Kernig's sign is a test used in physical examination to look for evidence of irritation of the meninges.

The test involves flexing the thighs at the hip, and the knees, at 90 degree angles, and assessing whether subsequent extension of the knee is painful (leading to resistance), in which case it is deemed positive.

[3] Karl et al. noted much of the literature on Kernig's sign is old and they could find no randomised trials of it.

Kernig's should not be relied on when meningitis is suspected and a lumbar puncture should be performed.

[4] The test is named after Woldemar Kernig (1840–1917), a Russian neurologist.