Abstract Summary
Neck pain (NP) is one of the most common and disabling musculoskeletal conditions in the world and is more prevalent in females. As a part of clinical examination for individuals with NP, ultrasound (US)-based imaging biomarkers of the cervical muscles have been increasingly utilized: cross sectional area, thickness, and stiffness measurements [via USbase shear wave elastography (SWE) technology]. However, reliability of such measurements and sex differences in healthy young individuals are limited. A total of 13 females and 11 males participated in the study. Measurements were repeated later within the same day for reliability analyses. Sex differences were examined with independent t-tests. Good to excellent reliabilities were found except for the sternocleidomastoid SWE stiffness. For sex comparisons,¶ males had significantly thicker sternocleidomastoid and cervical extensor muscles than females. Stiffness¶ measurements were not different between sexes.