What is the general function of antagonist muscles?

Antagonist muscles play an essential role in movement by performing the opposite action of the agonist muscles, which are responsible for the primary action during an exercise. When an agonist muscle contracts to produce a movement, the antagonist must relax and lengthen to allow for a smooth and controlled motion. This balance between agonist and antagonist actions is crucial for effective movement, ensuring that the body can function without injury and maintain proper mechanics.

For instance, when you flex your elbow, the biceps brachii acts as the agonist by contracting, while the triceps brachii, as the antagonist, relaxes to enable that movement. This relationship helps to regulate the motion and provides stability to the joint involved. In this way, antagonist muscles contribute to not only executing movements but also preventing excessive strain and maintaining joint health.