Which muscle protracts the scapula and inserts at the vertebral border of the scapula?

• A. Pectoralis Minor
• B. Trapezius
• C. Rhomboid Major
• D. Serratus Anterior

Answer: (D)

Protracting the scapula means moving the shoulder blade forward around the rib cage, and the serratus anterior is the primary muscle for this action. It travels along the ribs and inserts on the anterior surface of the medial (vertebral) border of the scapula. When it contracts, it pulls the medial edge of the scapula forward and keeps the blade pressed against the thoracic wall, which is essential for pushing movements and reaching forward.

Rhomboid major, although it attaches to the medial border, does the opposite—it retracts the scapula toward the spine. Pectoralis minor also helps move the scapula in a forward and downward direction but inserts on the coracoid process, not the vertebral border. The trapezius has multiple actions depending on the fibers, but it isn’t the primary protractor.

So the serratus anterior best fits the described action and insertion.