• 한국전문물리치료학회지
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• 제24권2호
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• pp.66-75
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• 2017

Background: After a stroke, the control of the trunk muscle may be severely impaired. Due to the importance of trunk control in complex daily postures, the ability to adopt a correct sitting posture is considered a determinant of the recovery of independent function after a stroke. Objects: The purposes of this study were to compare differences in buttock pressure between the left and right sides of hemiplegic patients and differences in their pelvic tilting angles (sagittal and coronal planes) after sitting training with visual biofeedback (VBF) in real time. Methods: Twenty-two individuals with unilateral strokes (11 left-side and 11 right-side hemiplegic stroke patients) participated in this study. Buttock pressure was measured using a pressure mat, and pelvic angles were measured using a palpation meter. Results: The asymmetry of pressure between the right and left (first and third chamber) sides was significantly decreased after the VBF training. The measurements obtained using the palpation meter revealed a significant decrease in the pelvic angles pre- versus post-intervention. Conclusion: VBF training may be distribute a patient's buttock pressure equally while in a sitting posture and increase the length of time a stroke patient can maintain a symmetrical sitting posture. It can also improve pelvic control while sitting in a neutral position.

• 한국전문물리치료학회지
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• 제19권1호
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• pp.1-9
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• 2012

The purpose of this study was to investigate the kinematic and kinetic changes that may occur in the pelvic and spine regions during cross-legged sitting postures. Experiments were performed on sixteen healthy subjects. Data were collected while the subject sat in 4 different sitting postures for 5 seconds: uncrossed sitting with both feet on the floor (Posture A), sitting while placing his right knee on the left knee (Posture B), sitting by placing right ankle on left knee (Posture C), and sitting by placing right ankle over the left ankle (Posture D). The order of the sitting posture was random. The sagittal plane angles (pelvic tilt, lumbar A-P curve, thoracic A-P curve) and the frontal plane angles (pelvic obliquity, lumber lateral curves, thoracic lateral curves) were obtained using VICON system with 6 cameras and analyzed with Nexus software. The pressure on each buttock was measured using Tekscan. Repeated one-way analysis of variance (ANOVA) was used to compare the angle and pressure across the four postures. The Bonferroni's post hoc test was used to determine the differences between upright trunk sitting and cross-legged postures. In sagittal plane, cross-legged sitting postures showed significantly greater kyphotic curves in lumbar and thoracic spine when compared uncrossed sitting posture. Also, pelvic posterior tilting was greater in cross-legged postures. In frontal plane, only height of the right pelvic was significantly higher in Posture B than in Posture A. Finally, in Posture B, the pressure on the right buttock area was greater than Posture A and, in Posture C, the pressure on the left buttock area was greater than Posture A. However, all dependent variables in both planes did not demonstrate any significant difference among the three cross-legged postures (p>.05). The findings suggest that asymmetric changes in the pelvic and spine region secondary to the prolonged cross-legged sitting postures may cause lower back pain and deformities in the spine structures.

• 융합신호처리학회논문지
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• 제24권1호
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• pp.15-20
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• 2023

일반적으로 잘못된 앉은 자세를 장시간 유지하는 것은 척추에 나쁜 영향을 미치는 것으로 널리 알려져 있다. 최근 여러 연구자들이 잘못된 앉은 자세와 척추질환의 인과관계에 관심을 두고 있으며, 척추질환 예방을 위해 앉거나 서는 자세의 변화를 정밀하게 측정할 수 있는 방법을 연구해왔다. 우리는 과거 연구에서 실시간 체위 변환 측정이 가능한 센서 디바이스를 개발하고 운동량 계산 알고리즘을 적용하여 실시간 자세 전환 측정 정확도를 향상시켰으며, 체위 변환 측정 센서의 정확도를 검증하였다. 본 연구에서는 좌압 측정을 통해 체중심의 변화를 고려한 자세 측정 및 분석 장치를 개발하였으며, 개발된 센서는 사용자의 시각적 피드백을 개선하여 자세 교정 훈련 정확도를 높이는 보조 도구로의 활용 가능성을 확인하였다.

• 한국생활과학회지
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• 제13권1호
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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.

• 한국생활과학회지
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• 제19권4호
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• pp.655-665
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• 2010

This study analyzed the effects of skinny jean on women's health by questionnaire survey and measuring the pressure experienced under the clothing and participants' subjective view of the pressure level. The average size women in their 20s' waists is 26 inches and so three pairs of jeans were prepared and worn by 4 female participants. A survey was conducted to investigate how often participants wear skinny jeans and whether they had had any feelings of discomfort as a result of this. Participants responded that they hadexperienced middle to high levels of discomfort due to the high pressure inside skinny jeans. For the maximum value of clothing pressures, jean f2 at the part of buttocks showed $48.7gf/cm^2$. The pressure inside the clothing was found to be highest around the buttocks followed by the knees and finally the belly. The mean values of 7 measuring parts are different according to the jean type; f3 $20.8gf/cm^2$ > f2 $16.4gf/cm^2$ > f1 $15.5gf/cm^2$, which is corresponding to the order of pressure sensation, but not corresponding to the order of ease amount of clothing pattern: f2 > f3 > f1. Mean pressure values were also measured according to the body posture: they were found to by highest when sitting on a chair (21.3gf/$cm^2$), second highest when sitting on the floor ($19.2gf/cm^2$) and lowest when standing ($15.0gf/cm^2$). This is not always same to the order of participants subjective perceptions of the pressure, which is, they estimated pressure to be highest when sitting on the floor followed by sitting on a chair and lowest in a standing position.

• 융합신호처리학회논문지
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• 제21권2호
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• pp.73-78
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• 2020

근골격 질환은 착석 자세로 업무 및 학업을 장시간 진행하거나 잘못된 자세 습관으로 발생하는 경우가 많다. 일상생활에서 근골격 질환을 예방하기 위해서는 실시간 착석자세 모니터링을 통해 잘못된 자세를 바른 자세로 유도하는 것이 가장 중요하다. 본 논문에서는 의자에 밀착된 착석 정보를 무 구속적으로 검출하기 위하여 다채널 압력센서 기반의 자세 측정 시스템과 사용자의 착석 자세 분류를 위한 CNN 모델을 제안한다. 제안된 CNN 모델은 착석 자세 정보를 기반으로 압력분포에 따른 사용자의 5가지 자세 분석이 가능하다. 필드테스트를 통한 자세 분류 신경망의 성능평가를 위하여 10명의 피실험자를 대상으로 분류결과에 대한 정확도, 재현율, 정밀도 및 조화 평균을 확인하였다. 실험 결과, 99.84%의 accuracy, 99.6%의 recall, 99.6%의 precision, 99.6%의 F1을 확인하였다.

• 운동과학
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• 제26권1호
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• pp.61-68
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• 2017

PURPOSE: To examine the cumulative (7 days) effect of breaking up prolonged sitting on systemic endothelial function in sedentary men. METHODS: Thirty sedentary men ($33.93{\pm}5.72years$) participated in two randomized 7 days sitting trial (Sit group (control) vs. Breaks group). The protocol of Breaks group is as follows: 4-minute of moderate-intensity marching in place (walking) every 1 hour during business hour (total: 8 breaks/day). Assessment of brachial artery endothelial function using flow-mediated dilation (FMD) and arterial stiffness indices (augmentation index, arterial pressure and pulse wave velocity) were measured before and after 7 days treatment. RESULTS: Brachial artery FMD significantly increased after 7 days breaking up prolonged sitting treatment (Breaks groups, $9.65{\pm}2.61$ to $9.62{\pm}2.6%$) compared with 7 days prolonged sitting (Sit group, $8.37{\pm}3.41$ to $10.11{\pm}3.75%$) (interaction effect, p=.004). Arterial pressure (AP) significantly increased after treatment (Breaks group, $2.75{\pm}2.19$ to $2.38{\pm}1.63mmHg$, p=.002) in Sit group but there was no change (Sit group, $1.00{\pm}3.18$ to $2.50{\pm}9.23mmHg$) in Breaks groups (interaction effect, p=.008). CONCLUSIONS: These finding show that 7 days regular breaking up prolonged sitting improve in FMD, compared with prolonged sitting. Therefore, regular breaking up prolonged sitting may improve systemic endothelial function in sedentary men.

• 한국의류학회지
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• 제17권2호
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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.

• 한국컴퓨터정보학회논문지
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• 제27권2호
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• pp.153-161
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• 2022

일상생활의 전반에 걸쳐 필요한 생활용품들이 자동화, 스마트화, 지능화됨으로 인해 물리적인 활동이 줄고 앉아 있는 시간이 늘어가는 추세이다. 최근 헬스케어 연구에서는 앉아 있는 시간에 비례해서 비만, 당뇨병, 심장혈관질환, 그리고 조기사망의 가능성이 높아진다고 보고되었다. 본 논문에서는 전도성 섬유 기반 전기용량성 압력 센서를 이용한 실시간 앉은 자세 교정 방석을 개발한다. 자세 교정 방석의 핵심 부품인 전도성 섬유를 이용한 압력 센서를 개발하고, 저전력 기반의 압력 측정 회로를 개발한다. 자세 교정 방석에서 BLE(Bluetooth Low Energy) 근거리 무선통신을 이용하여 실시간으로 측정된 센서값을 스마트 폰으로 전송할 수 있는 기능을 제공하고, 이 센서값을 통해 앉은 자세의 상태를 확인할 수 있도록 모바일 앱을 개발한다. 모바일 앱에서는 앉은 자세를 시각화하여 실시간으로 확인할 수 있고 잘못된 자세로 일정시간 유지할 경우 알람으로 알릴 수 있다. 또한, 앉아 있는 시간 및 자세 정확도를 그래프로 시각화할 수 있도록 한다. 본 논문의 교정 방석을 통해 사용자의 앉아 있는 자세 상태를 인지하여 실제적으로 사용자 자세 교정에 얼마나 효과적인지를 실험해 보고 타제품과 비교하여 차별성과 우수성을 제시한다.

• 대한인간공학회지
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• 제33권4호
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• pp.255-265
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• 2014

Objective: The purpose of this study was to evaluate comfort levels of functional and non-functional chairs using subjective comfort rating, interface pressure measurement, muscle activity measurement, and skin temperature measurement. Background: Chairs are used for a prolonged period of time for sitting in many places such as the office, at university, at school, in industry, and so on. Almost all people use chairs in their everyday life. The functional properties of the chair are associated with comfort. Method: The subjective evaluation contains questions regarding chair comfort which can be rated with five point scale. The body-seat interface pressure was measured using a pressure mat system. The symmetry of sitting was measured using electromyography. The change in body part (thigh and buttock) temperature before and after sitting on a chair was measured with an infrared camera. Results: Participants rated significantly (p < 0.05) higher comfort scores for the functional chair in relation to the buttock and thigh region. Also, the participants felt a better cushion effect in the functional chair. When using the functional chair, lower interface pressure, better thermal comfort, and better symmetry of erector spinae muscle activity were observed. Conclusion: Overall, interface pressure measurement, muscle activity measurement, thermal imaging and subjective comfort score results showed that the functional chair was more comfortable than the non-functional chair. Application: The adopted methodologies could be used to measure the seating comfort of train seats.