Neck Muscle Stiffness in Participants With and Without Chronic Neck Pain: A Shear-Wave Elastography Study

Objectives: The purpose of the present study was to investigate differences in neck muscle stiffness between patients with chronic neck pain and asymptomatic control group. Methods: Thirty-eve patients with chronic neck pain and 35 age-matched asymptomatic participants enrolled in the study. Shear wave velocity (SWV) of upper trapezius, levator scapulae, splenius capitis, and sternocleidomastoid muscles were obtained using an ACUSON S3000 Ultrasonography Device (Siemens Medical Solutions, Mountain View, California). In patients with chronic neck pain, pain intensity was measured by Numerical Rating Scale and disability level was measured by Neck Disability Index. Results: The SWV of splenius capitis was similar in both groups (P = .985); however, SWV of upper trapezius (P = .001), levator scapulae (P = .038), and stemocleidomastoid (P = .001) of the patients with chronic neck pain were higher compared with the asymptomatic controls groups. Numerical Rating Scale and Neck Disability Index scores did not correlate with the SWV of the selected muscles (P > .05). Conclusions: Stiffness of upper trapezius, levator scapulae, and stemocleidomastoid muscles in patients with neck pain were higher compared to asymptomatic participants. In addition, severity of pain and disability did not correlate to stiffness of these muscles in patient with chronic neck pain.