• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.117-124
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• 2015

In forest work, working conditions are very hard to improve. The good posture is believed to bring about direct improvements such as accident prevention. Therefore, this research carried on analysis of working posture in forest work (construct in stepping-stone) using OWAS analysis system. According to the analytical results provided by OWAS, the ratio of category III (Work posture has a distinctly harmful effect on the musculoskeletal system) has shawn that worker 2 was 32.2%, worker 1 was 25.2% and worker 3 was 15.5%. Furthermore, the ratio of category IV (Work posture with an extremely harmful effect on the musculoskeletal system) has shown that worker 2 was 9.8%, worker 3 was 1.4% and worker 1 was 1.2%. According to the OWAS method, percentage of OWAS action categories III and IV in the worker 2 was higher than another workers.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.63-68
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• 2002

This study performed to evaluated musculoskeletal disorders(MSDs) during sitting work. The musculskeletal system is affected by various work factors such as strength, weight, posture, repetition, duration and exertion. Ergonomic study on sitting work is necessary to evaluate these factors affecting human body. But the strength and work load data by the work factors are insufficient in Korea. Therefore, this study evaluated the work load using the elcctromyogram(EMG) and measured the arm strength by arm posture and push pull work during sitting work. to evaluated muscle load, the vertical height and horizontal angle of arm were adjusted around acromion. And EMG data were recorded on pc during the test.

• Journal of muscle and joint health
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• v.23 no.2
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• pp.125-137
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• 2016

Purpose: The purpose of this study was to identify the influences of hospital employees' daily life posture habits and work-related factors upon musculoskeletal subjective symptoms. Methods: This study was a descriptive survey study. Data were collected using structured a self-report questionnaire between April 1 and May 31, 2015. One hundred and ninety two employees were recruited in three hospitals. The collected data were analyzed using descriptive statistics, ${\chi}^2$ test, t-test, and binomial logistic regression. Results: The habit of leaning on one side and the habit of bending the back in an improper posture are key postures based on lifestyle affecting musculoskeletal subjective symptoms in neck, shoulders, arms, waist, and legs. Labours accompanying repeated arm movements for a long time are key work-related risk factors affecting musculoskeletal subjective symptoms in arms. Conclusion: The results of this study confirmed that, to prevent musculoskeletal diseases, it is necessary to identify and mediate personal factors like daily life posture habits as well as work-related risk factors. They may be utilized as basic materials for education of musculoskeletal health promotion and development of life guidance programs.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.119-124
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• 2003

Despite rapid technological advance and increased automation facilities, many jobs and activities in our living require manual materials handling(MMH). These include wide variety of activities such as moving things, lifting bags. boxes or cartons, etc. Many studies found that handle could affect on maximum acceptable weight of lifting, but there were few studies f3r the effects of work posture and coupling in lifting tote box. This study performed that ten male college students were required to lift a tote box with and without handle for three postures (bending, straight, right angle posture). From the experiment, following results were obtained. (1) MVC reduced maximum 23% by type of handle. (2) MVC was highest in straight posture, but was lowest in right angle posture. (3) As a result of ANOVA, MVC paid attention to posture and coupling. (p<0.01) (4) To all handle types, biceps brachii activity was increased in right angle posture. but reduced in straight posture. (5) To all posture, biceps brachii activity was most lively in no handle. The results of MVC measurement, subjective rating, EMG analysis, statistic analysis showed that maximum acceptable weight of lifting was influenced by type of handle and straight posture was more comfortable than other postures. Based on these results, it was concluded that acceptable weight of lifting has to differ for work posture and coupling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.72-73
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• 2016

Working Posture is an important factor directly connected with quality and productivity of the construction project. In particular, High-rise building construction is required to manage the working posture due to the repetitive task and unfavorable working condition such as high place work, limited space. However existing construction planning of high-rise building construction has a negative effect on the labor's productivity because it is not insufficiently considered for working posture. Therefore the purpose of this study is to suggest a work that needs improvement by analyzing labor's working posture quantitatively using OWAS method. These results would provide the basic information to improve the productivity of the construction project by supporting the construction plan considering the working posture in high-rise building.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.69
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• pp.51-64
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• 2001

A laboratory experiment was conducted to investigate the effects of working posture. work/rest ration, and task type on the physical workload in automobile assembly jobs. Ten healthy male university students participated as subjects in the experiment. East subject performed 18 experimental session with combination of 3 working posture 3 work/rest ratio and 2 task types. To examine the effect of various working conditions on workload, DMG analysis was performed on 4 different muscles in the neck an arm area, Also RPE scale and heart rate were taken as response variables. The result showed that all working conditions considered in the experiment had significant effects on the workload concluding that labor intensity in auto assembly jobs should be adjusted with respect to different levels of working posture, work/rest ratio, and task type. Detailed analysis are presented in the paper.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.601-608
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• 2013

PURPOSE: The purpose of this study was to investigate the effect of distance between trunk and desk on forward head posture and muscle activity of neck and shoulder muscles during computer work. METHODS: Twenty subjects who have healthy conditions were asked to perform computer work in two conditions (distance between trunk and desk was 0 and 15 cm). Forward head angle was analyzed with a SIMI motion analysis system. Surface electromyography recorded the upper trapezius and splenius capitis muscles. The significance of differences in distance between trunk and desk (0cm and 15cm) was tested by paired t-test. The alpha level was set at .05. RESULTS: The results showed that the change of forward head angle was significantly higher during the computer work when the distance between trunk and desk was 15cm than 0cm. The muscle activity of upper trapezius and splenius capitis was also significantly higher during the computer work when the distance between trunk and desk was 15cm than 0cm. CONCLUSION: Our study suggest that the distance between trunk and desk was should minimized for prevention of forward head posture during computer work.

• Journal of the Korean Society of Safety
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• v.26 no.3
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• pp.69-74
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• 2011

Despite most of tasks in manufacturing, construction and agriculture, etc., were currently mechanized and automated, manual materials handling still existed in atypical working condition. In case of manual materials handling, repetitive work, inappropriate working posture, excessive force, contact stress might cause overload, which could lead to work-related musculoskeletal disorders and low back pains. On this basis, the goal of this study is to reveal the effects of various lifting postures of trunk angles and lower extremity postures on maximum holding time(MHT). Twenty two subjects were recruited from a university population. The experiment was designed by a combination of three trunk angle ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) and three lower extremity postures(straight, bent, kneeling). Before experimental trials, subjects performed MVC(maximum voluntary contraction) exertions in three trunk angles ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) to calculate 30%MVC at designated postures. In each trial, they were required to hold the handheld load(30%MVC) for a designated posture as long as they could. The results of MVC by trunk angles were measured in $0^{\circ}$ > $20^{\circ}$ > $60^{\circ}$ orders, but those of MHT measured in $20^{\circ}$ > $0^{\circ}$ > $60^{\circ}$ orders. These results showed that straight posture is the ideal working posture in work exerted a strong force for a short time, but the ability to work might be improved in the trunk angle $20^{\circ}$ in work required 30%MVC for a long time. Also, results of MVC and MHT by lower extremity postures measured in straight > bent > kneeling orders.

• Physical Therapy Korea
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• v.15 no.4
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• pp.80-86
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• 2008

Cross-legged sitting postures are commonly assumed during computer work. The purpose of this study was to determine the effects of leg crossing on trunk muscle activity while typing at a computer. Trunk muscle activity was measured in three 8 different sitting postures, in random order. These posture were: normal sitting with a straight trunk and both feet on the floor (NS), upper leg crossing (ULC), and ankle on knee (AOK). The right leg was crossed onto the left leg in both cross-legged postures. Twenty able-bodied male volunteers participated in this study. Subjects typed on a computer keyboard for one minute. Surface electromyography (EMG) was used to record bilateral muscle activity in the external oblique (EO). internal oblique (IO), and rectus abdominis (RA). The EMG activity of each muscle in the NS posture was used as a reference (100% EMG activity) in relation to the two cross-legged postures. Muscle activity in the right EO. right IO, and left IO was significantly lower in the ULC posture than in the NS posture. In contrast, muscle activity in the right RA was significantly higher in the ULC posture than in the NS posture. Muscle activity in the tight RA was significantly higher in the AOK posture, as compared to the NS posture, whereas activity in the left IO was significantly lower in the AOK posture, as compared to the NS posture. The right-left muscle activity ratios in the EO and IO showed significantly different patterns in the cross-legged postures, suggesting that asymmetrical right-left oblique muscle activity had occurred.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.601-607
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• 2017

Objective: A method to assess the risk level of agricultural works considering work posture and working time was suggested, and the method was applied to the major fruit crops. Background: It is not complete to analyze only work postures when assessing risk level of agricultural works. Method: $3{\times}3$ matrix was employed, in which the severity level was taken from the REBA method and exposure level was taken from the working time, using the criteria of caution zone/hazard zone. Results: Among the 5 major fruit crops(apple, pear, grape, peach, persimmon), the highest level of ergonomic risk was found in the apple and pear, while medium level was found in other 3 crops, mainly because the working time was less in the 3 crops. Conclusion: It was found that when assessing the overall ergonomic risk of agricultural works, work posture and working time should be considered at the same time. Application: The suggested method could be applied to other non-cyclic tasks.