Investigation of Measurement Errors in Measuring Range of Trunk Rotation

Abstract

[Purpose] In this study, in order to clarify the inter-rater and intra-rater reliability in measurements of range of trunk rotation, we investigated the measurement reliability with and without pelvic fixation. [Subjects] The subject was one 28-year-old healthy male, and there were 10 examiners. [Method] For the measurement of trunk rotation, left and right rotation was measured twice, both with and without pelvic fixation. We determined and analyzed intra-rater reliability with the intra-class correlation coefficient (ICC) and inter-rater reliability by the coefficient of variation (CV) derived from the mean and standard deviation of the first and second measurements. [Results] We found the intra-rater reliability was high (p<0.05) both with and without pelvic fixation. For inter-rater reliability without pelvic fixation, left rotation CV was 22% and right rotation CV was 28%; with pelvic fixation the left and right CVs were 17% and 16%, respectively. [Conclusion] We found a wide dispersion in the measurements of trunk rotation range among the examiners.