• Title, Summary, Keyword: Center of pressure

Search Result 4,584, Processing Time 0.066 seconds

Qualitative Analysis of Pressure Intensity and Center of Pressure Trajectory According to Shoe Type

  • Yi, Kyung-Ock
    • Korean Journal of Sport Biomechanics
    • /
    • v.22 no.3
    • /
    • pp.261-268
    • /
    • 2012
  • The purpose of this study was to qualitatively analyze pressure intensity and the center of pressure(COP) trajectory according to shoe type. Subjects were ten first-year female university students. The EMED-AT 25/D(Novel, Germany) was used to measure pressure intensity and COP trajectory. The COP Excursion Index(CPEI) was used for within subject test design. Independent variables were bare feet and six types of shoes. Dependent variables were center of pressure trajectory and pressure intensity. Barefeet and five toed shoes had a similar pressure intensity and COP trajectory. COP trajectory for all other shoe types showed a medial wobble at the heel. Pressure intensity for all other shoe types was related to the structure of the shoes. In conclusion, different shoe types can not only affect gait, but they can also influence foot deformities, pain, and dysfunction.

Powder Forging of Rapidly Solidified hi-Si Alloy with Back Pressure

  • Kohno, T.;Kawase, K.;Otsuki, M.;Morimoto, K.
    • Journal of Korean Powder Metallurgy Institute
    • /
    • v.5 no.4
    • /
    • pp.319-323
    • /
    • 1998
  • Powder forging with a back pressure was investigated for production of automobile and compressor parts made of a rapidly solidified Al-Si alloy powder. Disk-shaped green compacts made of a rapidly solidified Al-Si alloy powder were hot forged, and hubs were formed by loading back pressure on their top. The influences of the back pressure and die temperatures on forgeabiliy and properties of parts made of a rapidly solidified Al-Si alloy powder were examined. This method was also applied to the production of a scroll part. The results of these studies are summarized as follows : 1. A back pressure on the hub top is very effective for consolidation and preventing crack formation in the hub. 2. When a back pressure tess than 98 MPa is applied, the forging pressure increases by the same amount of the applied back pressure. With more than 98 MPa, the forging pressure increases further due to an increased friction at the hub side. 3. Die temperatures higher than approximately 670k are needed in order to consolidate well the hub top without cracks.

  • PDF

The Optimization of the Number and Positions of Foot Pressure Sensors to Develop Smart Shoes

  • Yoo, Sihyun;Gil, Hojong;Kim, Jongbin;Ryu, Jiseon;Yoon, Sukhoon;Park, Sang Kyoon
    • Journal of the Ergonomics Society of Korea
    • /
    • v.36 no.5
    • /
    • pp.395-409
    • /
    • 2017
  • Objective: The purpose of this study was to optimize the number and positions of foot pressure sensors using the reliability analysis of the center of pressure (COP) in smart shoes. Background: Foot pressure can be different according to foot region, and it is important which region of the foot pressure needs to be measured. Method: Thirty adults (age: $20.5{\pm}1.8years$, body weight: $71.4{\pm}6.5kg$, height: $1.76{\pm}0.04m$) participated in this study. The foot pressure data were collected using the insole of Pedar-X system (Novel GmbH, USA) with a sampling frequency of 100Hz during 1.3m/s speed walking on the treadmill (Instrumented treadmill, Bertec, USA). The intraclass correlation coefficients (ICC) were calculated between the COP positions using 4, 5, 6, 7, 8, and 99 sensors, while one-way repeated measure ANOVA was performed between the standard deviation (SD) of the COP positions. Results: The medio-lateral (M/L) COP position using 99 sensors was positively correlated with the M/L COP positions using 6, 7, and 8 sensors; however, it was not correlated with the M/L COP positions using 4 and 5 sensors during landing phase (1~4%) (p<.05). The antero-posterior (A/P) COP position using 99 sensors was positively correlated with the A/P COP positions using 4, 5, 6, 7, and 8 sensors (p<.05). The SD of the COP position using 99 sensors was smaller than the SD of the M/L COP positions using 4, 5, 6, 7, and 8 sensors (p<.05). Conclusion: Based on our findings, it is desirable to arrange at least 6 sensors in smart shoes. Application: The study of optimizing the number and positions of foot pressure sensors would contribute to developing more effective smart shoes using foot pressure technology.

Development of a Measurement System of the Transferred Pressure from Intermittent Pneumatic Compression Device (간헐적공기압박장치의 전달압력 측정시스템 개발)

  • Lee, Wonhee;Seo, Jong Hyun;Kim, Jun;Kang, Seung Ho;Kim, Gook Han;Chung, Seung Hyun;Kim, Kwang Gi;Kang, Hyun Guy
    • Journal of Biomedical Engineering Research
    • /
    • v.37 no.1
    • /
    • pp.39-45
    • /
    • 2016
  • A pressure measurement system was developed to verify magnitude and position of transferred pressure on the body surface during the intermittent pneumatic compression (IPC) which is one of the most well-known methods for the prevention of deep vein thrombosis (DVT). Eighty force sensing resistors (FSR) were arranged on a mannequin leg and a hardware controller sensed, digitized, and transferred pressure data every second while IPC was being applied. Finally, sensed pressure data were color coded and visualized on the 3D model with lab-developed software. The pressure data were also saved to files for further analysis. Using this measurement system, the changing pattern of pressure was measured on the mannequin leg by changing both chamber pressure and cuff tightness. As a result, net pressure transferred onto the body surface is dependent on chamber pressure and cuff tightness. Under the same chamber pressure, the tighter a cuff was worn, the wider compressed area was and the shorter compression cycle was. Also transferred pressure was proportional to both chamber pressure and cuff tightness.

Study on the Relationship between Vascular Perfusion and Interface Pressure under the Ischial Tuberosity in the Sitting Posture (앉은 자세에서 좌골결절의 접촉압력과 혈류량과의 관계에 대한 연구)

  • Heo H.;Bae T.S.;Lee S.M.;Kim S.K.;Kim K.H.;Mun M.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.645-646
    • /
    • 2006
  • Pressure-induced decubitus is a serious disease among the elderly people. Interface pressure occluding vascular perfusion is known to be a cause of decubitus. Therefore, it is essential to quantify the relationship between vascular perfusion and interface pressure among the elderly people. Nine elderly normal people ($57.8{\pm}5.6\;years,\;63.3{\pm}7.0kg,\;1.68{\pm}0.05m$) were participated. Pressure was applied on the ischial tuberosity in the sitting posture from 0mmHg to 135mmHg as capillary vascular perfusion was recorded. The average interface pressure to occlude vascular perfusion under the ischial tuberosity is 120mmHg. Vascular perfusion values at the capillary occlusion is often lower than 60% of the vascular perfusion at 15mmHg. Higher sampling number is required to have more accurate results.

  • PDF

Socket Pressure Distribution of the Uni-Lateral Trans-Femoral Amputee with a Suction Socket (흡착식 소켓을 착용한 일측 대퇴절단환자의 소켓내부압력분포)

  • Chang, Y.H.;Kim, Y.H.;Yang, G.T.;Lim, S.H.;Mun, M.S.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1997 no.05
    • /
    • pp.249-252
    • /
    • 1997
  • A study on static and dynamic socket pressure distributions on a trans-femoral amputee with a suction socket was performed in order to assess an optimal socket fitting and function. Even for the amputee's static neutral position, pressure concentrations were observed in the lateral, medial, and posterior planes of the socket. During free walking, a significant movement of pressure concentration areas was observed. Large socket pressure was observed in the lateral, medial-anterior and posterior walls during mid-stance or push-off period. Socket pressure measurement will be one of the good tool to determine the optimal socket-limb interface.

  • PDF

Plantar-Pressure Distributions on Hallux Valgus Patients (엄지발가락외반증 환자의 발바닥압력분포)

  • Yang, G.T.;Kim, Y.H.;Park, Si-Bog;Lim, S.H.;Chang, Y.H.;Mun, M.S.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1997 no.05
    • /
    • pp.241-244
    • /
    • 1997
  • 23 hallux valgus patients were evaluated with clinical examinations and plantar pressure distribution measurements. A masking method for detailed plantar pressure distribution analyses was suggested. With higher grade of hallux valgus, pressure, contact length & area, and impulse on metartasus were significantly increased. Localized pressure concentration is very important in foot diseases and appropriate plantar pressure distributions should be considered on any shoe design.

  • PDF

Vitamin D and Hypertension

  • Jeong, Hye Yun;Park, Kyung Mi;Lee, Mi Jung;Yang, Dong Ho;Kim, Sang Hoon;Lee, So-Young
    • Electrolytes & blood pressure
    • /
    • v.15 no.1
    • /
    • pp.1-11
    • /
    • 2017
  • Vitamin D has the pleiotropic effects in multiple organ systems, and vitamin D deficiency was suggested to be associated with high blood pressure according to previous reports. Several interventional studies have examined the effect of vitamin D supplementation on high blood pressure patients, but the results have been inconsistent. In this article, we examined the literature that have proposed a mechanism involving vitamin D in the regulation of blood pressure and review previous observational and interventional studies that have shown the relationship between vitamin D and hypertension among various populations.

A Novel Air-cell Mattress Based on Approximate Anthropometric Model for Preventing Pressure Ulcer

  • Moon, In-Hyuk;Kang, Sung-Jae;Kim, Gyu-Seok;Mun, Mu-Seong
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.1278-1282
    • /
    • 2005
  • Air mattress is now used widely to prevent the pressure ulcer by reducing the localized pressure peaks. In this paper an air-cell mattress and its pressure control method based on an approximate anthropometric model are presented. The air-cell mattress has eighteen cylindrical air cells made of porous material allowing air leakage to contribute in reducing the development of pressure ulcer by lowering the pressure peak, temperature and humidity. To determine an optimal air-cell pressure appropriate for each user, we divide the parts of the body into four sections such as head, trunk, hip, and leg. Then, the pressure of each section is independently calculated from the weight of each part based on the individual body height and weight and the approximate anthropometric model. Air supply system for the air-cell mattress is implemented by using four electronic solenoid valves and an air compressor, and it is driven by a real-time micro-controller. The experimental results with seven subjects shows that the proposed air-cell mattress is effective for the prevention of the pressure ulcer.

  • PDF

Pressure Pain Threshold Measurement Using a Pressure Algometer in Myofascial Pain Syndromes (근근막 통증 증후군에서 Pressure Algometer를 이용한 골격근 압통 역치에 관한 연구)

  • Kwon, Young-Eun;Lee, Su-Jong;Yoon, Chae-Sik;Lee, Jun-Hak
    • The Korean Journal of Pain
    • /
    • v.14 no.1
    • /
    • pp.32-36
    • /
    • 2001
  • Background: There is no reliable objective test for the diagnosis of myofascial pain syndromes. The aim of this study was to evaluate the usefulness of a pressure algometer for the diagnosis of the trigger points and for the evaluation of the treatment in myofascial pain syndromes (MPS). Methods: Twenty female patients with clinical MPS of shoulder were included in this study. Pressure pain thresholds were measured by a pressure algometer at three different sites including the trapezius, supraspinatus and infraspinatus before, and then the 1st, 3rd and 7th days after TPI. Results: Mean pressure pain thresholds were lower in patients with MPS in than normal volunteers in all the examined skeletal muscles. Mean pressure pain thresholds in patients with MPS were increased significantly after TPI in all the examined skeletal muscles. Conclusions: Pressure algometer can be used as relatively objective diagnostic tool for locating trigger points and to quantify the effect of TPI in MPS. However, more investigation is necessary.

  • PDF