The purpose of this study is to evaluate the relationship between musculoskeletal disorder (MSDs) symptoms and risk factors of MSDs in Korean automobile component manufacturers across times.Methods
This study has been tracking blue collar workers in a factory via 5 consecutive surveys from 2004 to 2016. A questionnaire survey was conducted on all of the blue collar workers at the target workplace. About 10% of the blue collar workers has been selected and asked to participate in field surveys. Ergonomic risk factors were subdivided into categories such as musculoskeletal burden, ANSI checklist, ACGIH TLV for Hand activity, RULA and etc. Job stress was estimated by Korean Occupational Stress Scale (KOSS). Work intensity was classified into three categories; absolute, relative work intensity and work flexibility.Result
The prevalence of MSDs according to criteria 1(P1) decreased from 89.3% in 2010 to 79.5% in 2016. The prevalence of MSDs according to criteria 2, 3, and 4 (P2, P3, and P4) also decreased. Aspect of ergonomic risk factors, the longer the exposure time to musculoskeletal burdening work, the higher the prevalence of MSDs. First grade of ANSI checklist increased by time while those of 2nd and 3rd decreased. Overall, ergonomic risk factor has generally declined because of working environment improvement. In workplace stress assessment, the high job stress group had increased until 2010 then had decreased since 2010. In subcategories of KOSS, physical environment were high in MSD symptom group. In work intensity survey, symptom positive group had consistently scored high in all absolute and relative work intensity and work flexibility. Whereas both absolute and relative work intensity decreased since 2010, work flexibility increased in 2016 from 2013.Discussion
This study shows the effects of multiple risk factors on MSD symptoms. In depth analysis considering repetitive measure of longitudinal data will be shown.