Positive Kernig’s sign
It is a sign named after its discoverer Woldemar Kernig, a Russian doctor. He discovered that when a patient flexes his thigh on his hip and flexes his knee at a 90-degree angle then extended the patient’s knee, it will cause severe pain in the back and the neck. When the pain ensues, it will force the patient to resist the knee extension. This sign is indicative of meningitis, which is a condition that causes sciatica.