Reliability intra-and inter-examiner of the head postural assessment by computerized photogrammetry

Scientific articles about reliability of photogrammetry for cervical spine posture evaluation are infrequent. The aim of the present investigation is to verify intra-and inter-examiner reliability of the computerized photogrammetry method for head postural evaluation in lateral view. Twenty-five young women, between 20 and 30 years old, were positioned seated in an upright position and photographed in lateral view. The photographs were imported to Corel Draw X13 program for postural evaluation by computerized photogrammetry. Analyses of intra-and inter-examiner reliability were performed for the angles: condyle-acromion (ACA), menton-sternum (AME) and Frankfurt (AF). The photogrammetry was performed by two examiners: EA and EB. For intra-examiner analyses, EA assessed the pictures twice (A1 and A2) for the same angles within 3 months. For the inter-examiner analyses, EB performed the photogrammetry for the same angles (B1) in order to compare with the data from EA. Using the interclass correlation coefficient (ICC) we observed an excellent correlation in the intra-examiner analysis (A1 and A2) for the angles: ACA and AME (both with ICC=1.0); and AF (ICC=0.78). For the inter-examiner analyses between A1 and B1, it was observed: ACA (ICC=0.24), AME (ICC=0.26) and AF (ICC=0.00). For the comparison between A2 and B1, the ICC values were: 0.23; 0.27 and 0.00, respectively for ACA, AME and AF, classified as weak correlations. In conclusion, the photogrammetry is reliable when performed by the same examiner. The inter-examiner assess showed low reliability, what could have been compromised by the reduced experience of the EB in applying the method.

目前针对颈椎姿势评估中摄影测量法可靠性的学术研究较为少见。本研究旨在验证计算机辅助摄影测量法在侧位头部姿势评估中的检验者内与检验者间可靠性。本研究招募25名年龄介于20至30岁的年轻女性，使其取直立坐姿并拍摄侧位影像。将拍摄得到的影像导入Corel Draw X13软件，通过计算机辅助摄影测量法完成姿势评估。本研究针对髁突-肩峰角（condyle-acromion, ACA）、颏点-胸骨角（menton-sternum, AME）以及法兰克福平面角（Frankfurt, AF）三个角度开展检验者内与检验者间可靠性分析。本次摄影测量由两名检验者EA与EB完成。针对检验者内可靠性分析，EA在3个月内对同一组影像重复开展两次角度测量（记为A1与A2）。针对检验者间可靠性分析，EB对相同影像开展角度测量（记为B1），以与EA的测量结果进行对比。通过组内相关系数（interclass correlation coefficient, ICC）分析可知，检验者内分析（A1与A2）中，ACA与AME的相关性极佳（ICC值均为1.0），AF的ICC值为0.78。在A1与B1的检验者间对比分析中，ACA的ICC值为0.24，AME为0.26，AF为0.00。在A2与B1的对比分析中，ACA、AME与AF的ICC值分别为0.23、0.27与0.00，均属于弱相关性。综上，当由同一检验者开展操作时，该摄影测量法具有良好的可靠性；而检验者间评估的可靠性较低，这可能与EB对该方法的操作经验不足有关。