Lasegue Test (Straight Leg Raise) Special Test
Orthopedic Physical Examination & Clinical Assessment Guide
What is it used for?
- Diagnosing Sciatica or Lumbar Disc Herniation (specifically L4-S1 nerve roots).
How to Perform
- Position: Patient lies supine with legs straight.
- Action: Examiner slowly lifts the patient's straight leg by the heel until pain is felt.
Interpretation of Results
- Positive Test: Shooting pain down the leg (past the knee) between 30° and 70° of elevation.
- Why: At this angle, the sciatic nerve is fully stretched. Pain beyond 70° is typically due to tight hamstrings or SI joint issues, not the nerve.
Diagnostic Accuracy
- Sensitivity: 91%
- Specificity: 29%
Clinical Context & Limitations
The Lasegue Test (Straight Leg Raise) should be considered as one component of a comprehensive musculoskeletal assessment. No single special test has perfect diagnostic accuracy; thus, clinical decision-making should integrate test results with patient-reported symptoms, mechanism of injury, functional impairment, and relevant imaging.
Clinicians should be aware of potential false-positive results in patients with pain sensitisation, muscle guarding, or poor relaxation. For the Spine region, combining the Lasegue Test (Straight Leg Raise) with complementary examination tests significantly improves overall diagnostic confidence.
References
- Magee, D. J. Orthopedic Physical Assessment.
