Which muscle has elevation as its secondary action?

• A. Medial Rectus
• B. Inferior Oblique
• C. Superior Oblique
• D. Lateral Rectus

Answer: (B)

Elevation of the eye isn’t produced by a single muscle in every gaze; the effect depends on where you’re looking. The inferior oblique has a distinctive pattern: when the eye is adducted (turned inward), its pull tends to raise the eye. In that position its primary action is actually extorsion, but elevation appears as its secondary action. So, among these muscles, the inferior oblique is the one whose secondary action is elevation. The other muscles either don’t elevate as a secondary action in this context (for example, the superior oblique mainly depresses when adducted, not elevates), or they primarily move the eye in other directions.