Feasibility of using WERA Method to Assess Ergonomic Risk of Musculoskeletal Disorders

Using appropriate methods for ergonomic risk assessment of musculoskeletal disorders has an important role in controlling these risks and providing workforce health. The purpose of this study was to evaluate the feasibility of applying WERA method to assess the risk of musculoskeletal disorders through its correlation with the results of QEC.

This descriptive-analytical study was performed on 72 employees of workshop sections of a modern brick industry. Data were collected using a Nordic questionnaire to assess the prevalence of musculoskeletal disorders in the past 12 months and WERA and QEC methods to ergonomic risk assessment of musculoskeletal disorders. Data were analyzed by SPSS 18.

The prevalence of back, shoulder, neck and wrist disorders were 41.7%, 20.8%, 16.7% and 33.3%, respectively. Results of WERA showed that 88.9% of subjects had medium action level and 11.1% had high action level. In QEC method, 6.9% of subjects had exposure level ‘one’, 20.8% of subjects had exposure level ‘two’, 48.6% of subjects had exposure level ‘three’, and 23.7% of subjects had exposure level ‘four’. The correlation between QEC total score and prevalence of musculoskeletal disorders was (r=0.67, P=0.038). The correlation coefficient between the final scores of the two methods was (r=0.53, P=0.021).

Examination of the correlation between the mean scores of the two methods indicated a moderate correlation between them. Correlation between prevalence of disorders and QEC and WERA scores showed that QEC results were more consistent with Nordic results and it can be said that QEC method was more suitable for ergonomic assessment of musculoskeletal disorders risk for different tasks in this study.