Structural anatomy encourages the concepts of muscles being agonists and antagonists: suggesting that one muscle opposes another.  In very isolated single-joint, single-plane motions this can be true.  In most functional movements, the agonist and antagonist perspective is completely false.  In the second Vlog of our Functional Muscle Function series, Dr. Dave Tiberio provides further explanation on the concept of Synergistic muscle function that was first introduced in an earlier Blog.