Which muscle protracts the scapula and originates from ribs 1-8?

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

Answer: (D)

Protraction of the scapula is the forward movement of the shoulder blade along the rib cage, which you use when reaching forward or pushing against something. The Serratus Anterior is the muscle that does this best: its fibers originate on the outer surfaces of the upper eight (some sources say up to the ninth) ribs and insert on the anterior surface of the medial border of the scapula. When it contracts, it pulls the scapula forward against the thorax, producing protraction, and it also helps rotate the scapula to allow full arm elevation. The other muscles don’t fit this combination of origins and primary action: pectoralis minor originates from the anterior ribs 3–5 and protracts the scapula but not from ribs 1–8; trapezius and rhomboids originate from the spine and skull and are involved in different scapular movements like elevation, retraction, and rotation rather than pure protraction from rib origins.