Straight Leg Raise Modifications to Improve Sciatica Assessment
- Dr. Shawn Thistle
Radicular symptoms accompany low back pain (LBP) in a remarkably high percentage of cases, with some estimates suggesting that 60% of patients with LBP also present with some degree of radiating leg pain. The cause of this radiating pain is multifactorial, with mechanical compression comprising the most common cause, although inflammatory processes, neural adhesions, arachnoiditis or viral mononeuritis are possible, albeit less common causes.
The straight leg raise (SLR) test is the most performed physical test for diagnosis of sciatica and lumbar disc herniation and is considered positive when radiating pain along the course of the sciatic nerve is reported between 30 and 70 degrees of hip flexion. As a diagnostic tool, the SLR has shown high sensitivity but also low specificity. The addition of dorsiflexion of the ankle (also called the Bragard test or Bragard’s sign) is purported to lower the angle at which a positive SLR test is noted; however, the research on the Bragard test itself is limited.
To address the low specificity of the SLR, the authors examined the reliability (i.e. the ability to produce consistent results) of an extended SLR (ESLR) – which adds hip internal rotation and/or ankle dorsiflexion to the standard test – in low back pain patients, with and without sciatica.
THIS WEEK'S RESEARCH REVIEW: “Straight Leg Raise Modifications to Improve Sciatica Assessment”
This paper was published in BMC Musculoskeletal Disorders (2021) and this Review is posted in Recent Reviews, Lumbar Spine - Disc/Sciatica/Neurological, Clinical Testing & Procedures and the 2021 Archive.