• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.9 no.1
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• pp.19-28
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• 2003

Objectives : This study was to investigate the relationship analysis in VDT(visual display terminal) of work hours. Methods : Questionnaires were completed by 41 women in VDT operations. The information was used to estimate multiple regression for the VDT of work hours related factors association. Results : The prevalence of the VDT of work hours was significantly higher in the shoulder which followed by the neck, the hand and fingers, the arms, the lowback, the back. The VDT of work hours decreased with aging. The VDT of work hours increased with work duration, single, lower among habitual exercise. The desk height, the seat pan height, the posture on the sitting, the elbow angle all did not meet the recommended criteria. Conclusions : Data from this study support a statistically significant association with satisfaction for occupation.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.8.1-8.12
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• 2023

Background: Prolonged use of visual display terminal (VDT) can cause eyestrain, dry eyes, blurred vision, double vision, headache and musculoskeletal symptoms (neck, shoulder, and wrist pain). VDT working hours among workers have greatly increased during the coronavirus disease 2019 (COVID-19) pandemic. Therefore, this study aimed to investigate the relationship between VDT working hours and headache/eyestrain in wage workers using data from the sixth Korean Working Conditions Survey (KWCS) (2020-2021) conducted during the COVID-19 pandemic. Methods: We analyzed the sixth KWCS data of 28,442 wage workers aged 15 years or older. The headache/eyestrain that occurred in the last year was assessed. The VDT work group included workers who use VDT always, almost always, and three-fourth of the working hours, while the non-VDT work group included workers who use VDT half of the working hours, one-fourth of the working hours, almost never, and never. To analyze the relationship between VDT working hours and headache/eyestrain, the odds ratios (ORs) and 95% confidence interval (CI) were calculated using logistic regression analysis. Results: Among the non-VDT work group, 14.4% workers experienced headache/eyestrain, whereas 27.5% workers of the VDT work group experienced these symptoms. For headache/eyestrain, the VDT work group showed adjusted OR of 1.94 (95% CI: 1.80-2.09), compared with the non-VDT work group, and the group that always used VDT showed adjusted OR of 2.54 (95% CI: 2.26-2.86), compared with the group that never used VDT. Conclusions: This study suggests that during the COVID-19 pandemic, as VDT working hours increased, the risk of headache/eyestrain increased for Korean wage workers.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.8 no.1
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• pp.5-14
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• 2002

Objectives : In order to investigate industrial fatigue due to visual display terminal (VDT) work of post office. Methods : The questionnaire survey for subjective symptoms of fatigue was carried out on 39 post office clerks who had been engaged in VDT work for various length of work hours. The questionnaire comprised three groups of 10 items each, representing dullness and sleepiness, difficulty in concentration and bodily projection of fatigue. Results : The scores of dullness and sleepiness was 16.62, scores of concentration difficulty was 16.35, those of bodily fatigue was 16.23, and total scores was 49.21. Fatigue scores was significantly associated with age and work duration, VDT of work hours, ventilation, illumination, nosie. Conclusions : Data from this study support a statistically significant association between age and scores of dullness, scores of concentration difficulty, between work duration and scores of dullness, scores of bodily fatigue, between VDT of work hours and scores of bodily fatigue.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.3
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• pp.285-291
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• 2012

Purpose: This study was conducted to research any effect on visual function related to accommodation by VDT work. Methods: The refraction power, accommodative lag, accommodative facility, relative accommodation, amplitude of accommodation and blink rate were measured before and after VDT work for 2 hours on 48 university students (16 males and 32 females), without abnormal accommodative function and systemic and ocular disease, who had never undergone corrective eye surgery. All examinations were performed with distant refraction, and a survey was conducted on the items related to subjective symptoms of VDT syndrome. Results: After 2 hours of VDT work, refractive power increased by 0.23 D, the amount of change in accommodative lag were $0.17{\pm}0.42D$ in the right eye and $0.23{\pm}0.47D$ in the left eye (t=2.26, p=0.03). There were statistically significant differences. Both the accommodative facility and relative accommodation and amplitude of accommodation were decreased after work. However, blink rate were increased. After VDT work, 33.4% of the subjects showed subjective symptoms of asthenopia and 33.3% of them showed shoulder pain. Conclusions: As a result, the accommodative lag increased in response to the two hours of VDT work, and overall accommodative functions were decreased. In addition, as symptoms of providing visual strain, asthenopia showed the most prominent subjective symptoms.

• Journal of International Academy of Physical Therapy Research
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• v.8 no.2
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• pp.1168-1174
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• 2017

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.

• Management & Information Systems Review
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• v.6
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• pp.227-266
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• 2001

These days the use of personal computer has become generalized at factory, office, house, etc and this fact indicates that visual display terminal work became popular in every field of our society. The use of computer improves work efficiency, productivity & qualify but in addition, it also generated the physical and mental diseases or defects so called VDT syndrome to workers. The purpose of this paper is to analyse the computer-work-related anti-physical, anti-psychogenic symptoms & side effects through the data drawn from workers who use computers on their works, and to find out methods of improvement & humanization of computer works. The follows are the results of questions about personal sensibility of VDT syndrome. 1. Female workers are more sensitive to the side effects of computer labor than males. 2. Workers aged twenties feel more severe symptoms of VDT syndrome than thirties or fourties, but there are no level of significance. 3. Middle managements workers are the most sensitive group to VDT syndrome, on the other hand tow managements are less sensitive than operators. 4. The result of questions indicates that a phone conductress show more severe VDT syndrome symptoms than business affairs or an engineer workers, with level of significance. 5. The longer computer work engagement period, the more evident VDT syndrome symptoms appear. For instance, workers who have more than 2 year engagement period complain more severe symptoms, compared workers who have less than 2 year engagement period. 6. Long computer working time per day also increases VDT syndrome severity specially people who have more than 2 hours in working time in a day have much less severe symptoms, compared people whose daily working time exceeds 2 hours. 7. Specific body part which shows VDT syndrome symptoms is shoulder, wrist, neck, finger, eye, waist, arm in the order of severity. 8. Sensibility of VDT syndrome symptoms have effect on degree of vocational satisfaction.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.395-401
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• 2012

Purpose: The purpose of this study was to research any effect on vision protecting or decreasing VDT syndrome of extracted anthocyanine from fermented purple sweet potato and blueberry. Methods: Subjects were aged 19-20 years old who do not have ophthalmic and systemic diseases and over -N4.00 D of refraction error. 40 mg of extracted anthocyanine from fermented purple sweet potato, from blueberry, and control group, placebo were dosed at separate try. After 2 hours later, subjects were directed perform visual display terminal (VDT) work for 2 hours. Objective refractive error was measured before dosing anthocyanine and after VDT work for 2 hours. Degree of head ache, eye pain and strain and subjective symptoms of neck, shoulder and waist was also examined through interviews by dividing its degree into severe, moderate, slight or none. Results: After 2 hours VDT work, vision protection effect in terms of refractive error for dominant eye was decreased by $0.031{\pm}0.21$ D in the group of extracted anthocyanine from fermented purple sweet potato, $0.006{\pm}0.32$ D in the group of extracted anthocyanine from blueberry. However, there was significantly myopic progression in the placebo group by $0.144{\pm}0.28$ D (t=2.27, p=0.03). Conclusions: It is considered that extracted anthocyanine from fermented purple sweet potato inhibits increase of refraction anomalies of dominant eye rather than non-dominant eye after VDT work.

• Journal of Korean Physical Therapy Science
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• v.1 no.2
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• pp.265-273
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• 1994

In order to investigate the subjective symptoms of VDT workers according to the working condition, this qutionnaire survey was conducted on 477 workers of 11 general hospitals, 15 banks and 9 research institutions in Taejon city and Chungnam province from June, 1993 to october 1933. The following results were obtained : 1. The main subjective symptoms answered by VDT workers were "eye strain". "eye pain". "blurred vision" for eye symptoms, "fatigue", "tendency to be fed up", "impatience" for psychoneurotic symptoms and "shoulder stiffness", "neck stiffness", "low back pain" for musculoskeletal symptoms. Most of these symptoms of VDT workers higher in female than male. 2. The number of VDT workers who complained eye and musculoskeletal symptoms were significantly increased. Smoking VDT workers showed higher complained rate of eye, psychoneurotic and musculoskeletal symptoms than nonsmoking group but alcohol drinking group showed higher rate of symptoms complaints of eye and musculoskeletal symptoms than not drinking alcohol group. 3. The VDT wokers who worked longer hours continuously and more hours of daily work, complained more frequent eye and musculoskeletal symptoms. 4. All subjective symptoms showed positive correlation to the sex and daily VDT working hours.

• Journal of Korean Institute of Industrial Engineers
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• v.16 no.1
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• pp.67-81
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• 1990

Effectiveness of physical exercise in reducing work-related musculoskeletal stress was investigated. This was compared to the stress alleviation accomplished by using ergonomically designed work station. Tasks chosen for the study were data entry and file maintenance on the video display terminal (VDT). Three different measures, namely root-mean-square (RMS) values of electromyogram (EMG), subjective rating and task performance were used for the evaluation. Electromyograms were recorded from the neck, the left and right trapezius muscles in the shoulder region, and L2/L3 region of the back. Subjects rated discomfort levels for the same parts of their body. Task performance was measured by recording typing speed and errors. Each of the five subjects was tested for two days (8 hours/day) in two different work stations. These were the ergonomically designed adjustable work station and the fixed work station of traditional design with no adjustable features. Assigned physical exercises were performed for four minutes, every two hours during the breaks, by the subjects while working in the fixed work station. It was concluded that the physical exercise could be helpful in reducing musculoskeletal stress as effectively as the ergonomic design of the VDT work station.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.305-313
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• 1991

In order to investigate industrial fatigue due to visual display terminal (VDT) work of banking operations the questionnaire survey for subjective symptoms of fatigue was carried out on 470 bank clerks who had been engaged in VDT work for various length of work hours. The questionnaires comprised three groups of 10 items each, representing dullness and sleepiness (level of cerebral activation), difficulty in concentration (level of motivation) and bodily projection of fatigue. The results were as follows : 1. Of the 30 items of questionnaires, the highest percentage was accounted for by 'eye strain' (51.5% ), followed by 'feel stiffness in the neck or the shoulders'(33.4%), 'feel a pain in the low back'(26.8%), 'whole body feels tired'(19.6%) and 'feel headache'(17.9%) in the order of sequence. 2. The average weighted score for the first group of questionnaire items (dullness and sleepiness) was the largest among three groups and was followed by 'the third cup (bodily projection of fatigue) and the second item group (difficulty in concentration) in the order of sequence, suggesting the heavier mental stress of VDT work in banking operations rather than physical burden. 3. In terms of the age and sex of workers, work duration and VDT work percentage, the difference in average weighted score was noted only between sex, the score of female being larger than that of male. 4. The complaint rates of subjective symptoms showed close associations with the subjective optimums of room temperature, ventilation, illumination and noise level. 5. The significant correlation was showed between age, work duration and item of 'whole body feels tired', between VDT work percentage and items of 'eye strain' and 'feel stiffness in the neck or shoulders' and between all items of subjective symptoms.