Which trauma is common to the first and third items?

• A. Left torsion
• B. Right torsion
• C. Inferior vertical strain
• D. Left lateral strain

Answer: (A)

Think about how cranial strains arise from traumatic forces. A torsional pattern is produced by a twisting force around the anterior-posterior axis, causing the sphenoid and occiput to rotate in opposite directions. The direction of the torsion (left or right) reflects the direction of the twist imparted to the head.

If the trauma described or implied is a twist toward the left, the cranial bones are most likely to adopt a left torsion pattern. This makes left torsion the best match for the two findings that share that twisting mechanism. The other options describe different force directions or patterns—right torsion would be the mirror image twist, inferior vertical strain involves vertical compression without a torsional component, and left lateral strain reflects a side-to-side bend rather than a pure twist. Those patterns don’t align with a leftward twisting trauma, so they’re less likely to be common to the two items.