Different muscle contractions

Posted by Cags R under Fitness & Training on 21 Sep 2012 at 11:00 PM

There are 3 different types of contraction which your muscles perform when exercising:

1. Concentric contraction

This is often thought of as the protagonist in a movement - the muscle which shortens in order to the move the joint. The easiest example to visualise is the bicep curl - your bicep shortens, bringing your forearm up towards your shoulder.

Other examples would be the contraction of the hamstring which raises your foot up towards your bottom.

2. Eccentric contraction

The antagonist to concentric contractions, eccentric is when the muscle is lengthening but in a controlled manner; without eccentric contractions the forearm would drop down after the bicep curl rather than being lowered. The bicep lengthens slowly to ensure a smooth movement.

In the initial phase of a bicep curl, the tricep is eccentrically contracting to control the movement.

These 2 types of contraction work together in all movements of the body - for every concentrically contracting muscle, there will be a counteracting eccentric contraction in another muscle. In regards to building strength, it is benefitial to work on the eccentric contractions as well as concentric; these are known as negatives.

An example of how training negative movements would be chin ups: if you struggle with chin-ups then training the negative (lowering yourself down very slowly) is an excellent way to build strength for the full movement of the chin up.

3. Isometric

Isometric contractions are also known as static contractions; even though there is no movement, the muscle must maintain it's position. Some Tribesports staples such as planks, bridges and wall squats are classic examples of isometic contractions. As many of you may have experienced, concentric/eccentrically strong muscles can often struggle with isometric ones (it is very frustrating!) this is because you must train all 3 types of movement in order to have an all-round strong muscle.