Somatic dysfunction of the thoracic spine, ribs, and thoraco-abdominal diaphragm results in which of the following?

Somatic dysfunction of the thoracic spine, ribs, and thoraco-abdominal diaphragm results in which of the following?

• A. Increased negative intrathoracic pressure during inspiration
• B. Diminished negative intrathoracic pressure during inspiration
• C. No change in intrathoracic pressure
• D. Elevated intrathoracic pressure during expiration

Answer: (B)

During inspiration, the chest wall and diaphragm expand to create a more negative intrathoracic pressure that pulls air into the lungs. Somatic dysfunction of the thoracic spine, ribs, and thoracoabdominal diaphragm restricts this expansion, so the inspiratory pressure drop is blunted. In other words, intrathoracic pressure does not become as negative as it should, leading to diminished negative intrathoracic pressure during inspiration. This reduces inspiratory efficiency and ventilation. The other options imply either more negative pressure, no change, or changes during expiration, which don’t align with the restrictive effect on inspiratory mechanics caused by this dysfunction.

During inspiration, the chest wall and diaphragm expand to create a more negative intrathoracic pressure that pulls air into the lungs. Somatic dysfunction of the thoracic spine, ribs, and thoracoabdominal diaphragm restricts this expansion, so the inspiratory pressure drop is blunted. In other words, intrathoracic pressure does not become as negative as it should, leading to diminished negative intrathoracic pressure during inspiration. This reduces inspiratory efficiency and ventilation. The other options imply either more negative pressure, no change, or changes during expiration, which don’t align with the restrictive effect on inspiratory mechanics caused by this dysfunction.