For whom is the chin-down posture ineffective in eliminating thin-liquid aspiration?

The chin-down posture is primarily designed to help manage swallowing difficulties by narrowing the airway entrance and using gravity to assist in moving bolus material. It is particularly effective for individuals who may have trouble with coordination during swallowing or who are at risk for aspiration due to issues like impaired lingual function or poor airway closure.

For those who aspirate residue from the pyriform sinuses, this posture may be ineffective because the residue is located below the level of the airway, and simply tucking the chin may not adequately address the aspiration that occurs from that anatomical location. The chin-down posture does not help in clearing remnants from pyriform sinuses as effectively as it might for other issues, since the residue can still be positioned to move into the airway despite the posture change. In this way, it indicates a less appropriate strategy for managing that specific swallowing concern.

In contrast, the other options involve conditions that can benefit from this posture as they relate more directly to airway protection and bolus transportation.