Preferred VDT workstation settings, body posture and physical impairments.

In a field study an adjustable VDT workstation was given to each of the 68 operators for one week. The preferred settings, the body postures and subjective evaluations were assessed during normal working activities of the operators. The preferred ranges disclose the following figures: keyboard height (home row above floor) 71-87 cm, screen height (centre above floor) 92-116 cm, viewing angles (eye to screen centre) + 2 to -26 degrees, visual distance (eye to screen) 61-93 cm. There was practically no correlation between preferred settings and anthropometric data of body length or eye levels above floor. The study of body postures revealed that the great majority of operators tend to lean backwards with trunk inclinations between 97 degrees and 121 degrees (95% confidence interval). Some of the preferred settings strongly differ from those recommended in many brochures and standards. The physical complaints in the neck-shoulder and back area are diminished with the preferred settings.