INTRODUCTION: The objectives of this study were to determine normal reference values for ultrasonographic measurement of the cross-sectional area (CSA) of the axillary nerve and to standardize the measurement methods.
METHODS: Sixty healthy volunteers were evaluated. Ultrasonography was performed with the shoulder positioned in 100°-120° abduction and 90° external rotation. The CSA of the axillary nerve was measured bilaterally.
RESULTS: The normal CSA of the right axillary nerve was 2.9 ± 1.1 mm2 . The side-to-side discrepancy was 22.8% ± 17.8%.
DISCUSSION: These reference values may be helpful for investigating pathologies involving the axillary nerve.