SAM
https://sam.ensam.eu:443
The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Sat, 28 Mar 2020 18:16:28 GMT2020-03-28T18:16:28ZShear waves elastography for assessment of human Achilles tendon's biomechanical properties: an experimental study
http://hdl.handle.net/10985/17801
Shear waves elastography for assessment of human Achilles tendon's biomechanical properties: an experimental study
HAEN, Thomas-Xavier; ROUX, Anthony; SOUBEYRAND, M.; LAPORTE, Sébastien
Introduction: Achilles tendon is the most frequently ruptured tendon, but its optimal treatment is increasingly controversial. The mechanical properties of the healing tendon should be studied further. Shear waves elastography (SWE) measures the shear modulus, which is proven to be correlated to elastic modulus in animal tendons. The aim of our study was to study whether the shear moduli of human cadaveric Achilles tendon, given by SWE, were correlated with the apparent elastic moduli of those tendons given by tensile tests. Materials and methods: Fourteen cadaveric lower-limbs were studied. An elastographic study of the Achilles tendon (AT) was first done in clinical-like conditions. SWE was performed at three successive levels (0, 3 and 6 cm from tendon insertion) with elastographic probe oriented parallel to tendon fibers, blindly, for three standardized ankle positions (25° plantar flexion, neutral position, and maximal dorsal flexion). The mean shear moduli were collected through blind offline data-analysis. Then, AT with triceps were harvested. They were subjected to tensile tests. A continuous SWE of the Achilles tendon was performed simultaneously. The apparent elastic modulus was obtained from the experimental stress-strain curve, and correlation with shear modulus (given by SWE) was studied. Results: Average shear moduli of harvested AT, given by SWE made an instant before the tensile tests, were significantly correlated with shear moduli of the same AT made at the same level, previously in clinical-like condition (p < 0.05), only in neutral position. There was a statistical correlation (p < 0.005) and a correlation coefficient R² equal to 0.95 ± 0.05, between shear moduli (SWE) and apparent elastic moduli (tensile tests), for 11 tendons (3 tendons were inoperable due to technical error), before a constant disruption in the correlation curves. Discussion: We demonstrated a significant correlation between SWE of Achilles tendon performed in clinicallike conditions (in neutral position) and SWE performed in harvested tendon. We also found a correlation between SWE performed on harvested tendon and apparent elastic moduli obtained with tensile tests (for 11 specimens). As a consequence, we can suppose that SWE of AT in clinical-like conditions is related to tensile tests. To our knowledge, the ability of SWE to reliably assess biomechanical properties of a tendon or muscle was, so far, only demonstrated in animal models. Conclusion: SWE can provide biomechanical information of the human AT non-invasively.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/178012017-01-01T00:00:00ZHAEN, Thomas-XavierROUX, AnthonySOUBEYRAND, M.LAPORTE, SébastienIntroduction: Achilles tendon is the most frequently ruptured tendon, but its optimal treatment is increasingly controversial. The mechanical properties of the healing tendon should be studied further. Shear waves elastography (SWE) measures the shear modulus, which is proven to be correlated to elastic modulus in animal tendons. The aim of our study was to study whether the shear moduli of human cadaveric Achilles tendon, given by SWE, were correlated with the apparent elastic moduli of those tendons given by tensile tests. Materials and methods: Fourteen cadaveric lower-limbs were studied. An elastographic study of the Achilles tendon (AT) was first done in clinical-like conditions. SWE was performed at three successive levels (0, 3 and 6 cm from tendon insertion) with elastographic probe oriented parallel to tendon fibers, blindly, for three standardized ankle positions (25° plantar flexion, neutral position, and maximal dorsal flexion). The mean shear moduli were collected through blind offline data-analysis. Then, AT with triceps were harvested. They were subjected to tensile tests. A continuous SWE of the Achilles tendon was performed simultaneously. The apparent elastic modulus was obtained from the experimental stress-strain curve, and correlation with shear modulus (given by SWE) was studied. Results: Average shear moduli of harvested AT, given by SWE made an instant before the tensile tests, were significantly correlated with shear moduli of the same AT made at the same level, previously in clinical-like condition (p < 0.05), only in neutral position. There was a statistical correlation (p < 0.005) and a correlation coefficient R² equal to 0.95 ± 0.05, between shear moduli (SWE) and apparent elastic moduli (tensile tests), for 11 tendons (3 tendons were inoperable due to technical error), before a constant disruption in the correlation curves. Discussion: We demonstrated a significant correlation between SWE of Achilles tendon performed in clinicallike conditions (in neutral position) and SWE performed in harvested tendon. We also found a correlation between SWE performed on harvested tendon and apparent elastic moduli obtained with tensile tests (for 11 specimens). As a consequence, we can suppose that SWE of AT in clinical-like conditions is related to tensile tests. To our knowledge, the ability of SWE to reliably assess biomechanical properties of a tendon or muscle was, so far, only demonstrated in animal models. Conclusion: SWE can provide biomechanical information of the human AT non-invasively.Tensile response of the muscle-tendon complex using discrete element model
http://hdl.handle.net/10985/8765
Tensile response of the muscle-tendon complex using discrete element model
ROUX, Anthony; LECOMPTE, Jennyfer; GRAS, Laure-Lise; LAPORTE, Sébastien; IORDANOFF, Ivan
Tear of the muscle-tendon complex (MTC) is one of the main causes of sport injuries (De Labareyre et al. 2005). However, the mechanisms leading to such injury are still unclear (Uchiyama et al. 2011). Before modeling the tear of the MTC, its behavior in tensile test will be first studied. The MTC is a multi-scale, non isotropic and non continuous structure that is composed of numerous fascicles gathered together in a conjunctive sheath (epimysium). Many MTC models use the Finite Element Method (FEM) (Bosboom et al. 2001) to simulate MTC’s behavior as a hyperviscoelastic material. The Discrete Element Method (DEM) used for modeling composite materials (Iliescu et al. 2010) could be adapted to fibrous materials as the MTC. Compared to FEM, the DEM could allow to capture the complex behavior of a material with a simple discretization scheme in terms of concept and implementation as well as to understand the influence of fibers’ orientation on the MTC behavior. The aim of this study was to obtain the force/displacement relationship during a numerical tensile test of a pennate muscle model with DEM.
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10985/87652014-01-01T00:00:00ZROUX, AnthonyLECOMPTE, JennyferGRAS, Laure-LiseLAPORTE, SébastienIORDANOFF, IvanTear of the muscle-tendon complex (MTC) is one of the main causes of sport injuries (De Labareyre et al. 2005). However, the mechanisms leading to such injury are still unclear (Uchiyama et al. 2011). Before modeling the tear of the MTC, its behavior in tensile test will be first studied. The MTC is a multi-scale, non isotropic and non continuous structure that is composed of numerous fascicles gathered together in a conjunctive sheath (epimysium). Many MTC models use the Finite Element Method (FEM) (Bosboom et al. 2001) to simulate MTC’s behavior as a hyperviscoelastic material. The Discrete Element Method (DEM) used for modeling composite materials (Iliescu et al. 2010) could be adapted to fibrous materials as the MTC. Compared to FEM, the DEM could allow to capture the complex behavior of a material with a simple discretization scheme in terms of concept and implementation as well as to understand the influence of fibers’ orientation on the MTC behavior. The aim of this study was to obtain the force/displacement relationship during a numerical tensile test of a pennate muscle model with DEM.Influence of muscle-tendon complex geometrical parameters on modeling passive stretch behavior with the Discrete Element Method
http://hdl.handle.net/10985/17846
Influence of muscle-tendon complex geometrical parameters on modeling passive stretch behavior with the Discrete Element Method
ROUX, Anthony; LAPORTE, Sébastien; LECOMPTE, Jennyfer; GRAS, Laure-Lise; IORDANOFF, Ivan
The muscle-tendon complex (MTC) is a multi-scale, anisotropic, non-homogeneous structure. It is composed of fascicles, gathered together in a conjunctive aponeurosis. Fibers are oriented into the MTC with a pennation angle. Many MTC models use the Finite Element Method (FEM) to simulate the behavior of the MTC as a hyper-viscoelastic material. The Discrete Element Method (DEM) could be adapted to model fibrous materials, such as the MTC. DEM could capture the complex behavior of a material with a simple discretization scheme and help in understanding the influence of the orientation of fibers on the MTC's behavior. The aims of this study were to model the MTC in DEM at the macroscopic scale and to obtain the force/displacement curve during a non-destructive passive tensile test. Another aim was to highlight the influence of the geometrical parameters of the MTC on the global mechanical behavior. A geometrical construction of the MTC was done using discrete element linked by springs. Young's modulus values of the MTC's components were retrieved from the literature to model the microscopic stiffness of each spring. Alignment and re-orientation of all of the muscle's fibers with the tensile axis were observed numerically. The hyper-elastic behavior of the MTC was pointed out. The structure's effects, added to the geometrical parameters, highlight the MTC's mechanical behavior. It is also highlighted by the heterogeneity of the strain of the MTC's components. DEM seems to be a promising method to model the hyper-elastic macroscopic behavior of the MTC with simple elastic microscopic elements.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/178462016-01-01T00:00:00ZROUX, AnthonyLAPORTE, SébastienLECOMPTE, JennyferGRAS, Laure-LiseIORDANOFF, IvanThe muscle-tendon complex (MTC) is a multi-scale, anisotropic, non-homogeneous structure. It is composed of fascicles, gathered together in a conjunctive aponeurosis. Fibers are oriented into the MTC with a pennation angle. Many MTC models use the Finite Element Method (FEM) to simulate the behavior of the MTC as a hyper-viscoelastic material. The Discrete Element Method (DEM) could be adapted to model fibrous materials, such as the MTC. DEM could capture the complex behavior of a material with a simple discretization scheme and help in understanding the influence of the orientation of fibers on the MTC's behavior. The aims of this study were to model the MTC in DEM at the macroscopic scale and to obtain the force/displacement curve during a non-destructive passive tensile test. Another aim was to highlight the influence of the geometrical parameters of the MTC on the global mechanical behavior. A geometrical construction of the MTC was done using discrete element linked by springs. Young's modulus values of the MTC's components were retrieved from the literature to model the microscopic stiffness of each spring. Alignment and re-orientation of all of the muscle's fibers with the tensile axis were observed numerically. The hyper-elastic behavior of the MTC was pointed out. The structure's effects, added to the geometrical parameters, highlight the MTC's mechanical behavior. It is also highlighted by the heterogeneity of the strain of the MTC's components. DEM seems to be a promising method to model the hyper-elastic macroscopic behavior of the MTC with simple elastic microscopic elements.Influence of muscle-tendon complex geometrical parameters on modeling passive stretch behavior with the Discrete Element Method.
http://hdl.handle.net/10985/18009
Influence of muscle-tendon complex geometrical parameters on modeling passive stretch behavior with the Discrete Element Method.
ROUX, Anthony; LAPORTE, Sébastien; LECOMPTE, Jennyfer; GRAS, Laure-Lise; IORDANOFF, Ivan
The muscle-tendon complex (MTC) is a multi-scale, anisotropic, non-homogeneous structure. It is composed of fascicles, gathered together in a conjunctive aponeurosis. Fibers are oriented into the MTC with a pennation angle. Many MTC models use the Finite Element Method (FEM) to simulate the behavior of the MTC as a hyper-viscoelastic material. The Discrete Element Method (DEM) could be adapted to model fibrous materials, such as the MTC. DEM could capture the complex behavior of a material with a simple discretization scheme and help in understanding the influence of the orientation of fibers on the MTC׳s behavior. The aims of this study were to model the MTC in DEM at the macroscopic scale and to obtain the force/displacement curve during a non-destructive passive tensile test. Another aim was to highlight the influence of the geometrical parameters of the MTC on the global mechanical behavior. A geometrical construction of the MTC was done using discrete element linked by springs. Young׳s modulus values of the MTC׳s components were retrieved from the literature to model the microscopic stiffness of each spring. Alignment and re-orientation of all of the muscle׳s fibers with the tensile axis were observed numerically. The hyper-elastic behavior of the MTC was pointed out. The structure׳s effects, added to the geometrical parameters, highlight the MTC׳s mechanical behavior. It is also highlighted by the heterogeneity of the strain of the MTC׳s components. DEM seems to be a promising method to model the hyper-elastic macroscopic behavior of the MTC with simple elastic microscopic elements.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/180092016-01-01T00:00:00ZROUX, AnthonyLAPORTE, SébastienLECOMPTE, JennyferGRAS, Laure-LiseIORDANOFF, IvanThe muscle-tendon complex (MTC) is a multi-scale, anisotropic, non-homogeneous structure. It is composed of fascicles, gathered together in a conjunctive aponeurosis. Fibers are oriented into the MTC with a pennation angle. Many MTC models use the Finite Element Method (FEM) to simulate the behavior of the MTC as a hyper-viscoelastic material. The Discrete Element Method (DEM) could be adapted to model fibrous materials, such as the MTC. DEM could capture the complex behavior of a material with a simple discretization scheme and help in understanding the influence of the orientation of fibers on the MTC׳s behavior. The aims of this study were to model the MTC in DEM at the macroscopic scale and to obtain the force/displacement curve during a non-destructive passive tensile test. Another aim was to highlight the influence of the geometrical parameters of the MTC on the global mechanical behavior. A geometrical construction of the MTC was done using discrete element linked by springs. Young׳s modulus values of the MTC׳s components were retrieved from the literature to model the microscopic stiffness of each spring. Alignment and re-orientation of all of the muscle׳s fibers with the tensile axis were observed numerically. The hyper-elastic behavior of the MTC was pointed out. The structure׳s effects, added to the geometrical parameters, highlight the MTC׳s mechanical behavior. It is also highlighted by the heterogeneity of the strain of the MTC׳s components. DEM seems to be a promising method to model the hyper-elastic macroscopic behavior of the MTC with simple elastic microscopic elements.