Serratus anterior muscle

The serratus anterior (/ˌsᵻˈreɪtəs ænˈtɪəri.ər/) (Latin: serrare = to saw, referring to the shape, anterior = on the front side of the body) is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula.