02/09/2025
Straight Leg Raise (SLR) Test
Definition
The Straight Leg Raise (SLR) test is a common neurodynamic test used to assess for lumbar nerve root irritation or compression, especially involving the sciatic nerve and L4–S1 nerve roots.
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How to Perform
1. Patient lies supine (on their back).
2. Therapist lifts the patient’s straight leg (knee extended, ankle relaxed) slowly upward.
3. Observe the angle at which pain or symptoms appear.
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Positive Test
Reproduction of radicular pain (sharp, shooting, tingling, burning) radiating down the posterior thigh, calf, or foot between 30°–70° of hip flexion.
This indicates nerve root irritation (commonly due to lumbar disc herniation or sciatica).
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Differentiation
Back pain only (without leg radiation) → more likely lumbar strain or mechanical issue.
Pain below the knee → more specific for nerve root compression.
Dorsiflexion of the ankle (Bragard’s test) or flexing the neck (Slump test) can increase nerve tension and confirm neural involvement.
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Clinical Value
Highly sensitive for lumbar disc herniation (if negative, herniation is less likely).
Not very specific (positive test can also occur with other conditions like hamstring tightness, hip pathology, or piriformis syndrome).
