Obliquus Capitis Inferior inserts on which structure?

• A. Spinous Process of C1
• B. Inferior Nuchal Line
• C. Occipital bone
• D. Transverse Process of C1

Answer: (D)

Obliquus capitis inferior is a suboccipital muscle that links the axis (C2) to the atlas (C1) to help rotate the head. It originates from the spinous process of the axis and inserts on the transverse process of the atlas. That insertion point—the transverse process of the first cervical vertebra—is why this muscle primarily acts to rotate the atlas on the axis, turning the head to the same side. The other options point to different structures (a spinous process on C1 isn’t the attachment, the inferior nuchal line and occipital bone relate to other muscles), so they don’t match the actual insertion.