A micromechanical model of skeletal muscle to explore the effects of fiber and fascicle geometry.
A micromechanical model of skeletal muscle to explore the effects of fiber and fascicle geometry.
复制标题
DOI：
10.1016/j.jbiomech.2010.07.020
复制
发表时间：
2010-12
影响因子：
2.4
通讯作者：
Bahar Sharafi;S. Blemker
中科院分区：
文献类型：
--
作者：
Bahar Sharafi;S. Blemker
肌肉的计算模型通常将结缔组织、肌纤维和肌束的材料性质一起合并到一个假定横向各向同性微观结构的本构关系中。这些模型没有考虑肌肉微观结构的变化如何影响其宏观材料特性。这项工作的目标是开发肌肉的微观力学模型，以确定肌肉微观结构的变化对宏观本构行为的影响。我们创建的纤维和束水平的基础上，两个兔肌肉，股直肌（RF）和比目鱼肌的组织学横截面的微观力学模型，以确定肌肉的沿纤维剪切模量的微观结构的几何形状（纤维和束的形状）的影响。两个纤维水平模型预测相似的宏观剪切模量（在13.5%的差异），但是，两个束水平模型预测非常不同的宏观剪切模量（高达161%的差异）。我们还使用的微观力学模型来测试的假设，肌肉的宏观性能是横观各向同性的纤维（或束）方向。纤维级模型表现出与横向各向同性假设一致的行为;然而，束级模型表现出横向各向异性行为。需要结合纤维和纤维束力学实验的微观力学模型来理解微观结构中的正常或病理变化如何引起所观察到的肌肉宏观行为。
Computational models of muscle generally lump the material properties of connective tissue, muscle fibers, and muscle fascicles together into one constitutive relationship that assumes a transversely isotropic microstructure. These models do not take into account how variations in the microstructure of muscle affect its macroscopic material properties. The goal of this work was to develop micromechanical models of muscle to determine the effects of variations in muscle microstructure on the macroscopic constitutive behavior. We created micromechanical models at the fiber and fascicle levels based on histological cross-sections of two rabbit muscles, the rectus femoris (RF) and the soleus, to determine the effects of microstructure geometry (fiber and fascicle shapes) on the along-fiber shear modulus of muscle. The two fiber-level models predicted similar macroscopic shear moduli (within 13.5% difference); however, the two fascicle-level models predicted very different macroscopic shear moduli (up to 161% difference). We also used the micromechanical models to test the assumption that the macroscopic properties of muscle are transversely isotropic about the fiber (or fascicle) direction. The fiber-level models exhibited behavior consistent with the transverse isotropy assumption; however, the fascicle-level models exhibited transversely anisotropic behavior. Micromechanical models, combined with fiber and fiber bundle mechanical experiments, are needed to understand how normal or pathological variations in microstructure give rise to the observed macroscopic behavior of muscle.