Which of the following is an action of the pectoralis minor when the scapula is not fixed?

• A. Depress the scapula, abduct the scapula, downwardly rotate the scapula
• B. Elevate the scapula
• C. Assist to elevate the thorax during forced inhalation when the scapula is fixed
• D. Upwardly rotate the scapula

Answer: (C)

When the shoulder girdle is free to move, the pectoralis minor pulls the coracoid process forward and downward because it attaches from ribs 3–5 to the coracoid. This action moves the scapula in three ways: it depresses the scapula (lowers the shoulder blade), protracts or abducts it (pulls it forward away from the spine), and downwardly rotates it (tilts the glenoid cavity downward).

Elevating the scapula would involve other muscles like the trapezius or levator scapulae. Elevating the thorax during forced inhalation occurs when the scapula is fixed to the thorax, not when the scapula is moving. Upward rotation is primarily produced by serratus anterior and parts of the trapezius, not pectoralis minor.