Examination of the inter-operator reliability of ultrasound measures of multifidus muscle echo intensity

Abstract

[Purpose] We investigated the intra-operator reliability of ultrasound measurements of the multifidus muscle echo intensity and differences in bilateral multifidus muscle intensities. [Subjects and Methods] The subjects were 12 healthy adults who did not have chronic lumbar pain. Multifidus muscle echo intensity was measured with a diagnostic ultrasound scanner in the B mode. To investigate intra-operator reliability, measurements were made twice on the same day and on different days, and the intra-class correlation coefficients (ICCs) were calculated. The paired t-test was used to investigate the differences in bilateral multifidus muscle echo intensities. [Results] For measurements on the same day, the ICC was 0.981 on the right and 0.981 on the left. For measurements on different days, the ICC was 0.898 on the right and 0.775 on the left. There were no differences in bilateral multifidus muscle echo intensity measurements made either on the same day or on different days. [Conclusion] Multifidus muscle echo intensity can be measured with high intra-operator reliability. Our results suggest that there is no difference in bilateral multifidus muscle echo intensities in healthy individuals.