How to test the Lasègue sign?
The Lasègue sign is tested by first lying down on a couch. The affected person lies on his back. The examiner lifts the affected leg of the patient in an extension.
While the leg is lifted in a stretched position, passive flexion of the hip joint occurs. The Lasègue sign is positive if further flexion from an angle in the hip joint of 70 – 80° is no longer possible due to sudden shooting pain. Typically, the pain shoots into the hip at 40 to 60° of flexion.
The examiner notes the angle at which pain occurs. If the Lasègue sign is positive, pain suddenly shoots in and can spread to the motor and sensitive area of the affected nerve root. A positive Lasègue sign thus provides an indication of root irritation in the area from L4 to S1, damage to the sciatic nerve or irritation of the meninges. The Lasègue sign is negative if there is no pain.
