Sajad Zare, Naser Hasheminezhad, Tania Dehesh, Davoud Hasanvand, Saeid Ahmadi, Rasoul Hemmatjo
"Mental workload refers to the amount of effort put in by the mind during the accomplishment of a duty. It essentially has to do with individuals’ mental capacity and the way they receive and process information in order to make decisions and take appropriate actions. The present study aimed at investigating the relationship between mental workload and prevalence of musculoskeletal disorders among welders of Tehran Heavy Metal Structures Company. This cross-sectional descriptive study was conducted in 2016. The sample included 100 welders working at Tehran Heavy Metal Structures Company. Sampling was done by census method. A demographic features questionnaire, NASA-TLX workload questionnaire, and Nordic Questionnaire were used for data collection. Data were analyzed by the use of SPSS (Version 22). Various data analysis procedures, including independent samples t-test, Pearson correlation, chi-square, and Fisher’s exact test, were employed. The mean of participants’ overall score in mental workload was 65.88 ± 21.15. Eighty four percent of the studied welders reported that they had experienced musculoskeletal disorders during the past 12 months (leading to the study), with the highest prevalence being recorded for waist (65%). Furthermore, the results of Pearson correlation indicated that there was a significant relationship between the prevalence of disorders in the legs and physical demand (P = 0.032). Also, a considerable association was observed between disorders in the wrist / hand and overall NASA mental workload score during the past 12 months (P = 0.021). Mental workload and the prevalence of musculoskeletal disorders are relatively high among welders. Waist was the most important risk factor among the participants studied. Future studies should attempt to detect risk factors that cause such disorders and suggest ways to reduce or prevent these problems among welders as much as possible."