• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.123-149
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• 1991

This study has been attempted to be helpful for the back rehabilization of Korean workers by analyzing the general, occupational, social aspects of low back pain and to identify possible risk factors for back pain in White and Blue collar workers. The primary data were collected from 380 workers in Seoul city by means of a Questionnaire with random which was distributed from March 10 to 31, 1990. For the test of statistical significance, chi-square analysis was used to compare the back pain characteristics between above two groups. The results were as follows : 1. The incidence of low back pain in all walkers studied was $79.7\%$. The incidence of Blue collar with low back pain $(87.2\%)$ was higher than that of White collars $(75.0\%)$. 2. With regard to the relationship of back pain to the occupational characteristics, statistically significant differences were observed between workers with and without back pain concerning the job factors on work-time, job satisfaction, mental stress, chair fittness, work posture, work rotation, weight lifting, monotonous repetitive movements, vibration, and heavy noise (p<0.05). 3. With regard to the relationship of back pain to the social characteristics, there were no differences with respect to having car, personality types, drinking habits, and leisure-time activities. However, significant differences were showed between no pain and pain groups for the using bed, sleeping posture, traffic time amount, walking health state, smoking habits, and physical exercise (p<0.05). 4. The comparative analysis of back pain related to work factors showed highly significant differences with respect to mental stress, chair fittness, work posture, trunk rotation, weight lifting, monotonous repetitive work in White collar group (p<0.01) ; and job satisfaction, mental stress, trunk rotation, weight lifting, monotonus repetitive work, exposure to vibration and heavy noise in Blue collar group(p<0.01). 5. The comparative analysis of social factors in two groups showed differences with respect to the using bed, sleeping posture, walking amount, health state, physical exercise, smoking habits in White cellar group (p<0.05) ; and walking amount, traffic time amount, health state, smoking habits, physical exercise in Blue cellar group (p<0.05). 6. In regard to the general aspects of back pain between two groups, there were differences concerning etiolgy of back pain, counselling partners, treatment types, and sick-leaves(p<0.05), except pain duration, and awareness of back pain.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.33-39
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• 2023

Background: Most Pilates programs for older adults have been based on mat Pilates, and there has been limited research on Pilates with mini-balls. Therefore, this study aims to compare the effects of Pilates with mini-balls and mat Pilates interventions on strength, total body endurance, flexibility, and dynamic equilibrium to determine the differences. Methods: The elderly aged 65 or older living in Gyeongsan, Daegu, were divided into two groups, and the experimental group (n=10) conducted a Pilates exercise program using mini balls for 12 weeks, and the control group (n=10) conducted a mat Pilates exercise program for 12 weeks without mini balls. Strength, endurance, flexibility, and dynamic equlibrium were measured as a pre-test, and post-test was performed in the same way after 12 weeks of application. Results: Comparing the mini-ball Pilates group to the mat Pilates group, there was a significant difference (p<.05) in the 'chair sit and reach' after the intervention. In the within-group comparison, there was a significant increase (p<.05) in 'arm curl right', '30-second chair stand', '2-minute walk', 'back scratch', 'chair sit and reach', and '2.44m up and go' in the experimental group using the mini-ball Pilates program. Mat Pilates program significantly increased the within-group comparisons in '30-second chair stand' and 'chair sit and reach' (p<.05). Conclusion: It is suggested that mini-ball Pilates has a positive effect on the senior fitness and will be a good exercise method for using it as an exercise program for the elderly in the future.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.2
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• pp.56-62
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• 2015

In this study, we implemented an unconstraint ECG monitoring system on a chair. Nowadays, modern people spend most of their time sitting on the chair. Therefore, it is necessary to have an unconstraint ECG monitoring system that can be used for a long time. The implemented system can perform measurement even with clothes on and it has great advantage on motion artifacts. A pair of unconstraint electrodes are placed on the back of the chair. Amplifier and filters are designed to remove motion artifacts, The baseline noise and power line noise are filtered and very low level of bio-signal is amplified to give a final measurement. Control unit and wireless transmission unit are implemented. Analog signal is converted into digital signal and transmits biological signal to the PC and the smart phone. Therefore continuous ECG monitoring in daily life is made possible. A comparison experiment between Ag / AgCl electrode and unconstraint electrode is conducted to evaluate the performance of the implemented system. As a result, we confirm our unconstraint system can be used for daily life ECG monitoring.

• Korean Journal of Human Ecology
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• v.13 no.1
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• pp.153-158
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• 2004

With considerable development of comfortable and functional clothing in recent years, we need to evaluate the effects of garment pressure in daily wear on each parts of human body because the garment pressure is important to design the clothing. This study was designed to examine the effects of body postures on garment pressure on each parts of human body in the actual clothing conditions. All the data were collected from 50 volunteered subjects. The Garment pressure was measured in lune and December with 8 points CPMS clothing pressure system from scapular, upper am, elbow, under arm, front waist line, side waist line, abdomen, crista ilica, upper hip, middle hip, front thigh, back thigh, front knee and back knee. The postures of subjects were controlled with 3 positions such as standing (posture 1), sitting on the chair (posture 2), and sitting on the floor (posture 3) during measurement of clothing pressure. Clothing weights were more in men than in woman. It showed that clothing weights had no effects on the garment pressure. In this study, however, just the garment pressures on scapular and top of the hip increased significantly by clothing weight (p<. 05). Clothing horizontally pressed on scapular and top of hip but not on other parts. When subjects stood up, the garment pressure was the highest on the side waist. Especially, clothing pressure on the front waist point was lower than that of the left side waist. On the upper parts of the human body, the garment pressure of left side waist was the highest, and followed by front waist, crista ilica, and abdomen in order. When subjects were sitting on the chair, the garment pressure on the lower parts of the human body was the highest on the top of hip. When the subjects were sitting on the chair or on the floor, the surface area on their skin of hip and waist parts increased by postures. In addition, it showed that men felt more comfortable than women on higher clothing pressure level.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.35-39
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• 2016

PURPOSE: The purpose of this study was to examine changes in the neck flexion angle according to posture while using a smartphone and the duration of smartphone usage. METHODS: The subjects in this study were 16 healthy young students in their 20s. The subjects wore a cervical range of motion instrument. They were instructed to use a smartphone while standing, sitting on a chair, and sitting on the floor. In all postures, they could use the smartphone and use their arms freely while keeping their back connected to the wall or the back of the chair. When sitting on the floor, they assumed a cross-legged position. The neck flexion angle was measured at zero, three, six, and nine minutes for each posture. RESULTS: Neck flexion is affected by the posture while using a smartphone (p<.05). Neck flexion in the standing position is larger than that in the sitting on the floor position. Neck flexion was affected by smartphone usage duration (p<.05). In general, as usage time increases, the neck flexion angle increases as well. CONCLUSION: This study suggests that using smartphone in the standing position and for a short period of time is a method to reduce the neck flexion angle.

• Physical Therapy Korea
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• v.11 no.1
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• pp.19-25
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• 2004

The purpose of this study was to investigate the effects of backrests of varying degrees ($90^{\circ}$, $100^{\circ}$, $110^{\circ}$) on three abdominal muscles (upper rectus abdominis, external oblique, internal oblique) and back extensor activation during lower extremity exercise. The three different conditions during bilateral knee extention exercise were: (1) leaning on a chair with a $90^{\circ}$ backrest, (2) leaning on a chair with a $100^{\circ}$ backrest, (3) leaning on a chair with a $110^{\circ}$ backrest. Fifteen healthy muscle subjects (mean age=24.2 years [SD=2.96], mean height=175.6 cm [SD=7.46], mean weight=69.1 kg [SD=7.36]) with no history of neuromusculoskeletal disease voluntarily participated in this study. Electromyography was used to collect muscle activation, and the muscle activation was expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Repeated one-way analysis of variance (ANOVA) was used to determine the statistical significance. The results were as follows: (1) upper rectus abdominis, external oblique, internal oblique activation measured significantly lower. (2) measured significantly lower when lower degree.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.940-947
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• 2015

A Sitting posture is a very important issue for moderns who is mostly sedentary. Also, a wrong sitting posture causes back-pain and spinal disease. Many researchers have been proposed numerous approaches that classifying and monitoring for a sitting posture. In this paper, we proposed a real-time sitting posture monitoring system that was developed to measure pressure distribution in the human body. The proposed system consists of a pressure sensing module (six pressure sensors), data acquisition and processing module, a communication module and a display module for an individual sitting posture monitoring. The developed monitoring system can classify into five sitting postures, such as a correct sitting, sitting on forward inclination, leaning back sitting, sitting with a right leg crossed and a left leg crossed. In addition, when a user deviates from the correct posture, an alarm function is activated. We selected two kinds of chairs, one is rigid material and fixed form, the other one is a soft material and can adjust the height of a chair. In the experiments, we observed appearance changes for subjects in consequence of a comparison between before the correction of posture and after the correction of posture when using the proposed system. The data from twenty four subjects has been classified with a proposed classifier, achieving an average accuracy of 83.85%, 94.56% when the rigid chair and the soft chair, respectively.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.398-411
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• 2002

Objectives: The purpose of present study was to investigate the experience and point prevalence rate and factors related with Low Back Pain (LBP) in train egineers. Methods: Questionnaires were completed by 324 train engineers in Daejeon railroad administration from May 2002. The information was used to estimate odds ratio (OR) and 95$\%$ confidence intervals (CI) for factors relation to LBP. A retrospective study design was used. Results: The experience rate for LBP was 67.9$\%$, 54$\%$ in one year interval prevalence, 53.4$\%$ in 6 months interval prevalence, and 47.8$\%$ in a point prevalence rate. Variables significantly associated with LBP experience were age (p=0.0327), train vibration(p=0.0015), labour hour(p=0.0034), and pay(p=0.0534). As subjects got older, the higher experience for LBP was (OR=1.1, 95$\%$ CI 1.0-1.2). LBP experience rate for people who had felt train vibration was a higher than those who did not (OR=2.5, 95$\%$ CI 1.4-4.4, OR=2.3 95$\%$ CI 1.3-4.0 in a point prevalence). The people who worked for long hour was a higher than those who did not (OR=2.8, 95$\%$ CI 1.4-5.6, OR=2.2, 95$\%$ CI 1.1-4.5 in a point prevalence). The people who were not satisfied with pay was a higher than those who were (OR=1.7, 95$\%$ CI 1.0-3.0). Factors related to a point prevalence rate were train vibration(p=0.0027), chair vibration (p=0.0444), and labour hour(p=0.0340). LBP a point prevalence rate for people who had felt the vibration of train chair was a higher than those who did not (OR=1.8 95$\%$ CI 0.7-2.0). Conclusions: Results from present study indicated that a statistically significant factors associated with LBP experience were age, train vibration, labour hour, and pay, Factors related to a point prevalence rate were also train vibration, the vibration of train chair, and labour hour.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.197-206
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• 1993

We studied relation between the clothing pressure applied by foundations(waist nipper, girdle, body suit) on the waist of bodies and muscular activity, feeling of tightness. The main results were summerized as follows ; 1. Clothing pressure applied by foundations was high in order of girdle>waist nipper>body suit, also clothing pressure was higher back than front and side, sitting on the chair than standing posture, ventral flection than repose. Individual differences, even if size of body was equal, were shown in clothing pressure applied by foundations with subcutaneous fat's amount in measuring region. 2. The muscular activity of rectus abdominis than obliquus externus abdominis was more affected by foundations in all kinds of postures and motions. Amplitude of electromyogram was high sitting on the chair than standing posture, but there was little difference with motion variation. The wearing girdle strongly affected on the muscular activities of rectus abdominis and obliquus externus abdominis as compared with waist nipper and body suit. 3. The value for feeling of tightness by wearing waist nipper was higher than girdle and body suit. Also the case when sitting on the chair and ventral flection, the value for feeling of tightness was high. When the foundations were on the body, most tightened on the region of the body was anterior abdominal region.

• Journal of the Ergonomics Society of Korea
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• v.19 no.1
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• pp.23-36
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• 2000

In conventional ergonomics, consumer product can be made based on anthropometric data and specific design guideline. However, the product may not satisfy consumers because their emotional preference have not been properly considered in design phase. Therefore, in this study a new chair design process was introduced by which both consumer's emotional need and traditional ergonomic requirement can be satisfied. As a part of the process, the traditional Kansei engineering technique was modified to collect quantitative information of consumer's visual appreciation and physical feedback of various types of chairs. Furthermore, we developed an interface, so called, KADAS(Kamsung Analysis and Design Assistance System), for designers to use the technique in chair design. This software can help designers to understand what should be the most suitable shape in designing items such as seat, back and arm rest, etc. to meet the emotional need of consumers. This software displays the result of modified quantification theory I, and explains how to use the statistics. This study suggested a new approach for ergonomic design incorporated with Kansei Engineering technique. This technique can be also applied to other products by extending the database of KADAS.