The Relationship between the Circadian Type and Workload in Assembly Workers of Manufacturing Company

Musculoskeletal disorders in the upper limb are highly observable in industry. When the factors that caused these disorders are correctly identified, they can be prevented. Workload assessment is a key parameter in assessing the comfort, satisfaction, productivity and safety. The aim of this study to evaluate the workloads and the relationship between disability of upper limb in the assembly lines workers. The study was a descriptive -analytic and cross-sectional and was carried out among 120 assembly lines workers. For the evaluation of work load and disability of upper limbs, the Iranian version of NASA-TLX and DASH have respectively been used. Data analysis was carried out by using SPSS20. It is noteworthy to mention that P value <0.05 was considered significant. In this study, the most effective dimension on the work load was recognized to be the physical load. 45% of the subjects were placed in the mild group due to their upper limb disability. Moreover, findings indicated that there was a significant relationship between the workload and disability of upper limb (P value <0.05). On the basis of the results, it can be calculated that mental workload leads to different levels of upper limb disability in different levels. Furthermore, the reduction in physical workload will result in a decrease in mental workload and disability of upper limb.