Angle of humeral torsion is ___ degrees?
**Core Concept**
The angle of humeral torsion refers to the **angle of rotation** of the humerus, which is crucial for understanding the anatomy and function of the shoulder joint. This angle is determined by the **twisting** of the humerus during fetal development and bone growth.
**Why the Correct Answer is Right**
The correct answer is based on the average **anatomical measurement** of the humeral torsion angle in adults. The angle of humeral torsion is approximately **130-150 degrees**, but the most commonly cited average is around **137 degrees** for a retroverted humeral head.
**Why Each Wrong Option is Incorrect**
**Option A:** This option might be too low for the average angle of humeral torsion.
**Option B:** This option might be too low for the average angle of humeral torsion.
**Option D:** This option might be too high for the average angle of humeral torsion.
**Clinical Pearl / High-Yield Fact**
The angle of humeral torsion is important for understanding **shoulder function** and **pathology**, as variations in this angle can affect the range of motion and predispose to certain injuries or conditions.
**Correct Answer:** B. 130-150 degrees, most commonly cited as around 137 degrees for a retroverted humeral head, but since the exact number isn't provided in the options and based on standard reference the closest is: **Correct Answer: B. 130-150 degrees.**