In an infant, how is the Kernig sign elicited during a neurologic examination?

In an infant, how is the Kernig sign elicited during a neurologic examination?

• A. Extending the leg at the knee with the infant supine.
• B. Flexing the infant's neck to touch chin to chest.
• C. Turning the infant's head from side to side.
• D. Bending the infant at the waist to touch fingers to toes.

Answer: (A)

Kernig sign is a test for meningeal irritation. In an infant, you assess it by having the infant lie on the back and extend the leg at the knee. If meningitis or meningeal irritation is present, extending the knee stretches the meninges and nerve roots, causing pain or resistance. This precise response—pain or limited extension when the leg is straightened in a supine infant—points to meningeal involvement. Other maneuvers test neck stiffness or hamstring flexibility, but the Kernig maneuver focuses on extending the leg in the supine position to reveal meningeal irritation.

Kernig sign is a test for meningeal irritation. In an infant, you assess it by having the infant lie on the back and extend the leg at the knee. If meningitis or meningeal irritation is present, extending the knee stretches the meninges and nerve roots, causing pain or resistance. This precise response—pain or limited extension when the leg is straightened in a supine infant—points to meningeal involvement. Other maneuvers test neck stiffness or hamstring flexibility, but the Kernig maneuver focuses on extending the leg in the supine position to reveal meningeal irritation.