A comprehensive evaluation of the reliability of ultrasound imaging in assessing axioscapular muscle thickness in individuals with and without neck pain.

BACKGROUND

With a greater impact of altered axioscapular muscles on musculoskeletal disorders, attention is being focused on the use of ultrasound imaging to assess these muscles. However, ultrasound measurements can be influenced by several factors. This study aimed to evaluate inter- and intra-rater reliability of ultrasound imaging for measuring axioscapular muscle thickness in individuals with and without neck pain.

METHODS

Twenty healthy adults and 20 individuals with non-specific neck pain were recruited into the study. Measurements were taken using ultrasound imaging at rest and during muscle contraction at 120° of shoulder flexion with a 1-kg load for upper trapezius (UT), lower trapezius (LT), serratus anterior (SA) and levator scapulae (LS). Inter- and intra-rater reliability was examined using intraclass correlation coefficients (ICCs), standard errors of measurements (SEMs), minimum detectable change (MDC) and Bland-Altman plots.

RESULTS

Good to excellent inter- and intra-rater reliability was demonstrated at rest and during muscle contraction for all muscles in healthy adults (ICCs = 0.77 to 0.93 and ICCs = 0.78 to 0.96, respectively) and individuals with neck pain (ICCs = 0.79 to 0.95 and ICCs = 0.79 to 0.98, respectively). Overall, the SEMs and MDCs were relatively small. There were good agreements between examiners and between days, with minimal bias.

CONCLUSIONS

Ultrasound imaging proves to be a reliable tool for assessing axioscapular muscle thickness (i.e., UT, LT, SA and LS), both at rest and during arm elevation in healthy adults and individuals with neck pain. However, standardized protocols and proper training are essential for ensuring consistent results.