The early history of the Laségue sign has been reviewed, and credit is given to Fajersztajn for the first demonstration of the crossed or well-leg-raising test. Numerous observers have shown that flexion of the thigh on the abdomen with the leg extended causes rostral movement of the contralateral extradural nerve roots at the fourth and fifth lumbar and first. sacral levels, with approximation of these nerve roots to the anterior spine wall; these findings have been confirmed. It has been shown that approximately one-third of all Patients with verified disc protrusions have a positive well-leg-raising test, and that almost all of these have large protrusions. In the cases which this relationship has been studied, the disc protrusion has been found on the medial aspect of the affected nerve root.