Fig. 3.

Schematic drawing of agonist and antagonist muscles of bow shoulder at aiming phase during archery shooting. At aiming phase, bow arm (solid line between A and B) should maintain its position. Therefore, the shoulder girdle (A) must be stabilized against force from hand (B). To stabilize the shoulder girdle, the shoulder muscle at the opposite side of force contracts as an antagonist whereas the shoulder muscle contracts as an agonist at same side. More antagonist force is required to stabilize the shoulder girdle (straight arrow, force from bow; black curve arrow, agonist muscle force; gray curved arrows, antagonist muscle force).