Investigating of the relationship between musculoskeletal Discomforts and the permissible levels of manual load lifting and postural assessment score (Case study in a printing industry)

Introduction: Musculoskeletal Discomforts are one of the main problems in all occupations and industries. Printing industry workers are involved in tasks that increase the risk of musculoskeletal Discomforts. So, the aim of this study was to investigate the relationship between musculoskeletal Discomforts and manual load lifting and workers’ postures in a printing industry. Methods: In this study, the prevalence of musculoskeletal Discomforts among the workers was investigated, using the Cornell questionnaire. Manual load lifting tasks in the industry were also assessed in three methods: Snook tables, WISHA and KIM-LHC. Workers' postures were assessed using the REBA method. Results: The results of the Cornell questionnaire showed that the most complaints are related to pain in the lower extremities, including feet, legs, and knees. Comparing the results of Cornell questionnaire and the results of WISHA method using Kruskal-Wallis test showed that the neck (p= 0.016), right shoulder (p= 0.028), left shoulder (p= 0.031), back (p= 0.022) and right forearm (p= 0.045) have significant relationship with WISHA results. Conclusion: The association of the prevalence of some musculoskeletal Discomforts with the results of WISHA method indicates the superiority of this method to KIM-LHC and Snook tables methods for assessing the tasks of manual load lifting in printing industries. Also, the lack of correlation between musculoskeletal Discomforts and posture assessment, results using the REBA method, indicates that the reasons for the prevalence of these Discomforts in the industry should be sought in cases other than inappropriate postures.