INTRARATER AND INTERRATER RELIABILITY OF PHOTOGRAPHIC MEASUREMENT OF UPPER-BODY STANDING POSTURE OF ADOLESCENTS

Objective: The purposes of this study were to determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and analyze differences in postural angles between sexes. Methods: This cross-sectional study was conducted in 2 secondary schools in Portugal where 275 adolescent students (146 females and 129 males) aged 15 to 17 years were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and the Postural Assessment Software. Results: For interrater reliability, all of the intraclass correlation coefficient (ICC) values for the 3 angles were higher than 0.85. For intrarater reliability, the ICC values for the sagittal head angle, shoulder angle, and cervical angle were 0.83, 0.78, and 0.66, respectively. Mean values of sagittal head, cervical, and shoulder angles were 17.2 degrees +/- 5.7 degrees, 47.4 degrees +/- 5.2 degrees, and 51.4 degrees +/- 8.5 degrees, respectively. Anterior head carriage was demonstrated by 68% of the adolescents, whereas 58% had protraction of the shoulder(s). Males had significantly higher mean cervical and sagittal head angles. Conclusions: Forward head posture and protracted shoulders were common postural disorders in adolescents 15 to 17 years old, with females revealing a lower mean cervical angle. The intrarater and interrater evaluation of standing sagittal posture of the cervical spine and shoulders by photogrammetry was reliable.