69) | .028 | 2.43 (0.94) | 2.55 (0.78) | .377 |
| PIN | Proximal forearm | 1.83 (0.64) | 2.13 (0.69) | 2.15 (0.72) | .088 | 2.24 (0.62) | 1.82 (0.69) | .001 |
| MACN | Mid-arm | 3.2 (1.22) | 3.53 (1.22) | 3.11 (0.8) | .342 | 3.76 (1.19) | 2.88 (0.9) | <.001 |
| LACN | Elbow | 3.18 (1.28) | 3.48 (1.47) | 3.15 (0.99) | .54 | 3.92 (1.38) | 2.7 (0.85) | <.001 |
| MC | Axilla | 3.78 (1.25) | 3.9 (1.43) | 3.74 (1.13) | .96 | 4.18 (1.35) | 3.48 (1.13) | .004 |
All values are in mm2 except for WFR. CSA = cross-sectional area, CT = cubital tunnel, LACN = lateral antebrachial cutaneous nerve, MACN = medial antebrachial cutaneous nerve, MC = musculocutaneous nerve, ME = medial epicondyle, n = number of subjects, PIN = posterior interosseous nerve, SD = standard deviation, SG = spiral groove, SRS = superficial radial sensory, WFR = wrist-to-forearm median nerve CSA ratio, y = years.
∗
P-values calculated using the Kruskal–Wallis test or ANOVA test.
†
P-values calculated using Wilcoxon rank sum test or t test.
‡
The CSA values at the wrist obtained from 98 subjects were analyzed (male = 47, female = 51, <40 = 37, 40–59 = 36, ≥60 = 25).