The Straight leg raise also (also called Lasegue’s sign or Lasegue test) is a test done during the physical examination to determine whether a patient with low back pain has an underlying herniated disc.
Patient lied down on his back on an examination table, the examiner lifts the patient’s leg while the knee is extended. A variation is to lift the leg while the patient is sitting but that reduces the sensitivity of the test.
The test is positive if pain in the sciatic distribution is reproduced between 30 and 70 degrees of flexion of the straight leg.
The test has rported sensitivity of 91% and specificity of 26%
However if raising the opposite leg causes pain (cross straight leg raising), it has sensitivity 29% and specificity 88%.