• Journal of the Ergonomics Society of Korea
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• v.10 no.2
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• pp.3-13
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• 1991

As the VDT work constrains work postures because of its work characteristics. VDT worksta- tions should be properly designed so as to be fitted to various types of physical conditions of op- erators. Therefore, in this study, the preferred settings of VDT wrokstation dimensions of operators. Therefore, in this study, the preferred settings of VDT workstation dimensions and work postures were studied in order to determine the appropriate dimensions and the work postures for VDT operators which will alleviate the musculoskeletal troubles or visual fatigue. The scpoe of the study is as follows. 1. Measurement and analysis of the preferred settings of the height of workstation, keyboard, seat, and screen among the experienced VDT operators. 2. Anaysis of the relationship between the preferred settings of workstation height and the seat height control among the experienced VDT operators. 3. Analysis of the work postures of the experienced VDT operators.

• Industrial Engineering and Management Systems
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• v.3 no.2
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• pp.140-150
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• 2004

Repetitive stress injury at the wrist has been reported as a common injury among visual display terminal (VDT) users (i.e., computer users). Adjusting a VDT workstation (computer table and chair) to maintain a correct seated posture while operating a keyboard is perhaps the most frequently recommended preventive solution. This paper proposes an analytical design methodology based on ergonomic design principles for recommending appropriate VDT workstation settings and layout of individual computer accessories on the computer table. The proposed design methodology consists of two interrelated phases: (1) determination of VDT workstation settings, and (2) design of computer accessories layout. Based on the information about the VDT user, dominant task to be performed, typing skill, and degrees of physical and visual interactions between the user and computer accessories, adjustment and layout solutions are recommended to allow having a correct seated posture while minimizing both physical and visual movements. The results from an experiment show that when adjusting the workstation and locating the computer accessories according to the recommendations given by the proposed design methodology, the user's hand movements can be significantly reduced.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.4
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• pp.459-465
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• 1999

A new-concept VDT workstation chair with adjustable keyboard/mouse support was proposed to minimize physical discomfort and the risk of cumulative trauma disorders (CTDs) at work sites in this study. First, a three-dimensional human modeling tool $(SAFEWORK^{(R)})$ was used to design the new chair satisfying the anthropometric specifications of Korean population. Second, based upon the result of 3-D graphical simulation, a mock-up chair was constructed with an adjustable keyboard/mouse support directly attached to the chair body. Third, muscle fatigue and subjective discomfort were measured to evaluate the newly developed chair. An experiment was conducted to compare the new workstation chair to the traditional computer chair without keyboard/mouse support. Six volunteer subjects participated in six one-hour word-processing sessions with two different chairs and three different postures. Statistical results indicate that the new-concept VDT chair generally improved subjective comfort level and reduced fatigue in finger flexor/extensor and low back muscle. In conclusion, this new VDT workstation chair is expected to reduce physical discomfort and prevent occupational CTD problems in the long run. Implications of the new design and suggestions for the further development are also addressed.

• The Journal of Korean Physical Therapy
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• v.22 no.4
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• pp.91-96
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• 2010

Purpose: Among computer users, the awkward posture and workstation setups of workers contribute to work-related upper limb musculoskeletal disorders. The purpose of this study was to evaluate the efficacy of a traditional physical therapy and ergonomic intervention by physical therapists in 4 computer users. Methods: After checking Visual Analogue Scores (VAS), four subjects who were treated by physical therapy for neck and shoulder problems related to VDT syndrome were enrolled in the study. All subjects spent at least 40 hours per week at a computer workstation. All subjects had pain and ergonomic states evaluated using methods such as VAS, Neck Disability Index (NDI), Workstyle short form, Rapid Upper Limb Assessment (RULA), and OSHA VDT checklist (Occupational Safety and Health Administration video display terminal) before a physical therapy + ergonomic intervention. Participants were re-evaluated 1 month later. Results: Participants showed more improvement of their neck pain after being treated with a physical therapy plus ergonomic intervention than when treatment consisted only of physical therapy. Improvements in RULA, Workstyle short form, and OSHA VDT checklist also were achieved. Conclusion: This case study suggests the importance of examining the work habits and work-related postures of subjects who complain of neck and shoulder pain that is exacerbated by computer use. Personalized ergonomic interventions and physical therapy can lead to improvement of patients with VDT syndrome.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.3
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• pp.236-241
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• 2006

Monitor height is one of the key factors in the VDT workstation design. Most of the previous studies have focused on traditional VDT workplace where the operators performed data entry or word processing tasks using single monitor. This study aimed to suggest proper monitor height when the main task was monitoring information from different number of information sources. Twelve male students participated in three experiments: single information source (one monitor), two information sources (one monitor and one CCTV), and three information sources (one monitor, one CCTV and a window). Subjects performed monitoring tasks for 10 minutes with 3 different monitor center heights : 89.0 cm (Low), 111.3 cm (Middle), and 124.8 cm (High). Surface EMG signals of five neck muscles, subjective discomfort ratings, preference, and working postures were recorded. Results indicated that the middle height was proper for one monitor condition, but the low monitor height was recommended for more than two information sources.

• Industrial Engineering and Management Systems
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• v.6 no.2
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• pp.146-157
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• 2007

This paper discusses two algorithms for recommending notebook computer (NBC) and workstation adjustments so that the user can assume an ergonomic seated posture during NBC operation. Required input data are the user's anthropometric data and physical dimensions of the NBC and the workstation. The first algorithm is based on an assumption that there are no workstation constraints while the second algorithm considers the actual seat height and work surface height. The results from the algorithms include recommendations for adjusting the NBC (tilt angle of the NBC base unit, angle between the base and screen units, and base support height) and the workstation (heights of seat support and footrest, and distance between the body and the NBC).

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.05a
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• pp.133-138
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• 1997

인간공학 및 생체공학을 근거한 종합적인 연구 모델 제시로, 산업체에 산재해있는 작업 중에 VDT Workstation과 관련된 근로자의 상지에 대한 직업성 누적적 질환의 연구로, 상지의 외상성 누적적 질환을 일으킬 수 있는 ergonomic stressor의 감지, 진단, 및 공학적 control를 이용 직업성 누적적 질환 예방을 궁극적 목적으로 하여, 근무 교대 및 일시적 보직 변경 등 근무 순환의 적절한 인사관리 및 누적적 피로를 극소화 할 수 있는 근무/휴식의 적절한 시간 안배를 제시하며, VDT 주변 환경과 근로자 사이의 적절한 운용에 대한 교육 program을 개발, 또한 휴식 시 stretch exercise (근육의 피로 이완을 목적) 방법 등을 제시하며, 누적적 질환의 조기 증상을 감지하여 업무의 적절한 순환을 통하여 직업성 질환으로서의 발전을 방지하고자 하는 것을 취지로 기초연구를 수행하고자 하였다. (중략)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.1
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• pp.71-77
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• 2002

This study deals with noise occurring in the process of human information transmission. Human process many kinds of information by receiving them from the outside or using their own thought and express the processed information to the outside by acting. In this process, Channel Noise ($C_N$) is defined as the characteristics of noise generating the incomplete result for the external stimulus. To evaluate $C_N$, keyboard-typing experiment has been performed to the 87 subjects. In this experiment, the subject consists of college students who have abundant experience in computer usage. In the experiment, there were some cases that typing order was unconsciously reversed. In this study, we deal with only these cases since these cases can be used as important data to study humans information transmission system.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.3-6
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• 1996

Cumulative trauma disorders (CTDs) are becoming a major health hazard among phone directory service operators. In order to clarify the causes and to reduce the occurrence of CTDs, a site survey was done. The survey includes observation of the task and the working environment. Also, operators were closely examined and diagnosed to understand the exact causes of CTDs. Different types of CTDs were identified and the most cases were developed in a two or three-years after using new VDT-based workstations. The various design features of workstation aggravated the developemtn of CTDs together with the intense workload. The ergonomic resolutions were suggested based upon these observations.

• Archives of design research
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• v.12 no.1
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• pp.157-166
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• 1999

With the increase in use of the computer, the VCT syndrome has occured as a new socialJhea/health problem. ErgonomicaI design standards are a for the users to reduce stress and poor physical posture in the human body. In this study. we have suggested design dimensions recommended from previous studies. We also have reviewed users' preference dimenision, and analyzed differences between users' preference dimenision. and the previous design aiteria to verify physical appropriateness. We analyzed how each design dimension was reached and affected the tunan body by objective EMG evaluation. and subjective evaluation of physical discomfort and oorrIort. We have found that keyboard height is very important in a workstation. If the elbow's height is lower than the keyboard's height. it effedS the hand and wrist. If higher, it brings fatigue to the shoulder and neck. As a result of this experiment. we suggested that the height of a keyboard desk for Koreans be 660mm for the fixed type and 540-774mm for the adjustable type. Also other design reoommendations were suggested in the thesis. In ooncIusion, our research will be very important in the database because it provides adjustable ranges to fit user's body types in the various design flekIs.