Key term: observational method

Reviews 2010;36(1):3-24   pdf
Systematic evaluation of observational methods assessing biomechanical exposures at work
Takala E-P, Pehkonen I, Forsman M, Hansson G-Å, Mathiassen SE, Neumann WP, Sjøgaard G, Veiersted KB, Westgaard RH, Winkel J