Why is apical expansion limited on the left in Superior T4 Syndrome?

• A. Because the left side is naturally restrictive in expansion.
• B. Because the left diaphragm is weaker.
• C. Because the left apical expansion is unaffected.
• D. Because the right scalene externally rotates the right upper ribs, which internally rotates the left upper ribs, reducing airflow to the left chest wall.

Answer: (D)