If the restriction is P-A with L-M only, which listing is most likely?

• A. PI
• B. IN
• C. EX
• D. AS

Answer: (B)

Focusing on how a listing is determined by the direction of restriction helps here. A restriction described as posterior-to-anterior means the joint is limited when trying to move from the back toward the front in the sagittal direction. If it’s limited on the left side only (left of the midline), then there’s a single, left-sided P-A constraint with no restriction on the right.

The listing that matches a left-sided, posterior-to-anterior restriction is the one that corresponds to that pattern, so it’s the IN listing. The other options would imply additional directional components (such as restrictions in other planes or on the opposite side) that do not align with a pure P-A restriction confined to the left.