Reliability and Validity of Postural Evaluations with Kinect v2 Sensor Ergonomic Evaluation System

Abstract

Postural evaluations are becoming a priority in a world where occupational diseases derivatives from ergonomic situations are progressively common with serious consequences. This document proposes a semi-automatic ergonomic evaluation system with Kinect V2, which use the RULA method. It makes possible the discovery of conditions with postural risk and reduces errors in the estimating the evaluators’ measurements due to lack of experience, expertise and handling of measurement instruments. Reducing the ergonomic evaluation time, compared to the direct postural evaluation method at a low cost. In a controlled environment, 30 participants with homogeneous characteristics are evaluated their postural work, using a direct method (goniometer) and a non-invasive (Kinect V2) method, to then compared the statistically results using the coefficient of correlation named Cohen’s Kappa and vagueness type A. The final RULA scores issued by the direct method of postural evaluation and the proposed system are correlated. The uncertainty results established in the angular measurements on the arm, forearm, wrist, trunk and neck were respectively (±0.36°, ±0.22°, ±0.59°, ±0.27° and ±0.28°). A Cohen’s Kappa correlation coefficient of 0.953 was obtained, which means an almost perfect correlation between the evaluations of both systems.