• Journal of the Ergonomics Society of Korea
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• v.14 no.2
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• pp.15-24
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• 1995

The purpose of this study is to provide ergonomic research data for the redesign of the car license plate in Korea. Several alternatives having various combinations of fonts, stroke-width ratios, color contrasts, and arrays were considered in order to find the best one in terms of the reading-distance and the misreading-rate. Experiments investigating the reading-distance, misreading-rates were conducted. In addition, the alternatives were tested in a real driving situation. The results can be summarized as follows : The typography having mixed type numeric forms with quasi-Gothic and NAMEL, stroke-width ratio of 1:7 .approx. 1: 8, the black on yellow contrast showed a good reading-distance. The array with Hangul(showing territorial office and use-sign) at the upper row and 6 mumbers ( showing car class-sign and serial number) at the lower row showed relatively low misreading-rate.

• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.109-115
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• 2009

The objective of this paper is to compare two national guidelines on the VDT work management published by Ministry of Labor(MOL) and Korean Standard(KS), and suggest possible modifications of them. The scope of this paper was limited to the desktop type of VDT jobs, excluding laptop environment. In addition, questionnaires were administered to office workers to collect information on the discomfort levels in meeting the MOL Notification. From ergonomic point of view, the most noticeable differences between two guidelines were found with respect to the heights of chairs and desks. In fact, the ranges specified in each guideline were not the same. In the field surveys, it could be known that work environments should be improved.

• PNF and Movement
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• v.19 no.2
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• pp.243-250
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• 2021

Purpose: The purpose of this study was to observe office workers' postural behaviors during computer work to identify the risk factors for head and thorax postural behaviors. Methods: The participants included 57 office workers who worked longer than 20 hours on a computer. Postural behaviors during computer work were measured using 3-D wearable motion sensors on the forehead and sternum. A multivariate linear regression model evaluated the association between various risk factors (neck pain, demographics, and environmental factors) and non-head and thorax postural behaviors. Results: The participants maintained their head and thorax in neutral postures (defined as 10° extension~10° flexion and 5° extension~10° flexion, respectively) for 24.7% and 39.3% of the total recorded time. Those who reported neck pain at the measurement of postural behaviors showed less time spent in thorax postures. Current neck pain, high desk height, and the distance between the keyboard and the edge of the desk (cm) were found to be related to less time spent in a neutral thorax posture. Conclusion: Office environment factors and current neck pain might affect workers' thorax postures, which might also determine the orientation of head postures during computer work.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.151-165
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• 2015

Objective: This study aims to develop and scientifically investigate the efficacy of the Spine S-curve Reactive Backrest that responds to the spine curvature of the user when seated, and maintains and enhances the natural S-curve of the lower back, thereby helping to relieve fatigue, correct posture and prevent spine deformities. Background: The focus of current development, design guidelines and/or standards for office chairs is mainly placed on the chair's dimensions, incline angle, adjusting features and lumbar support. Research and development was called for developing a chair backrest that maintains and improves the S-curve of the full spine. Method: The Spine S-curve Reactive Backrest was ergonomically designed to maintain correct posture and enhance user comfort. When leaned on, the backrest responds to the user's spine line and the whole lower back sits closely against the backrest, thereby aligning the user's lower back and backrest as one to maintain and improve the natural S-curve formation of the spine. In order to evaluate the efficacy of the newly designed chair (new design) and the comparison target (chair), five male college students of standard body type with normal spine curvature were selected as test subjects, and a motion analyzer and electromyography were utilized to measure S-curve and erector spinae muscle activity when seated. Results: The spine S-curve was better maintained and improved when sitting in the new design than in the comparison chair. Particularly notable was the greater displacement gap of the thoracic spine than the cervical spine, and also that of the lumbar more than the thoracic spine, with the increase of the backrest tilting angle. Furthermore, the electromyogram results showed the new design caused a lower fatigue level of the erector spinae muscles compared to the comparison chair, and also earned a higher preference in the subjective opinion results. Conclusion: The newly designed chair in this study responds to the user's spine curvature and maintains and enhances the lower back's natural S-curve, and thereby relieves fatigue, promotes better posture, and helps to prevent spine deformities better than existing office chairs. There is a need to widely introduce and supply this new design. Application: The new design is applicable to office and student chairs, and is expected to improve concentration and work efficiency.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.1-10
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• 2007

As drivers spend more time in their cars, perception of driving a vehicle turns from utilizing a transportation means into residing in a personal space or even in moving office. Such a perception renders automobile manufacturers incorporate more vehicle functions, especially in-vehicle information systems As the number of system functions increases, the complexity of control and 2 types of display menus were designed after a literature review and a market analysis. With these controls and display menus, the experiment was performed to look into the difference of driver performance and preference on the integrated vehicle control type. Finally, the study suggests the integrated vehicle control type to minimize driver's cognitive load, and to use various functions efficiently. The study also discusses the practical use of the final integrated vehicle control type.

• Journal of the Ergonomics Society of Korea
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• v.34 no.4
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• pp.353-362
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• 2015

Objective: This study aims to analyze occupational accidents of moving helpers by work place type which means the type of residence where moving operation is done. Background: Most efforts have been focused on the industry base comprising various occupational spectrum and provided industry general preventative policies. But occupation specific policies are required for the workers involved and will reduce the occurrences of occupational accidents for the workers subject to similar working environment and process. Method: This study analyzes 208 non-motor vehicle collision related occupational accidents of moving helpers working for used household and office goods moving industry occurring from 2010 to 2012. Accident Type, agencies, event or exposure, parts of body affected are characterized by work places according to the work environment. Results: Accidents characteristics showed the difference between high-rise type and low-rise type on the size of enterprise, age, gender and work experience of the injured. Also the accident type, source of accident and parts of body affected are different between the two work place types. Finally, Accidents occurred on the specific operational processes of moving service also showed different characteristic between the two types. Conclusion and Application: The findings of accident characteristics according to workplace types and operational process of moving service can be used as baseline data for establishing systemized preventative policies for occupational accidents of moving helpers.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.405-422
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• 2010

Occupational musculoskeletal disorders currently account for the largest proportion of the occupational illnesses in Korea. In this research, status of musculoskeletal disorders among the occupational illnesses was examined through workers' compensation claims data. Types and characteristics of musculoskeletal disorders were looked at other data set as well. The data sets included epidemiological investigation data reported by Occupational Safety and Health Research Institute, and data collected from occupational disease surveillance reports and Korean occupational health-related scientific journals. Number of cases, incidence rate and insurance benefits for occupational musculoskeletal disorders in Korea are increasing every year. In addition, musculoskeletal disorders occurrence is shifted from large enterprises group to small-and-medium group, from manufacturing to service sector, and from production workers to office and professional workers. Although low back pain is still most common, its occurrence characteristics is gradually shifted from traumatic to cumulative while musculoskeletal disorders are somewhat seemingly moved from lumbar to upper limb body part. Musculoskeletal disorders were observed to be more diverse and prevalent in epidemiological investigations or surveillance data rather in workers' compensation claims data. Musculoskeletal disorders occurrence is related to demographic factors, occupational psychosocial factors, and ergonomic risk factors at workplace for which appropriate preventive measures needed to be made accordingly.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.101-105
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• 2010

According to the Korea National Statistical Office data in 2008, the population over ages of 65 years would possess to 10.7% whole population of Korea in 2009 denoting Korea is already in the aging society. It is well-known that the possibility to work longer and to live better is highly related to the work ability of individuals. The objective of this study is to evaluate the work ability of each aged group using the Work Ability Index(WAI) in the shipbuilding industry, machinery industry and Korea housing corporation, and to assess the effect of the type of business, age and job on the WAI score. The results showed that no significant difference was identified on the effect of aging although work ability of some group(over 55 years) was a little higher than that of others. Also, type of business and job had a significant effect on WAI score. These results suggested that the work ability is not necessarily related to aging in Korean society. One possible explanation for this might be different cultural characteristics of Korean society.

• Safety and Health at Work
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• v.11 no.2
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• pp.207-214
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• 2020

Background: Prolonged sitting at work can lead to adverse health outcomes. The health risk of office workers is an increasing concern for the society and industry, with prolonged sitting work becoming more prevalent. Objective: This study aimed to explore the variation in muscle activities during prolonged sitting work and found out when and how to take a break to mitigate the risk of muscle symptoms. Methods: A preliminary survey was conducted to find out the prevalence of muscle discomfort in sedentary work. Firstly, a 2-h sedentary computer work was designed based on the preliminary study to investigate the variation in muscle activities. Twenty-four participants took part in the electromyography (EMG) measurement study. The EMG variations in the trapezius muscle and latissimus dorsi were investigated. Then the intervention time was determined based on the EMG measurement study. Secondly, 48 participants were divided into six groups to compare the effectiveness of every break type (passive break, active break of changing their posture, and stand and stretch their body with 5 or 10 mins). Finally, data consisting of EMG amplitudes and spectra and subjective assessment of discomfort were analyzed. Results: In the EMG experiment, results from the joint analysis of the spectral and amplitude method showed muscle fatigue after about 40 mins of sedentary work. In the intervention experiment, the results showed that standing and stretching for 5 mins was the most effective break type, and this type of break could keep the muscles' state at a recovery level for about 30-45 mins. Conclusions: This study offers the possibility of being applied to office workers and provides preliminary data support and theoretical exploration for a follow-up early muscle fatigue detection system.

• Proceedings of the ESK Conference
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• 1994.04a
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• pp.85-85
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• 1994

It is important to provide the opportunity and means to change body posture frequently during the work period. Maintaining a given posture, even if it appears comfortable in the beginning, becomes stressful as time goes on. In order to design most products some knowledge of the dimensions of the human body is required. Data concerning human body dimensions are referred to as anthropometric data. Anthropometric data are used to establish many product dimensions such as the heights of work surfaces, minimum size for access openings, spacing between controls, mounting angles for displays, distance between user and controls, and so forth. The usual procedure is to design to accommodate 90% of the population of anticipated product users. In sosme instances it is necessary to provide a method for adjusting because it allows users to alter the produst's dimensions to meet their individual needs. When the user makes the proper adjustments, the product will be easier to use (e.g., the seat and rearview mirror adjustment mechanisms on automobiles) or more comfortable (e.g., office chairs and stereo headphones).