• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.390-402
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• 2009

This study aimed to examine the general characteristics of individual workers, psychosocial working environment, and ergonomic risk factors which affect the status of musculoskeletal disorders. Self-report was carried out for musculoskeletal symptoms and ergonomic risks in working environment in 856 production workers in 16 small to medium sized manufacturing companies. Musculoskeletal symptoms were examined with a standardized questionnaire, and ergonomic risks were evaluated with a qualitative self-administered instrument for the tasks related to musculoskeletal disorders. Major findings were as follows: 1) Complaint rate for musculoskeletal symptoms was higher in female, aged, married workers with longer working hours, less leisure/hobby activity, longer household working hours and history of disease or accident. 2) Complaint rate for musculoskeletal symptoms was significantly higher in workers with dissatisfaction, difficult tasks, and no self-control at work. 3) Complaint rate for musculoskeletal symptoms was significantly higher in workers involved in tasks with major ergonomic risk factors, and handling heavy equipment. 4) Explanatory power increased the model with the musculoskeletal symptoms as dependent variable and demographic variables, psychosocial working environment and ergonomic risk factors included, and total explanatory power of 18.6% revealed the significant effect. Based on the results, we can conclude that musculoskeletal symptoms in manufacturing workers are associated with individual demographic characteristics, psychosocial working environment and ergonomic risk factors.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.933-942
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• 2010

Objective: To develop an ergonomic evaluation tool which can be apply to assess the lower-limb postures associated with farming tasks. Background: In general, most of existing ergonomic assessment tools was developed to investigate the work-related musculoskeletal disorders of the upper-limb postures in manufacturing industry. Methods: As the first step of development of the evaluation tool, 13 lower-limb postures that were commonly observed in farming task were investigated by the subjective discomfort ratings, heart rates, and muscle activities. And then, an ergonomic evaluation tool for the lower-limb postures was developed based on results of the first experiment. Lastly, the ergonomic checklist which was developed in the current study was compared with other existing ergonomic assessment tools. Results: Based on the results of comparisons between a newly developed assessment tool and other existing assessment tools, it was found that a newly developed tool can perceive more sensitively for the various lower-limb postures than other assessment tools. Conclusions: Lower-limb posture assessment tool which can evaluate and assess risks of lower-limb WMSDs which were prevalent in farming tasks more easily and accurately was developed in this study. The lower-limb assessment tool can also be utilized to prevent WMSDs related with lower-limbs as well as improve working environments.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.2
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• pp.104-113
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• 2005

A variety of ergonomic assessment methods of lifting tasks known as a major cause of work-related lower back pain have been used. But there is a limited information in choosing the most appropriate assessment method for a particular job and in finding out strengths and weakness of the methods. The purpose of this study was to assess and compare the ergonomic risks of lifting tasks in a marine diesel engine production industry by three lifting ergonomic assessment tools widely used: the National Institute for Occupational Safety and Health(NIOSH) Revised Lifting Equation(NLE), the Washington Administrative Code 296-62-0517(WAC), and the Snook Tables. Lifting index(weight of load/Recommended Weight Limit) of NLE($LI_{NLE}$) was above 1 at 34 tasks(75.6%) of a total number of 45 lifting tasks. LI of WAC($LI_{WAC}$) was above 1 at 11 tasks(24.4 %). LI of Snook Table($LI_{Snook}$) was above 1 at 29 tasks(64.4%). Thus, LI was high in orders of $LI_{NLE}$ > $LI_{Snook}$ > $LI_{WAC}$. There were significantly high correlations among three Lls(p<0.01). The correlation coefficients between $LI_{NLE}$and the other three Lls($LI_{WAC}$ and $LI_{Snook}$) were r=0.93 and r=0.88, respectively. The linear regression equations were y = 0.444x + 0.11(r=0.93) between $LI_{NLE}$ and $LI_{WAC}$, y = 0.93x + 0.008(r=0.88) between LI(NLE) and $LI_{Snook}$. The LI values by WAC was significantly lower than those by the other tools. The compared features, strength and limitation among these tools were described in this paper.

• Journal of Biomedical Engineering Research
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• v.45 no.2
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• pp.75-80
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• 2024

This research investigates the influence of chair tilt functionality on biometric signals and user comfort, addressing the ergonomic challenges posed by modern sedentary lifestyles. Through an experimental study involving eight male participants, the impact of chair tilt on electromyography (EMG), heart rate, metabolic rate, pressure distribution, and distance between the lumbar spine and the lumbar support part of the chair was measured across different seating postures. The study utilized chairs with both synchronous and non-synchronous tilt mechanisms to explore how adjustments in chair design affect user comfort and physiological responses during prolonged sitting. Key findings suggest that chair tilt functionality can significantly reduce muscle activity and energy expenditure, enhancing user comfort and potentially mitigating health risks associated with prolonged sedentary behavior. Notably, the study revealed a preference among participants for chairs that aligned the rotational center of the tilt with the hip joint, highlighting the importance of this ergonomic feature in enhancing user comfort. Additionally, the research proposes a novel methodology for assessing seating comfort through the analysis of both biometric and physical signals, providing valuable insights for the development of ergonomic chair designs focused on user health and comfort.

• Journal of the Ergonomics Society of Korea
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• v.30 no.4
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• pp.481-489
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• 2011

Objective: The aim of this study was to develop an ergonomic checklist (AULA: Agricultural Upper-Limb Assessment) which can assess the risks of the work-related upper limb disorders of farming tasks in Korea. Background: There are few assessment tools that reflect the current condition of agricultural works as of now. Method: AULA was developed as following three stages. First of all, a physiological experiment was conducted with selected 14 upper limb postures which are frequently occurred in farming tasks and then, an ergonomic checklist was developed with determining risk levels of each body posture based on the experimental findings. Lastly, the ergonomic checklist was validated by comparing with the existing assessment tools. Results: When comparing the AULA which was developed in this study with the existing assessment tools, it was found that the AULA may get over limits of the existing ones which are sensitive to particular postures, but aren't sensitive to the rest of them. Conclusion: It is predicted that the developed upper limb posture assessment tool which gets over the existing tools' limits and is proper for domestic farm work conditions, will help to reduce musculoskeletal disorders caused by farm works, by assessing farm works more easily and objectively. Application: By further developing the theoretical groundwork on the induction of muscular skeletal system symptoms relating to agricultural works, it is expected to improve the level of preventing and managing such muscular skeletal system symptoms in the field of agricultural and farming works, which is relatively less advanced in terms of labor difficulties.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.153-159
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• 2005

The purpose of this study was to assess the ergonomic risks of lifting tasks in a marine diesel engine manufacturing industry using the National Institute for Occupational Safety and Health(NIOSH) Revised Lifting Equation(NLE). Average Lifting Index(LI=Weight of Load/Recommended Weight Limit) of a total number of 45 lifting tasks was $1.6{\pm}0.7$. The LIs were above 1 at 34 tasks(75.6%), and above 2 at 11 tasks(24.4%). Parts management showed the highest average LI value (LI=2.3) in all departments, which resulted from high frequency and heave load of lifting. The common and significant ergonomic risk factors in the processes were the heavy weight of diesel engine parts and the long horizontal distance. In addition, some lifting tasks had such potential risk factors as the long vertical distance, the high frequency of lifts or the long work duration.

• Journal of Korean Academy of Nursing
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• v.39 no.4
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• pp.549-561
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• 2009

Purpose: Work-related stress and risk factors among Korean employees were identified in this study. Methods: Data were obtained from employees aged 20 to 64 using the Korean Working Conditions Survey 2006 (KWCS). Multiple logistic regression analysis using SAS version 9.1 was performed to examine risk factors of work-related stress by gender. Results: The age-adjusted prevalence of work-related stress among male and female employees was 18.4% and 15.1% respectively. After adjustments for multiple variables among both male and female employees, there was a significant relationship between work-related stress and risk factors including education, company size, work time, ergonomic risks, biological chemical risks, and job demands. The significant variables for male employees were housework load, occupational class, and shift work, and for female employees, type of employment. Conclusion: There is a need to develop and support intensive stress management programs nationally giving consideration to work-related stress associated with working time, physical working environment, and job demands. Based on gender specific approaches, for male employes, stress management programs should be developed with consideration being given to occupational class and shift work. For stress management programs for female employees, consideration needs to be given to permanent employment status, specifically those in small companies.

• Safety and Health at Work
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• v.8 no.4
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• pp.371-377
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• 2017

Background: Social status might be a determinant of occupational health inequalities. This study analyzed the effects of social status on both work environments and health outcomes. Methods: The study sample consisted of 27,598 wage employees aged 15 years and older from among the Korean Working Condition Survey participants in 2011. Work environments included atypical work, physical risks, ergonomic risks, work demands, work autonomy, social supports, and job rewards. Health outcomes comprised general health, health and safety at risk because of work, the World Health Organization-5 Well-being Index, work-related musculoskeletal disease, and work-related injury. Multivariable logistic-regression models were used to identify the associations between social status and work environments and health outcomes. Results: Employees in the demographically vulnerable group had lower occupational status compared with their counterparts. Low social status was largely related to adverse work environments. Especially, precarious employment and manual labor occupation were associated with both adverse work environments and poor health outcomes. Conclusion: Precarious and manual workers should take precedence in occupational health equity policies and interventions. Their cumulative vulnerability, which is connected to demographics, occupational status, adverse work environments, or poor health outcomes, can be improved through a multilevel approach such as labor market, organizations, and individual goals.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.91-100
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• 2007

The purposes of this research are to survey work-related risk factors of musculoskeletal disorders(MSDs) in various departments and tasks at general hospitals in non-manufacturing sectors, and to use basic data derived from the survey results in preventing work-related MSDs in hospital workers. Investigation started in March of 2006 and continued for 6 months in 220 general hospitals at Seoul, Incheon, Kyeongi, and Kangwon area. Investigators visited and interviewed workers in hospitals to identify the presence of tasks of musculoskeletal burden, the investigation results of ergonomic risk factors required by the Occupational Safety and Health Law, statistical analysis from questionnaire for musculoskeletal symptoms, and major departments and tasks that have such risk factors. Twenty-seven percents of hospitals finished the investigation of ergonomic risk factors, and 69% did not do the investigation while remained 4% did not have such factors in their hospitals. The rank order of major departments that had such musculoskeletal burdens was kitchen rooms of 143, managing departments/computer rooms/dispensaries of 137, physical treatment rooms of 109, nursing departments of 96, radiological and clinical laboratories of 63. Eighteen hospitals that did not hold legal duties by the section 148 of labor minister decree practiced prevention programs of MSDs according to the labor-management cooperation. Nursing departments ranked in the first place for the numbers of musculoskeletal symptoms of 438. Managing departments/computer rooms/dispensaries, kitchen rooms, and medical treatment departments held 127, 52 and 45 symptoms, respectively. The magnitude order of physical symptom areas followed shoulder of 185, backs and waist of 166, hand wrists of 120, necks of 110, and legs/feet of 106. The departments and jobs that had major work-related ergonomic risks were patient transporting, central supplying, patient nursing (moving patients into wheel-chairs, changing of patient posture and sheet alteration), manual transporting, operation, and managing/computer departments.

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.286-294
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• 2009

A high prevalence of protected horticulture 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 product transporting. The purpose of this study is to evaluate quantitatively the spinal load of operator using manual vehicles to predict and prevent musculo-skeletal risks. Spinal load in operators using 4 kinds of manual vehicle were analyzed. Before evaluating spinal load on operator using the manual vehicles 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 Operators pushed the manual vehicles(wheelbarrow, Trolley, 2 wheel cart, and 4 wheel cart) contained loads that were 0 N and 800 N, their spinal loads(compression force, shear force) were evaluated. The compression force demonstrated under the NIOSH action limits - 3410N - for all 4 manual vehicle's operators(McGill 1997; Marras 2000). However, the lateral shear force demonstrated over the University of Waterloo - 500N - for all 3 manual vehicle's operators except 4Wheel cart (Yingline and McGill, 1999). Therefore, operators have risks in prevalence of the musculo-skeletal disorders due to shear force. The findings of this study suggest that it need to be determine the spinal load, especially lateral shear force in designing the manual vehicles in the future.