Lasegue Test

 Lasegue Test

What is Lasegue Test?

  • Lasegue test, also called Straight Leg Raise Test, aimed to assess the sciatic compromise due to lumbosacral nerve root irritation.

How it's Performed?

  • The straight leg raise test (Lasegue test ) is performed with the patient in a supine position.
  • The examiner gently raises the patient’s leg by flexing the hip with the knee in extension until the patient reports pain.

What does a positive Lasegue Test mean?

  • Lasegue Test (Straight Leg Raise Test) is Considered positive: when the patient experiences pain along the lower limb in the same distribution of the lower radicular nerve roots (usually L5 or S1).

Sensitivity & Specificity

  • Sensitivity: 91 %
  • Specificity: 29 %


  • The patient often attempts to avoid the pain by lifting the pelvis on the side being examined.

    • The angle achieved when lifting the leg is estimated in degrees.
    • This angle gives an indication of severity of the nerve root irritation present (genuine Lasegue test is at 60° or less).
  • Sciatica can also be provoked by adducting and internally rotating the leg with the knee flexed.
    • This test is also described as a Bonnet or piriform is sign (adduction and internal rotation of the leg stretches the nerve as it passes through the piriformis).
  • Increases in sciatic pain on raising the head (Kernig sign) and/or passive dorsi-flexion of the great toes (Turyn sign) are further signs of significant sciatic nerve irritation (differential diagnosis should consider meningitis, subarachnoid hemorrhage, and carcinomatous meningitis).
  • Sacral or lumbar pain that increases only slowly as the leg is raised or pain radiating into the posterior thigh is usually attributable to degenerative joint disease (facet syndrome), irritation of the pelvic ligaments (tendinitis), or increased tension or shortening in the hamstrings (indicated by a soft end point, usually also found on the contralateral side). It is important to distinguish this “pseudo-radicular” pain (pseudo-Lasègue sign) from genuine sciatica (true Lasegue test).
  • Normally the leg can be raised 15 to 30° before the nerve root is stretched in the intervertebral foramen.
  • Pain occurring at over 60° of flexion suggests joint pain in the lumbar area (e.g., facet joints or sacroiliac joints).
  • It is important to differentiate whether one is dealing with joint pain, soft tissue pain, or nerve root pain.
  • If one leg is lifted and pain occurs on the opposite side, it suggests a herniated disk or a tumor. This may be called the crossover sign and usually indicates a rather large medial intervertebral disk protrusion.
  • Lasegue test and crossover sign give an indication of the degree of disk injury.
  • Many patients with large, central disk herniations are candidates for surgery, especially if there are bowel and bladder symptoms.
  • For patients who have difficulty lying supine, a modified straight leg raise test in the lateral position is possible.
    • The patient lies with the tested leg uppermost with the hip and knee flexed to 90°.
    • The lumbosacral spine is normally in a neutral position, but may be slightly flexed or extended as the patient’s condition allows.
    • The examiner then slowly extends the patient’s knee passively on the affected side.
    • The occurrence of pain or resistance to stretching the knee indicate a positive test.
  • It can also be impossible to lift the leg at the hip if the patient consciously resists and attempts to press the leg downward against the examiner’s hand.
  • Occasionally one will encounter this behavior in experienced patients undergoing examination within the scope of an expert opinion.


  • Research Gate
  • Clinical Tests for the Musculoskeletal 3rd Ed. Book

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