• Journal of International Academy of Physical Therapy Research
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• v.3 no.1
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• pp.391-396
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• 2012

The purpose of this study is to identify which width of the base of support(BOS) is safer and more effective in lifting by comparing muscle activations and body sways when lifting objects under the width variation of the BOS. A total of fifteen healthy adults participated in this study. For the width variation of the BOS, the participants changed the width between their feet into three different types(10cm, 32cm, 45cm) and lifted a 10kg four times in each type after going up on a force plate. In order to measure body sways according to the width variation of the BOS, a motion analysis system was used. In addition, in order to measure the muscle activations of lower extremities, including the erector spinae, gluteus maximus, rectus femoris, and tibialis anterior, an electromyogram(EMG) analysis was employed. In addition, the Borg's scale was drawn by quantifying the subjective discomfort levels felt from each width of the BOS. In conclusion, no statistically significant differences according to the width variation of the BOS were observed(p=.295, .308)(p>.05). However, a statistically significant difference was exhibited between the Borg's scale, which indicates the discomfort levels from lifting performances, and the width variation of the BOS (p=$.000^*$).

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.1
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• pp.56-62
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• 2004

This paper examined the change in reaction time and accuracy of mental work by physical activity. A treadmill-equipped instrument is used to attain several levels of physical activity. Subjects were recruited from college students and football players; and they were instructed to run on a treadmill at different speeds. In order to determine the individual levels of physical activity of subjects, in this paper, Borg's-RPE scales which indicates subjective levels of physical activity were obtained. And reaction time was evaluated before and after running by arithmetic calculation test Restricted within the limit of this experiment, the results of this study showed that arithmetic calculation performance as a scale of accuracy of mental work rather increase after the exercise even though there are slight difference among the subjects.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.67-79
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• 2007

The objective of this study is to investigate a perceived discomfort and cause of Korean elderly in various activities such as work and leisure as well as in daily activities. 120 subjects (30 female and 30 male for each age: the young and elderly) participated in the interview type of questionnaire. Each participant answered to 41 items of activities of daily living. The examination of each item was progressed with 3 steps: whether to do the activity or not, degree of activity discomfort, and the reasons or causes of discomfort. Borg's CR10 scale is used to measure the degree of discomfort of daily activities. As a result, there are differences for the proportion of performers between two age groups, except for essential activities such as individual maintenance and housekeeping. The elderly complained about their daily activities more than the young did, and the degree of discomfort of women was significantly larger than that of men with aging. There are seven items, the mean degree of discomfort of which is over three points for the elderly, and they showed significant difference between two age groups. It was the important reason that physical capacities such as muscle strength and suppleness are declined. The results showed the characteristics of Korean elderly in the whole daily activities. These will be used to understand various life styles of them and to propose a field or direction of study related to the aging.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.105-110
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• 2008

This study focused on the decreased effect of the work load on using the lower extremity supporter in kneeling posture. Fatigue measures included subjective discomfort ratings through the use of the Borg's CR-10 scale based parameters. The resting period and work method were considered as independent variables. The break time conditions are grouped into 10 seconds after work for 1 min and not exist break time. The method of work conditions are divided into four types. There are kneeling with the lower extremity supporter, kneeling with the knee protector, just kneeling and squatting. The result of the ANOVA of the shift value of subjective discomfort showed the followings: 1) There were differences as regards to the method of the work, the break time and the part of body($p{\leq}0.05$). 2) The lower extremity supporter showed the least subjective discomfort in other part of body except the upper leg.

• Physical Therapy Korea
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• v.27 no.4
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• pp.278-285
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• 2020

Background: Individuals with forward head posture (FHP) have neck pain. To correct the FHP, a posture correction band is commonly used. However, we do not know the posture correction band influenced the pulmonary function in individuals with FHP. Objects: This study aimed to elucidate the effects of the posture correction band on the pulmonary function in young adults with neck pain and FHP and to monitor how the pulmonary function changed over time. Methods: Twenty subjects with chronic neck pain and forward head posture were recruited. Subjects performed pulmonary function test four times: before, immediately, and 2 hours after wearing the postural band, and immediately after undressing the postural band. Vital capacity (VC), forced vital capacity (FVC), peak expiratory flow (PEF), and forced expiratory volume at one second (FEV1) were measured. The modified Borg dyspnea scale was used to measure each subject's responses to the posture correction band. The mixed-effect linear regression was used to the effect of the posture correction band over time. Results: There were no significant differences in VC, FVC, PEF, FEV1 values over time (p > 0.05), although all values slightly decreased after applying posture correction band. However, the score of the modified Borg scale significantly changed after wearing the postural bands (p < 0.05), indicating the subject felt discomfort with posture correction band during breathing. Conclusion: Because the posture correction band did not change the pulmonary function over time, but it induces psychological discomforts during breathing in people with FHP. Therefore, this posture correction band can be used for FHP realignment after discussion with the subjects.

• Journal of the Korean Society of Safety
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• v.16 no.1
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• pp.79-83
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• 2001

Posture of the upper limbs in field works is known to be an important risk factor associated with CTD(Cumulative Trauma Disorders). In particular, uncomfortable posture and highly repetitive works in shipbuilding industry(for instance, sand blasting, grinding and blast painting, etc) made workers exposed to a great risk of injuries. The purpose of this paper is to analyze recruitment pattern of the muscles according to posture(joint angle displacement) during grinding. In this study, EMG signals of pectoralis major, latissimus dorsi, and posterior deltoid muscle were measured and analyzed from FlexComp EMG solution. And subjective ratings of perceived exertion were made using Borg's CR-10 rating scale.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.2
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• pp.99-104
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• 2013

With diversity of mobile services (e.g., messenger, and social network service) on smartphone, the demand of text input using a soft keyboard is increasing. However, studies on subjective and physiological responses of users for various touch locations are lacking. The present study investigated the ergonomic effects according to touch locations of a soft keyboard on smartphone. The experiment of the present study measured perceived discomfort using Borg's CR-10 scale and electromyography (EMG) on forearm (abductor pollicis longus, and extensor digitorum communis) and thumb (abductor pollicis brevis, and first dorsal interossei) muscles. Perceived discomfort was significantly varied from 0.7 (extremely weak discomfort) to 2.5 (weak discomfort) depending on touch locations. %MVC according to touch locations was only significant at abductor pollicis brevis which varied from 10% to 23%. The experimental results of the present study can be utilized in the ergonomic design of a soft keyboard.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.185-189
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• 2012

Objective: The aim of this paper is to introduces Hyundai Heavy Industry's ergonomic risk assessment tool, H-OWAS, which is considering work load and frequency compared to the OWAS. Background: As prevalence of work-related musculoskeletal disorders(WMSDs) in ship building industries has been much higher than that in other industries, most of the large scaled corporations have implemented their own prevention program since legislation on the prevention of WMSDs had introduced in 2003. Method: This paper introduces WMSDs prevention program, HEMP(HHI Ergonomics Management Program) which consists of risk assessment, improvement efforts of working environments, medical treatment and training/evaluation and describes how to operate the program. We also describe application of OWAS method considering work load and frequency for risk factor analysis(H-OWAS) and shows methodology for assessing the ergonomic risk factor. And comparison of the assessment results between OWAS and H-OWAS is carried out by statistical analysis. Result: There was statistically significant difference in the assessment results between OWAS and H-OWAS, and regression shows H-OWAS explains the borg's scale of perceived exertion more clearly than OWAS. Conclusion: H-OWAS has been proved more effective tool than OWAS to evaluate ergonomic risk factor under real working condition. Application: H-OWAS can be widely applied to the many other companies when implementing the ergonomics risk assessment.

• Journal of the Ergonomics Society of Korea
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• v.18 no.2
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• pp.103-120
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• 1999

The purpose of this study was to evaluate the manual workload in repetitive wrist and finger motion. To evaluate manual workload, angular displacement of the joint, EMG of the muscle and subjective rating were studied. Both wrist motion and finger motion were studied. A screw-driving task was used for the wrist motion experiment. A keyboard typing task was used for the finger motion experiment. All finger joint angles and wrist angles were measured by an angle-measuring glove($CyberGlove^{TM}$, Virtual Technologies, Inc.). Surface EMG was recorded from FCU muscle and FDS muscle simultaneously with the angle measurement. Subjective ratings of exertion were also recorded using the modified Borg's CR-10 scale. Repetition rates of 0.5, 1, 2 motions per second were used with each task. As a result, manual workload increased with increasing repetitiveness. Peak spectral magnitude and frequency components corresponded closely with joint angular displacement amplitudes and repetition rates. Results of the correlation analysis showed that there were significant correlation among EMG, frequency-weighted motion and subjective measurement. Both EMG and frequency-weighted filtering showed consistent workload estimation with increasing task frequency. Subjective ratings showed slight over-estimation of the workload as the task frequency is increased.

• Journal of the Korean Society of Safety
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• v.23 no.2
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• pp.30-36
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• 2008

This paper suggests the best work conditions, including short break time and number of mouse clicks on a computer, to prevent MSDs(Musculoskeletal Disorders) on VDT(Visual Display Terminal) work. Discomfort measures are calculated according to the Borg's CR-10 Scale. The short break time conditions are grouped into 7, 15, and 30 seconds after every 10-minute work period and the number of mouse clicks are divided into 10 clicks/min, 20clicks/min, and 30clicks/min. The result of the ANOVA on the shift value of subjective discomfort shows the following: 1) Regarding the break time and the number of mouse clicks, there are statistical differences between the measured values for the neck and the wrist(p<0.05). 2) Regarding the number of mouse clicks, there are statistical differences between the measured values for the shoulder and the forearm(p<0.1). 3) Regarding the break time and the number of mouse clicks, there are no statistical differences between the measures values for the eyes, upper arms and back(p<0.1).