When the leg is slowly elevated above 60°, and sometimes less, straight leg raising may induce pain that radiates down the leg. This finding is suggestive of Sciatica; however, pain spreading down the affected leg when the contralateral leg is lifted (crossed straight leg lifting) is more specific. The straight leg raise test is performed when the patient is seated, with the hip joint flexed at 90°; the lower leg is steadily raised until the knee is fully extended. When a person has Sciatica, the pain in the spine (and often radicular symptoms) worsens when the leg is extended.
The slump test, like the straight leg raise test, can be performed with the patient "slumping" (thoracic and lumbar spines flexed) and the neck flexed. The slump test is more sensitive for disc herniation but less specific than the straight leg raise test.
