In muscle physiology, what term describes the muscle that performs the primary action in a movement?

The term that describes the muscle performing the primary action in a movement is the agonist. This is the muscle that contracts to create movement at a joint, facilitating the desired action, such as lifting or pushing. For example, when performing a bicep curl, the biceps brachii acts as the agonist, contracting to flex the elbow.

Understanding the role of the agonist is crucial in exercise programming and rehabilitation, as it helps in identifying which muscles are targeted during specific movements, allowing for more effective training regimens that enhance strength and function while also considering muscular imbalances and coordination.