A Nonlinear Model of Passive Muscle Viscosity
A Nonlinear Model of Passive Muscle Viscosity
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DOI：
10.1115/1.4004993
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发表时间：
2011-09-01
影响因子：
1.7
通讯作者：
Lieber, R. L.
中科院分区：
文献类型：
--
作者：
Meyer, G. A.;McCulloch, A. D.;Lieber, R. L.
被动骨骼肌的材料特性对于正常功能至关重要，并且经常是治疗和介入策略的目标。对肌肉被动粘弹性的研究主要集中在表征弹性行为，很大程度上忽略了粘性成分。然而，在被动拉伸过程中，粘度对肌肉应力和伸展性有很大影响，因此需要表征肌肉粘弹性的粘性和弹性成分。对单只小鼠肌纤维进行增量应力松弛测试，以表征被动肌肉应力对时间、应变和应变率的依赖性。然后开发了一个模型来描述结合观察到的非线性的纤维粘弹性。该模型的结果与两种常用的线性粘弹性模型在表示纤维应力松弛和应变率敏感性的能力方面进行了比较。小鼠肌纤维应力的粘性成分并不像通常假设的那样是线性的，而是时间、应变和应变率的更复杂的函数。这里开发的模型结合了这些非线性，与常用的线性粘度模型相比，能够更好地表示测试条件下纤维的应力松弛行为。它提供了一种新工具来研究肌肉粘性应力随年龄、损伤和废弃而变化的情况。 [DOI：10.1115/1.4004993]
The material properties of passive skeletal muscle are critical to proper function and are frequently a target for therapeutic and interventional strategies. Investigations into the passive viscoelasticity of muscle have primarily focused on characterizing the elastic behavior, largely neglecting the viscous component. However, viscosity is a sizeable contributor to muscle stress and extensibility during passive stretch and thus there is a need for characterization of the viscous as well as the elastic components of muscle viscoelasticity. Single mouse muscle fibers were subjected to incremental stress relaxation tests to characterize the dependence of passive muscle stress on time, strain and strain rate. A model was then developed to describe fiber viscoelasticity incorporating the observed nonlinearities. The results of this model were compared with two commonly used linear viscoelastic models in their ability to represent fiber stress relaxation and strain rate sensitivity. The viscous component of mouse muscle fiber stress was not linear as is typically assumed, but rather a more complex function of time, strain and strain rate. The model developed here, which incorporates these nonlinearities, was better able to represent the stress relaxation behavior of fibers under the conditions tested than commonly used models with linear viscosity. It presents a new tool to investigate the changes in muscle viscous stresses with age, injury and disuse. [DOI: 10.1115/1.4004993]