The sudden increase in work-related musculoskeletal disease is caused by sociopsychological factors and ergonomic risk factors of the work process. This study evaluates the relationship between the symptoms of musculoskeletal disease and the sociopsychological factors.

A questionnaire survey and ergonomic evaluation were administered to workers of a shipyard company with a high incidence rate of musculoskeletal disease. To quantify the pain score associated with a diagnosis of musculoskeletal disease, the pain degree(1~5points), frequency (1~4 points) and duration (1~4 points) were multiplied to give a maximum score of 80. A score above 64 points on the pain score was defined as ‘severe pain group’. This ‘severe pain group’ was chosen as the dependent variable and the sociopsychological factors were evaluated as independent variables with structural equation modeling based on a decision tree of exhaustive CHAID.

The standardized regression weights value with reference to the REBA score(0.54) had the largest value by the type of company, followed in order by joining and acting labor union(.313), job demand(.172), senior support(−.095), insufficient sleep (.092), and colleague support (.061).

The symptoms of musculoskeletal disease were greatly affected by sociopsychological factors such as whether joining and acting labor union, job demand, and senior or colleague support.