Abstract
There are several modalities of muscular activity, which are divided into: concentric contractions (shortening of muscle fibers); the eccentric contractions (increase of the tension in a state of lengthening of the muscular fibers). Finally, isometric contractions appear that use an increase in muscle tone without changing the initial joint range. Both the eccentric and concentric modalities are part of the isotonic contractions
This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. The authors keep the copyright and publication rights in the journal the right of the first publication and this possibility to edit, reproduce, distribute, expose and publicly communicate on the magazine's website. Likewise, it assumes the commitment on any litigation or claim related to the rights of intellectual property, exonerating of responsibility to the Science and Health Magazine of the UCIMED. In addition, you can see how they are published in this journal (eg, Include in an institutional repository or publish it in a book) as long as they clearly indicate the work published for the first time in the magazine Science and Health of the UCIMED.