Which term describes a chest segment movement opposite to normal during breathing?

• A. Paradoxical Movement
• B. Flail Chest
• C. Pneumothorax
• D. Open Pneumothorax

Answer: (A)

Paradoxical movement describes a chest wall segment that moves opposite to the normal breathing pattern. Normally, the chest expands outward during inspiration and recoils inward during expiration. When a segment of the chest wall is freely mobile due to blunt trauma (as in a flail chest), that section moves inward during inspiration and outward during expiration, opposite to the rest of the chest. This paradoxical motion signals significant chest wall injury and potential respiratory compromise.

Pneumothorax and open pneumothorax refer to air in the pleural space and lung collapse, not to abnormal chest wall movement. Flail chest describes the injury pattern that produces paradoxical movement, but the movement itself is best described by the term paradoxical movement.