If the anteroposterior diameter exceeds the transverse diameter, what condition is suggested?

• A. Barrel chest
• B. Kyphosis
• C. Scoliosis
• D. Pectus excavatum

Answer: (A)

Assessing chest shape by comparing the front-to-back (anteroposterior) diameter with the width (transverse diameter) is the key idea. Normally the chest is wider than it is deep, so the AP diameter is smaller. If the front-to-back dimension becomes equal to or larger than the width, the chest takes on a rounded, barrel-like appearance. This barrel configuration is commonly seen with hyperinflation of the lungs, such as in COPD, where air trapping expands the chest in the AP direction.

Kyphosis alters spinal curvature and can change posture but doesn’t necessarily make the AP dimension exceed the transverse. Scoliosis is a lateral (side-to-side) curvature of the spine, not a disproportion of AP to transverse chest dimensions. Pectus excavatum depresses the sternum and reduces the AP diameter, producing a sunken chest rather than an enlarged AP dimension.

Therefore, the described proportion points to a barrel chest.