Study on the Pressure Distribution Measuring System of Knee Joint

2002 ◽  
Vol 2002 (0) ◽  
pp. 167-168
Author(s):  
Keita SATO ◽  
J. H. Mun ◽  
Tadaatsu SATOMI
Keyword(s):  
Knee Joint ◽  
Pressure Distribution ◽  
Measuring System

Study on Photoelastic Method for Measuring Elastohydrodynamic Lubrication Pressure in Line Contact

2013 ◽  
Vol 281 ◽  
pp. 329-334
Author(s):  
Jun He ◽  
Huang Ping ◽  
Qian Qian Yang
Keyword(s):  
Film Thickness ◽  
Pressure Distribution ◽  
Reynolds Equation ◽  
Friction Pair ◽  
Elastohydrodynamic Lubrication ◽  
Ccd Camera ◽  
Measuring System ◽  
Line Contact ◽  
Basic Equations ◽  
Plastic Disk

In the present paper, a new method for measuring elastohydrodynamic lubrication (EHL) pressure in line contact is proposed, which is based on the photoelastic technique. The pressure distribution of EHL film and the inner stresses in the friction pairs are fundamental issues to carry out EHL research. The film thickness, pressure and temperature have been successfully obtained with solving the basic equations such as Reynolds equation and energy equation simultaneously or separately, with numerical model of EHL problem. The film thickness can be also measured with the optical interference technique. However, the pressure measurement is still a problem which has not been well solved yet, so as the inner stresses inside the friction pairs. With the experimental mechanics, the photoelastic technique is a possible method to be used for measuring the pressure distribution of EHL film and inner friction pair in the line contact. Therefore, A flat plastic disk and a steel roller compose the frictional pairs of the photoelastic pressure measuring rig with combining the monochromatic LED light source, polarizer CCD camera and stereomicroscope to form the whole pressure measuring system of the line contact EHL. The experimental results with the rig display the typical features of EHL pressure. This shows that the method is feasible to be used for measuring the pressure of EHL film and the inner stresses of the friction pairs in the line contact.

Lower Extremity Jogging Mechanics in Young Female with Mild Hallux valgus

2015 ◽  
Vol 22 ◽  
pp. 37-47
Author(s):  
Dong Sun ◽  
Feng Ling Li ◽  
Yan Zhang ◽  
Chang Feng Li ◽  
Wen Lan Lian ◽  
...  
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Pressure Distribution ◽  
Hallux Valgus ◽  
Plantar Pressure ◽  
Joint Angle ◽  
External Rotation ◽  
Normal Group ◽  
Knee Joint Angle ◽  
Plantar Pressure Distribution

The purpose of this current study was to measure the knee joint angle and plantar pressure distribution between hallux valgus group and normal group under jogging condition. To reveal relationship of plantar pressure distribution and knee joint angle. Investigated that lower extremity mechanics of jogging in young female with mild hallux valgus. Sixteen young, healthy females volunteered to take part in this study. Kinematic data from a three-dimensional motion analysis system and plantar pressure distribution from Pedar-X system were collected to describe lower extremity mechanics while hallux valgus subjects jogging at a natural speed. The results found that knee joint angle of hallux valgus in frontal and transverse plane was obviously different under jogging condition. In frontal plane, the initial state of adduction angle (control group (CO) = 1.73 °, hallux valgus group (HV) = 8.33 °) of two group was markedly different at the beginning of the support (0-10%). During jogging gait cycle, knee abduction angle peak of normal group was 8.46°, and knee adduction angle peak of hallux valgus group was 8.61°. In the transverse plane, knee external rotation angle in the initial state of normal group was 21.93° while knee external rotation angle of hallux valgus was 4.89°. The results of plantar pressure found that bearing pressure regions was offshore in hallux valgus group. These changes would affect the movement of knee joint, and it suggested that hallux valgus group have higher risk for knee osteoarthritis. These results also suggested that hallux valgus deformity has influence on knee joint. We cannot be ignored in the process of the research and therapeutic with hallux valgus.

PVDF Sensors – Research on Foot Pressure Distribution in Dynamic Conditions

2012 ◽  
Vol 79 ◽  
pp. 94-99 ◽  
Author(s):  
Ewa Klimiec ◽  
Wiesław Zaraska ◽  
Jacek Piekarski ◽  
Barbara Jasiewicz
Keyword(s):  
Pressure Distribution ◽  
Input Resistance ◽  
Open Circuit ◽  
Measuring Circuit ◽  
Measuring System ◽  
Pvdf Film ◽  
Foot Pressure ◽  
Pass Filter ◽  
Polymer Sensors ◽  
A Charge

The paper presents a dynamic measurement method of the distribution of foot pressure exerted on the ground by a four-point shoe insole, developed by authors, which can be placed in any sport footwear. The value of pressure was measured on the heel, medial midfoot, metatarsal, and great toe by recording values of a generated voltage by sensors which were made of piezoelectric polymer PVDF film 110 µm thick with printed silver electrodes. As confirmed by scanning microscope studies, the foil applied in the sensors is semi-crystalline. The shoe measurement insert consists of two polyester films without piezoelectric properties between them, electroactive polymer sensors were placed. The films were glued together. To match the measuring circuit to the sensors used, two circuits were tested, a voltage measuring circuit with an input resistance of above 1012 Ω (open circuit), and a charge measuring circuit (shorted circuit). The charge measuring circuits with the RC high-pass filter, which attenuates the slow-changing pyroelectric signal was selected as it ensures the desired measurement accuracy. As presented in the paper, as PVDF sensors are very sensitive to any mechanical deformation, it is important to properly design the shoe insole to ensure its correct use during pressure distribution measurements. The measuring system developed by the authors, allows testing of foot pathology for any length of time in a dynamic way.

scholarly journals Evaluation of Denture Functions in Complete Denture Wearers by Using Electromyography and Pressure Distribution Measuring System.

1991 ◽  
Vol 35 (4) ◽  
pp. 804-816
Author(s):  
Toshio Hosoi ◽  
Yoshikazu Ishikawa ◽  
Tsutomu Okajima ◽  
Takashi Sagae ◽  
Ryuichi Masuo ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Complete Denture ◽  
Measuring System

scholarly journals An exploration of changes in plantar pressure distributions during walking with standalone and supported lateral wedge insole designs

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Calvin T. F. Tse ◽  
Michael B. Ryan ◽  
Jason Dien ◽  
Alex Scott ◽  
Michael A. Hunt
Keyword(s):  
Knee Joint ◽  
Knee Osteoarthritis ◽  
Pressure Distribution ◽  
Contact Area ◽  
Plantar Pressure ◽  
Load Distribution ◽  
Plantar Pressure Distribution ◽  
Arch Support ◽  
Knee Joint Load ◽  
Joint Load

Abstract Background Lateral wedge insoles (LWI), standalone or with medial arch support (supported-LWI), have been thoroughly investigated for their effects on modifying gait biomechanics for people with knee osteoarthritis. However, plantar pressure distribution between these insole types has not been investigated and could provide insight towards insole prescription with concomitant foot symptoms taken into consideration. Methods In a sample of healthy individuals (n = 40), in-shoe plantar pressure was measured during walking with LWI, with or without medial arch support (variable- and uniform-stiffness designs), and a flat control insole condition. Pressure data from the plantar surface of the foot were divided into seven regions: medial/lateral rearfoot, midfoot, medial/central/lateral forefoot, hallux. Plantar pressure outcomes assessed were the medial-lateral pressure index (MLPI) for the whole foot, and the peak pressure, pressure-time integral (PTI), and contact area in each plantar region. Comfort in each insole condition was rated as a change relative to the flat control insole condition. Repeated-measures analyses of variance were calculated to compare the plantar pressure outcomes between insole conditions. Results Regionally, medial rearfoot and forefoot pressure were reduced by all wedged insoles, with the variable-stiffness supported-wedge showing greater reductions than the standalone wedge. Lateral rearfoot and forefoot pressure were reduced by both supported-LWI, but unchanged by the standalone wedge. In the midfoot, the standalone wedge maintained pressure but reduced regional contact area, while both supported-LWI increased midfoot pressure and contact area. All LWI increased the MLPI, indicating a lateral shift in plantar pressure distribution throughout the weightbearing phase of gait. Comfort ratings were not significantly different between insole conditions. Conclusions Regional differences in plantar pressure may help determine an appropriate lateral wedge insole variation to avoid exacerbation of concomitant foot symptoms by minimizing pressure in symptomatic regions. Lateral shifts in plantar pressure distribution were observed in all laterally wedged conditions, including one supported-LWI that was previously shown to be biomechanically ineffective for modifying knee joint load distribution. Thus, shifts in foot centre of pressure may not be a primary mechanism by which LWI can modify knee joint load distribution for people with knee osteoarthritis.

Pressure distribution at the knee joint

1993 ◽  
Vol 113 (1) ◽  
pp. 12-19 ◽  
Author(s):  
J. Bruns ◽  
M. Volkmer ◽  
S. Luessenhop
Keyword(s):  
Knee Joint ◽  
Pressure Distribution

Development of in vivo measuring system of the pressure distribution under the denture base of removable partial denture

2009 ◽  
Vol 53 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Kei Kubo ◽  
Tetsuo Kawata ◽  
Hanako Suenaga ◽  
Nobuhiro Yoda ◽  
Ryuji Shigemitsu ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Measuring System ◽  
Removable Partial Denture ◽  
Denture Base ◽  
Partial Denture
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