연구목적 : 본 연구는 착석시 의자등받이가 사용자의 허리를 감싸안고 척추형태에 반응하여 자연스러운 척추 곡선을 유지 및 증진시켜 줌으로써 바른 자세 유지 및 허리 피로감 해소에 도움을 주는 척추 굴곡 반응형 의자등받이를 개발하고 이의 효과를 과학적으로 검증하는데 목적을 두었다. 연구방법 : 척추 굴곡 반응형 등받이는 일반 사무용 의자에 탈부착이 가능하며 사용자가 허리를 기댔을 때 등받이가 사용자의 척추라인에 따라 반응하도록 하여 허리 전체가 등받이에 밀착됨으로써 척추의 자연스러운 굴곡 형태를 유지하고 증진시키도록 개발하였다. 개발된 등받이의 효과성 검증을 위해 표준체형의 남자대학(원)생 10명을 피실험자로 선정하여 동작분석기와 근전계를 활용하여 착석시 척추 굴곡의 변화 측정과 척추 세움근의 활성도를 측정하였다. 결과 : 개발된 등받이와 비교 대상 의자에 착석시 척추 곡선 변화에 대한 동작분석기 평가결과, 등받이 각도 105o부터 시작하여 리클라이닝 각도가 125o로 커짐에 따라 요추의 전만곡과 흉추의 후만곡이 커짐으로써 척추 곡선이 증진됨을 보였다. 근전계를 활용한 척추 세움근(L5/S1)의 평가결과 개발된 의자를 사용했을 때 모든 등받이 각도에서 사후 중앙주파수 값이 사전 중앙주파수 값보다 높게 측정됨으로써 피 로지수가 낮아졌음을 알 수 있었다. 결론 : 본 연구에서 개발한 척추 굴곡 반응형 등받이는 착석시 바른자세를 유지하게 하여 허리근육의 긴장완화와 허리디스크에 가해지는 압력을 감소시켜 장시간 앉아서 업무를 보거나 공부하는 학생들의 피로감을 줄여줄 의자로써 활용이 가능하며 향후 이의 도입과 확산을 위한 추가적인 연구개발의 필요성을 제안한다.

목적 : 본 연구의 목적은 욕창방지용 쿠션 종류와 등받이 각도가 착석압력에 미치는 영향을 알아보기 위한 것이다. 연구방법 : 성인 남, 여 각각 14명의 피험자를 대상으로 연구를 실시하였다. 실험은 착석면에 추가되는 욕창방지용 쿠션인 5종류(공기형, 마블형, 폼형, 혼합형, 젤형)와 등받이 각도 2종류(90도, 110도)의 각각에 따른 착석 압력 분포를 측정하였다. 욕창방지용 쿠션 종류와 등받이 각도에 따른 착석면의 평균압력을 비교하기 위해 반복측정 이원분산분석(Repeated Two way-ANOVA)을 실시하였다. 결과 : 분석결과 욕창방지용 쿠션 종류와 등받이 각도에 따른 압력 지수인 착석면의 압력 평균 지수(Average Index), 착석면의 압력 표준편차 지수(Standard Deviation), 최대 압력 지수(Peak Pressure Index), 분산지수 (Dispersion Index)가 통계적으로 유의한 차이가 있다고 나타났다. 결론 : 공기형 쿠션이 착석 압력분포가 낮게 나타났고, 등받이 각도가 110도일 때 압력을 재분배하는 올바른 착석 자세를 유지시킬 수 있는 적정 쿠션 및 등받이 각도라고 제언할 수 있다.

Pressure sores are painful and needless complications of critical illness. and manifest as a localized area of ischemic necrosis of tissue caused by pressure. This study analyzed the bed-backrest elevation system combined with hip and knee flexion for lower extremity lower pressure reduction. Eight healthy adults aged 21 to 26 years were recruited. The Body Pressure Measurement Mat of the TekScan system was used to measure the location and magnitude of the peak pressures on the body bed interface. The SPSS statistical package was used to analyze the significance of differences between the general bed-backrest elevation system and the bed-backrest elevation system combined with hip and knee flexion using the paired t-test. The result showed that the body-pressure of the lower extremity was more significantly reduced for the bed-backrest elevation system combined with hip and knee flexion (26.6±4.3 mmHg) than a general bed-backrest elevation system (37.3±5.2 mmHg) (p<.05).

This study was purposed to provide basic information on the correct application of a wheelchair's backrest angle by investigating the change in cardiopulmonary function according to backrest angle during propulsion. This study examined the effects of the wheelchair's backrest angle on the cardiopulmonary function by varying the angle to 0°, 10° and 20° and with a propulsion velocity of 60 m/min. The experimental parameters were respiration rate, oxygen consumption rate and oxygen consumption rate/kg which were measured by a portable wireless oxygen consumption meter (COSMED, K4b²). The results of the study were as follows: 1) There were no statistically significant differences in respiration rates due to changes in the wheelchair backrest angle (p>.05). 2) There were statistically significant differences in oxygen consumption rates due to changes in the wheelchair backrest angle (p<.05). 3) There were also statistically significant differences in the oxygen consumption rate/kg due to changes in the wheelchair backrest angle (p<.05). In conclusion, changes in the backrest angle of wheelchairs during propulsion influences oxygen consumption rates and heart rates, while respiration rates are not affected. Therefore, a training program for good seating and posture needs to be provided, and the wheelchair seating system should be equipped with the unadjustable-angle wheelchair to reduce the functional load on the cardiopulmonary system.

The purpose of this study was to investigate the effects of backrests of varying degrees (, , ) 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 backrest, (2) leaning on a chair with a backrest, (3) leaning on a chair with a 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.

In modern society, people spend most of their time on various types of chairs. However, it is not easy for a designer to design a comfortable chair because satisfaction with the chair depends not only on the quantitative elements such as size, but also on the qualitative element such as the user’s feeling. To deal with these problems, there have been many studies on designing ergonomic chairs. This paper proposes the haptic-aided design (HAD) system to design an ergonomic chair. Based on the HAD system, the designer can experience whether the chair is comfortable or not through the haptic device, and also can modify the design parameters instantaneously. The haptic chair capable of controlling the design parameters in real time was proposed as a haptic simulator. The controllable parameters, such as seat height, reclining angle, stiffness of the backrest, and so on were selected based on the previous research related to ergonomic chairs. The proposed methodology will help reduce the development cost and time by replacing the process of making the real mock-ups and prototypes with the haptic chair.