A software toolbox to improve time-efficiency and reliability of an observational risk assessment method

Abstract

OCRA is a standard risk assessment method addressing manual handling of low loads at high frequency. This method requires the operator to perform a video analysis checking kind and extension of the movements made by workers. The analyst has to take note about number of performed actions and joint angles amplitude. Often this turn out to be a poorly reliable and time-consuming operation because of the inherent 2D nature of the data. The main goal of this work was to design a software toolbox able to support the operator in collecting, organizing and analyzing the information to obtain the Checklist OCRA index in a more reliable and time-effective way. This toolbox presents three different GUIs to: (1) support the operator in counting the number of technical actions; (2) help the operator in determine the percentage of time in which the worker has an incorrect upper limb posture; (3) automatically perform posture analysis considering real 3D angles data acquired through an IMU-based movement analysis system. Preliminary analysis on reliability was performed on three different operators. Obtained findings confirmed our hypothesis; the automatic analysis, in particular, reduced significantly intra- and inter-operator variability thus making the analysis more objective and reliable. Further evaluations will include structured assessment including several operators with different expertise levels and collecting information about user experience (usability, GUI design, etc.) and overall performance compared to standards (operation time and results accuracy).