From Surf Wiki (app.surf) — the open knowledge base

Straight leg raise

Body movement and diagnostic test

Field	Value
name	Straight leg raise
image	Straight-leg-test.gif
caption	Straight leg test sometimes used to help diagnose a lumbar herniated disc. Usually the legs are raised alternatingly, not simultaneously.
purpose	determine if a herniated disc is the cause of leg pain

The straight leg raise is a test that can be performed during a physical examination, with the leg being lifted actively by the patient or passively by the clinician. If the straight leg raise is done actively by the patient, it is a test of functional leg strength, particularly the rectus femoris element of the quadriceps (checking both hip flexion and knee extension strength simultaneously). If carried out passively (also called Lasègue's sign, Lasègue test or Lazarević's sign), it is used to determine whether a patient with low back pain has an underlying nerve root sensitivity, often located at L5 (fifth lumbar spinal nerve). The rest of this article relates to the passive version of the test.

Technique

With the patient lying down on their back on an examination table or exam floor, the examiner lifts the patient's leg while the knee is straight.

A variation is to lift the leg while the patient is sitting. However, this reduces the sensitivity of the test.

In order to make this test more specific, the ankle can be dorsiflexed and the cervical spine flexed. This increases the stretching of the nerve root and dura.

Interpretation

If the patient experiences sciatic pain, and more specifically pain radiating down the leg (radiculopathy), when the straight leg is at an angle of between 30 and 70 degrees, then the test is positive and a herniated disk is a possible cause of the pain. A negative test suggests a likely different cause for back pain.

A positive straight leg test reproduces radiating leg pain. If it only causes back pain, then the test is negative.

A meta-analysis reported the straight-leg test as having:

sensitivity 91%
specificity 26%

If raising the opposite leg causes pain (cross or contralateral straight leg raising):

sensitivity 29%
specificity 88%

Lasègue's sign

Lasègue's sign was named after Charles Lasègue (1816–1883). In 1864 Lasègue's medical student J.J. Forst described the signs of developing low back pain while straightening the knee when the leg has already been lifted. In 1880 Serbian doctor Laza Lazarević described the straight leg raise test as it is used today, so the sign is often named Lazarević's sign in Serbia and some other countries.

References

(1980). "Nonorganic physical signs in low-back pain". Spine.
(2007). "The sensitivity of the seated straight-leg raise test compared with the supine straight-leg raise test in patients presenting with magnetic resonance imaging evidence of lumbar nerve root compression". Archives of Physical Medicine and Rehabilitation.
(December 1997). "The Slump Test: The Effects of Head and Lower Extremity Position on Knee Extension". Journal of Orthopaedic & Sports Physical Therapy.
Speed C. (2004). "Low back pain". BMJ.
(2000). "The test of Lasègue: systematic review of the accuracy in diagnosing herniated disks". Spine.
"Whonamedit - dictionary of medical eponyms".
[http://www.inet.hr/~fruzic/zdravlje/knjiga/Lazaricev%20znak.htm Lazarevićev znak] {{in lang. hr

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

symptoms-and-signs:-nervous-system medical-signs musculoskeletal-examination

Want to explore this topic further?

Ask Mako anything about Straight leg raise — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report