Whats difference between eccentric and concentric muscle contractions and examples of when in use?

Answer 1

Eccentric and Concentric contractions are both types of Isotonic Contraction. In isotontic contractions the length of a muscle changes, ie movement occurs, unlike an Isometric Contraction where force is applied but no movement occurs. Concentric contraction is the more obvious type of sixe change a muscle can have, it is when the muscle Shortens to move the Load. For example id one was to bend the elbow whilslt holding a weight (called a Bicep Curl) the Brachialis and, to a lesser extent, the Biceps Brach would shorten and pull the forearm up with the weight. Eccentric contracion is the type that muslce builder who wish to bulk up with inefficient muscle use. This is where the muscle Lengthens under conrtaction. To continue the same example above, imagine the weight was too heavy to hold up so it starts to fall under control. The brachialis and biceps muscles are still contracting trying to hold the weight in place but they are not producing enough force so the load is stretching them out.