define agonist muscles
Antagonist. An antagonist is a muscle that is capable of opposing the movement of a joint by producing torque that is opposite to a certain joint action. This is usually a muscle that is located on the opposite side of the joint from the agonist.gonist (Prime Mover). As stated above, agonist muscles are muscles that are responsible for causing a certain joint motion. However, the term is often defined incorrectly to mean ALL the muscles that have a role in producing a movement. By this definition stabilizers, neutralizers, and fixators are also agonists.