What is a diagnostic sign for meningitis marked by the person's inability to extend the leg completely when the thigh is flexed upon the abdomen and the person is sitting or lying down?

The answer to this question would be: Kernig sign

When doing Kernig sign, you put the thigh in flexed position about 90 degrees from abdomen then trying to extend the leg. The test is positive if the patient is complaining pain or trying to prevent the leg movement.