The purpose of this study was to investigate the health conditions of occupation group and hobby group related to visual display terminal (VDT) syndrome. The VDT occupation group was mainly composed of the worker in banks, telephone companies, and general offices. The VDT-related hobby group was composed of high school students, and Internet cafe users. A questionnaire survey was conducted to classify the subjects according to hours of computer usage. The results indicated that the occupation group represented a higher level of subjective symptoms than VDT-related hobby group. In the VDT occupation group, ‘Poor body condition’, ‘Feeling uncomfortable or pain in the neck’‘, Feeling uncomfortable or pain in the back’‘, Feeling stressed out’, and‘ Feeling uncomfortable or pain in the shoulder’ items indicated a high level of subjective symptoms. In the VDT-related hobby group, ‘Feeling uncomfortable or pain in the neck’, and‘ Feeling uncomfortable or pain in the back’ items indicated a high level of subjective symptoms. According to the hours of computer usage, 4-6 hours and 6 hours or more groups represented a higher level of subjective symptoms than 2-4 hours group. These findings suggest that Visual display terminal (VDT) work effects the individual's health conditions.

The purpose of this study was to examine the relative effectiveness of immediate feedback and informational prompt on safe sitting behaviors that may cause VDT syndromes. Participants were three white color workers and an ABCB within-subject design was adopted. Safety Posture System was developed specifically for the present study. The system could detect participants' unsafe sitting postures using sensors and provide feedback and prompt on the computer monitors. The results indicated that both immediate feedback and informational prompt considerably increased safe sitting behaviors. More importantly, the immediate feedback was more effective than the informational prompt in increasing safe sitting behaviors.