scholarly journals A mathematical method for quantifying in vivo mechanical behaviour of heel pad under dynamic load

2015 ◽  
Vol 54 (2-3) ◽  
pp. 341-350 ◽  
Author(s):  
Roozbeh Naemi ◽  
Panagiotis E. Chatzistergos ◽  
Nachiappan Chockalingam
Keyword(s):  
Mathematical Method ◽  
Mechanical Behaviour ◽  
Dynamic Load ◽  
Heel Pad ◽  
Quantifying In

Quantifying in vivo dopaminergic D2-receptors Bmax and KdVr with microPET® focus after a single injection of [11C]raclopride

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S649-S649
Author(s):  
Laurent Besret ◽  
Jean-Dominique Gallezot ◽  
Frédéric Dollé ◽  
Philippe Hantraye ◽  
Marie-Claude Grégoire
Keyword(s):  
Single Injection ◽  
D2 Receptors ◽  
Quantifying In

Investigation on the load-displacement curves of a human healthy heel pad: In vivo compression data compared to numerical results

2012 ◽  
Vol 34 (9) ◽  
pp. 1253-1259 ◽  
Author(s):  
C.G. Fontanella ◽  
S. Matteoli ◽  
E.L. Carniel ◽  
J.E. Wilhjelm ◽  
A. Virga ◽  
...  
Keyword(s):  
Numerical Results ◽  
Heel Pad ◽  
Compression Data ◽  
Load Displacement

scholarly journals Baseline Stiffness Modulates the Non-Linear Response to Stretch of the Extracellular Matrix in Pulmonary Fibrosis

2021 ◽  
Vol 22 (23) ◽  
pp. 12928
Author(s):  
Constança Júnior ◽  
Maria Narciso ◽  
Esther Marhuenda ◽  
Isaac Almendros ◽  
Ramon Farré ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pulmonary Fibrosis ◽  
Strain Hardening ◽  
Mechanical Behaviour ◽  
Cyclic Stretch ◽  
In Vivo Model ◽  
Micromechanical Properties ◽  
Order Of Magnitude ◽  
Mechanical Homeostasis

Pulmonary fibrosis (PF) is a progressive disease that disrupts the mechanical homeostasis of the lung extracellular matrix (ECM). These effects are particularly relevant in the lung context, given the dynamic nature of cyclic stretch that the ECM is continuously subjected to during breathing. This work uses an in vivo model of pulmonary fibrosis to characterize the macro- and micromechanical properties of lung ECM subjected to stretch. To that aim, we have compared the micromechanical properties of fibrotic ECM in baseline and under stretch conditions, using a novel combination of Atomic Force Microscopy (AFM) and a stretchable membrane-based chip. At the macroscale, fibrotic ECM displayed strain-hardening, with a stiffness one order of magnitude higher than its healthy counterpart. Conversely, at the microscale, we found a switch in the stretch-induced mechanical behaviour of the lung ECM from strain-hardening at physiological ECM stiffnesses to strain-softening at fibrotic ECM stiffnesses. Similarly, we observed solidification of healthy ECM versus fluidization of fibrotic ECM in response to stretch. Our results suggest that the mechanical behaviour of fibrotic ECM under stretch involves a potential built-in mechanotransduction mechanism that may slow down the progression of PF by steering resident fibroblasts away from a pro-fibrotic profile.

Shock Absorbency of Factors in the Shoe/Heel Interaction—With Special Focus on Role of the Heel Pad

Foot & Ankle ◽  
1989 ◽  
Vol 9 (6) ◽  
pp. 294-299 ◽  
Author(s):  
Uffe Jørgensen ◽  
Finn Bojsen-Møller
Keyword(s):  
Force Plate ◽  
Heel Strike ◽  
Overuse Injuries ◽  
Special Focus ◽  
Shock Absorption ◽  
Ethyl Vinyl ◽  
Shock Absorbers ◽  
Heel Pad ◽  
Eva Foam

The heel pad acts as a shock absorber in walking and in heel-strike running. In some patients, a reduction of its shock-absorbing capacity has been connected to the development of overuse injuries. In this article, the shock absorption of the heel pad as well as external shock absorbers are studied. Individual variation and the effect of trauma and confinement on the heel pad were specifically investigated. Drop tests, imitating heel impacts, were performed on a force plate. The test specimens were cadaver heel pads (n = 10); the shoe sole component consisted of ethyl vinyl acetate (EVA) foam and Sorbothane inserts. The shock absorption was significantly greater in the heel pad than in the external shock absorbers. The mean heel pad shock absorption was 1.1 times for EVA foam and 2.1 times for Sorbothane. The shock absorption varied by as much as 100% between heel pads. Trauma caused a decrease in the heel pad shock absorbency (24%), whereas heel pad confinement increased the shock absorbency (49% in traumatized heel pads and 29.5% in nontraumatized heel pads). These findings provide a biomechanical rationale for the clinical observations of a correlation between heel pad shock absorbency loss and heel strike-dependent overuse injuries. To increase shock absorbency, confinement of the heel pad should be attempted in vivo.

An Elaborate Data Set for Mechanical Characterization of the Foot

2008 ◽  
Author(s):  
Pavana Sirimamilla ◽  
Ahmet Erdemir ◽  
Antonie J. van den Bogert ◽  
Jason P. Halloran
Keyword(s):  
Mechanical Response ◽  
Experimental Testing ◽  
Experimental Tests ◽  
Shear Loading ◽  
Data Set ◽  
Material Response ◽  
Heel Pad ◽  
Biaxial Tests

Experimental testing of cadaver specimens is a useful means to quantify structural and material response of tissue and passive joint properties against applied loading[1,4]. Very often, specific material response (i.e., stress-strain behavior of a ligament or plantar tissue) has been the goal of experimental testing and is accomplished with uniaxial and/or biaxial tests of prepared tissue specimens with uniform geometries[2,5]. Material properties can then be calculated directly and if testing data involves individual sets of multiple loading modes (e.g. compression only, shear only, volumetric) an accurate representation of the global response of the specimen may be possible. In foot biomechanics, however, it is practically impossible to perform isolated mechanical testing in this manner. The structural response, therefore the stiffness characteristics, of the foot have been quantified, usually using a dominant loading mode: e.g., whole foot compression [6], heel pad indentation [3]. This approach ignores the complexity of most in vivo loading conditions, in which whole foot deformation involves interactions between compression, shear (e.g. heel pad) and tension (e.g. ligaments). Therefore, the purpose of this study was to quantify the mechanical response of a cadaver foot specimen subjected to compression and anterior-posterior (AP) shear loading of isolated heel and forefoot regions as well as whole foot compression. Results from the experimental tests represent a novel methodology to quantify a complete structural biomechanical response. Combined with medical imaging, followed by inverse finite element (FE) analysis, the data may also serve for material characterization of foot tissue.

In vivo biomechanical behavior of the human heel pad during the stance phase of gait

2001 ◽  
Vol 34 (12) ◽  
pp. 1661-1665 ◽  
Author(s):  
Amit Gefen ◽  
Michal Megido-Ravid ◽  
Yacov Itzchak
Keyword(s):  
Stance Phase ◽  
Biomechanical Behavior ◽  
Heel Pad

Estrogen Alters The Mechanical Behaviour Of The Human Achilles Tendon in vivo

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S81
Author(s):  
Adam L. Bryant ◽  
Ross A. Clark ◽  
Simon Bartold ◽  
Aron Murphy ◽  
Erik Hohmann ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Mechanical Behaviour

scholarly journals Quantifying in vivo MR spectra with circles

2006 ◽  
Vol 179 (1) ◽  
pp. 152-163 ◽  
Author(s):  
Refaat E. Gabr ◽  
Ronald Ouwerkerk ◽  
Paul A. Bottomley
Keyword(s):  
Quantifying In

In Vivo Examination of the Dynamic Properties of the Human Heel Pad

1993 ◽  
Vol 14 (06) ◽  
pp. 312-319 ◽  
Author(s):  
H. Kinoshita ◽  
T. Ogawa ◽  
K. Kuzuhara ◽  
K. Ikuta
Keyword(s):  
Dynamic Properties ◽  
Heel Pad
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