THE Laségue test, used in the evaluation of patients with sciatica, is sometimes confused with the Kernig test, which it closely resembles.1-4
Sciatica, which is now defined as pain along the course of the sciatic nerve, was first described by the early Greek and Roman physicians.5 However, it was not related to dysfunction of the sciatic nerve until 1764, when Domenico Cotugno of Naples published his De Ischiade Nervosa Commentarius.6 Irritation of the sciatic nerve and its component nerve roots was subsequently found to result from different underlying conditions, such as spinal arthritis, intraspinal and extraspinal neoplasms, and spondylolisthesis.7 Recently, it has become apparent that sciatica is often caused by nerve root compression from a herniated nucleus pulposus of a lumbar intervertebral disk.8 The common awareness of lumbar disk disease at the present time has led to widespread use of the Laségue test.
Robert H. Wilkins, Irwin A. Brody. Laségue's Sign. Arch Neurol. 1969;21(2):219–220. doi:10.1001/archneur.1969.00480140119015