THE MECHANICAL PROPERTIES OF CROSS-BRIDGES AND THEIR RELATION TO MUSCLE CONTRACTION
1981; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-08-026817-0.50006-8
Autores Tópico(s)Muscle activation and electromyography studies
ResumoThis chapter discusses mechanical properties of cross-bridges and their relation to muscle contraction. Estimates of the mechanical properties of the cross-bridges can be obtained by applying a sudden change of either load or length during the plateau of an isometric tetanus. The earliest experiments with adequate time resolution to show the complex phenomena which occur were those of Podolsky (1960) and Civan & Podolsky (1966), in which shortening against a preset load was suddenly permitted and the length changes were recorded. This type of experiment has been repeated and generally similar results were obtained. However, now the focus was on the converse type of experiment in which a sudden length change is imposed and the time course of tension is recorded. Typical records are shown in the chapter. The later stages are attributable to detachment and re-attachment of cross-bridges. The chapter highlights that although the existence of a mechanical compliance within each cross-bridge is fairly certain on experimental grounds, there is no evidence on either its location within the cross-bridge or its nature.
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