What is the term for the lengthening of a muscle?

The term for the lengthening of a muscle is referred to as eccentric contraction. During an eccentric contraction, the muscle generates force while being lengthened. This typically occurs when a muscle is controlling the descent of a weight or opposing an external force. For example, when lowering a heavy object back to the ground, the muscle must lengthen to control the motion, thereby engaging in an eccentric contraction.

This type of contraction is crucial for various activities, including deceleration in movements, the controlled lowering of weights during resistance training, and is also significant in rehabilitation settings as it can help improve muscle strength and control. Understanding eccentric contractions is pivotal for fitness professionals when designing programs that enhance strength, flexibility, and injury prevention strategies.