Accuracy and reliability of a low-cost methodology to assess 3D body posture based on commercial cameras and Excel templates

Abstract

Analysing posture in 3D generally requires expensive equipment and complex software, not accessible to most healthcare centres. The aim was to evaluate a 3D postural analysis methodology based on commercial cameras, a portable calibration device and Excel, a popular spreadsheet software. The accuracy and reliability of the methodology were studied using a 3D optical motion capture system with submillimetre accuracy as reference. 99 length and 99 angular anthropometrics parameters of 9 subjects were measured and Lin’s concordance correlation coefficient (Lin’s CCC), magnitudes of errors and Bland Altman graphs were computed. The measurement errors were of approximately 2 mm and of 1–2 deg, and the methodology was reliable (Lin’s CCCs above 0.99). The suggested low-cost methodology could be used for applied 3D postural studies, analysing asymmetries, postural alterations or population-based anthropometric parameters, where usually submillimetre accuracy is not required and therefore can be useful for medical centres with a limited budget.