During a concentric contraction, muscle fibers shorten as they generate force. This type of contraction occurs when the muscle’s tension exceeds the resistance, and it leads to the movement of the body or a particular body part. For instance, when you lift a weight by curling your bicep, the bicep muscle shortens to lift the weight.
Shortening of the muscle fibers is a key feature of concentric contractions, distinguishing it from other types of contractions such as eccentric contractions, where muscles lengthen while still under tension, or isometric contractions, where muscles maintain the same length without changing. Understanding these muscle actions is essential for effective training and rehabilitation in Pilates and other movement disciplines.