What is an example of an isometric contraction?

An isometric contraction occurs when a muscle exerts force without any visible movement or change in muscle length. This happens when muscles are activated and generate tension while remaining in a fixed position. Holding a weight steady without moving is a classic example of an isometric contraction. In this scenario, the muscles are engaged to maintain the position of the weight, but there is no movement of the joints or alteration in the length of the muscle.

In contrast, other types of exercise, such as push-ups, sprinting, or jumping, involve dynamic movements where muscles lengthen and shorten, thus qualifying them as isotonic or eccentric contractions rather than isometric. Therefore, maintaining a static hold with a weight illustrates the principle of isometric contraction effectively, as the muscles are working hard, yet there is no change in their length or position.