Barrett Jeff M, Callaghan Jack P
University of Waterloo, Department of Kinesiology, Waterloo, Ontario, Canada.
University of Waterloo, Department of Kinesiology, Waterloo, Ontario, Canada.
J Theor Biol. 2021 Jan 21;509:110488. doi: 10.1016/j.jtbi.2020.110488. Epub 2020 Sep 12.
Strains and sprains of soft tissues, including tendons and ligaments, are frequently occurring injuries. Musculoskeletal models show great promise in prediction and prevention of these injuries. However, these models rarely account for the viscoelastic properties of ligaments and tendons, much less their failure properties. The purpose of this project was to develop, simplify, and analyze a collagen-distribution model to address these limitations.
A distribution-moment approximation was applied to an existing partial differential equation model to reduce its computational complexity. The resulting model was equipped with a Voigt model in series, which endowed it with viscoelastic properties in addition to failure properties.
The model was able to reproduce the characteristic toe, linear, and failure regions ubiquitous throughout in-vitro tests on tissue specimens. In addition, it was able to reproduce a tri-phasic creep test consisting of an initial deformation, a steady-state, and failure. Stress-relaxation and hysteresis were also reproducible by the model.
The ability to reproduce so many characteristics of biological tissues suggests more bio-fidelity was achieved by the reduced model was other currently available models. Future work to further improve its bio-fidelity is proposed for specific tendons and ligaments.
软组织（包括肌腱和韧带）的拉伤和扭伤是常见的损伤。肌肉骨骼模型在预测和预防这些损伤方面显示出巨大潜力。然而，这些模型很少考虑韧带和肌腱的粘弹性特性，更不用说它们的失效特性了。本项目的目的是开发、简化并分析一种胶原蛋白分布模型，以解决这些局限性。
将分布矩近似应用于现有的偏微分方程模型，以降低其计算复杂度。所得模型串联了一个沃伊特模型，使其除了具有失效特性外，还具有粘弹性特性。
该模型能够再现组织标本体外测试中普遍存在的特征性趾部、线性和失效区域。此外，它能够再现由初始变形、稳态和失效组成的三相蠕变试验。该模型还能再现应力松弛和滞后现象。
能够再现生物组织的如此多特征表明，简化后的模型比其他现有模型具有更高的生物逼真度。建议针对特定的肌腱和韧带开展进一步提高其生物逼真度的未来工作。
