Objective To compare the application of two job posture load assessment methods, the Ovako working posture analysis system (OWAS) and the rapid entire body assessment (RULA), in the iron and steel industry and to understand the ergonomic load of workers, providing the basis for ergonomic intervention measures.
Methods Totally 35 main work activities in an iron and steel industry were investigated, and video capture of each activity was carried out. OWAS and RULA were used to assess the postural overloads, and the results derived from the two methods were compared.
Results The assessment with the OWAS method showed there were 4 low (11.4%), 20 medium (57.1%), 9 high (25.7%), and 2 extremely high risk activities (5.7%). The assessment with the RULA method evaluated showed there were 4 low (11.4%), 17 medium (48.6%), 10 high (28.6%), and 4 extremely high risk activities (11.4%); 30 work activities were assessed at the same level of risk by these two methods with a consistency rate of 85.7%, and for the remaining 5 activities, OWAS assessed a lower risk level than RULA. The Kappa statistic showed that the two methods had strong consistency (Kappa value = 0.773, P < 0.05). The results showed that the risk grade of iron-making, steel-making, and special steel divisions was higher (P < 0.05).
Conclusions These two methods of risk assessment were highly consistent in the iron and steel industries. Compared with OWAS, RULA was more sensitive to the working posture with high biomechanical load on upper limbs and neck-back and could better reflect the risk level of working activities in the iron and steel industries.