Serratus anterior muscle
Serratus anterior muscle extends from the side of the ribs to the scapula. It helps move the upper arms forward and assists in breathing.
Origin: Anterior surfaces of the ribs 1-9
Insertion: Anterior surface of the medial border of scapula
Innervation: long thoracic nerve
- Holds the scapula close to the rib cage and thus stabilizes it
- During a forward movement of the upper arm, like during a boxing punch, it abducts (moves laterally, away from the spine) and protracts it (brings it forward)
- Rotates the scapula upwards while abducting an arm or lifting weight over the head
Overuse of serratus anterior (sprints, boxing, lifting objects with extended arms) can cause sharp pain on the either side of the chest aggravated by deep breathing.
- Side stitch
- Trapped wind
- Kidney stones
- Spontaneous pneumothorax