An isometric contraction is the kind of contraction that leads to development of tension but no increase in length.
An isometric contraction occurs as the muscle produces tension without changing the angle of a skeletal joint. Isometric contraction is a static muscle action that helps to maintain the posture. For example, the antigravity muscles. It occurs in the biceps when the arms may be holding a weight. In such a posture, the biceps enlarge due to holding of weight and produces tension but do no increase in length. It stops the flexion of elbow. In such contraction, no work is done, and lesser amount of heat energy is released in comparison to isotonic contractions.
