Kernig sign

Kernig's sign (after Waldemar Kernig (1840–1917), a Baltic German neurologist) is positive when the thigh is bent at the hip and knee at 90 degree angles, and subsequent extension in the knee is painful (leading to resistance).  This may indicate subarachnoid hemorrhage or meningitis Patients may also show opisthotonus—spasm of the whole body that leads to legs and head being bent back and body bowed backwards