Serratus anterior: Innervation and Action

"SALT- 567"

•  Serratus Anterior is innervated by Long Thoracic nerve which arises from the roots- C5, C6, and C7.

Or, "5, 6, 7- Raise your wings up to heaven"

•  C5, 6, 7 injury causes inability to raise arm past 90 degrees towards heaven, and results in winging of the scapula.

To summarize, the Long Thoracic nerve (Nerve of Bell) supplies the Serratus anterior muscle, which keeps the medial border of the scapula against the thoracic wall. Injury to the nerve causes the medial border to become more prominent (winging of scapula) when actions such as pushing, punching or raising the arm above 90° are attempted.

Did you know?

The nerve to serratus anterior is a branch of the brachial plexus and arises from the roots C5, 6, 7.

Winging of scapula is a condition in which the medial border of a person's scapula is abnormally positioned outward and backward. The resulting appearance of the upper back is said to be wing-like as the inferior angle of the shoulder blade protrudes backward rather than remaining almost flat as in normal people.