Objective: At present there is no systematic observation protocol for the assessment of the multi-factorial aspects of physical exposure related to the back used within the constraints of occupational epidemiological research. In this context, a new preliminary systematic observation protocol is proposed to assess exposure to physical loading of the back using nine categories of physical risk factors: the SOPE back protocol. The objective of this study was to investigate whether the new protocol can correctly identify the level of exposure related to measured physical loading of the back.
Methods: The subjects of this closed cohort study were 451 manual workers at a natural gas distribution company. The assessment of exposure was made with the protocol using groups with different job titles. The workers were followed for a 2 yr period to establish the risk of a new occurrence of complete disability related to the back (NOCD back injury) in each job grouping.
Results: Based on the median of the total scores derived from the protocol, two levels of exposure were identified (high and low).
Conclusion: Taking into account the limitations of this study, the protocol in development may be a good tool to establish two levels of exposure to physical loading of the back in large epidemiological studies of occupational low back pain. Further research is needed to replicate these results with larger samples and to test the reliability and predictive validity of the protocol.