What is the characteristic sign of a nursemaid's elbow?

A nursemaid's elbow, also known as radial head subluxation, commonly occurs in young children when a force is applied to the arm, often during activities like being pulled or swung by the arms. The characteristic sign of this condition is that the child typically holds the arm in a position of flexion and pronation.

The specific position of the arm in pronation is due to the child instinctively trying to minimize pain and avoid using the affected arm, which is often held close to the body and slightly flexed at the elbow. This position helps to alleviate discomfort, as any movement that might increase the stretch or pressure on the elbow joint exacerbates the pain.

When examining a child with nursemaid's elbow, recognizing that the arm is held in this way can guide the clinician toward an appropriate diagnosis and treatment, which often involves simple manipulation to reduce the dislocation and restore normal function.

In contrast, other positions such as full extension, flexion without pronation, or abduction do not align with the typical presentation of this injury and are less indicative of the underlying condition.