What indicates a patient experiencing Kernig's sign?

Kernig's sign is a clinical indication often associated with meningitis or irritation of the meninges. It is characterized by the inability to straighten the leg when the hip is flexed to 90 degrees. This occurs due to resistance and pain generated by tension in the hamstring muscles as well as irritation of the meninges; both of these can be triggered by flexing the hip.

Understanding this sign is crucial in the context of neurological assessments, as it helps differentiate potential meningeal irritation from other causes of leg pain or discomfort. Observing this inability to straighten the leg provides important diagnostic information and warrants further investigation for conditions such as meningitis.