Nishikawa Kiisa C, Lindstedt Stan L, LaStayo Paul C
Center for Bioengineering Innovation and Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA.
Department of Physical Therapy and Athletic Training, University of Utah, 520 Wakara Way, Salt Lake City, UT 86011, USA.
J Sport Health Sci. 2018 Jul;7(3):265-274. doi: 10.1016/j.jshs.2018.06.002. Epub 2018 Jun 20.
The peculiar attributes of muscles that are stretched when active have been noted for nearly a century. Understandably, the focus of muscle physiology has been primarily on shortening and isometric contractions, as eloquently revealed by A.V. Hill and subsequently by his students. When the sliding filament theory was introduced by A.F. Huxley and H.E. Huxley, it was a relatively simple task to link Hill's mechanical observations to the actions of the cross bridges during these shortening and isometric contractions. In contrast, lengthening or eccentric contractions have remained somewhat enigmatic. Dismissed as necessarily causing muscle damage, eccentric contractions have been much more difficult to fit into the cross-bridge theory. The relatively recent discovery of the giant elastic sarcomeric filament titin has thrust a previously missing element into any discussion of muscle function, in particular during active stretch. Indeed, the unexpected contribution of giant elastic proteins to muscle contractile function is highlighted by recent discoveries that twitchin-actin interactions are responsible for the "catch" property of invertebrate muscle. In this review, we examine several current theories that have been proposed to account for the properties of muscle during eccentric contraction. We ask how well each of these explains existing data and how an elastic filament can be incorporated into the sliding filament model. Finally, we review the increasing body of evidence for the benefits of including eccentric contractions into a program of muscle rehabilitation and strengthening.
肌肉在收缩时被拉伸这一独特属性已被关注近一个世纪。可以理解的是，肌肉生理学的重点主要放在缩短和等长收缩上，正如A.V. 希尔及其学生所充分揭示的那样。当A.F. 赫胥黎和H.E. 赫胥黎提出肌丝滑行理论时，将希尔的力学观察结果与这些缩短和等长收缩过程中横桥的作用联系起来是一项相对简单的任务。相比之下，延长或离心收缩在一定程度上仍然是个谜。由于被认为必然会导致肌肉损伤，离心收缩更难纳入横桥理论。最近发现的巨大弹性肌节细丝肌联蛋白，为任何关于肌肉功能的讨论，特别是在主动拉伸过程中，增添了一个此前缺失的元素。事实上，最近关于肌动蛋白相互作用导致无脊椎动物肌肉“捕捉”特性的发现，凸显了巨大弹性蛋白对肌肉收缩功能的意外贡献。在这篇综述中，我们研究了目前提出的几种解释离心收缩时肌肉特性的理论。我们探讨这些理论对现有数据的解释程度，以及弹性细丝如何能纳入肌丝滑行模型。最后，我们回顾了越来越多的证据，证明将离心收缩纳入肌肉康复和强化计划的益处。
