Abstract
BACKGROUND: The reliable assessment of cervical muscle morphology is essential for both clinical and research use. However, evidence on the reliability of ultrasound measurements remains limited. OBJECTIVE: To investigate the intra-rater and test-retest reliability of morphological measurements of the Longus Colli, Sternocleidomastoid, Multifidus Cervicis, and Semispinalis Capitis muscles using musculoskeletal ultrasound. METHODS: Cross-sectional area, anteroposterior, and lateral dimensions were assessed using B-mode ultrasound. Anterior neck muscles were scanned in the supine position, while posterior neck muscles were scanned in the prone position. Each muscle was measured three times (to assess intra-rater reliability), which was repeated after 30 min (to assess test-retest reliability). Measurements were also normalized according to BMI and neck circumference. RESULTS: Intra-rater reliability was found to be good to excellent for the Longus Colli (ICC = 0.77-0.92), excellent for the Sternocleidomastoid (ICC = 0.93-0.99), good to excellent for the Semispinalis Capitis (ICC = 0.89-0.97), and moderate to excellent for the Multifidus Cervicis (ICC = 0.69-0.92). Test-retest reliability was found to be moderate to good for the Longus Colli (ICC = 0.73-0.87), good to excellent for the Sternocleidomastoid (ICC = 0.84-0.98), good to excellent for the Semispinalis Capitis (ICC = 0.78-0.95), and good to excellent for the Multifidus Cervicis (ICC = 0.80-0.92). CONCLUSIONS: Musculoskeletal ultrasound demonstrates strong reliability for cervical muscle assessment, supporting its clinical use.