Intra- and inter-examiner reliability for popliteal angle assessment by photogrammetry

Abstract

Introduction: Angles used by photogrammetry need reliability studies for routine use. Objective: To evaluate the reliability intra- and inter-examiner by photogrammetry software SAPO in popliteal angle measures. Methods: Participated 20 volunteers and three goniometric measures were performed and photographs were taken, showing the goniometer and the popliteal angle (M1). Three observers examined the photos using SAPO. The measurements were repeated 48 h after M1 (M2) and the data analyzed by paired and independent t-test, by Pearson coefficient (r), coefficient of variation (CV) (relative and absolute reliability, respectively) and consistency by intraclass correlation coefficient (ICC), with p<0.05. Results: The t-test did not detect differences between the results. The r ranged from 0.9031 to 0.9983, with p<0.0001. The goniometric and photogrammetric ICC were classified as very good and excellent (p<0.0001). The CV presented inter-examiner data of 0.21% in M1 and 0.17% in M2 and intra-examiner data of 1.32%. Conclusion: Reliability inter and intra-examiners were established to evaluate popliteal angle.