Lasegue's Test (Straight Leg Raise): Checking for Sciatica

Lasegue's Test, widely known as the Straight Leg Raise (SLR) Test, is the gold standard neurodynamic test for the lower limb. It is used to detect nerve root irritation in the lumbar spine, often referred to as sciatica.

1. Purpose

The primary purpose of Lasegue's Test is to **identify** lumbar nerve root compression or irritation, most commonly caused by a herniated disc at the L4-L5 or L5-S1 levels (Sciatica).

2. How to Perform

1. The patient is positioned in supine (lying on their back) without a pillow.
2. The examiner passively flexes the patient's hip while keeping the knee fully extended.
3. The leg is lifted slowly until the patient complains of pain or tightness.
4. Sensitization (Confirmation): If pain is felt, lower the leg slightly until the pain stops, then dorsiflex the foot (Bragard's sign) or ask the patient to flex their neck. This increases dural tension to confirm the pain is neural.

3. Positive & Negative Sign

Positive Sign (Test is POSITIVE):
A positive test is the reproduction of the patient's familiar radiating leg pain (sciatica) occurring between 30 and 70 degrees of hip flexion.

• Pain extending below the knee is a strong indicator of nerve root pathology.

Negative Sign (Test is NEGATIVE):
A negative test involves minimal or no pain, or pain that only occurs in the lower back or hamstrings (simple tightness) at angles greater than 70 degrees.