• Korean Journal of Human Ecology
• /
• v.13 no.6
• /
• pp.985-995
• /
• 2004

The purpose of this study is to provide useful footwear information for manufacturers and teenagers so that they can produce or purchase proper footwear that would minimize discomfort. For this study, 486 junior high school students were surveyed with a questionnaire. SPSS WIN10 was used to process a statistical analysis such as ferq., factor analysis, t-test, ANOVA(LSD), crosstab, and coefficient correlation. The results are as follows: A significant difference existed between male and female students in purchasing footwear and using evaluation criteria. When they wear shoes for a long time, they usually experience numbness in toes, blisters, heel, bottom on the feet and peeled skin. Female students experienced more foot injuries than males. There were meaningful correlations among purchasing, evaluation criteria, and satisfaction of footwear. Providing proper information is believed very important for teenagers in choosing right footwear. Footwear manufacturers should help them produce suitable shoes, and further help them establish different marketing strategies. To ease the foot discomfort, shoes should be developed with various widths and sizes. Shock absorbing soles and more flexible materials are also necessary.

• Journal of the Ergonomics Society of Korea
• /
• v.22 no.1
• /
• pp.43-56
• /
• 2003

Observational methods such as OWAS, RULA, and REBA have been widely used to identify posture-related risks of musculoskeletal disorders in industry, since they are useful and efficient in evaluating postural stresses. However. there are few studies comparing the methods and providing guidelines for selecting and using the methods. They have been developed based on different backgrounds and with different application areas. Each method has its own characteristics. which must be considered in selecting and using them. In this study. 17 male subjects evaluated 42 different working postures that frequently assumed in the automobile assembly line using a psychophysical method. The postures were then evaluated by different observational methods. The results of the observational methods were compared with psychophysically evaluated stresses. The observational methods resulted in different values of stresses for certain postures. For some postures showing high values of perceived discomfort. the observational methods showed different values of stresses. These results showed that the observational methods should be used differently according to application area and they have some weak points to be improved.

• Industrial Engineering and Management Systems
• /
• v.8 no.2
• /
• pp.121-130
• /
• 2009

Subjective evaluation has always been regarded as a branch of social science research. Hence, in scientific and especially engineering points of view, its development is always taken for granted despite the importance of its effects on the design and development decisions. In the past, at least two automotive seat survey questionnaires have been developed with high statistical validity and reliability. Nonetheless, both were not local while subjective perception very much depends on demographic background factors. It is felt that since vehicle seat comfort is an important aspect in a seat design, a local sense should be put into the survey that is used as the subjective tool. The proposed vehicle seat discomfort survey questionnaire was developed in dual languages; English and Malay. Malay language is the national language of Malaysia, where the survey was tested. Beside inputs from literatures, key informant interviews helped in establishing the appropriate terms used as survey items. Three experimental runs on two different seats by 22 paid subjects showed that the developed questionnaire is reliable and valid. Furthermore, criterion validity analysis on the survey and previously developed survey showed significant correlation at 0.01 significance level.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.5
• /
• pp.671-681
• /
• 2011

Objective: The purpose of this study is to compare the workload level at each lower limbs posture and suggest the ergonomic workstation guideline for working period by evaluating the imbalanced lower limbs postures from the physiological and psychophysical points of view. Background: Many workers like welders are working in various imbalanced lower limbs postures either due to the narrow working conditions or other environmental conditions. Method: Ten male subjects participated in this experiment. Subjects were asked to maintain 3 different lower limbs postures(standing, squatting and bending) with 3 different working conditions(balanced floor with no scaffold, imbalanced floor with 10cm height of scaffold, and imbalanced floor with 20cm height of scaffold). EMG data for the 4 muscle groups(Retus Femoris, Vastus Lateralis, Tibialis Anterior, Gastrocnemius) from each lower limbs posture were collected for 20 seconds every 2 minutes during the 8 minutes sustaining task. Subjects were also asked to report their discomfort ratings of body parts such as waist, upper legs, lower legs, and ankle. Results: The ANOVA results showed that the EMG root mean square(RMS) values and the discomfort ratings(CR-10 Rating Scale) were significantly affected by lower limbs postures and working time(p<0.05). The correlation was analyzed between the EMG data and the discomfort ratings. Also, prediction models for the discomfort rating for each posture were developed using physical condition, working time, and scaffold height. Conclusion: We strongly recommend that one should not work more than 6 minutes in a standing or squatting postures and should not work more than 4 minutes in a bending posture. Application: The results of this study could be used to design and assess working environments and methods. Furthermore, these results could be used to suggest ergonomic guidelines for the lower limbs postures such as squatting and bending in the working fields in order to prevent fatigue and pain in the lower limbs body.

• Journal of the Ergonomics Society of Korea
• /
• v.15 no.2
• /
• pp.51-62
• /
• 1996

This research utilized the psychophysical methodology, where secrw drivers are used, to determine the effects of i) the location and orientation of work objects, and ii) wearing gloves, on ratings of perceived exertion at various body parts. The validity of the psychophysical methodology in determining a preferred work pace was also studied. The subjects drove screws with a screw driver into thick wooden sheet at three vertical and three horizontal locations. They drove serews for 3 minutes at each location and assessed the condition using the psychophysical scale. The results showed that only the vertical location was a significant factor in determining the discomfort ratings. Driving screws at elbow height on the vertical surface and with the lower arm close to the body on the horizontal surface were the work locations with the smallest ratings of perceived discomfort. Wearing gloves had significant effects on reducing the pain of the hand. From the experiment in which a comfortable work pace was identified using 20 minute psychophysical adjustment, it was found that the psychophysical method is sensitive to workers perception of the physical stress when the upper limbs are employed. This was confirmend by the high correlation between the psychophysical results and EMG measurement.

• Journal of the Ergonomics Society of Korea
• /
• v.29 no.1
• /
• pp.61-66
• /
• 2010

The objective of this paper is to study the usability of the ingress/egress of elderly people, and analyze the physiological workload electromyography (EMG). We investigated the factors of discomfort while the elderly people are using the ingress/egress. Experiments were performed using a seating buck with 22 elderly participants (over 65 years old). The results showed that different muscles are activated during ingress and egress. A system called "easy access" was found which helps to access easily when a driver gets into a car. The current easy access was compared a newly proposed one. It was found that elderly people use less muscle during in/egress in the new easy access system.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.10 no.2
• /
• pp.73-82
• /
• 2004

Objectives : In order to develop the measuring tool of visual display terminal (VDT) syndrome and investigate the variables affecting the development of VDT syndrome. Methods : A questionnaire study accompanied with the evaluation of working environment was performed with 42 VDT users from banking operations. Results : As a results of analysis with data colleted by newly developed questionnaire, VDT syndrome included five factors named as eye-related component, and psychological component. general body discomfort component. musculoskeletal component, and skin-related component. The scores of eye-related symptoms was 15.17, scores of psychological symptoms was 7.36, scores of general body discomfort symptoms was 10.52, scores of musculoskeletal symptoms was 9.38, scores of skin-related symptoms was 3.67, and total scores was 46.10. Scores of 2.05 eye fatigue in the level of eye-related symptoms were higher significantly. Scores 50.52 of female was statistically higher than scores 41.67 of male. Conclusions : The subjective symptoms of VDT syndrome scores was significantly associated with gender and age.

• Archives of design research
• /
• v.12 no.1
• /
• pp.157-166
• /
• 1999

With the increase in use of the computer, the VCT syndrome has occured as a new socialJhea/health problem. ErgonomicaI design standards are a for the users to reduce stress and poor physical posture in the human body. In this study. we have suggested design dimensions recommended from previous studies. We also have reviewed users' preference dimenision, and analyzed differences between users' preference dimenision. and the previous design aiteria to verify physical appropriateness. We analyzed how each design dimension was reached and affected the tunan body by objective EMG evaluation. and subjective evaluation of physical discomfort and oorrIort. We have found that keyboard height is very important in a workstation. If the elbow's height is lower than the keyboard's height. it effedS the hand and wrist. If higher, it brings fatigue to the shoulder and neck. As a result of this experiment. we suggested that the height of a keyboard desk for Koreans be 660mm for the fixed type and 540-774mm for the adjustable type. Also other design reoommendations were suggested in the thesis. In ooncIusion, our research will be very important in the database because it provides adjustable ranges to fit user's body types in the various design flekIs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.2
• /
• pp.1-9
• /
• 2009

Impact of daylighting on the visual environment can improve occupant's well-being by providing visual comfort. Also, daylighting can save energy. However, glare from window can be a direct hazard to vision and can cause serious discomfort. Selecting glare source on a window plane is very important for evaluating discomfort glare from windows. But former glare indices can not identify the range of the glare source properly. In this study, difference in glare sensation with uniform and non-uniform glare sources are evaluated to identify the range of the glare source. The glare source was assumed as $120{\times}120[cm]$ window model. The window was divided into three parts with different luminance values. The experiment was conducted under 1[m], 1.5[m], 3[m] distance from the glare source. Two results were obtained from the experiments. First, the degree of discomfort glare increased as average window luminance increased. Second, the middle and lower part of the window plane can affect evaluation of discomfort glare as well as the upper part of the window plan. These results can be used for selecting the glare source in a window with non-uniform luminance.

• Journal of KSNVE
• /
• v.9 no.1
• /
• pp.77-84
• /
• 1999

The sharp and highly fluctuating characteristics of the building services noises cause much psychological discomfort to dwellers. To evaluate the noises effectively. it is necessary to develope an evaluation procedure which can well reflect the psychological influences of the noises. In this study, to develope the effective evaluation procedure for the building services noise. Korean vocabularies which can express the feelings for them was investigated. And then, through a series of psycho-acoustical experiments for various housing equipment noises. we analyzed psychological factors that influence to subjective feelings of persons.