Reliability and validity of angular measures through the software for postural assessment. Postural Assessment Software

Introduction Static posture analysis with the aid of specific software with images is beneficial for large-scale studies and facilitates the diagnosis, planning and follow-up of any physiotherapy treatment. Therefore, this study aimed to determine test-retest and inter-rater reliability and validity of computerized photogrammetry using the Postural Assessment Software (PAS) in relation to goniometry. Materials and methods Universal Goniometers were placed in a wall of the Lab, making it possible to obtain four angular measures. A digital camera was positioned on a tripod at a height of 147 cm and at a distance of three meters from the wall. A photo was taken with the four goniometers. Two more photos were taken, and the goniometer angles were changed within each photo, obtaining 12 different angular values. Each photograph was analyzed by the three raters using the Postural Assessment Software. Bland-Altman method was used to document the agreement between raters and between Goniometry and Postural Assessment Software. Results There were no statistical differences between the two evaluation methods: goniometry and PAS software. The Bland-Altman graph supported the strong consistency between methods, with an average difference equal to 0.06. The use of PAS software was also shown to be intra-rater reliable, with the three raters (A, p = 0.17; B, p = 0.31; C, p = 0.17) with no statistical significant differences between the first and the second measurement, and to have good inter-rater reliability with no statistical differences between raters. Conclusions Postural Assessment Software is an accurate and reliable method when compared to the goniometry.