• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.465-475
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• 2014

Objective: The aim of this study is to investigate the effect of workload on musculoskeletal degeneration. Background: It is important that workers maintain a health body for a long time as a measure of aging workers. In order do so, it is necessary to find out if workload can effect on musculoskeletal degeneration. Method: Epidemiological studies on workload or occupation and disc degeneration, osteoarthritis of knee were identified through database and bibliography searches. Results: Epidemiological studies showed that workload certainly effect on musculoskeletal degeneration. But we couldn't know which of individual factors and occupational factors further contribute to the musculoskeletal degeneration. And we could find that studies on workload and genetic factors were very few. In addition, there was also very few studies that it was possible interaction between individual factors as obesity and occupational factors as heavy manual lifting. Conclusion: Our reviews suggest that it need to conduct study between workload and genetic factors for musculoskeletal degeneration. This further study can identify attributable risk of workload for musculoskeletal degeneration, and contribute to the measure of aging workers. Application: This paper can help to establish research plan for the measure of aging workers.

• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.25-34
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• 2009

A cross-sectional study was conducted to assess the association between musculoskeletal workload and psychosocial job stress variables from 100 employees from a cable making industry. It was found that the employees who had to do musculoskeletal hazardous tasks suffered higher psychosocial stress in 'decision latitude', 'job insecurity' and 'psychological job demands' also. The employees with higher level of psychosocial job stress in 'psychological job demands' and 'score of the "type A" personality' responded that they had higher 'physical job demands' from the task irrespective of its musculoskeletal hazardousness. These results confirm that musculoskeletal workload were associated with both physical and psychosocial work factors. Attention should be paid to psychosocial work factors along with physical workload to prevent musculoskeletal disorders in the manufacturing industries.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.7-15
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• 2009

The objective of this study is to survey the working environmental conditions and musculoskeletal workload(DMQ) in red pepper farmers. 155 full-time farmers(males=91, females=64) lived in Chungnam and Jeonbuk participated in the study. To offer the fundamental data for agricultural improvement of red pepper farms, information about working farm conditions, health condition, musculoskeletal disorders(MSDs), labor intensity and musculoskeletal workload was obtained by questionnaire and interviews. The results are as follows: 1. The farmers reported sunlights, high temperature and cold/ draught as uncomfortable work environment. 2. Physical and mental fatigue in females is higher than that of males. 3. The prevalence rates of medical diagnosed diseases are higher in order of osteoarthritis, herniated nucleus pulposus(HNP), and chronic gastritis/gastric ulcer. 4. Prevalence rates of musculoskeletal symptoms more than standard 1 among the various pain areas are higher in order of low back, shoulders and knees. These results can be used practically for agricultural improvement of red pepper farms to prevent MSDs.

• Physical Therapy Korea
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• v.16 no.1
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• pp.42-51
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• 2009

The purpose of this study was to develop a checklist of risk factors for quantitative assessment of musculoskeletal complaints in shipbuilding workers. A key point was to develop comprehensive a checklist including the worker's physical ability, as ergonomic and workload factors. ln the first, through correlation analysis between musculoskeletal complaints and physical abilities in shipbuilding workers, risk factors related to physical abilities were selected. In the second, after the development of a checklist was composed of physical, ergonomic and workload factors, factor analysis was used to test the validity of the developed checklist. Each factors selected finally showed that physical factors were hand grip strength, spinal curvature, and flexibility (sit to reach), ergonomic factors were posture, total exposed time, duration, and force of working, and workload factors were physical and psychological workload perceived by worker. The results showed that musculoskeletal complaints was associated with physical abilities (p<.05). The developed checklist had a reliability of .761 (Cronbach=.761) and a validity and explanation of 54.9%. The criterion of management was classified in 4 stages by relative weights of each factor. It is suggested that active intervention is needed to reduce musculoskeletal complaints in workers with more than a 14.31 score.

• Journal of the Ergonomics Society of Korea
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• v.24 no.3
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• pp.43-52
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• 2005

A two-dimensional posture measurement system was developed to evaluate the risks of work-related musculoskeletal disorders(MSDs) easily on various conditions of work. The posture measurement system is an essential tool to analyze the workload for preventing work-related musculoskeletal disorders. Although several posture measurement systems have been developed for workload assessment, some restrictions in industry still exist because of its difficulty on measuring work postures. In this study, an image recognition algorithm was developed based on a neural network method to measure work posture. Each joint angle of human body was automatically measured from the recognized images through the algorithm, and the measurement system makes it possible to evaluate the risks of work-related musculoskeletal disorders easily on various working conditions. The validation test on upper body postures was carried out to examine the accuracy of the measured joint angle data from the system, and the results showed good measuring performance for each joint angle. The differences between the joint angles measured directly and the angles measured by posture measurement software were not statistically significant. It is expected that the result help to properly estimate physical workload and can be used as a postural analysis system to evaluate the risk of work-related musculoskeletal disorders in industry.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.100-106
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• 2013

According to the Statistics Korea, in 2011, people over the age of 65 years old accounted for 11.8% of Korea's population. This number is expected to rise to 15.0% by 2019, making Korea an "aged society". As age increases, physical ability degrades to the point that the workload must be adjusted limitations. However, workloads are given regardless of workers' ages or abilities. In addition, a decline in work efficiency due to aging also increases the risk of work-related injuries. Furthermore, the cases of stress related diseases along with musculoskeletal disorders(MSDs) rise as main factors of industrial disasters and excessive job stress gives negative influence not only on mental health but also on physical health so that job stress becomes a hot issue as a main cause of work ability falloff and turnover. The purpose of this research is to examine how the sociodemographic characteristics, MSDs symptoms and musculoskeletal workload of workers in the manufacturing industry of automobile parts influence work ability and job stress. As a result of the research, job ability showed significant differences statistically according to age, working year, sex, marital status and musculoskeletal workload and job stress showed significant differences statistically according to age, working year, marital status and musculoskeletal workload. In addition, it showed that as the worker's job ability decreases, job stress increases.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.349-356
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• 2011

Objective: The purpose of this study was to analyze the risk factors of the musculoskeletal workload of mid-old-age female caregivers by identifying work postures and subjective symptoms. Method: This study was carried out on a total of 206 subjects 206 mid-old-age caregivers(45~65 years old) from November 2009 to April 2010: 206 mid-old-age caregivers (45~65 years old) at the long-term hospital. A questionnaires survey on general factors and subjective symptoms of subjects was conducted. The risk factors of the musculoskeletal workload evaluation method is based on OWAS, RULA, REBA according to occupation properties. Results: The analysis of the rates of the subjective symptoms showed that 78.6% subjects experience low back pain. The analysis of the work type showed that transfer is the highest rate(36.3%) and position change is the second(18.2%). The analysis of the work postures showed that the thrusted back with twisting position over $20^{\circ}$ is highest rate(37.4%), the bended back forward with twisting position is the second(27.5%). Conclusion: This study suggested that the need of preventive education for caregivers and workload improve. It is hoped that subsequent study on the difference of subjective symptoms between educated caregivers and non educated caregivers will be conducted.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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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.

• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.687-694
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• 2012

Objective: This study aims to survey the prevalence of musculoskeletal disorders(MSD) among Korean hospital workers and to analyze the relationship of MSD symptoms and workload perceived by workers. Background: Despite of high exposure to the MSD risk factors and high MSD symptom prevalence among health care workers, there were not enough studies of MSD prevalence among the hospital workers. Method: This study designed a survey based on Nordic questionnaire to obtain MSD symptoms and the degree of four perceived workloads: work repetition, urgency, physical exertion and satisfaction. In this survey, 1,846 workers in a hospital participated. The prevalence of MSD was analyzed for each body part, and MSD cases, which were predetermined in this study, were identified. The relationship between the MSD cases and each perceived workload was analyzed using chi-square test. Results: The pain in the shoulder was the most prevalent among the workers as 52%, and the low back(37%) and leg discomfort(36%) followed. The MSD cases, in which degree of pain was more than severe, were also the most prevalent in the shoulder(13%). Female workers had higher rate of MSD cases than the males. Among the four workload variables, the physical exertion was the statistically related to MSD cases for all the body parts. In addition, the others also had significant relation to MSD cases except one or two body parts. Conclusion: This study found that Korean hospital workers had MSD symptoms mainly in the shoulder, low back and legs in order, and the perceived workload surveyed in this study was highly correlated with MSD symptoms. Application: This study provides another evidence that subjective physical exertion perceived by workers is an important factor to explain MSD cases as same as the objective one.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.137-147
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• 2007

Dentists are known to be highly exposed to the musculoskeletal disorders (MSD). The present study investigated the prevalence of MSD among Korean dentists and association between their MSD and physical workload. In addition, work-related causes of high physical workload were identified and needs of dentists were collected for improvement of dental instrument and environment. Four types of questionnaires including the Nordic questionnaire were used to investigate body troubles, physical workload, causes of physical workload, and improvement priority of dental components. A total of 104 dentists in Seoul were participated in the survey. Neck trouble (82%) was the most prevalent in the participated dentists and shoulder (68%) and low back trouble (56%) followed, while low back trouble was reported to be most common in previous western studies. The body troubles were related to the physical workload of the corresponding body parts, although they were not associated with personal characteristics. Most dentists selected 'to keep direct view inside patient's mouth' and 'no support of the hand with dental instruments' as causes of awkward and strenuous work postures. They wanted design improvement for some components in their operating room such as operating light and arrangement of workplace.