Straight leg raise test or Lasegue's sign
Definition: Assessing the sciatic nerve, lower lumbar and upper sacral nerve roots for irritation.
Test Procedure The examiner lifts the patient's leg from the plinth by holding it at the calcaneum whilst keeping the knee straight. The hip is flexed up to 90°, if tolerated. The leg should be rotated medially. If no symptoms are provoked the ankle is dorsiflexed thus placing a further stretch on the sciatic nerve. If the posterior musculature is fully tensed then the leg is lowered by 5° before dorsiflexing.
Test findings: The test is positive if significant back pain, or radicular pain in the lower extremity is present. A positive test may indicate sciatic or lumbosacral nerve root irritation, for example due to a prolapsed lumbar disc. If the leg pain increases but without spinal symptoms consider piriformis syndrome.
Considerations: If the leg pain increases but without spinal symptoms consider piriformis syndrome.