An analysis of work-related musculoskeletal disorders and ergonomic loads in male welders in shipbuilding industry

Abstract

Objective: To investigate the prevalence of work-related musculoskeletal disorders (WMSDs) in male welders in different work areas of shipbuilding industry based on their operational working position and body position characteristics and to analyze the operational positions and ergonomic loads. Methods: In February 2017, 412 male welders from the hull and block work areas of a large ship factory were selected by stratified sampling. The prevalence and effects of WMSDs within a year were investigated using the Nordic Musculoskeletal Disorders Questionnaire, and a rapid exposure checklist was used to obtain the ergonomic load index by comprehensive scoring; the exposure-response relationship between the ergonomic loads and WMSDs symptoms of subjects in the hull and block work areas was evaluated. Results: Among the male welders working in the hull work area of shipbuilding industry, WMSDs occurred more commonly in the neck, lower back/waist, and legs, accounting for 53.16% (126/237) , 51.90% (123/237) , and 41.77% (99/237) , respectively; among those working in the block work area, WMSDs occurred more commonly in the lower back/waist, wrist, and legs, accounting for 52.57% (92/175) , 49.14% (86/175) , and 45.14% (79/175) , respectively. There were significant differences in the distribution of cases of pain within the last 7 days and one month, pain lasting more than one month, or absence from work due to pain within a year in the four positions between the two work areas (P<0.05). In the hull work area, high and extremely high exposure levels were mainly seen in the neck, lower back/waist, and legs, accounting for 76.79%(182/237), 69.20%(164/237), and 59.49%(141/237), respectively; in the block work area, high and extremely high exposure levels were mainly seen in the lower back/waist, wrist, and legs, accounting for 77.71%(136/175), 50.29% (88/175), and 46.29% (81/175), respectively. The detection rates of WMSDs in these four positions significantly increased as the exposure levels rose (P<0.01). Conclusion: The WMSDs of male welders working in the hull and block work areas of shipbuilding industry occurs more commonly in the lower back/waist and legs. The risk of WMSDs symptoms increases with the rise of ergonomic load.