what muscles that oppose or reverse a particular movement
Muscles are arranged in such a way that whatever one muscle can do, other muscles can reverse. Because of this, muscles are able to bring about an immense variety of movements. Prime mover. The muscle that has the major responsibility for causing a particular movement is called the prime mover. Antagonists. Muscles that oppose or reverse a movement are antagonists; when a prime mover is active, its antagonist is stretched and relaxed. Synergists.