The serratus anterior muscle is one of the major muscles of the pectoral girdle. It plays a vital role in the protraction of the scapula and greatly improves the range of motion of the shoulder joint. The serratus anterior is also referred to as the “boxer’s muscle” thanks to its prominent role in throwing punches.
The serratus anterior muscle is a wide, fan-shaped muscle of the lateral chest. It arises from several muscular slips on the first eight or nine ribs. Each of its origins is pointed, giving it a saw-like shape. This shape is why it was named serratus, which is Latin for “saw-shaped.” From its insertions, the slips of the serratus anterior pass around the lateral side of the rib cage and anterior to the subscapular fossa of the scapula. They insert on a narrow band along the medial border of the scapula on the costal (ribcage) side of the scapula.
Contraction of the serratus anterior muscle protracts the scapula by drawing the scapula anteriorly toward the sternum. This motion is extremely useful for various activities, including throwing punches, reaching across the chest to the other side of the body, pushups, bench presses, and pushing an object away from the chest.