Kokshenev Valery B
Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Caixa Postal 702, CEP 30123-970, Belo Horizonte, Brazil.
J Biomech. 2008;41(4):912-5. doi: 10.1016/j.jbiomech.2007.11.005. Epub 2007 Dec 21.
Biomechanical macroscopic models of the muscle organ as whole are conceptually limited in explaining muscle function in relation to structure. The examples are Hill-type and rheological muscle models where elastic properties of the muscle's contractible element are approached by a spring arranged in series and parallel, respectively. A new scaling model of the activated muscle powering a particular function is proposed. This model is based on the physical similarity suggested between the action-production muscle force and resulting reaction elastic muscle forces. Considered at a macroscopic scale, this force similarity provides four patterns of constraints in development of muscle architecture in different-sized animals. As the result, the analytical modeling predicts the primary motor, brake, strut and spring functions of individual muscles revealed earlier in work-loop experiments and now provided in terms of the scaling exponents for muscle cross-sectional area and fiber length. The model reliability is tested via literature available from muscle allometric data. The conceptual outcome of the study is that the architecture design of skeletal muscles is likely effected by the powering contractions of last fibers known as having higher myofibril volume than slow fibers.
将肌肉器官作为一个整体的生物力学宏观模型，在解释肌肉功能与结构的关系方面存在概念上的局限性。例如希尔型和流变学肌肉模型，其中肌肉可收缩元件的弹性特性分别通过串联和并联的弹簧来近似。本文提出了一种为特定功能提供动力的激活肌肉的新缩放模型。该模型基于作用产生的肌肉力与产生的反作用弹性肌肉力之间的物理相似性。从宏观尺度来看，这种力的相似性在不同大小动物的肌肉结构发育中提供了四种约束模式。结果，分析模型预测了个体肌肉的主要运动、制动、支撑和弹簧功能，这些功能在工作循环实验中早已揭示，现在通过肌肉横截面积和纤维长度的缩放指数来呈现。该模型的可靠性通过肌肉异速生长数据的现有文献进行了测试。该研究的概念性成果是，骨骼肌的结构设计可能受最后收缩纤维的驱动影响，已知这些纤维的肌原纤维体积比慢纤维更大。
