Crossed Straight Leg Raise Test

The Crossed Straight Leg Raise Test (XSLR) – also known as Fajersztajn’s sign or the well-leg raise – is a neurological provocation test used when lumbar nerve root compression due to central disc herniation is suspected¹. First described by Fajersztajn in 1901, the XSLR is more specific but less sensitive than the standard Straight Leg Raise (SLR) test².

A positive finding occurs when pain radiates into the symptomatic (ipsilateral) leg while the opposite, asymptomatic leg is passively lifted. This typically indicates a large central herniation compressing multiple roots simultaneously.

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Test execution

PurposeTo detect severe nerve root involvement (most often L5 or S1) due to central lumbar disc herniation compressing the dural sac or multiple roots.

Procedure

• Patient lies supine.

• Clinician identifies the affected side based on symptoms.

• The unaffected (contralateral) leg is lifted passively in full extension.

• Hip flexion is slowly increased to ~40°.

• The test is positive if the patient experiences radiating pain in the affected leg.

Interpretation

• Positive test: Pain in the symptomatic leg when the opposite leg is raised.

• Clinical significance: Suggests large central disc herniation with bilateral or crossing nerve root compression.

• Differentiation: More specific than SLR, but less sensitive².

What it tests

• Structures: Mechanical irritation of lumbar roots (L5 or S1).

• Biomechanics: Raising the contralateral leg stretches dura mater and bilateral roots.

  Large herniations reduce space and produce contralateral pain³.

Common errors

• Lifting the affected leg (standard SLR, not XSLR).

• Bending the knee during the maneuver.

• Raising the leg too quickly, causing muscle strain.

• Misinterpreting local back pain as radicular pain.

Evidence and reliability

• Specificity: High (90–97 %) for central disc herniation¹.

• Sensitivity: Low (<40 %), especially compared to standard SLR².

• Clinical use: Helpful in identifying surgically relevant herniations, but not suitable for primary care screening⁴.

• Reliability:

  • Intra-rater: moderate to good⁵

  • Inter-rater: weak to moderate⁵

Clinical considerations

The XSLR provides important diagnostic value in detecting severe root compression. However, due to its low sensitivity and variable inter-rater reliability, the test should not be used in isolation. Always interpret in combination with:

• Patient history

• Other clinical tests

• Imaging (MRI/CT)

Best applied in specialist settings or pre-surgical evaluations.

Kilder:

1. Hudgins WR. The crossed-straight-leg-raising test. New England Journal of Medicine. 1977;297(20):1127–.

2. Windt D, Simons E, Riphagen I, Ammendolia C, Verhagen A, Laslett M, et al. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain. Cochrane Database of Systematic Reviews. 2010;2011(2):CD007431.

3. The Student Physical Therapist. Crossed Straight Leg Raise Test. Tilgjengelig fra: https://www.youtube.com/watch?v=5oFp7Krd9qk&ab_channel=TheStudentPhysicalTherapist (sist åpnet 05.07.2025)

4. Windt D, Simons E, Riphagen I, Ammendolia C, Verhagen A, Laslett M, et al. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain. Cochrane Database of Systematic Reviews. 2010;2011(2):CD007431.

5. Nee RJ, Coppieters MW, Boyd BS. Reliability of the straight leg raise test for suspected lumbar radicular pain: A systematic review with meta-analysis. Musculoskeletal Science & Practice. 2022;59:102529.