ACTION: upward rotation & protraction of scapula
REFERRAL: lateral torso

COMMENTS: This muscle attaches to the rib cage and the edge of the underside of the scapula. It counters the action of the rhomboid muscle. When you put your arm over your head, this muscle helps to rotate the scapula up and keep it close to your rib cage. If this muscle becomes paralyzed, the scapula will wing out.