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
- Patient supine, examiner flexes patient’s hip to 90° with knee flexed.
- Examiner then extends patient’s knee.
Positive Kernig’s Sign
- Leg pain: Radiculopathy
- Increased resistance : Hamstring tightness
- Involuntary flexion of the opposite knee and hip: Meningitis
Extension of the knee increases nerve and/or root tension on the sciatic nerve, resulting in radicular symptoms.