## Core Concept
A pulled elbow, also known as nursemaid's elbow, is a common injury in young children where the radial head subluxates due to a sudden pull on the extended arm. This condition typically occurs in children under the age of 5 years.

## Why the Correct Answer is Right
The correct answer is related to the mechanism and presentation of a pulled elbow. A pulled elbow usually happens when a child is lifted by the hands or wrists, causing a subluxation of the radial head. The typical presentation includes the child holding the affected arm still and close to the body, with the elbow slightly flexed.

## Why Each Wrong Option is Incorrect
- **Option A:** Typically, a pulled elbow occurs due to a sudden longitudinal traction on the arm, which causes the annular ligament to slip over the head of the radius. This option might describe a mechanism, but without specifics, it's hard to judge its accuracy directly.
- **Option B:** This might relate to the age group or the common mechanism of injury. Pulled elbow is indeed more common in younger children.
- **Option C:** This could potentially describe a characteristic of a pulled elbow, such as the child not moving the arm.
- **Option D:** This option likely describes something not characteristic of a pulled elbow.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that a pulled elbow is usually easily reduced by suplexing the forearm while gently flexing the elbow. A classic maneuver involves having the child hold their arm in a position of slight flexion and pronation; then, with the elbow flexed, gently supinate the forearm. This often results in a palpable and sometimes audible click as the radial head reduces back into place.

## Correct Answer: D.