• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.565-575
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• 2014

Objective: The aim of this study is to evaluate the effect of weight of load and time on the physical workload of repetitive upper-limb tasks with handling light weight loads using EMG and perceived discomfort, and to investigate the relationship between EMG and perceived discomfort for those repetitive tasks of moving light weight loads. Background: Repetitive upper-limb motion is known as one of the main risk factors of musculoskeletal disorders, and a lot of repetitive tasks are carried out while handling light weight loads in the industry. In evaluating the workload of repetitive tasks handling light weight loads, EMG and perceived discomfort can be used, though their relationship in those work conditions are not much investigated. Method: A laboratory experiment with 18 healthy males were conducted to record EMG signals from 5 muscle sites of the right arm and shoulder and rate perceived discomforts for the body parts and the whole body while carrying out repetitive materials-handling tasks for 52min. The subjects were divided into 3 groups which handled the loads of 1kg, 2kg and 3kg, respectively. ANOVAs were conducted to analyze the effects of the weight and time on RMS of EMG amplitude (normalized RMS: NRMS), median frequency of power spectrum of EMG (normalized MDF: NMDF) and perceived discomfort. The correlations between NRMS and NMDF and perceived discomfort were also analyzed. Results: Statistically significant muscular fatigue effects were not found from NRMS and NMDF in most muscles, while there were significant increases of discomfort as the task time elapsed. It was shown that there were an increasing trend of the muscular activity as the weight of load increased and a decreasing trend of median frequency of EMG of upper and lower arms as time elapsed. It was found that there were significant negative correlations between NMDFs from the lower arm and discomfort ratings, though the relationships were weak. Conclusion: It can be concluded that the working conditions adopted in this study were not enough to induce muscular fatigue, while there was significant increase in perceived discomfort. A further study is necessary to integrate the objective and subjective measures for more reliable and sensitive evaluation of workload of repetitive tasks of handling light weight loads. Application: This study can be used as a basic study for the evaluation of workload of repetitive tasks handling light weight loads.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.24-32
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• 2008

The ultimate purpose of the study is to develop a discomfort glare forecasting formula that can be practically used in Korea in order to effectively forecast discomfort glare considering the optical characteristics of the Koreans. The study was to examine the relations between discomfort glare and the variables such as luminance, background luminance, solid angle, luminous area and louver. To this end, experiments were conducted in a mock-up office that emulates the lighting environment of an ordinary office. The study was conducted by four steps as follow. First, previous studies on discomfort glare rating to define and rate discomfort glare were analyzed and modified to be applied to the experiments of this study. Second, experiment variables, variable scope, evaluation objects and evaluation points were determined after review on existing discomfort glare evaluation experimental formulas. Third, experiments were conducted in a mock-up office to be able to control variables. Finally, sensitivity of experiment variables were analyzed through examination of the relation between discomfort glare and the variables such as luminance, solid angle, louver, luminous area and subject's position. The result showed that the most influential variables on discomfort glare of an artificial light source is luminance and louver, luminous area and subject's position(solid angle) followed.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.95-102
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• 2009

Ten young females were participated in this study to investigate the effects of types of shoes (sneakers, high heels, kill heels), types of tasks (standing, walking floor, step up and down), and areas of foot (fore foot, middle foot, rear foot) on foot pressures as well as subjective discomfort ratings. Results showed that kill heels had the most discomfort shoes, followed by high heels and sneakers. Generally, as the heel was higher, the discomfort of foot increased. For the analyses of task types, generally discomfort ratings were highest for the step down and up, followed by walking floor and standing. Especially discomfort ratings of high heels and kill heels were more evident in case of step up and step down than standing and walking floor. Standing task was rated as the lowest levels of discomfort on users' foot. Peak and mean foot pressures were also evaluated in this study. The findings represented that there was no significant differences between types of shoes in both peak and mean foot pressures. The peak pressure (82.14kPa) and mean pressure (40.32kPa) for standing task were significantly lower than those of other tasks [walking floor (190.55kPa, 55.46kPa), step up (191.43kPa, 53.80kPa), and step down (200.66kPa, 52.62kPa)]. Generally discomfort ratings and peak/mean pressures associated with foot showed that fore foot had higher discomfort ratings as well as peak and mean pressures than middle and rear foots. In particularly, this trend was more obvious in case of high heels and kill heels. For the high heels and kill heels, the peak pressures of fore foot were 4.5~4.8 times and 2.3~2.5 times greater than that of middle foot and rear foot, respectively, whereas the peak pressures of fore foot were 2.9 times and 1.7 times greater than that of middle and rear foots, respectively, in case of sneakers.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.2
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• pp.259-263
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• 2012

This case series present four patients, who were suffered from chest discomfort due to various underlying disease improved by korean traditional herbal medicine Haewoolhwajoongtang. Four patients in this study with chest discomfort due to various underlying disease in terms of the Western Medicine. But these four patients all have chest discomfort worsened at night caused by 'Yure(鬱熱)'. We treated this four patient by korean herbal medicine Haewoolhwajoong-tang. After treatment, their chief complains that chest discomfort was almost reduced. These result suggests that Haewoolhwajoong-tang was effective on chest discomfort caused by 'Yure(鬱熱)'.

• Perspectives in Nursing Science
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• v.7 no.1
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• pp.55-64
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• 2010

Purpose: The purpose of this study was to examine the effects of position change from supine to Fowler's on back pain and discomfort in patients who remained on bed rest after undergoing PCIs with a vascular closure device. Methods: Data was collected from 35 inpatients who were hospitalized in coronary-care unit to perform PCIs with a vascular closure device at S hospital in Seoul from December, 2006 to May, 2007. Back pain, discomfort, presence and grade of bleeding and hematoma from femoral arterial puncture site and blood pressure/pulse rate were measured prior to, 10 minutes, 1 hour and 2 hours after position change. Data was analyzed with descriptive statistics, $x^2$ tests and t-tests using SPSS/WIN 12.0 for Windows program. The level of significance (${\alpha}$) was set at 0.05 for this study. Results: We found that there was no significant difference in back pain and discomfort in 10 minutes after position change between the two groups. However, the experimental group reported significantly less back pain and discomfort than the control group in 1 hour (p<.01, respectively) and 2 hour (p<.01, respectively) after position change. There was no significant difference in the presence and grade of bleeding and hematoma at the puncture site, blood pressure, and pulse rate in 10 minutes, 1hour and 2hours after position change between the two groups. Conclusion: Fowler's position change after PCIs in, therefore, safe and effective method of reducing back pain and physical discomfort without causing additional bleeding and changes in blood pressure and pulse rate.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.403-407
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• 2002

The objective of this study is to establish the new evaluating method of tinnitus and to evaluate the effect of acupuncture therapy. Fourteen patients with tinnitus were studied. The patients answered the questionnaire designed to identify and describe the subjective symptoms of tinnitus and discomfort in daily life due to tinnitus. After acupuncture therapy, the survey was conducted again among the patients and we evaluated the difference between pre-acupuncture therapy and post-acupuncture therapy. 1. Precipitating factors of tinnitus among the patients group consisted of 14 members were stress, noise, drug, overwork, URI, and otitis media in order. 2. Significant improvements in subjective symptoms of tinnitus and discomfort in daily life after acupuncture therapy were identified among the patient group of 14 members 3. Patient group of 14 members were divided into 2 groups by digestion status: patients who have poor digestion and patients who have good digestion. The patients who have good digestion showed significant improvement both in subjective symptoms of tinnitus and in discomfort in daily life after acupuncture therapy. 4. Patient group of 14 members were divided Into 2 groups by urination and defecation status: patients who have poor urination and defecation and patients who have good urination and defecation. The patients who have good urination and defecation showed significant improvement both in subjective symptoms of tinnitus and in discomfort in daily life after acupuncture therapy. 5. Patient group of 14 members were divided into 2 groups by sleeping status: patients who sleep well and patients who don't sleep well. The patients who sleep well showed significant improvement both in subjective symptoms of tinnitus and in discomfort in daily life after acupuncture therapy. This study shows that the subjective symptoms of tinnitus and discomfort in daily life due to tinnitus are involved in urination and defecation factor, sleep factor, and digestion factor. This study also shows that acupuncture therapy is effective in improving the subjective symptoms of tinnitus and discomfort in daily life due to tinnitus.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.3
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• pp.127-145
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• 2011

Purpose: The purpose of this study is to analyze the effect of oriental-western medicine integrative care after gynecology surgery by DSOM((Diagnosis System of Oriental Medicine) and improvement of major symptoms. Methods: 66 patients belonged to the experimental group and 47 patients belonged to the control group out of 113 patients taken gynecology surgery. We studied general characteristics and difference on DSOM results between the two groups. And we had patients answer questionnaires about major symptoms such as abdominal discomfort, headache, fatigue, urinary discomfort, constipation, lumbago, edema, tingling, digestive disorder, cough, pruritus, arthralgia, cold feeling by VAS (Visual Analogue Scale) in order to analyze improvement and difference between two groups. Results: Experimental group had significantly high score on deficiency of blood, blood stasis, dryness, spleen, kidney, phlegm and high frequency on deficiency of blood, dampness, kidney, phlegm pathogenesis in DSOM. It had significantly high intensity in symptoms of abdominal discomfort, headache, fatigue, urinary discomfort, constipation, lumbago at the first time, and headache at 1 month after western hospital discharge out of symptoms associated with surgery. And it had significantly high improvement in symptoms of abdominal discomfort, headache, urinary discomfort, constipation at oriental-western integrative hospital discharge, and headache, fatigue, urinary discomfort, constipation, lumbago at 1 month after western hospital discharge out of symptoms associated with surgery. Conclusion: We recognized that oriental-western medicine integrative care after gynecology surgery has significant effect.

• Journal of the Ergonomics Society of Korea
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• v.33 no.3
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• pp.215-227
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• 2014

Objective: The purpose of this study was to evaluate Korea's Honam express train's first- and second-class seat discomfort by using pressure measurement, subjective discomfort rating, and physical compatibility. Background: Over the years, the demand for an express train service is continually increasing. A comfortable ride is important to achieving passenger satisfaction. A train seat plays a significant role in fulfilling passenger seating comfort. With this in view, a field survey and pressure measurements were performed on the selected train seat. Method: The pressure ratio at the body-seat interface (thigh and buttock regions) was measured by the pressure mat system. The interface pressure ratio was calculated and compared. The subjective discomfort rating scale was used to evaluate the subjects' overall feeling. The dimensions of train seats were analysed according to the anthropometric and demographic characteristics of the population data from Size Korea. Results: The results highlighted that the interface pressure ratio was greater while participants sat on the second-class seat than the first-class seat in the left- and right-side thigh regions. Also the pressure ratio was greater for the participants in the 1st~25th percentile height groups (149.8~160.8cm). The subjects rated higher discomfort for the second-class seat than the first-class seat. The physical compatibility results showed that the second-class seat's breadth was inadequate for the 95th and 99th percentile male. Conclusion: Overall, interface pressure measurement, subjective discomfort score and physical compatibility results showed that the second-class seat was more uncomfortable for the passengers than the first-class seat. Application: The adopted methodologies could be used to measure the seating comfort of the train seats.

• Industrial Engineering and Management Systems
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• v.10 no.3
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• pp.185-190
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• 2011

A driver interacts directly with the car seat at all times. There are ergonomic characteristics that have to be followed to produce comfortable seats. However, most of previous researches focused on either static or dynamic condition only. In addition, research on car seat development is critically lacking although Malaysia herself manufactures its own car. Hence, this paper integrates objective measurements and subjective evaluation to predict seat discomfort. The objective measurements consider both static and dynamic conditions. Steven's psychophysics power law has been used in which after expansion; ${\psi}\;=\;a+b{\varphi}_s^{\alpha}+c{\varphi}_v^{\beta}$ where ${\psi}$ is discomfort sensation, ${\varphi}_s^{\alpha}$ is static modality with exponent ${\alpha}$ and ${\varphi}_v^{\beta}$ is dynamic modality with exponent ${\beta}$. The subjects in this study were local and the cars used were Malaysian made compact car. Static objective measurement was the seat pressure distribution measurement. The experiment was carried out on the driver's seat in a real car with the engine turned off. Meanwhile, the dynamic objective measurement was carried out in a moving car on real roads. During pressure distribution and vibration transmissibility experiments, subjects were requested to evaluate their discomfort levels using vehicle seat discomfort survey questionnaire together with body map diagram. From subjective evaluations, seat pressure and vibration dose values exponent for static modality ${\alpha}$ = 1.51 and exponent for dynamic modality ${\beta}$ = 1.24 were produced. The curves produced from the $E_{q.s}$ showed better $R_{-sq}$ values (99%) when both static and dynamic modalities were considered together as compared to Eq. with single modality only (static or dynamic only R-Sq = 95%). In conclusion, car seat discomfort prediction gives better result when seat development considered both static and dynamic modalities; and using ergonomic approach.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.553-563
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• 2014

Objective: The purpose of this study was to evaluate the effect of gender (male, female) and grip spans (45, 50, 60, 70, 80mm) on total grip strength, resultant force, finger force and subjective discomfort rating. Background: In order to prevent musculoskeletal disorders, studies of hand tools need to be preceded based on grip strength, finger force, and subjective discomfort rating. However, experimental apparatus using tools such as pliers that reflect the actual work place was almost non-existent. Method: Fifty-Two (26 males and 26 females) participants were recruited from the student population. In this study, a pair of revised pliers, which can change grip span from 45 to 80mm was applied to estimate total grip strength, resultant force and individual finger forces. All participants were asked to exert a maximum grip force with three repetitions, and to report the subjective discomfort rating for five grip spans of pliers (45, 50, 60, 70, 80mm). Results: There were significant differences of total grip strength, resultant force, individual finger forces and subjective discomfort rating according to grip span. The lowest total grip strength was obtained from the grip span of 80mm for both genders. For resultant force, the highest resultant force was exerted at grip spans of 50, 60 and 70mm for females and 50 and 60mm for males. The lowest subjective discomfort rating was observed in the 50mm for both genders. Conclusion: Based on the result, 50mm and 60mm grip spans which provide the highest force and lowest discomfort rating might be recommendable for the male and female pliers users. Application: The findings of this study can provide guidelines on designing a hand tool to help to reduce hand-related musculoskeletal disorders and obtain better performance.