A Short Review of Subjective Measures in Mental Workload Assessment

Abstract

A large number of specialists, technicians, and postgraduate students use microscopes in the laboratory for a long time and are at high risk for musculoskeletal disorders and eye fatigue. Long-time working with a microscope can be negatively affecting both the visual and musculoskeletal systems. This study was aimed to evaluate the occupational health status of microscope users in two dimensions of musculoskeletal problems and eye fatigue at Tehran University of Medical Sciences. A group of 40 microscope users at Tehran University of Medical Sciences was selected in this cross-sectional study. The instrument used in this study was the Eye Fatigue Questionnaire, Flicker Fusion System (PM-SS22881-Pars Madar Asia) for measuring eye fatigue, Nordic questionnaire, and Berg scale. Eye fatigue was measured in two stages before starting work and 60 minutes after work with a microscope. The Borg scale was used to compare the amount of discomfort and pain in the upper and lower limbs before and at the end of the work. The Nordic questionnaire was also used to assess the prevalence of musculoskeletal problems. The descriptive data were analyzed using paired T-test, and simple linear regression via SPSS software version 22. More than half of the users suffered from pain and discomfort in the neck, upper back, and shoulder. There were significant differences in the mean score of visual fatigue symptoms and the mean score of flicker value between two stages, respectively (P< 0.001). Simple regressions were obtained for changes in the questionnaire score (R² = 0.708). The correlation coefficient indicated an inverse and significant association of flicker value changes with changes in questionnaire scores and visual fatigue symptoms. A majority of the participants were experienced musculoskeletal disorders and visual fatigue. Early symptoms recognition could be an effective way to control the incidence of visual fatigue at higher levels among microscope users. In addition, ergonomic equipment and training may be useful to decrease most musculoskeletal disorders.