Eccentric and Concentric are two words that are often confused in terms of their meanings and connotations. The two words are related to the contractions of the muscle. They are both types of isotonic contraction. When the muscle shortens to move a load then the muscle undergoes concentric contraction.
A bicep curl is one of the best examples of a concentric contraction. While holding a weight too, a man has to bend his elbow thereby, resulting in what is called concentric contraction. In other words, concentric contraction is all about muscular movement. The forearm gets pulled along with the weight in the case of concentric contraction.
The biceps brach would shorten its movement during the course of concentric contraction. Inefficient muscle use results in the other type of isotonic contraction called as the eccentric contraction. In short, it can be said that both concentric and eccentric type of muscle contraction is tried and practiced by the weight lifter during his workouts at the gym during body building exercises.
Hence, both these terms are associated with body building and weight lifting. If the muscle lengthens under contraction it amounts to eccentric contraction. Hence, eccentric contraction is exactly the opposite of concentric contraction. If the weight is too heavy to hold then the weight lifter feels that it is beginning to fall under control. This results in eccentric contraction.
It is important to note that the brachialis and biceps begin to contract trying to hold the extra weight. On the other hand, although the biceps try to hold the extra weight, they are unable to produce the extra force to hold the weight long, and hence, they give way resulting in eccentric contraction. These are the differences between the two words that are associated with body building and weight lifting, namely, eccentric and concentric.