In an inferior vertical shear, the sphenoid's greater wing moves which way relative to the occiput, and the occiput moves which way?

In an inferior vertical shear, the sphenoid's greater wing moves which way relative to the occiput, and the occiput moves which way?

• A. Greater wing of sphenoid → Superior; Occiput → Inferior
• B. Greater wing of sphenoid → Inferior; Occiput → Superior
• C. Both bones move superior
• D. Both bones move inferior

Answer: (A)

In vertical strains, the two cranial bones at the SBS move in opposite directions along the vertical axis. An inferior vertical shear specifically means the occiput moves downward (inferiorly) while the sphenoid moves upward (superiorly) relative to it. Since the greater wing of the sphenoid is part of the sphenoid’s motion, it moves in the superior direction relative to the occiput. So the sphenoid’s greater wing moves superior, and the occiput moves inferior. This opposite-moving pattern along the vertical axis is what defines the inferior vertical shear.

In vertical strains, the two cranial bones at the SBS move in opposite directions along the vertical axis. An inferior vertical shear specifically means the occiput moves downward (inferiorly) while the sphenoid moves upward (superiorly) relative to it. Since the greater wing of the sphenoid is part of the sphenoid’s motion, it moves in the superior direction relative to the occiput. So the sphenoid’s greater wing moves superior, and the occiput moves inferior. This opposite-moving pattern along the vertical axis is what defines the inferior vertical shear.