What does eccentric action refer to in muscle movement?

Eccentric action refers to the process where a muscle elongates while under tension, usually in response to an opposing force or resistance. This occurs when a muscle is actively engaged while still lengthening, as seen during activities like lowering a weight after a lift. For instance, when performing a bicep curl, as you lower the weight back down, your biceps are still working against the gravitational force, resulting in an eccentric contraction.

This type of muscle action is crucial for activities that require controlled descent or stabilization, as it helps prevent injuries by allowing muscles to better absorb shock and manage forces. Understanding eccentric action is fundamental in training and rehabilitation as it plays a significant role in muscle development and functional movement patterns.