Contribution of situational operational leeway for ergonomic assessment in the evaluation of work situations

This study investigates the problems related to identifying MSD risk factors using simple risk assessment tools. The purpose is to study the contribution of situational operational leeway (SOL) indicators as a complementary method to the information provided by simple MSD risk assessment tools and to show how SOL might be a supplement to these established tools. Eight simple tools (OSHA, RULA, REBA, QEC, CE, EAWS, NIOSH, and MAC) were used to evaluate ten workstations in the metallurgy industry. The indicators of SOL, derived from the human-centred activity model, were also explored in the same workstations to define whether SOL is adequate. The results of these two approaches were compared to identify the difference between them. Analysing the risk of MSD on ten workstations using eight simple tools showed the variability of exposure between tools for identical work situations. We analysed the same workstations with the SOL indicators, and disagreement was found in judgment between the two approaches of MSD risk identification. The SOL indicators estimated a lower risk of MSD than the simple tools. This study proposes that SOL indicators might improve the phase of MSD risk identification as a complement to the current simple tools.