Serratus Anterior Muscle

Serratus Anterior Muscle

Question 1. Give the origin, insertion, nerve supply, and actions of the serratus anterior muscle.
Answer.

Serratus anterior is a broad, flat muscle of the trunk in the medial wall of the axilla. It lies between the ribs and scapula at the upper lateral part of the chest.

Serratus Anterior Muscle Origin

Arises by eight digitations from the outer surfaces and upper borders of the upper eight ribs. Each digit arises from the corresponding rib but the 1st digit arises from both the 1st and 2nd ribs.

Serratus Anterior Muscle Insertion

Into the whole length of the medial border of the costal surface of the scapula.

The 1st digit is inserted into a triangular area on the superior angle. The next two or three digitations are inserted in the whole length of the medial border. The lower four or five digitations are inserted into the large triangular area over the inferior angle.

serratus anterior muscle

Serratus Anterior Muscle Nerve Supply

The nerve to the serratus anterior (also called the long thoracic nerve of Bell), which arises from C5, C6, and C7 roots ofthe brachial plexus.

Serratus Anterior Muscle Actions

• Rotation of the scapula, which helps in the abduction of the shoulder beyond 90°.
• Chief muscle concerned with pushing and punching movements, as in boxing. Hence, it is also called ‘boxer’s muscle’.