• Journal of Biosystems Engineering
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• 제36권1호
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• pp.58-67
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• 2011

A high prevalence of protected horiculture farmer's work-related musculo-skeletal disorders (MSDs) have been reported in precedent studies. One of the tasks required ergonomic intervention to reduce the musculo-skeletal risks is the task of harvesting. The purpose of this study is to evaluate quantitatively the spinal load of worker harvesting with squatting posture to predict and prevent musculo-skeletal risks. Spinal load in Squatting posture with asymmetric trunk motion were analyzed. Before evaluating spinal load on harvesting worker by bio-mechanical approach, it is needed to validate human model. In this study, ADAMS LifeMOD human model shows satisfactory results, comparing with already validated model's results or measured results. While worker reached arms (20%, 40%, 70% arm reach) with various asymmetric trunk motion (0, 45, 90 degree), their spinal loads (extension, twisting and lateral bending moment) were evaluated. In case of extensor moment at lumbo-sacral joint, the more the arm reach got increased, the moment increased. however, in case of twisting moment and lateral bending moment, the more both arm reach and asymmetric trunk motion got increased, the moment increased significantly. The findings of this study suggest that it need to be determine the spinal load, especially twisting, lateral bending moment in evaluating musculo-skeletal workload in squatting posture.

• 산업경영시스템학회지
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• 제41권4호
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• pp.42-49
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• 2018

Pilot Aptitude Research Equipment (PARE) is a simulator developed to measure or research pilot aptitude and train for student pilots. Design of an ergonomic PARE operation console is required to operate the equipment effectively. This study carried out five steps : (S1) operator questionnaire survey, (S2) anthropometric design formula development, (S3) usability evaluation, (S4) improvement design, and (S5) validation considering both Physical User Interface (PUI) and Graphic User Interface (GUI) of PARE operation console. The operator questionnaire surveyed needs for each PUI and GUI part of the console from two PARE actual operators. In terms of PUI, the anthropometric design formula was developed by using design variables, body dimensions, target population characteristics, and reference posture related to the PARE console. In terms of GUI, the usability evaluation was conducted by three usability testing experts with a 7-point scale (1 : very low, 4 : neutral, 7 : very high) on GUI of the PARE operation console by seven usability criteria. The improved PARE operation console was designed to reflect the optimal values of design variables calculated from design formula, the results from usability testing, and the operator's needs. The improvement effect was observed by 20 people who had experience with the PARE operation console. As a result of the validation, monitor visibility and cockpit visibility for the improved PUI design and visibility and efficiency for the improved GUI design were significantly increased by more than 90% respectively. The improved design of the PARE operation console in this study can contribute to enhance operation performance of the PARE.

• 대한인간공학회지
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• 제28권3호
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• pp.81-85
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• 2009

Work related musculoskeletal disorders(WMSDs) was a leading cause of sick leave and injuries in the industries of our country. Posture was an important consideration in the design of work method and workplaces, because it affected the ability of workers to use various equipments and influenced how long they could perform their job without feeling discomfort, fatigue, and musculoskeletal disorders. Imbalanced lower limb postures such as a squatting posture were awkward working postures common to the shipbuilding shops, farms, automobiles assembly lines in our country. Different awkward working postures were known to be associated with specific musculoskeletal disorders. Eight postures in lower limb postures divided into balanced and imbalanced postures were evaluated by electromyographic(EMG) activity for lower limb muscles. Twelve male subjects participated in this study. This paper was to analyze the effects of lower limb muscles workload according to lower limb postures(knee angle) and working time. The ANOVA results showed that most EMG root mean square(RMS) values were statistically significant effect according to lower limb postures(knee angle) and working time. Therefore, the results of this study will provide the basis to evaluate workload of lower limb postures correctly adopted by workers in various jobs and the ergonomic reference to prevent WMSDs.

• 한국의류산업학회지
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• 제20권6호
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• pp.704-712
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• 2018

This study analyzed working postures using the Ovako Working Posture Analysis System (OWAS) to improve work clothes for construction workers. A video taken at a construction work site was stopped at regular intervals and the postures of relevant body parts proposed by OWAS was recorded. Additionally, based on analysis of the working postures code, the level of work action for each postures was classified from stage I to IV. General workers frequently straightened or bent forward at the waist, and used their legs to stand, bend, or walk. Wood workers moved extensively from the waist, keeping their legs relatively straight and their arms held below their shoulders, repeatedly tapping with a hammer weighing less than 10.0kg. Rebar bending workers mainly bent forward at the waist, with both legs bent or standing with one leg bent. Rebar transport and fixing workers walked with the waist straight, and occasionally one or both hands held above the shoulders. Their work also involved holding a hook, which weigh less than 10.0kg, in their hands, and the difficult task of lifting and placing long rebars, which weigh from 10.0 to 20.0kg or more. Concrete pouring workers bent or twisted their back to the side. Therefore, this study suggests that design goals should be different when developing workwear for each type of worker.

• 대한인간공학회지
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• 제29권6호
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• pp.831-841
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• 2010

Usability evaluation of physical products involves characterizing complex physical interactions between humans and products. Human models known as manikins have been widely utilized as usability evaluation tools for automobile interior package design. When combined with computer-aided design software programs, such manikins can be used to simulate driving postures and evaluate driver-interior fits early in the design process, and therefore, may greatly facilitate achieving high-quality design in a cost-efficient manner. The purpose of this study was to define a set of manikins for designing automobile interior packages for the South Korean male population. These manikins were conceptualized as "boundary" manikins, which represent individuals lacking in certain physical capacities or having usability-related issues (e.g., an individual with the 5th percentile forward reach capability, an individual with the 95th percentile shoulder width). Such boundary manikins can serve as an efficient tool for determining if an automobile interior design accommodates the majority of the population. The boundary manikins were selected from the large sample of Korean males whose anthropometric dimensions were described in the recent Size Korea anthropometric database. For each male in the database, his comfortable driving posture was represented using a kinematic body linkage model and various physical capacity measured and usability-related characteristics relevant to driver accommodation were evaluated. For each such measure, a boundary manikin was selected among the Korean males. The manikins defined in this study are expected to serve as tools for ergonomic design of automobile interior packages. The manikin selection method developed in this study was implemented as a generic software program useful for various product design applications.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 춘계학술대회
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• pp.69-78
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• 2009

The goal of this study is to propose the effective method of investigating the injurious factors and making improved plans that prevents the workers against musculoskeletal disorders at an autoparts company and the same business field with similar working conditions and process. A questionnaire were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an ergonomic assessment method such as RULA, OWAS were performed to find out harmful factors of workplace and working posture. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. It can be concluded that the method and process described in this paper could be helpful for diagnosing the musculoskeletal disorders and making improvement plans to the autopart company and the same business field with similar working conditions and process.

• 한국산업보건학회지
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• 제16권2호
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• pp.161-171
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• 2006

The objectives of this study were to ergonomically evaluate varying tasks performed in a general hospital and to propose their improving measures based on the evaluation results. The tasks found in the hospital were largely classified into two groups of manual materials handling and awkward posture related tasks. Ergonomic tools of NLE, 3-D SSPP and RULA were used for evaluating workload of the tasks. The major findings are: 1) L5/S1 compressive force of patient transferring by one person exceeded the maximum permissible limit(6,400N) by NIOSH. The L5/S1 compressive forces for most of the patient transferring tasks by 2-4 persons were larger than the action limit (3,400N), and the tasks by five persons were analyzed to be safe in the view of L5/S1 compressive force; 2) patient repositioning tasks by 2-3 persons were hazardous on the basis of L5/S1 compressive force, while most of the tasks by 4-5 persons were safe; 3) many tasks performed in wards were found to be stressful, most of which resulted from improper heights of their working tables or working points. Of varying tasks in general hospitals, patient transferring was the most stressful. Based on the results of this study and high prevalence of musculoskeletal disorders from other studies, it is recommended that the ergonomics program be introduced and enforced for doing improving activities systematically

• 한국전문물리치료학회지
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• 제19권2호
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• pp.69-79
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• 2012

Importance of the work-related musculoskeletal disorders (WMSDs) has been increasing in the hospital industry such as health care industry and financial industry. This study investigated in order to identify the factors like general, occupational and ergonomically characteristics of the subjects related to musculoskeletal disorders (MSDs) of physical therapists (PTs). Ergonomic tools of rapid upper limb assessment (RULA) were used for evaluation workload of the tasks. Prevalence of MSDs were 13 PTs (26.0%) for neck, 31 PTs (62.0%) for shoulder, 9 PTs (18.0%) for arm/elbow, 27 PTs (54.0%) for hand/wrist, 28 PTs (56.0%) for back, 14 PTs (28.0%) for leg/foot. The analysis of the rate of the pain intensity showed that 53.5% subjects experience moderate pain and 14.0% subjects experience severe pain. Factors which were general characteristics, for example, height, ergonomically characteristics such as 'Posture Score A' were related musculoskeletal subjective symptoms in logistic analysis (p<.05). Among physical therapists, action level of RULA were action level 2 (6.0%), action level 3 (52.0%), action level 4 (42.0%). Physical therapists were estimated one of the highest risk factor in this study. This study suggested that the need of preventive education and program for PTs (physical therapists). Comprehensive and systematic management plans should be established to include both ergonomic and sociopsychological aspects.

• 한국생활과학회지
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• 제24권2호
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• pp.255-266
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• 2015

In this study, we have developed the ergonomic pattern from the 3D human body reflecting cycling posture and extensibility of the stretch fabrics. Adjusting pressure level in the construction of athlete's tight-fitting stretch garments by reducing the original pattern is a challenging subject, which influence on the performance of the wearer directly. Therefore, in this study, relationships between the reduction rates of the 2D pattern obtained from the 3D human scan and resultant clothing pressure were explored to improve the fit and pressure exerted by reduced clothing pattern. Subjective wear sensations of the experimental garments were rated using a seven-point Likert scale on two consecutive days. While wearing the garments, subjects were asked to take five different postures including waist flexion, sitting and others. A Likert-type scale was used for the evaluation, with 7 points indicating the best fit in tight-fitting pants. Comparing 2/3T-pattern with T-pattern, the latter was superior to 2/3T-pattern in terms of adhere well to the waist and hip area in the 0.032 significance level. T-pattern was superior to 2/3T-pattern in terms of fitting and wear comfort. As results, the pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the skin while cycling posture, so that the extra ease for movement and good fit was not need to be considered. The optimized reduction rates were determined with the proposed reduction rate, the resultant pressure range was within the range of $0.5{\sim}3.0gf/cm^2$ at eight locations on the body except front waist band and thigh band.

• 대한인간공학회지
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• 제30권3호
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• pp.427-435
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• 2011

Objective: The objective of this study was to evaluate a work of building cleaners using the ergonomic methods. Background: Previous studies about cleaning worker describe typical physical demands of this work. They found that the most significant risk factors associated with the physical work of cleaners are static loads and repetitive movements and high output of force. Method: A head of ergonomics estimation was work analysis(define of combined task, work tool, work time and frequency of combined task) and posture analysis of worker. Results: The results showed that combined task of building cleaners was classification sweeping, mopping(wet), mopping(oil), moving barrels/carts, dumping trash bags, scrubbing, arrangement of cleaning tool, arrangement of circumferential, moving of cleaning tool, and waiting. The work time of combined task such as mopping(wet) and scrubbing indicated high ratio. The posture analysis of building cleaners indicated high value in bending of the head, lower arm, and hands. Conclusion: The findings appear to indicate that building cleaner were related to high risk of work-related musculoskeletal disorders. So, building cleaner would be required an interventional strategy, improvement of cleaning tools and working environment. Application: If ergonomics rule can be integrated into existing cleaning tools and work environments, the risk of occupational injuries will be reduced.