Nonlinear Elastic Behavior of Achilles Tendon at the Fascicle Scale

2007 ◽  
Author(s):  
Oluseeni A. Komolafe ◽  
Todd C. Doehring
Keyword(s):  
Achilles Tendon ◽  
Computational Models ◽  
Insertion Site ◽  
Biomechanical Properties ◽  
Collagen Fibers ◽  
Fiber Bundles ◽  
Elastic Behavior ◽  
Functional Behavior ◽  
Functional Tissue ◽  
Nonlinear Elastic

Parallel collagen fibers such as ligaments and tendons are composed of fiber bundles, or fascicles, enclosed in a sheath of reticular membrane. In the Achilles tendon, these fascicles can be long, extending from the gastro-soleus unit to the calcaneal insertion site (Fig. 1). Although the overall functional behavior of the whole tendon is well established[1], there is little information detailing properties of individual fascicles or their interactions. Knowledge of the structural and biomechanical properties at the “mesostructural” scale (i.e. fascicle-scale) is critical to understanding tissue pathologies; in particular the processes involved in injury and healing, and the development of improved computational models and functional tissue engineered constructs.

scholarly journals Anisotropic and age-dependent elastic material behavior of the human costal cartilage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthias Weber ◽  
Markus Alexander Rothschild ◽  
Anja Niehoff
Keyword(s):  
Costal Cartilage ◽  
Indentation Test ◽  
Biomechanical Properties ◽  
Material Behavior ◽  
Cartilage Tissue ◽  
Elastic Behavior ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Young’S Moduli ◽  
Age Related

AbstractCompared to articular cartilage, the biomechanical properties of costal cartilage have not yet been extensively explored. The research presented addresses this problem by studying for the first time the anisotropic elastic behavior of human costal cartilage. Samples were taken from 12 male and female cadavers and unconfined compression and indentation tests were performed in mediolateral and dorsoventral direction to determine Young’s Moduli EC for compression and Ei5%, Ei10% and Eimax at 5%, 10% and maximum strain for indentation. Furthermore, the crack direction of the unconfined compression samples was determined and histological samples of the cartilage tissue were examined with the picrosirius-polarization staining method. The tests revealed mean Young’s Moduli of EC = 32.9 ± 17.9 MPa (N = 10), Ei5% = 11.1 ± 5.6 MPa (N = 12), Ei10% = 13.3 ± 6.3 MPa (N = 12) and Eimax = 14.6 ± 6.6 MPa (N = 12). We found that the Young’s Moduli in the indentation test are clearly anisotropic with significant higher results in the mediolateral direction (all P = 0.002). In addition, a dependence of the crack direction of the compressed specimens on the load orientation was observed. Those findings were supported by the orientation of the structure of the collagen fibers determined in the histological examination. Also, a significant age-related elastic behavior of human costal cartilage could be shown with the unconfined compression test (P = 0.009) and the indentation test (P = 0.004), but no sex effect could be detected. Those results are helpful in the field of autologous grafts for rhinoplastic surgery and for the refinement of material parameters in Finite Element models e.g., for accident analyses with traumatic impact on the thorax.

Biomechanical properties of different techniques used in vitro for suturing mid-substance Achilles tendon ruptures

2017 ◽  
Vol 50 ◽  
pp. 78-83 ◽  
Author(s):  
Carlos De la Fuente ◽  
Carlos Cruz-Montecinos ◽  
Helen L. Schimidt ◽  
Hugo Henríquez ◽  
Sebastián Ruidiaz ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Biomechanical Properties ◽  
Tendon Ruptures

Collagen and elastin fibers in human pulmonary alveolar walls

1988 ◽  
Vol 64 (4) ◽  
pp. 1659-1675 ◽  
Author(s):  
S. S. Sobin ◽  
Y. C. Fung ◽  
H. M. Tremer
Keyword(s):  
Transpulmonary Pressure ◽  
Collagen Fibers ◽  
Capillary Blood ◽  
Fiber Bundles ◽  
Cube Root ◽  
Inflation Pressure ◽  
Frequency Distributions ◽  
Normal Distributions ◽  
Statistical Frequency ◽  
The Mean

The morphology and morphometric data of collagen and elastin fibers in the pulmonary alveolar walls are presented. Specimens were obtained from postmortem lungs quick-frozen at specified transpulmonary pressures. Collagen was stained by silver, and elastin was stained by orcein. Photomicrographs were composed by computer. Young lungs typically show small collagen fibers that radiate from the "posts," whereas larger fiber bundles traverse the septum irrespective of capillary blood vessels. In older lungs, rings of collagen around the posts appear enlarged. Elastin bundles do not show obvious variation in pattern with age and inflation pressure. Statistical frequency distributions of the fiber width and curvature are both skewed, but the square root of the width and the cube root of the curvature have approximate normal distributions. Typically, for young lungs at transpulmonary pressure of 4 cmH2O, the mean of (width)1/2 (in micron1/2) for collagen fibers is 0.952 +/- 0.242 (SD), that of (curvature)1/3 (in micron-1/3) is 0.349 +/- 0.094. The corresponding values for elastin are 0.986 +/- 0.255 and 0.395 +/- 0.094.

scholarly journals DEFICITS OF CALF MUSCLES STRENGTH AND RATE OF FORCE DEVELOPMENT AFTER ACHILLES TENDON RUPTURE

2019 ◽  
Vol 2 (8) ◽  
pp. 118
Author(s):  
Vaida Aleknavičiūtė - Ablonskė ◽  
Agnė Savenkovienė ◽  
Albertas Skurvydas
Keyword(s):  
Achilles Tendon ◽  
Achilles Tendon Rupture ◽  
Biomechanical Properties ◽  
Calf Muscle ◽  
Plantar Flexors ◽  
Adaptive Changes ◽  
Motor Strategy ◽  
Neural Factors ◽  
Muscle Changes

<p>The Achilles tendon is the thickest and the strongest tendon in the human body. Many studies, investigating biomechanical properties of plantar flexors muscle-tendon unit after ATR surgery, reported an incomplete calf muscle contractile functional recovery. However, these studies only investigated the plantar flexors muscle function failing to provide information about the adaptive changes in motor strategy. In fact, the development of adaptive changes in motor strategies, due to both mechanical and neural factors, may result in pathological musculoskeletal conditions over the long term. Understanding physiological calf muscle changes due to long-term immobilization may help prevent Achilles tendon re-rupture cases.</p>

scholarly journals The ultrasonographic dynamic heel-rise test of the Achilles tendon

2021 ◽  
Vol 21 (86) ◽  
pp. e260-e266
Author(s):  
Beata Ciszkowska-Łysoń ◽  
◽  
Urszula Zdanowicz ◽  
Robert Śmigielski ◽  
◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Tendon Rupture ◽  
Dynamic Assessment ◽  
Healing Process ◽  
Achilles Tendon Rupture ◽  
Recovery Process ◽  
Biomechanical Properties ◽  
Resonance Imaging ◽  
Ultrasound Monitoring ◽  
And Function

The treatment of Achilles tendon rupture attempts to restore the primary anatomical structure and principal biomechanical properties of the damaged tendon. Postoperative clinical assessment of the healing progression and function monitoring may be difficult and require experience. Diagnostic imaging (ultrasonography and magnetic resonance imaging) helps monitor the healing process. In the following paper, we propose a heel-rise test – a dynamic assessment of the Achilles tendon performed under direct observation and ultrasound monitoring to establish the tension of the Achilles tendon. The test allows for a simple assessment of tendon function and may be safely repeated at any postoperative stage. It may be performed by a physician, radiologist and physiotherapist to monitor the recovery process following Achilles tendon damage.

scholarly journals A set of measures for the systematic classification of the nonlinear elastic behavior of disparate rocks

2015 ◽  
Vol 120 (3) ◽  
pp. 1587-1604 ◽  
Author(s):  
Jacques Rivière ◽  
Parisa Shokouhi ◽  
Robert A. Guyer ◽  
Paul A. Johnson
Keyword(s):  
Elastic Behavior ◽  
Systematic Classification ◽  
Nonlinear Elastic

scholarly journals Avulsion Fracture of the Calcaneal Insertion Site of the Achilles Tendon in Patient with Diabetes Mellitus: A Case Report

2010 ◽  
Vol 59 (3) ◽  
pp. 536-540
Author(s):  
Akihiro Yanagisawa ◽  
Eiichi Nakamura ◽  
Azusa Tanaka ◽  
Yasunari Oniki ◽  
Hiroaki Nishioka ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Case Report ◽  
Achilles Tendon ◽  
Avulsion Fracture ◽  
Insertion Site

A Physically-Based Anisotropic Discrete Fiber Model for Fibrous Soft Tissues

2010 ◽  
Author(s):  
C. Flynn ◽  
M. B. Rubin ◽  
P. M. F. Nielsen
Keyword(s):  
Soft Tissues ◽  
Mechanical Response ◽  
Continuous Distribution ◽  
Collagen Fibers ◽  
Fiber Bundles ◽  
Parameter Study ◽  
Rabbit Skin ◽  
Pig Skin ◽  
Proposed Model ◽  
Physically Based

Physically-based fibrous soft tissue models often consider the tissue to be a collection of fibers with a continuous distribution function to represent their orientations. This study proposes a simple model for the response of fibrous connective tissues in terms of a discrete number of fiber bundles. The proposed model consists of six weighted fiber bundles orientated such that they pass through opposing vertices of an icosahedron. A novel aspect of the proposed model is the use of a simple analytical function to represent the undulation distribution of the collagen fibers. The mechanical response of the elastin fiber is represented by a neo-Hookean hyperelastic equation. A parameter study was performed to analyze the effect of each parameter on the overall response of the model. The proposed model accurately simulated the uniaxial stretching of pig skin with an 8% error-of-fit for stretch ratios up to 1.8. The model also accurately simulated the biaxial stretching of rabbit skin with a 10% error-of-fit for stretch ratios up to 1.9. The stiffness of the collagen fibers determined by the model was about 100 MPa for the rabbit skin and 900 MPa for the pig skin, which are comparable with values reported in the literature. The stiffness of the elastin fibers in the model was about 2 kPa.

scholarly journals Random Fiber Networks With Superior Properties Through Network Topology Control

2019 ◽  
Vol 86 (8) ◽  
Author(s):  
S. Deogekar ◽  
Z. Yan ◽  
R. C. Picu
Keyword(s):  
Network Architecture ◽  
Elastic Behavior ◽  
Fiber Networks ◽  
Linear Elastic ◽  
New Class ◽  
Link Density ◽  
Cross Link Density ◽  
Random Fiber Networks ◽  
Nonlinear Elastic ◽  
Poisson Contraction

In this work, we study the effect of network architecture on the nonlinear elastic behavior and strength of athermal random fiber networks of cellular type. We introduce a topology modification of Poisson–Voronoi (PV) networks with convex cells, leading to networks with stochastic nonconvex cells. Geometric measures are developed to characterize this new class of nonconvex Voronoi (NCV) networks. These are softer than the reference PV networks at the same nominal network parameters such as density, cross-link density, fiber diameter, and connectivity number. Their response is linear elastic over a broad range of strains, unlike PV networks that exhibit a gradual increase of the tangent stiffness starting from small strains. NCV networks exhibit much smaller Poisson contraction than any network of same nominal parameters. Interestingly, the strength of NCV networks increases continuously with an increasing degree of nonconvexity of the cells. These exceptional properties render this class of networks of interest in a variety of applications, such as tissue scaffolds, nonwovens, and protective clothing.

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