Kernig’s Sign

Kernig’s Sign, is often used to produce a sign of meningitis. The examination can also be used to reproduce radiculopathy in root compression, or nerve tension (sciatic nerve). The action of the test is identical to Lasège’s Differential/Sign

Procedure

  1. Patient supine, examiner flexes patient’s hip to 90° with knee flexed.
  2. Examiner then extends patient’s knee.
Kernig Test used for examining meningitis

Examiner flexes patient’s hip to 90° with knee flexed and then extends patient’s knee.

Interpretation

Positive Kernig’s Sign

  1. Leg pain: Radiculopathy
  2. Increased resistance : Hamstring tightness
  3. Involuntary flexion of the opposite knee and hip: Meningitis

Clinical Notes

Extension of the knee increases nerve and/or root tension on the sciatic nerve, resulting in radicular symptoms.