Serratus Anterior

Description

Running along the lateral thoracic wall, the serratus anterior is seen as a series of saw toothed digitations arising from the external surfaces of the upper ribs and wrapping posteriorly toward the medial border of the scapula. From this posterior male view, the scapulae sit posterolaterally on the rib cage, with the vertebral column centered and the posterior ribs curving laterally beneath the muscle slips. Latissimus dorsi occupies the posteroinferior trunk, and the proximal humerus appears laterally at the shoulder, framing the scapulothoracic region where serratus anterior acts on the scapula. Clinically, serratus anterior matters because it is the prime protractor and a key upward rotator of the scapula, keeping the medial border apposed to the thoracic cage during pushing and overhead elevation. Injury to the long thoracic nerve (C5 to C7), often after axillary surgery, chest tube placement, or repetitive traction in athletes and boxers, produces medial scapular winging and weak forward flexion above shoulder level. This posterior perspective makes scapular position easy to judge, and it clarifies how loss of serratus tone lets the inferior angle drift medially and posteriorly. Use this artwork for gross anatomy and kinesiology teaching on the thoracic wall and scapulothoracic mechanics, or for clinical texts covering long thoracic nerve palsy, scapular dyskinesis, and rehabilitation of shoulder girdle stability. It also fits surgical education on the axillary region where the long thoracic nerve courses superficially on serratus anterior. Anatomical accuracy verified by SciePro's Medical Advisory Board.