Ultrasound shear wave elastography to assess neck somatic dysfunction and OMT effects.

Context: Osteopathic assessment and osteopathic manipulative treatment (OMT) have been utilized in managing chronic neck pain (CNP) and neck somatic dysfunction. However, osteopathic assessments lack quantitative measures to detect muscle abnormalities and evaluate the effect of OMT.

Objectives: This study aims to investigate the feasibility of utilizing ultrasound shear wave velocity (SWV) and shear wave relative anisotropy coefficient (SWRAC) to assess neck somatic dysfunction and the effect of OMT.

Methods: After receiving Institutional Review Board (IRB) approval and informed consent, we measured upper trapezius muscle (UTM) SWV in both longitudinal and transverse planes. We calculated SWRAC utilizing the formula: (SWV _longitudinal - SWV _transverse)/SWV _transverse. We analyzed differences in muscle SWV and SWRAC between different age groups utilizing one-way analysis of variance (ANOVA). For the comparison in SWV and SWRAC between UTMs with and without neck somatic dysfunction, we utilized an unpaired t-test, although we examined the changes in SWV and SWRAC before and after OMT utilizing a paired t-test. We also evaluated correlations between SWV and muscle somatic dysfunction utilizing Spearman correlation. The diagnostic performance of SWV in identifying neck somatic dysfunction was assessed utilizing the area under receiver operating characteristic curve (AUC). Inter- and intra-observer reliability in measuring muscle SWV was analyzed utilizing intraclass correlation coefficient (ICC).

Results: From November 2022 to August 2024, we measured muscle SWV in 158 adults (68 men, 90 women, mean age 49 years) without (51) and with (107) neck somatic dysfunction. We observed significant differences in SWV and SWRAC between UTMs with and without somatic dysfunction, and before and after OMT (p<0.01). Longitudinal muscle SWV was high in elderly subjects and those with neck somatic dysfunction. Longitudinal SWV positively correlated to neck somatic dysfunction (R ²=0.69). AUC of SWV for determining neck somatic dysfunction was 0.86. ICCs for measuring SWV ranged from 0.80 to 0.99.

Conclusions: The SWV in longitudinal muscles shows a positive correlation with neck somatic dysfunction, demonstrating moderate diagnostic accuracy and strong observer reliability. Application of OMT significantly decreases muscle stiffness measured by SWV, providing an objective and quantitative method to assess the effectiveness of OMT.