Several observational methods are available for ergonomists to evaluate the exposure to musculoskeletal disorder (MSD) risk factors associated with work. Those methods can be used to evaluate the impact of modifications done at a workstation on the exposure to risk factors. Three methods (QEC, OCRA and 4D Watbak) were used to assess the exposure to MSD risk factors before and after the implementation of changes at a saw and block opening workstation. The results from those 3 methods served to compare the methods and evaluate their consistency. Comparisons among the methods showed positive association between QEC and OCRA indices, and between the QEC back index and 4D Watbak.