What is the characteristic finding in meningitis when performing Kernig's sign?

In meningitis, the characteristic finding when performing Kernig's sign is the inability to flex the knee when the hip is flexed. When assessing for Kernig's sign, the patient lies supine, and the examiner flexes the hip and knee at 90 degrees. If there is resistance or pain preventing the extension of the knee, it suggests meningeal irritation, which is commonly seen in cases of meningitis.

This sign is particularly important in the evaluation of a patient with suspected meningitis, as it indicates irritation of the meninges surrounding the brain and spinal cord. The presence of this neurological sign, alongside other findings such as fever and nuchal rigidity, aids in forming a diagnosis.

While the other options may be related to various clinical signs or symptoms, they do not specifically represent the Kernig's sign observed in the context of meningitis.