Effect of Office Strain Level on Mental Workload and Musculoskeletal Disorders in Employees of the Design Department: A Case-Control Study Publisher Pubmed



Vosoughi S ; Ahmadi M ; Keyvani Brojeni M ; Moradi Hanifi S ; Vosoughi A ; Kheirandish Sarabi S
Source: Work Published:2026

Abstract

Background: CAD (Computer Aided Design) designers spend long hours in front of visual displays, using specialized automotive design software. In addition to musculoskeletal disorders that may result from prolonged static activities, these individuals are also exposed to high mental workloads. Objective: This study aims to assess the effect of office strain levels on the mental workload and musculoskeletal disorders of the design department. Methods: This descriptive-analytical study included 48 cases, consisting of the occupation of CAD designing from the computer design department, and 48 control participants, comprised of non-computer users. It assessed musculoskeletal disorders using the CMDQ (Cornell Musculoskeletal Discomfort Questionnaire), ergonomic risk with the ROSA (Rapid Office Strain Assessment), and mental workload with the NASA-TLX (NASA Task Load Index). Data were analyzed using SPSS version 22. Results: In the case group, 37.5% were categorized as high risk for strain, compared to 31.25% in the control group. 27.08% of participants experienced an unacceptable level of mental workload according to NASA-TLX criteria, while only 17.71% were within the acceptable level. Significant relationships were found between office strain, musculoskeletal disorders, and mental workload, with a direct correlation between ROSA, NASA-TLX, and CMDQ scores (<0.011). Conclusions: The most significant factors influencing office strain and mental workload among the occupation of CAD designing include ergonomic conditions in the workplace, duration of computer use, temporal demand, and the nature of job tasks. Factors such as health status, physical characteristics, and work experience are crucial in determining the intensity of mental workload and office strain. © The Author(s) 2025