• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.19 no.1
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• pp.9-20
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• 2013

Background: This study was conducted to provide preventive measure for the musculoskeletal disorders in automobile parts manufacturing workers. Method: The author surveyed to the musculoskeletal symptoms prevalence and its related factors from 10th to 17th April 2011 with structured self administered questionnaires. 223 out of 225 collected questionnaires were used for final analysis, excluding 2 questionnaires with no valid response. Based on the diagnostic criteria of NIOSH (National Institute for Occupational and Health), an investigation was made into the prevalence of musculoskeletal symptoms as well as into the factors related to individual items. Results: The prevalence of musculoskeletal symptoms according to the criteria of NIOSH was the highest in the shoulder (52.9%), followed by the neck (39.%), the hand/wrist (35%), the waist (29.6%), the arm/elbow (24.7%), and the leg/food (23.8%). One-way analysis showed that among general characteristics, age was the musculoskeletal risk factor with the greatest effect. Whereas among work-related characteristics, significant risk factor didn't find. Yet it was shown that among ergonomic work postures, high degree of musculoskeletal risk was shown by the posture involving frequent and repetitive movement of the arm and the hand/wrist and also by the posture involving standing for a long time. Multiple regression analysis showed that musculoskeletal risk was 1.795 times higher in those age 50 and over than in those under age 50; 1.67 times higher in the high risk stress group than in the low risk stress group; and 1.131 higher in the group involving the repetitive use of the hand/arm than in the other groups (p<.05). Conclusion: The prevalence and stress score of automobile parts manufacturing workers were higher than other occupation workers. Among general characteristics, drinking and smoking were shown to be related to stress score; while age was shown to have significant effect on musculoskeletal risk.

• Journal of the Ergonomics Society of Korea
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• v.25 no.3
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• pp.17-24
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• 2006

In this paper, we propose a stress analysis on foot by lifting task attitudes. Maximum force and peak pressure were measured on 8 body regions by Pedar system in order to analysis the stress which is affected by task style and angle on foot when Manual Materials Handling task. As for the peak pressure of the whole foot as to the task height during the lifting task, the height from Knuckle to Shoulder was the least in the peak pressure. Also, as for the maximum force and the peak pressure of the whole foot as to the task angle during the lifting task, it could be seen that the more an angle increases, the stress influencing on a foot jumps. As for the maximum force and the peak pressure by foot region as to the task height in case of the lifting task, the height from Knuckle to Shoulder is indicated the smallest value in the maximum force and the peak pressure, thus there is necessary to attain the work design that considered this. Also, as for the maximum force by foot region as to the task angle in case of the lifting task, 0° tasking is indicated to be least, thus there is necessity to be attained the tasking design in a bid to prevent the existence of an angle. The results of this paper are thought to be helpful to the suitable work design, to the prevention of musculoskeletal disorders related to the lower limbs, and to the design of ergonomic safety shoes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.3
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• pp.319-329
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• 2018

Objectives: The object of this paper is to analyze difference of general and occupational characters, risk exposure and ill health symptom depending on the special type of employment. Methods: 50,007 participants from Fourth Korean Working Condition Survey conducted in 2014 was analyzed. Cross-tabulation analysis was conducted for deriving difference in general and occupational characters, mulitvariate logistic regression analysis was conducted after controlling general and occupational characters for deriving difference in risk exposure and ill health symptom depending on the special type of employment. Results: In the special type of employment, female, ages of 50, education levels of high school, monthly income of 2,000-3,000 thousand won, job types of sales person, enterprises of less than 100 workers, working duration of 2-10 years and long working hours worker's proportion was higher than general employment. Physical(OR: 0.84, 95% CI: 0.76-0.94) and ergonomic (OR: 0.48, 95% CI: 0.42-0.55) risk exposure was lower, psychological(OR: 1.77, 95% CI: 1.54-2.04) risk exposure was higher than general employment, and there was no significant difference between the special type of employment and general employment in chemical/biological risk exposure(OR: 1.06, 95% CI: 0.94-1.20) and ill health symptom(OR: 0.98, 95% CI: 0.89-1.09). Conclusions: This article offers the analysing difference between the special type of employment and general employment using huge size cross sectional data represent Korean employees.

• Safety and Health at Work
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• v.13 no.4
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• pp.440-447
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• 2022

Background: Agricultural handle equipment is present on all production areas' farms. They are handy and portable; however, excessive use can lead to acute traumas or accidental injuries. Repetitive movements, awkward postures, and hand-arm vibrations predispose them to pain and work-related musculoskeletal disorders. The purpose of this study was to observe the interaction of handle equipment in terms of electromyographic activity and analyze the postural work-related alterations. Materials and methods: Twenty male agricultural operators, mean age 24±1.54 years, underwent the electromyographic analysis testing their muscular activities with a brushcutter, electric saw, and hedge trimmer in four different test conditions. Results: The brushcutter proved to be the agricultural handle equipment with the higher mean frequency (3.37±0.38 Hz) and root mean square (5.25±1.24 ms^-2). Furthermore, the digital postural analysis showed a general asymmetry of the main arm and the respective side of the trunk. The head resulted right inclined in the anterior frontal plane by 5.7°±1.2°; the right scapula lower than the left in the posterior frontal plane (8.5°±1.8°), and a working trunk inclination of 34.15°±5.7°. Conclusions: Vibrations of handle equipment and awkward working postures represent a risk for agricultural operators. Preventive measures are required to avoid young operators from experiencing musculoskeletal disorders all lifelong.

• Korean Journal of Childcare and Education
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• v.8 no.2
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• pp.139-155
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• 2012

This study aimed to glean lessons for desirable early childhood physical education programs by contouring the current paradigms on body or physical activities in the area of early education for young children. It also aimed to analyze their postures while participating in daily activities. The research method for analysis of children's postures while doing daily activities was OWAS(Ovako Working Posture Analysing System) which has been extensively used in ergonomics. Components of data analysis have been redesigned on the basis of information gathered from OWAS with the help of ergonomic experts. The results showed different percentages of children's movements according to activities such as whole class meeting, small group activity and outdoor activity. Small group and outdoor activities can be considered the most desirable physical activities not only for cognitive and social development but also for physical development. And it is recommended to reconstruct the quality and nature of whole class meetings in order to coordinate the physical nature of young children.

• Journal of Fashion Business
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• v.20 no.3
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• pp.17-29
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• 2016

To develop baseball catcher leg guards, 3-dimensional (3D) methodologies, which are 3D human body data, reverse engineering, modeling, and printing, optimized guard design for representative positions. Optimization was based on analysis of 3D body surface data and subjective evaluation using 3D printing products. Reverse engineering was used for analysis and modeling based on data in three postures: standing, $90^{\circ}$ knee flexion, and $120^{\circ}$ knee flexion. During knee flexion, vertical skin length increased, with the thigh and knee larger in anterior area compared to the horizontal dimension. Moreover, $120^{\circ}$ knee flexion posture had a high radius of curvature in knee movement. Therefore, guard designs were based on increasing rates of skin deformation and numerical values of radius of curvature. Guards were designed with 3-part zoning at the thigh, knee, and shin. Guards 1 and 2 had thigh and knee boundaries allowing vertical skin length deformation because the shape of thigh and knee significantly affects to its performance. Guard 2 was designed with a narrower thigh and wider knee area than guard 1. The guards were manufactured as full-scale products on a 3D printer. Both guards fit better in sitting than standing position, and guard 2 received better evaluations than guard 1. Additional modifications were made and an optimized version (guard 3) was tested. Guard 3 showed the best fit. A design approach based on 3D data effectively determines best fitting leg guards, and 3D printing technology can customize guard design through immediate feedback from a customer.

• Fashion & Textile Research Journal
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• v.11 no.5
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• pp.764-770
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• 2009

This study was conducted to analyze the wearing condition on gloves for pilots and to suggest the developments for pilot gloves design. This survey was performed with 99 pilots and the questionnaires included items about discomfort, materials and problems when wearing pilot gloves. The respondents felt uncomfortable on the finger tip, the hollow area of the hand and the end of thumb when they move their hands with the gloves. They replied that the finger length, palm length, and circumference of the fingers did not match well. Also they complained there was severe abrasion in the tip of the thumb, finger tips and the middle of the palm of the gloves. The result of these analyses supports the following suggestions. It is necessary to improve durability by applying the additional materials to the severely worn parts. Punching on the glove materials could improve sweat rate and ventilation, and careful washing should be accompanied to prevent the occurrence of linters and transformation after laundering. And it is needed to prepare an accurate and more diversified size system and to design the gloves fitted to the individual hands. With these in mind, it is required to propose solutions for pilot gloves with reference to the survey results in order to design appropriate pilot gloves in terms of movement, size and material. It was concluded that an analysis of the wearing condition and developments are useful for ergonomics pilot gloves design.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.113-120
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• 2010

This research is to evaluate the arousal level by using cardiovascular response. PPG was used in this study as one of the method of measuring it rather than ECG (Electrocardiography) for the purpose of solving ergonomic problem of sensing. The participants were in the age group of 20 (mean=24, standard deviation=1.25): five men and five women. Each experiment composed with four identical sets. First, a black screen was displayed for 30 second rest. Then, the prepared 6 pair images were randomly presented for 10 second stimulation and for 30 second non-stimulation. PPG was measured on the earlobes of experimenters at 200Hz sampling frequency. PPG amplitude, PPI(Pulse to Pulse Interval), and PRV(Pulse Rate Variability) were analyzed according to arousal level. T-test was performed to compare between the PPG variables of rest and relaxation, rest and arousal, and relaxation and arousal. Relative to the rest state, PPG amplitude decreased in relaxed state and increased in aroused state. Relative to the rest state, PPI decreased in both emotional states. However, more significant decline was observed in aroused state. PRV's LF and HF were used in the form of LF/HF to compare between the relaxed and the aroused state. Therefore, PPG signal showed significant differences between relaxed and aroused state. In conclusion, evaluation of human arousal level used in the PPG analysis demonstrated that PPG has better usability and comforter measurement than ECG and is clearly an alternative method of measuring arousal level.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.1
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• pp.63-76
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• 2015

This study conducted a survey to gauge the buying and wearing propensities of wearers of leg guards made for baseball catchers, as well as product characteristics of preferred leg guards. Data from the survey were analyzed to obtain basic data for the development of an advanced leg guard design. Degree of compression, horizontal distance, cross section view and outline 3D sketch were also analyzed from the 3D data of leg guards; in addition, mobility and kinematic analysis were conducted through a wearing test. The survey indicated that imported products dominate the current retail market because they are appreciated by customers in terms of fit, price, brand, and protection. Representative complaints of products were discomfort, pressure, and the heavy-weight of the leg guards in general attributed to overall structure and 3D shape. When the pressure was lower on the front area of knee, it feels better to wear and the average knee angular velocity during the up and down motion increased, which suggests a better design from a kinematic point of view. The knee is the primary part of the body responsible for any movement of the lower limbs; consequently, the degree of compression and support stability of the leg guards near the knee area are important factors to evaluate the performance of leg guards. The results of our study indicate significant opportunities for improvement in product design and the development of baseball leg guards along with an ergonomic design that considers the mobility of the knee, skin deformations is necessary to improve performance. The process followed in this study will be applicable to studies on other personal protective equipment for sports.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.412-422
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• 2009

This study was conducted to assess exposure to musculoskeletal disorder(MSD) risk factors in hospital personnel who performed non-routinized work tasks. A tool ("PATH-KOSHA" version) was newly revised from PATH(Posture, Activity, Tools and Handling) method and uploaded into a personal digital assistant(PDA). The version was used, on a basis of direct-observation, to collect PATH data at the 2 hospital settings in different regions. Job analysis was performed to get various information (e.g., work and rest time, task type) as well. The data collected were visually checked for data cleaning and stored for future data analysis. A total of 1,992 PATH observations were made for 37 hospital workers. Exposure levels varied across 18 items of the MSD risk factors. The highest percent time spent on non-neutral postures was 53% for wrist deviation, followed by 47%(pinch grip), 35%(trunk posture), 23%(neck posture), and 20%(shoulder/arm posture). The highest percent time spent among hand activity level(HAL) variables was 55% for HAL-cat2 (HAL: 3.3 - <6.7). The percent time of items with respect to both loads with more than 5kg and contact stress was less than 4%. Vibration was not exposed in the study workers. Different aspects were discussed for findings. The study results showed that wrist deviation was highest in percent time spent on awkward posture while HAL-cat2 was highest in hand repetition. The study suggests that distal upper extremity posture and HAL should be primarily addressed and controlled in non-routinized work including the hospital settings.