The non-explicit observational method is reproducible and valid in the analysis of occupational biomechanical...

An analysis of workers' exposure to biomechanical risk factors in the workplace with a high methodological quality allows for stronger evidence of the relationship between risk factors and musculoskeletal disorders.

To evaluate the measurement properties of non-explicit observational methods.

Psychometric study design that included 50 workers in an analysis of occupational tasks (n = 50 video tasks) using a non-explicit observational method, the Rapid Entire Body Assessment (REBA) method, and a workers' self-report on their perception of their biomechanical occupational exposure. The reliability was tested by a non-explicit method and the REBA method. The validity of the non-explicit method was tested using the REBA method and the workers' self-report, according to COSMIN guidelines.

The intra- and inter-evaluator reliability of the non-explicit observational method ranged from moderate to strong (ICC2.1  = 0.45 to 0.87), and the agreement was acceptable (SEM = 0.60 to 2.79), expect for neck region. The REBA method showed intra-evaluator reliability to be moderate to excellent (ICC2.1  = 0.50 to 1.00), inter-evaluator reliability to be poor to strong (ICC2.1  = -0.17 to 0.83), and intra- and inter-evaluator agreement to be poor to moderate (SEM = 0.00 to 0.74). The concurrent validity between the non-explicit and REBA methods showed a strong positive correlation.

The non-explicit observational method of biomechanical exposure analysis presented reproducible and valid measurement properties. Methods that present better measurement properties provide professionals with a better basis for analysis and assist in decision-making to reduce or eliminate risk exposure.