Straight leg raising test (or Lasègue test): The test is performed with the patient lying in a comfortable position with the head and pelvis flat. While full knee extension is maintained, the patient’s leg is slowly lifted off the table. The limb is progressively elevated until maximal hip flexion is reached or the patient asks the examiner to stop due to pain. The angle formed by the lower limb and the examination table at the point of maximal elevation is noted. The leg is brought back until no pain is felt anymore and the foot is dorsiflexed. For further neurological tissue provocation, the patient is asked to bring the chin to the chest. The patient is encouraged to report reproduction of symptoms during the whole test. The procedure is repeated with the opposite limb.
The test is positive when radiating symptoms (sciatica) are reproduced.
The SLR has a relatively high sensitivity (91%) but modest specificity (26%) for diagnosing herniated disc (Casey et al. 2007; Bezemer et al. 2000). The diagnostic accuracy of the straight leg raising test is limited by its low specificity (Bezemer et al 2000).