Intraclass correlation coefficients were calculated using the first and second measurements of each observer to evaluate intra-rater reliability and correlation coefficients were calculated using the first measurements of the three observers to evaluate inter-rater reliability. Measurements of the L4-L5 level and the entire lumbar spine of T12-S1 were used as representative values to evaluate reliability.
For statistical analysis, the unpaired t-test was used for comparison between the two groups, and ANOVA followed by the Tukey-Kramer test was used for multiple comparisons. The correlation coefficient between age and intervertebral ROLB was calculated. Statistical processing was performed using JMP (ver. 15.0; SAS Institute Inc. Cary, NC). A difference of P < 0.05 was considered statistically significant.
For statistical analysis, the unpaired t-test was used for comparison between the two groups, and ANOVA followed by the Tukey-Kramer test was used for multiple comparisons. The correlation coefficient between age and intervertebral ROLB was calculated. Statistical processing was performed using JMP (ver. 15.0; SAS Institute Inc. Cary, NC). A difference of P < 0.05 was considered statistically significant.