• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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• pp.312-317
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• 2000

The relationship between riding comfort and the properties of flexible polyurethane foam used in car seats was quantitatively illustrated through vibration experiments with humans sitting in car seats, which were vertically shaken by vibrator. Riding comfort was estimated according to SD (Semantic Differential)-method using questionnaire, and was analyzed with a factor analysis which demonstrated the principal factors of riding comfort. At the same time, riding comfort was related to the properties of the flexible polyurethane foam with coefficients of correlation. It was also related to the behaviour of its vibration of humans sitting in the seats. As a result, it was demonstrated that the relationship between riding comfort and the flexible polyurethane foam properties varies according to the frequency of the vibration shaking the human sitting in the seat. and it was demonstrated that the frequency dependence of the relationship is strongly affected by the physical changes of the vibration modes of the human-seat vibration system.

• Physical Therapy Rehabilitation Science
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• 제9권3호
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• pp.155-164
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• 2020

Objective: This study aimed to compare muscle structure, balance, and gait parameters between healthy adults and persons with stroke and to analyze the correlation among these variables. Design: Cross-sectional study. Methods: Twenty persons with stroke (11 male, 9 female) and twenty healthy participants (9 male, 11 female) were included. Ultrasound images of the triceps surae and the tibialis anterior were acquired in sitting resting, sitting co-contraction, and standing resting positions and also during the functional reach test (FRT) and single leg anterior reaching test (SLART). Muscle thickness and fascicle length were measured. Spatiotemporal parameters of gait were measured using a pressure walkway. Gait speed, cadence, step length, stride length, stance time, and swing time were measured. Results: Changes in percent fascicle length were significantly greater in the gastrocnemius and soleus (SOL) muscles of healthy adults in the sitting co-contraction position (p<0.05). The percent fascicle length of the SOL in FRT and SLART were significantly greater in healthy adults (p<0.05). The mid-stance phase of stroke patients was shorter than healthy adults (p<0.05). A negative correlation was observed between percent fascicle length of the SOL in the sitting co-contraction position and the proportion of the mid-stance phase (p<0.05). Conclusions: The function of the triceps surae is affected in persons with stroke when compared with healthy adults. This can lead to difficulty in performing tasks that involve forward transfer of weight. If the triceps surae is not sufficiently secured, the possibility of compensation in the stance phase increases during gait.

• Safety and Health at Work
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• 제11권2호
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• pp.207-214
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• 2020

Background: Prolonged sitting at work can lead to adverse health outcomes. The health risk of office workers is an increasing concern for the society and industry, with prolonged sitting work becoming more prevalent. Objective: This study aimed to explore the variation in muscle activities during prolonged sitting work and found out when and how to take a break to mitigate the risk of muscle symptoms. Methods: A preliminary survey was conducted to find out the prevalence of muscle discomfort in sedentary work. Firstly, a 2-h sedentary computer work was designed based on the preliminary study to investigate the variation in muscle activities. Twenty-four participants took part in the electromyography (EMG) measurement study. The EMG variations in the trapezius muscle and latissimus dorsi were investigated. Then the intervention time was determined based on the EMG measurement study. Secondly, 48 participants were divided into six groups to compare the effectiveness of every break type (passive break, active break of changing their posture, and stand and stretch their body with 5 or 10 mins). Finally, data consisting of EMG amplitudes and spectra and subjective assessment of discomfort were analyzed. Results: In the EMG experiment, results from the joint analysis of the spectral and amplitude method showed muscle fatigue after about 40 mins of sedentary work. In the intervention experiment, the results showed that standing and stretching for 5 mins was the most effective break type, and this type of break could keep the muscles' state at a recovery level for about 30-45 mins. Conclusions: This study offers the possibility of being applied to office workers and provides preliminary data support and theoretical exploration for a follow-up early muscle fatigue detection system.

• 한국전문물리치료학회지
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• 제8권2호
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• pp.55-63
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• 2001

For spinal flexibility measurements to be meaningful to clinicians or researchers, they must have a normative information and an understanding of how different variables affect spinal range of motion (ROM). Normal spinal ROM measurements are influenced to differing degrees by many factors. These factors include age, gender, time of day, leisure activities, previous history of low back pain, warming up, and the techniques with which normative data are collected. The additional variables of standing height, ratio of standing height to sitting height, and obesity had not been previously studied extensively and were shown to have a significant effect on flexibility in the sagittal plane. These relationship cannot be explained easily. Thus, the purpose of this study was to determine the relationship between spinal flexibility and individual factors (weight, standing height, and ratio of standing height to sitting height) that influence it. Fifteen healthy subjects between the ages of 20 and 27 years were studied. Two physical therapists measured independently the spinal forward bending ROM in the sagittal plane by Remodified Schober test and Finger-to-floor test. In order to determine the statistical significance of the result the Pearson's correlation was applied at the .05 level of significance. The results of this study were as follows: 1) Significant relationship was not identified between spinal flexibility and weight. 2) Significant relationship was not identified between spinal flexibility and standing height. 3) Significant relationship was not identified between spinal flexibility and ratio of standing height to sitting height.

• 한국전문물리치료학회지
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• 제13권4호
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• pp.39-46
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• 2006

The purpose of this study was to determine the effects of slump sitting postures on the masticatory, neck, shoulder, and trunk muscles associated with work-related musculoskeletal disorders (WRMD). Eleven healthy adults (age, $23.3{\pm}2.7$ yrs; height, $174.0{\pm}4.1$ cm; weight, $61.4{\pm}6.6$ kg) participated in this study. The participants were free of injury history and neurologic deficits in the masticatory, neck muscles and upper extremities at the time of participation. The subjects were asked to perform erect and slump sitting postures under the guidance of physical therapists. The surface electromyography (EMG) was recorded from the anterior temporalis, masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique, gluteus maximus muscles of 11 adults as they performed visual terminal display work, which are known as the weakened and tightened muscles owing to WRMD. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The results of study were as follows: The masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique muscles significantly differed in the slump sitting posture (p<.05). The muscle activities of the serratus anterior, middle trapezius muscle, and external abdominal oblique were significantly lower and that of the masseter, upper trapezius, L3 paraspinal muscles were significantly higher. Further research is needed to assess the motor control problems and the function of the deep muscles in posture stability of patients with WRMD.

• 대한물리의학회지
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• 제14권3호
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• pp.13-20
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• 2019

PURPOSE: Sitting with crossed legs may have an effect on maintaining a healthy body posture and proper functioning of the respiratory system. Thus, this study's objective was to identify whether or not sitting with crossed legs affects the vertebral angle, chest wall mobility, the pulmonary function, and the activity of the respiratory muscles. METHODS: Thirty healthy subjects were recruited for this study (16 males and 14 females). The vertebral angle, chest wall mobility, pulmonary function, and the activity of the respiratory muscle were measured while the subjects sat in the correct posture and these factors were again measured with the subjects seated with their legs crossed. Three-dimensional motion analysis was used to determine the trunk and lumbar vertebral angles. Surface electromyography was employed to measure the sternocleidomastoid, the rectus abdominis, and the external and internal oblique abdominis muscles. A tapeline was utilized to evaluate the subjects' chest wall mobility. Spirometry was assessed to determine the forced vital capacity and forced expiratory volume in one second. Paired t-tests were then performed (p<.05). RESULTS: There were significant differences in the trunk and lumbar flexion angles, the chest wall mobility, the activity of the right external oblique muscle, and the left internal oblique abdominis muscle. However, the difference in pulmonary function did not reach statistical significance. CONCLUSION: A crossed leg posture caused slight thoracic extension and lumbar flexion, which may lead to a decrease of the chest wall mobility and also to an imbalance of the abdominal muscles. Therefore, sitting with a crossed leg posture should be avoided. Yet a crossed leg posture did not have any clinical effect on the pulmonary function of healthy people. It may be necessary to study the effects of sitting with crossed legs over an extended period of time for patients suffering with impaired respiratory function.

• 한국전문물리치료학회지
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• 제3권3호
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• pp.44-58
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• 1996

The purpose of this study was to compare and evaluate various hand functions in the most common position (chair sitting, standing, floor sitting) used by cerebral palsied children with spastic diplegia. The results, analysed statistically, could be useful in suggesting treatment strategy for the improvement of hand function in such patient. For this study, 27 children mild or moderate spastic diplegia were chosen. They were patients of the Rehabilitation Hospital, Yonsei University Medical Center. Both dominant and nondominant hands were tested by the Box and Block Test. Bilateral hand function was tested by bead striding and card sorting activities. Collected data was analysed using univariate correlation analysis and MANOVA. Results were as follows: 1) In chair sitting there was a significant positive correlation between dominant hand scores in the Bloc and Box Test and chronological age, gestation period, and time of treatment initiation. In bilateral hand function, card sorting scores correlated positively with time of treatment initiation. 2) In standing, there was a significantly positive correlation between dominant hand scores in the Block and Box Test and time of treatment initiation. 3) In floor sitting, there was a significantly positive correlation between the dominance hand scores in the Block and Box Test and the tine of treatment initiation. Bead stringing, a bilateral hand activity, correlated positively with gestation period and birth weight but negatively with the postnatal incubation period. 4) That score of children who walked showed no significant difference in any of the three postures. 5) Highest test scores in children who could nat walk were in the Box and Block Test for nondominant hand in bead stringing for bilateral hand function. There scores occurred with the children in thee chair sitting posture. The results showed that, in order to improve hand function in children with spastic diplegia, it is necessary to maintain a well supported upright trunk posture with variations allowed for relevance to the chosen position of thee improvements hand activity being performed.

• 전기학회논문지
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• 제67권7호
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• pp.940-945
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• 2018

In this study, we make a study on a system to determine a person's sitting posture by measuring the distribution of pressure in the floor of a chair or in a cushion using pressure sensors. If the wrong sitting posture is detected, a warning message is given through the vibration motor in real time to correct the imbalance of the wrong habits and posture, and prevent Bulging disc or Herniated disc.

• 대한물리의학회지
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• 제18권4호
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• pp.29-35
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• 2023

PURPOSE: High-intensity physical therapy may help improve some gross motor developmental delays through an increased treatment frequency. This study describes an increase in physical therapy frequency and intensity over an eight-week time frame for a child with a rare genetic neurodevelopmental disorder. METHODS: A single-subject research was performed. The subject was a nine-year-old boy with MECP2 Duplication Syndrome. The outcome measure consisted of one time before and after the intervention. An intensive physical therapy program was applied to this subject. The treatments included reciprocal crawling, high kneeling, tailor sitting, weight-bearing and shifting training to facilitate ankle balance strategies and training to walk without assistance. RESULTS: After the eight-week follow-up, the child achieved a gradual improvement in the gross motor function measures, and the mother reported that the child frequently engaged in tailor sitting and independently walking. CONCLUSION: This case study highlights that intensive physical therapy improved the overall motor function of a child with MECP2 duplication syndrome.

• 융합정보논문지
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• 제11권7호
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• pp.278-287
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• 2021

본 연구는 직업군별 좌식시간과 고위험음주가 고요산혈증의 유병률과 위험도에 차이가 있는지 성별 분석을 중심으로 수행되었다. 이를 위해 국민건강영양조사 자료를 활용하였으며, 연구대상으로 16,366명을 선정하였다. 분석방법으로 카이제곱 독립성 검정과 로지스틱 회귀분석을 사용하였다. 남성은 여성보다 좌식시간과 고위험음주에 따른 고요산혈증 유병률이 각각 22.2%와 25.2%로 상대적으로 높았으며 위험도는 1.274와 1.310으로 유의하였다. 고요산혈증에 대한 좌식시간의 유병률과 위험도는 남성에서만 '농림어업종사자' 직업군에서 유의하였다. 반면, 고위험음주의 유병률과 위험도는 남녀 모두 '관리자, 전문가 및 관련종사자', '사무종사자'에서 유의한 차이를 보였으며, 여성에서만 '서비스 및 판매종사자', '기능원, 장치 및 기계조립 종사자', '무직'에서 유의한 차이를 보였다. 이러한 결과는 남성에서 고요산혈증의 유병률과 위험도가 높다는 것을 알릴뿐만 아니라 직업군별로 이를 예방할 수 있는 보건의료정책과 의료서비스가 필요함을 시사한다.