• 한국안전학회지
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• 제14권4호
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• pp.192-198
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• 1999

Work-related musculoskeletal disorders constitute a major source of employee disability and lost wages. Cumulative Trauma Disorders(CTD) refers to a category of physical conditions which result from chronic musculoskeletal injury. Assessment of CTD risk in industry at early stage allows for early control, a safe environment, and a healthier workforce. In this study, the physical load of the shipping work in the cold storage warehouse were especially investigated. Employees were working with almost unnatural posture in a very restricted work space. The questionnaire and biomechanical analysis were used to evaluate the physical load. Results from analyses showed that they were sufficiently exposed to CTD due to repetition and unnatural posture. Based on the analysis, ways for improving working conditions are proposed. The analysis and proposals in this paper will serve as a basic tool for designing/redesigning working environment such as improvement of tools and equipments, design of times for work/rest cycle.

• 산업공학
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• 제18권3호
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• pp.288-296
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• 2005

Many jobs and activities in our daily lives require squatting postures. The fore part includes housekeepers, farmers, and welders and the latter includes a wide variety of activities such as housekeeping; planting, cultivating and harvesting various agricultural products; grinding, welding, etc. It is speculated that prolonged squatting postures without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is conducted to examine the proper height of stools according to the position of the working materials and to develop wearable stools for workers with squatting posture. Forty male and female subjects participated in the experiment to find the proper height of stools according to the position of the working materials. Subjects were asked to squat and work with 3 different working positions: floor level; ankle level; shank level of 3 different stool height conditions: 10cm height; 15cm height; and 20cm height. After 5 minutes of maintaining a squatting work posture while sitting on the different height stools, Likert summated rating method as well as pairwise ranking test was applied to evaluate the user preferences for provided stools under the conditions of different working positions. The results of statistical analysis show that the subjects preferred 10cm height stool for floor level, 15cm height stool for ankle level, 20cm height stool for knee level. We thus strongly recommend to use appropriate height stools in accordance with the different working positions. Moreover, a prototype wearable stool was designed such that workers with squatting posture do not need to move the stool while they are moving about. The purpose of developing wearable stool was to decrease the physical stress and hence promote worker's health who work with squatting posture.

• 대한인간공학회지
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• 제32권5호
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• pp.469-474
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• 2013

Objective: The purpose of this study was to analyze the risk factors of MSDs for the types of office work. Background: Physical risk factors of VDT(Video Display Terminal) associated with shoulder and neck musculoskeletal disorders(MSDs) include static work postures and workstation status. Method: In this study, office work was divided into data search, data entry and design work(drawings, etc.), and then we were surveyed 7 major work places which was included these works. We recorded working postures and obtained still images, depending on the types of office work. Then, RULA(Rapid Upper Limb Assessment) and ROSA(Rapid Office Strain Assessment) were used to analysis the risk factors. Results: The results of RULA showed that design work was under risk levels and required change, but ROSA showed that data entry and design work were high risk. The RULA is to evaluate the level of risk factors based on the working posture; on the other hand, the ROSA is to consider the use of peripheral, same as chair, keyboard/mouse, monitor and computer workstations. Conclusion: Conclusions of this study, the office work is necessary to identify the risk factors caused by the use of peripheral, as well as working posture.

• Industrial Engineering and Management Systems
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• 제7권1호
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• pp.90-98
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• 2008

This research selects the lifting task to be the main subject. Four experiments were designed to measure which among lifting postures, lifting heights, waist-belt, and breathing control significantly influences intra-abdominal pressure (Gallagher, 1991; Lavender, Andersson and Natarajan, 1999). The experimental results were taken to be the recommendations of the manual materials handling work design. The research findings reveal that the symmetrical stoop posture is the most significant to the intra-abdominal pressure within all lifting postures. When the lifting height is increased, the intra-abdominal pressure produced relatively goes up. Also, the combination of symmetrical stoop posture, waist-belt use, and inspiration and holding at the same time is the most efficient in carrying out lifting tasks. Simultaneously, the research discovers that for any posture, the volume of the intra-abdominal pressure is much bigger when using the waist-belt compared to when it is not used. Therefore, the waist-belt design for the lifting works might be the future research approach.

• 산업공학
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• 제24권4호
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• pp.387-395
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• 2011

This study was aiming to examine work time, frequency, work environment, and postures of retail grocery store workers to evaluate the risk of musculoskeletal disorders. An ergonomic evaluation was conducted using job analysis and posture analysis. The four most time-consuming tasks were inspecting (27.4%), arranging (21.4%), cutting (17.6%), and displaying (15.6%). The height and length of the shelves evaluated in the field was inappropriate for workers. The most common posture was a standing posture with neutral back, and bent head, right upper arm, lower arms, and hands. Finally, this paper concluded that 'arranging,' 'cutting,' and 'displaying' seemed more stressful than other operations. The result of the ergonomic evaluation would contribute to design a better workspace in ergonomics.

• 대한산업공학회지
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• 제41권6호
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• pp.551-558
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• 2015

The purpose of this paper is to investigate the development of mechanical projectile transfer system to prevent musculoskeletal problems in the firing test range. Prior to 2010, the projectile has been transferred from the worktable to the loading device of 155mm K9 fixed-type artillery by manual. Because the amount of firing test has been increased drastically since 2010, two types of mechanical projectile transfer system were developed to prevent musculoskeletal problems. The NIOSH lift equation and the working posture assessment system such as OWAS, RULA and REBA were used to evaluate the appropriacy of working weight and posture by manual transfer of projectile. The configuration and operation procedure of projectile transfer systems which were developed to improve work efficacy and to reduce the burden of manual transferring were described. The improvements were assessed by the number of processes, the tact time and the working posture assessment for operation of this system by comparing to the manual transfer of projectile.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.629-630
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• 2017

최근 현대인들이 많은 업무와 학업으로 인하여 좌식 생활의 빈도가 매우 높아지고 있으며, 장시간 동안 의자에 앉아 있으면서 올바르지 않은 자세와 습관으로 인해 습관성 척추 질환환자가 증가하고 있다. 따라서 이러한 질환을 실시간 모니터링을 통해 사전에 방지하고 사용자가 올바른 자세의 중요성을 인지할 수 있도록 가이드 제시가 요구된다. 본 연구에서는 압력센서 기반의 체중분포 시스템을 사용하여 사용자의 앉은 자세를 판단하고 피드백 함으로써 자세를 교정하는 데 도움을 줄 수 있는 자세 판별 시스템을 구현하였다. 체중의 분포 패턴을 분석하여 1가지의 정상 자세와 6가지의 비정상 자세를 판단하였으며, 비정상 자세를 지속적으로 유지하고 있다면 알림이 울려 바른 자세로 유도하는 어플리케이션의 구현에 대해 기술하였다.

• 한국안전학회지
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• 제20권4호
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• pp.148-153
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• 2005

Computer dominated jobs and industrial automation have rapidly created work-related musculoskeletal disorders(WMSDs) and WMSDS are expanding to employee of other general industry. Specific risk factors associated with WMSDs include repetitive motion, heavy lifting, forceful exertion, contact stress, vibration awkward posture and rapid hand and wrist movement. The purpose of this paper is to analyze the effects of the neck muscle workload according to posture(joint angle) and load weight. Seven male students participated in this study. To analyze neck muscle workload was studied on electromyographic(EMG) activity for sternocleidomastoid and trapezius, was subjectively rated using a Borg's CR-10 scale. ANOVA showed that the CR-10 ratings and most EMG root-mean-square (RMS) value were statistically significant improvement according to posture(joint angle) and load weight. The results of this study indicate the joint angle and weight of neck muscle workload to provide safe working conditions. To reduce the large number and severity of WMSDs employees have been experiencing, we need to redesign the job in workplace to identify and control hazards that are reasonably likely to be causing or contributing to the WMSDs.

• 한국직업건강간호학회지
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• 제14권1호
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• pp.5-15
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• 2005

Purpose: The purpose of this study are to identify the influencing factors on work-related musculoskeletal disorders of women workers. Method: Data were collected by questionnaires from 616 women workers from in such industries as electronics, food product, garment product and analyzed using descriptive statistics, multiple logistic regression. Result: As its result, 71.3% of female manufacturing workers had musculoskeletal symptom. When Multiple logistic regression analysis on factors relating to musculoskeletal symptoms was carried out, age, work posture, job demand, type of industry, working hour, type of work, family support were statistically significant variables. Conclusion: In conclusion, this study identifies that age, work posture, job demand, type of industry, working hour, type of work, family support are important factors affecting WMSDs.

• 대한인간공학회지
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• 제30권5호
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• pp.637-644
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• 2011

Objective & Background: When applying various evaluation tools that analyze work posture risk through observation, accurate measurement of body flexion angle is very important. Method: This study investigated differences and appropriateness of 5 different existing reference points commonly used in the analysis of the work posture. Twenty five ergonomist and trained professionals were participated in this study. A Same flexion angle was utilized for the evaluation of risk assessment of musculoskeletal disorders using five different reference points to investigate the degree of difference between them. To investigate how different the observers' preferred flexion angle measuring methods were compared to the ISO 11226 Reference Posture, a virtual body model was constructed using the Poser 6.0 program. Six types of body flexion postures were constructed, and since neck flexion differs according to body angle, five types of neck flexion postures were constructed with the trunk bending $20^{\circ}$ forward, making up a total of 30 virtual flexion postures. Results: Results showed that the observers used personally preferred reference points instead of reference points recommend in the evaluation tools. Also the results revealed the their seems to be 6 types of flexion angle for the trunk and 11 types of measurement methods for the neck flexion angle in the form of personally preferred reference points. The results showed that a mean difference of $14^{\circ}$($4{\sim}23^{\circ}$) occurred in the trunk, and a mean difference of $20^{\circ}$($-8{\sim}51^{\circ}$) occurred in the neck. To increase accuracy when using the 5 evaluation tools in combination, the ISO 11226 standards, observers' preferred flexion posture standards, and common flexion posture standards of the evaluation tools were compared with the reference points of the 5 evaluation tools. Results showed considerable variance in angle difference for each evaluation tool. Conclusion: According to the results of this study, considering the angle difference between the flexion angle reference points of the evaluation tool and the reference points selected by the observers, it is concluded that instead of personally preferred reference points, the standardized reference points to enhance the accuracy and the objectivity. Application: The result of this study can be used as reference guide to develop the standardized reference point in the future.