Four Different Types of Muscle Actions

There are essentially four types of muscle actions: Isotonic, Concentric, Eccentric and Isometric contractions.

By HourlyTraining
Edited by Tom Amitay

Published September 30, 2020.

A muscle fiber generates tension through actin and myosin cross-bridge cycling. While under tension, muscles can lengthen, shorten, or remain unchanged.

Although the term "contraction" usually refers to a shortening action, when referring to the muscular system, it refers to the generation of tension within a muscle fiber.

Several types of muscle contractions occur and are defined by the changes in the length of the muscle during contraction.

There are essentially 4 types of muscle actions:

  • Isotonic Muscle Contractions
  • Concentric Muscle Contractions
  • Eccentric Muscle Contractions
  • Isometric Muscle Contractions