• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.37-43
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• 2013

Purpose: The present study was conducted to investigate whether the directions of eye movement in playing computer games for certain period affected the change of near point of convergence (NPC) and fusional reserve (FR) or not. Methods: Total 40 subjects in 20s who have the visual acuity of 1.0 or higher without any ocular disease and accommodative dysfunction were asked to successively play computer games. After the subjects were moving eyes in horizontal and vertical directions for 40 and 90 minutes, their horizontal fusional reserves, vertical fusional vergence and near point of convergence were measured. Results: The near point of convergence showed a tendency to be receded after computer gaming in the horizontal and vertical directions, and both of horizontal and vertical fusional reserves were significantly reduced. The range of declined fusional reserves and receded near point of convergence after computer gaming for 90 minutes was smaller than those after computer gaming for 40 minutes. The change of binocular vision was affected by the horizontal eye movement rather than the vertical movement when analyzed by the direction of eye movement. Conclusions: This study revealed that the change in FR and NPC was different along with dominant direction of eye movement during visual display terminal (VDT) tasks. Therefore, the adjustment of VDT working time is required to prevent the dysfunction of binocular vision according to the dominant direction of eye movement during VDT task.

• Korean Journal of Health Education and Promotion
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• v.25 no.3
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• pp.95-109
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• 2008

Objectives: The study was conducted to investigate visual display terminal(VDT) and related risk factors in office workers. Method: The study subjects were 539 officers at 3 places of business in Gwangju. The data were collected by self-administered questionnaire between October 12 and October 17, 2007. and they agreed to participate in this study. The tool was developed by Moon, Jaedong(1991) for VDT syndrome. Data analysis by using SPSS/win 10.0 was performed with descriptive statistics, t-test and ANOVA. Results: The summary of results is as follows: 1) The mean score of total VDT syndrome was $1.17{\pm}.65$ of full score 4.00, which was lower than other research. 2) For relation between general characteristics and total VDT, sex (t=-5.777, p=.000), age (F=3.516, p=.015), satisfaction of job (F=9.540, p=.000), self-awareness of health (F=25.015, p=.000) had statistically significant difference. 3) For relation between behavioral work factors and total VDT, break time of work(t=-5.363, p=.000), eye movement during computer work(t=2.176, p=.031), wrist exercise during(t=2.337, p=.020), distance between monitor and eyes(F=3.682, p=.012) had statistically significant difference. 3) For relation between environmental work factors and total VDT, height of chair(F=8.801, p=.000), space under desk(F=4.244, p=.015), reflection of monitor(t=2.697, p=.008) had statistically significant difference. Conclusion: To prevent and relieve VDT syndrome and musculoskeletal disorders in office workers, it is important to teach good posture and stretching exercise during work.

• Journal of the Korean Society of Safety
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• v.23 no.2
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• pp.30-36
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• 2008

This paper suggests the best work conditions, including short break time and number of mouse clicks on a computer, to prevent MSDs(Musculoskeletal Disorders) on VDT(Visual Display Terminal) work. Discomfort measures are calculated according to the Borg's CR-10 Scale. The short break time conditions are grouped into 7, 15, and 30 seconds after every 10-minute work period and the number of mouse clicks are divided into 10 clicks/min, 20clicks/min, and 30clicks/min. The result of the ANOVA on the shift value of subjective discomfort shows the following: 1) Regarding the break time and the number of mouse clicks, there are statistical differences between the measured values for the neck and the wrist(p<0.05). 2) Regarding the number of mouse clicks, there are statistical differences between the measured values for the shoulder and the forearm(p<0.1). 3) Regarding the break time and the number of mouse clicks, there are no statistical differences between the measures values for the eyes, upper arms and back(p<0.1).

• 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.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.863-866
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• 2010

병원 근로자의 VDT 자각 증상에 대한 선행연구를 보면 대부분이 간호사 관련 직종으로 한정되어 있고, 방사선사에 대한 연구는 수행되지 않았다. 본 연구는 2009년 10월 15일부터 11월 2일까지 대전광역시에 소재하고 있는 종합병원에 VDT 작업을 시행하는 보험심사, 원무, 의무기록, 전산, 행정부서 근무자와 방사선사를 대상으로 구조화된 설문지를 활용하여 분석하였다. VDT 증후군 자각 증상 점수를 종속변수로 한 다중선형회귀 분석 결과 관련요인으로 안관련 증상에 영향을 미치는 요인을 보면 성별, 건강염려, 일상생활 방해이며, 전신증상은 운동, 스트레스, 건강상태 인지 관련, 근골격 증상에서는 임상경력 6-10년, 대인관계, 건강상태 인지 관련 건강염려와 일상생활 방해로 나타났으며, 통계적으로 유의한 차이를 보였다. 피부 증상으로는 연령 20-29세, 결혼여부, 식습관, 건강상태 인지 관련 소화 정도와 일상생활 방해로 나타났으며, 심리 증상으로는 성별, 결혼 여부, 스트레스, 소화 정도, 일상생활 방해로 나타났으며, 통계적으로 유의한 차이를 보였다. 타부서 근로자와 방사선사의 VDT 증후군 자각점수 차이가 크게 나타나지 않았으며, 이는 방사선사의 업무가 VDT 환경으로 변함으로써 VDT 증후군 자각 증상이 일어날 수 있다는 것을 나타내는 것이다. 이는 정기적인 순환근무를 시행함으로써 VDT 환경에 지속적인 노출을 피하는 것이 예방 대책이라 할 수 있다.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.41-47
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• 2016

PURPOSE: Forward head posture (FHP) is one of the most common postural problems among white-collar workers who perform highly repetitive tasks in the same position. The aim of this study was to research the effects of thoracic and lumbar support fixtures on forward head posture (FHP) during visual display terminal (VDT) work. METHODS: The subjects were 36 healthy male students with no problems in their medical history or respiratory systems. The subjects were randomly assigned to three groups: control group (n=12), thoracic support fixtures (n=12), and lumbar support fixtures (n=12). We conducted a text typing task of the same content for 20 minutes, and evaluated the angles, including the craniovertebra angle (CVA), craniorotation angle (CRA) with photogrammetry. RESULTS: The thoracic and lumbar support fixture groups showed a statistically significant difference at the CVA and CRA to the control group (p<.05), and the post-hoc test showed an increase of the CVA and decrease of the CRA than the control group. However, when we compared the effects of thoracic and lumbar support fixtures on FHP, there was no significant difference in the difference in decrease of the CVA or increase of the CRA (p>.05). CONCLUSION: We determined that VDT work using thoracic and lumbar support fixtures has a positive effect on forward head posture in white-collar workers. Further studies are required to find the more effective location of support fixtures.

• Physical Therapy Korea
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• v.28 no.2
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• pp.117-122
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• 2021

Background: Flat-back posture refers to a posture in which the pelvis is tilted backward, the lumbar spine is bent, the upper thoracic spine is increasingly bent, and the lower thoracic spine is straight. Given that most of the day is spent sitting, we need to develop exercise programs and devices that are suitable for people who spend less time exercising than sitting. Objects: This study investigated the effects of resistance footrest exercise on spine posture angles in visual display terminal (VDT) workers with flat back. Methods: We measured the upper lumbar angle (ULA) and lower lumbar angle (LLA) using a flexible ruler for the ULA and LLA. Then, after 1 week of resistance footrest exercise designed to strengthen the lumbar spine musculature, we measured these angles again. We measured each angle three times and then compared measurements from before and after exercise. Results: There were no significant differences in the ULA following the strengthening exercise, but significant differences were observed in LLA. Conclusion: The resistance footrest exercise strengthened the muscles affecting the pelvic and lumbar lordotic angles, and increases in the LLA were changed. This suggests that the role of the lower lumbar spine in the lumbar lordotic curve is greater than that of the upper lumbar spine. In addition, considering the contemporary tendency to lead fairly sedentary lives, these results indicate that exercising while seated can be effective.

• 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 radiological science and technology
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• v.34 no.4
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• pp.297-303
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• 2011

The existing studies of VDT syndrome have been researched only about for nurse groups without radiological technologists. The target of this study was workers who perform VDT task in general hospital placed in Daejun City such as insurance judgement, patient affairs, medical record management, medical computing service, hospital administration, and radiological sections. This study was conducted at October 15, 2009 to November 2, 2009 using structured questionnaire. Results of group A (age 20-29, less than 5 years experience at clinical site, normal staff, and unmarried group) showed significant skin and psychological conditions among recognition symptoms of VDT syndrome. Group B (age 30-39, 6-10 years experience at clinical site, managing staff, and married group) tends to be similar at orbital, whole body and muscles' frame response among recognition symptoms of VDT syndrome. Results of "Multiple Linear Regression" with dependent variable that is scores of recognition symptoms of VDT syndrome are as follows. The factors which influences for orbital-related problem is gender, health cares and obstacles during daily life. The factors which influences for whole body-related is exercise, stress and recognition for health condition and the factors which influences muscles' frame-related is 6-10 years experience at clinical site, human relationship, health cares and obstacles during daily life. These are proved to be similar by statistic analysis. There is small difference at recognition symptom of VDT syndrome between the radiological technologist and other groups in general hospital. Yet, as the working circumstance of radiological technologist gradually changes to VDT environment, the recognition symptom of VDT syndrome became conscious. This can be prevented by regular job rotation, which will escape the continuous repetition of working pattern.

• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.433-449
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• 1995

The study subjects in this study are 295 workers who work on one electronics industry, and they were composed of 93 VDT and 202 non-VDT workers. This study was carried out to obtain the prevalence of subjective symptoms and to compare psychological symptom scores from SCL-90-R between VDT and non-VDT work groups. And to verify the relationship between VDT work related symptoms and psychological symptoms, the author compared SCL-90-R T scores between symptom complaining and non-complaining groups. The results are summarized as follows : 1. Throughout the prevalence study of VDT work related symptoms according to VDT work state, the author could select the final 10 symptoms by sex;'eye fatigue', 'foggy vision', 'neck discomfort or pain', 'shoulder discomfort and pain', 'light headedness', 'dizziness', 'acne', 'itching sensation on face', 'difficulty in concentration', 'memory disturbance' in males, and 'blurred vision', 'foggy vision', 'neck discomfort or pain', 'shoulder discomfort and pain', 'abdominal distention', 'indigestion', 'acne', 'prickling sensation on face', 'difficulty in concentration', 'memory disturbance' in females. 2. Throughout comparison of psychological symptom scores from SCL-90-R between VDT and non-VDT workers, except 'Interpersonal sensitivity' in female, Mean T score were higher in VDT workers, but not significantly different between the two groups. These results indicate that the relation between VDT work status and psychological symptoms are not strongly correlated. 3. Because of the nonspecific characteristics of VDT work related symptoms, from the 40 subjective symptoms, the author selected the final 10 symptoms by sex, especially correlated to VDT, and divided the study subjects into symptom complaining and non-complaining groups. The mean SCL-90-R T scores between the two groups were compared. Except for the opthalmologic symptoms in females, the scores were significantly different between the two groups in all symptoms. And this indicates that the VDT work related symptoms strongly correlated with the present individual psychological conditions. 4. Due to understand that which of the 9 psychological symptom dimensions are strongly correlated with the subjective symptoms, the author excuted muliple logistic regression analysis, and the result were as follows; 'depression' and 'somatization', in male, and 'obsessive-compulsive' and 'somatization' in female.