Camera angle variation in the range of motion’s assessing by computerized photogrammetry

ABSTRACT The computerized photogrammetry has been highlighted as a non-invasive resource for evaluation, with good reproducibility of results, but its application parameters are still lacking standardization. This study compared outcomes of range of motion obtained with photogrammetric assessments from images photographed in different camera inclinations in relation to the object (0°, 5°, 10°, 15°, 20°, 25°, and 30°). The images were analyzed with computerized photogrammetry by six raters who assessed the joint range present in the images. The outcomes showed that even with 5° in camera inclination, there was significantly different results between assessments, and the margin of error increased as the camera inclination was intensifying.摘要 计算机化摄影测量法（computerized photogrammetry）作为非侵入性评估工具，因其结果具备良好可重复性而备受关注，但其应用参数仍缺乏统一的标准化规范。本研究针对相机相对拍摄对象呈不同倾斜角度（0°、5°、10°、15°、20°、25°及30°）时拍摄的图像，对比了通过摄影测量评估获取的关节活动度结果。六名评估者采用计算机化摄影测量法对上述图像进行分析，评估图像中呈现的关节活动范围。结果显示，即便相机倾斜角度仅为5°，不同评估间的结果即存在显著差异；且随着相机倾斜角度增大，误差幅度亦随之扩大。