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

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.3
• /
• pp.279-291
• /
• 2015

Objective: The purpose of the study is to evaluate appropriate weight for aged farmers in manually handling livestock feed in bags using ergonomic methods. Background: In the livestock industry in South Korea, despite the trend of aging of labor manpower, heavy items are still manually handled in many farms. In particular, among stockbreeding works, the handling of feed in bags weighing 25~30kg is reported as a cause of frequent injuries and musculoskeletal system diseases. However, studies on the standard for recommended weight allowed considering the physical characteristics of aged farmers older than 60 years with greatly decreased physical strength and muscle strength are insufficient. Method: To evaluate appropriate weight for handling of heavy livestock feed in bags, physical techniques for measuring recognized levels of physical work loads, the NLE (NIOSH lifting equation) a method that is an observation type technique, and an ergonomic modeling technique to predict compressive force imposed on L5/S1 were used. Subjects who participated in the experiment were organized into two groups of males/females with mean age exceeding 60 years, and lifting tasks were evaluated for nine weight levels. Results: Based on the results of psychophysical measurement, females showed a tendency of more drastic increases compared to males when weight was over 19kg. The results of estimation of regression models for the weight, 18.0 kg ($r^2=0.97$) and 15.3kg ($r^2=0.97$) were evaluated as stable load for males and females, respectively. In addition, both the observation type evaluation and ergonomic model evaluation showed stable loads in a range of 15~18kg. Conclusion: Given the results of the study, the weight of the feed in bags currently distributed to farms can become a cause of not only overexertion but also farm work related disasters such as musculoskeletal disorders and safety accidents. Providing livestock feed in bags weighing not more than 19kg for aged farmers is judged desirable, and managerial improvement for this matter is considered necessary. Application: The results of the present study can be utilized as useful data for institutional improvement of the weight of livestock feed in bags.

• KIEAE Journal
• /
• v.7 no.2
• /
• pp.39-46
• /
• 2007

A high-rise building construction in Korea has some problems in engineering, construction and management technologies although the high-rise building construction is recently booming. In addition, the lack of skilled construction labors is increasing, so the development for methods is needed to reduce the labors by prefabrication and mechanization. A re-bar work is one of very important works with regard to cost and schedule management in the high-rise building construction. Nevertheless, the re-bar work has some problems that it is needed many re-bars for joints linking and much time for lifting due to high-rise buildings, and it is difficult to level the skill of labors. So, in this study, the pre-fabrication of three-story height in column re-bars is proposed and the results of an implementation are analyzed and explored by a case study. As the results of case study, the pre-fabrication of three-story heights in column re-bars could reduce the cost in the re-bar work and accelerate the time in the structural frame work. In addition, the pre-fabrication of three-story height in column re-bars could solve the problems such as the waste of many re-bars for joints linking, and the lack of the skilled labors.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.10 no.3
• /
• pp.232-241
• /
• 2017

This study was carried out to design the stable elements of the aerial work machinery used in the orchard and farmland which had been conducted in the previous research. A hydraulic lifting lift has been developed to work safely at irregular and inclined locations using an auto leveling system and a horizontal sensor. The development of a centralized controller including remote control has been carried out in order to control the elevated work platform. Through the developed module, we carried out on-site test run to check whether the control is stable in the elevation workbench. Through the structural analysis of the elevation workbench, the maximum load and the equal load amount that the worker can safely work on the workbench are presented.

• Korean Journal of Social Welfare
• /
• v.68 no.2
• /
• pp.53-77
• /
• 2016

This research is performed to verify a suggestive understanding and undertone on radical social workers's balanced practical experiences responding to the current situation to discover the new practical way of Korean social work so as to overcome the limitation of the above mentioned microscopic approach. It focuses on Giorgi's descriptive phenomenological study and further relating areas to provide information on Radical Social Workers'(RSW) social work practical and specific experiences and fundamental implication. This research has been participated with 9 RSWs, led the past democratic movement, have participated with this research. The data covers 84 meaningful units, 24 exposed topics, and 7 essential themes. The essential themes are as follow; lifting a latch into prepared changes, unavoidable destiny, drive for change from the bottom, collaborated forces of minority groups, changing the oppressive laws and institutions to more favorable ones for minorities, being patient and waiting required as birds breaking eggs to become a bird. Based on the collected data, Researchers discuss the main features and issues of our instituted social work practices.

• Journal of the Korea Institute of Building Construction
• /
• v.8 no.1
• /
• pp.37-42
• /
• 2008

As use of construction equipment has been increasing continuingly, the proportion of equipment expense to the total construction cost has become higher. However, there is a difference between the equipment expenses section in 'Poom-Sam' and practical data, because 'Poom-sam' does not consider non-working days due to weather conditions, legal holidays and management conditions. Therefore, 'Poom-Sam' does not present a reasonable standard for estimating construction equipment expenses. In this study, to estimate realistic construction equipment operating hours, firstly, construction equipment was classified according to work, and weather conditions, in which each work could not be executed, were established. Then, weather data on Seoul and Busan($2004{\sim}2006$) and legal holidays were analyzed to suggest annual standard operating hours. The annual standard operating hours of earthmoving & excavating, compaction, and drilling equipment was estimated to be 1,430 hours, and lifting equipment, concrete paving equipment, asphalt paving equipment, concrete equipment, and crushing & conveying equipment were estimated to be 2,124 hours, 1,156hours, 1,188hours, 1,688hours, and 2,152hours respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.4
• /
• pp.385-397
• /
• 2006

A high prevalence of farmer's work-related musculoskeletal disorders(MSDs) have been reported in precedent studies. To offer the basic data for reducing the melon farmer's MSDs, a questionnaire survey about MSDs symptoms and work loaded body part and video analysis by 3 checklist(REBA, RULA, OWAS) for musculoskeletal risk assessment were carried. 94 melon farmers for this questionnaire and 1 typical farm for risk assessment were participated. A total of 80.9% of the farmers reported musculoskeletal symptoms and 60.6% reported musculoskeletal symptoms over NIOSH standard. The mainly symptom body part is low back, knee and shoulders. Main risk factors in melon farm are awkward postures, heavey/frequent lifting and repetitive hand/arm motions. The high risk tasks induced by video analysis were harvesting, removing the sprouts and covering with rags. These result can be used practically for planning intervention strategy and programs to prevent farmer's MSDs.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.4
• /
• pp.503-507
• /
• 2011

Objective: This paper presents the factors influencing the effectiveness of materials handling equipments in agriculture. Background: Agriculture is one of the job categories where work-related musculoskeletal disorders(MSDs) are the most common. Statistics shows that majority of farm workers is exposed to repetitive and forceful body movements, lifting, lowering, pushing, pulling, or carrying heavy materials. In such a working environment, materials handling equipments are required and introduced to assist in the prevention of MSDs and other farm injuries. Method: Examples of materials handling equipments are rail carts, portable lifts, and bale handlers. Contributing factors influencing the effectiveness of materials handling equipments supplied in agriculture were identified based on the lessons learned from previous government-funded ergonomic projects. Results: Contributing factors identified include: (1) forward-looking attitude for the standardization of farming, its environments, and handling equipments, (2) participation of farm members in the process and evaluation of project, (3) leadership of project manager, (4) reinforcement of safety education and training, and (5) project selection and priority of handling equipment. Conclusion: Government-funded research planners, farmers, ergonomists, and farm machine experts are recommended to consider the factors identified when implementing materials handling equipments in agriculture. Application: Actual or potential application of this research includes recommendation for the effective implementation of material materials handling equipments in agricultural sectors.

• Korean Journal of Occupational Health Nursing
• /
• v.8 no.2
• /
• pp.156-161
• /
• 1999

The EMG(Electromyography) analysis was used to identify the fact the degree of inclined step was selected as dependent variable and feet muscle fatigue was selected as a independent variable. In a final result from EMG test. the shift in median frequency (MF) with 20, 25, 30, 35 degree of inclined steps indicated that 30 degree step was identified as most effective for a decrease in feet muscle fatigue. In a department store, 80% of the workers are female standing sales workers. They work at standing on average 10 hours per day. They performed heavy duty jobs such as lifting, lowering. packing and carrying heavy materials. Furthermore, even though they have work shoes, they usually use various kind of high heels. Eventually, this situation develops low-back-pain (LBP) problems for female workers. In conclusion, it is recommended that a particular branch in a department store claimed this step can effectively to circulate blood and significantly decrease feet muscle fatigue in lower extremity.

• Korean Journal of Occupational Health Nursing
• /
• v.3
• /
• pp.21-30
• /
• 1993

For the purpose of disclosing the magnitude of low back pain problems of hospital nursing personnel and its possible causes, a questionaire survey was carried out on 418 nurses and nurse aides if a university hospital in Seoul. The results were as follows : 1. Of 418 nurse and nurse aides, 268 persons(64.1%) have experienced 1,145 spells of low back pain during 6-month period. 2. The pain and/or discomfort was mostly limited to the back, although 19% of the episodes accompanied radiating pain to the low extremities. 3. Of those with low back pain, 23 persons(8.6%) were medically diagnosed and 17 persons(6.3%)-underwent medical treatment. Those who sick leave amounted to 8 persons(3.0%). 4. The occurrence of low back pain showed significant association with assignment of duties(wards) and work shifts, while the association was not significant in terms of ranks, careers and overtimes. 5. The occurrence of low back pain was closely associated with lifting and carrying of loads, standing and twisting postures as well as the amount of work. 6. Among the nonoccupational factors, drinking showed statistically significant association with the occurrence of low back pain.