Where does serratus anterior insert?

Where does serratus anterior insert?

• A. Spine of scapula
• B. Acromion
• C. Anterior surface of medial border of scapula
• D. Inferior angle of scapula

Answer: (D)

Serratus anterior anchors to the scapula along its medial border on the anterior (costal) surface, with the lower fibers reaching toward the inferior angle. This placement lets the muscle protract and stabilize the scapula against the thoracic wall and aids in upward rotation for raising the arm. Choosing the inferior angle as the site of insertion reflects that the insertion extends along the medial border and ends near the inferior angle, which is the distal end of the medial border where some fibers attach. The other options point to landmarks for different muscles (spine of the scapula for some rotator cuff and back muscles, acromion for deltoid, etc.), not the insertion pattern of serratus anterior.

Serratus anterior anchors to the scapula along its medial border on the anterior (costal) surface, with the lower fibers reaching toward the inferior angle. This placement lets the muscle protract and stabilize the scapula against the thoracic wall and aids in upward rotation for raising the arm.

Choosing the inferior angle as the site of insertion reflects that the insertion extends along the medial border and ends near the inferior angle, which is the distal end of the medial border where some fibers attach. The other options point to landmarks for different muscles (spine of the scapula for some rotator cuff and back muscles, acromion for deltoid, etc.), not the insertion pattern of serratus anterior.