Reproducibility of the low back clinical postural grouping in adolescents

OBJECTIVE: The purpose of this study was to analyze the intra- and inter-rater reliability of the Low Back Clinical Postural Grouping (LBCPG). METHODS: Fifty-eight school adolescents were evaluated by lateral photography. The examiners classified the posture of the participants as: hyperlordotic, sway back, flat back or neutral. The intra- and inter-rater reliability were quantified by the percentage agreement between clinicians and the kappa coefficient with 95% confidence intervals (95% CI). RESULTS: The intra-rater percentage agreement was 91.4%, k = 0.87 (95% IC 0.77-0.98, p < 0.001) for the more experienced rater, and 86.2% k = 0.79 (IC 95% 0.62-0.96, p < 0.001) for the less experienced rater. The percentage agreement between clinicians was 55.17% k = 0.39 (95% CI: 0.23-0.55, p < 0.001). The agreement rose to 70.69%, k = 0.58 (95% CI 0.41-0.74, p < 0.001) when an optional second opinion of the raters was also considered. CONCLUSION: The LBCPG was reliable when used by the same clinician. The strategy of a second opinion could be used to improve the inter-rater reliability in epidemiological studies with large samples.