Agonist Muscle

The agonist muscle is the main muscle that creates movement at a joint.

The agonist muscle is also called the “primary mover.” During tummy time, a baby pushes up from the floor with their arms and extends their elbows. In this case the, elbow extenders or triceps brachii are the agonists!

A baby in a red sweater pushes up with straight arms in tummy time. A label for the agonist muscle points to the back of the upper arm.