What exam movements should be used to assess sciatica in a 30-50 year old adult with a history of lower back pain?

Physical Examination Maneuvers for Sciatica Assessment

The straight leg raise (SLR) test is the primary examination maneuver for assessing sciatica, with 91% sensitivity for detecting lumbar disc herniation causing nerve root compression, and should be supplemented with the crossed SLR test, Slump test, and Bowstring test when the standard SLR is negative but clinical suspicion remains high. 1

Core Examination Maneuvers

Straight Leg Raise (SLR) Test

• Technique: Raise the affected leg while the patient is supine, keeping the knee extended 1
• Positive result: Reproduction of radicular pain radiating below the knee in the sciatic nerve distribution 1
• Sensitivity: 91% (95% CI, 82% to 94%) 1
• Specificity: 26% (95% CI, 16% to 38%) - meaning many false positives occur 1
• Critical limitation: A negative SLR does not exclude sciatica, as it misses 9% of true cases, and sensitivity drops below 50% in patients over 60 years old 1

Crossed Straight Leg Raise Test

• Technique: Raise the unaffected leg and assess whether this reproduces pain in the symptomatic leg 1
• Positive result: Pain in the affected leg when raising the contralateral leg 1
• Sensitivity: 29% (95% CI, 24% to 34%) - lower than standard SLR 1
• Specificity: 88% (95% CI, 86% to 90%) - much higher than standard SLR, making it useful for confirmation 1

Bragard Test (Enhanced SLR)

• Technique: At the end of the standard SLR, add passive ankle dorsiflexion 2
• Advantage: More sensitive than SLR alone for detecting nerve root tension 2
• Clinical value: Can be positive when standard SLR remains equivocal 2

Slump Test

• Technique: Patient sits with legs extended, examiner passively flexes the patient's neck, then extends the painful leg 2
• Alternative sequence: Extend the leg first, then flex the neck 2
• Clinical value: Particularly useful when SLR is negative but lumbar root damage is suspected in patients with poorly defined lower extremity pain 2
• Advantage: Can detect sciatica missed by standard SLR 2

Bowstring Test

• Technique: At the end of a positive SLR, slightly flex the knee, then press on the peroneal and/or tibial nerves in the popliteal fossa 2
• Positive result: Reproduction of the patient's exact sciatic pain 2
• Clinical value: Helps confirm nerve root involvement when other tests are equivocal 2

Comprehensive Neurological Examination

The SLR tests must be interpreted within a complete neurological examination that assesses specific nerve root levels, as the combination of radicular pain pattern, dermatomal sensory changes, and motor weakness establishes the diagnosis even without positive SLR. 1

L4 Nerve Root Assessment

• Motor testing: Knee extension strength and patellar reflex 1, 3
• Sensory distribution: Anterior lateral thigh and medial lower leg 3
• Pain pattern: Anterior lateral thigh radiating to lower leg 3

L5 Nerve Root Assessment

• Motor testing: Great toe dorsiflexion and foot dorsiflexion strength 1
• Pain pattern: Lateral leg radiating to dorsum of foot 3
• Sensory distribution: Lateral leg and dorsal foot 3

S1 Nerve Root Assessment

• Motor testing: Foot plantarflexion and ankle (Achilles) reflex 1
• Pain pattern: Posterior thigh and leg 1
• Sensory distribution: Posterior leg and lateral foot 1

Clinical Interpretation Algorithm

When SLR is Positive

• Proceed with crossed SLR to increase specificity 1
• Complete nerve root-specific motor, sensory, and reflex examination 1
• Document pain distribution (must extend below the knee to qualify as sciatica) 1

When SLR is Negative but Sciatica is Suspected

• Perform Bragard test (SLR with ankle dorsiflexion) 2
• Perform Slump test in sitting position 2
• Perform Bowstring test if any SLR variant reproduces symptoms 2
• Combined testing takes less than 2 minutes and improves both sensitivity and specificity 2

Diagnostic Confirmation Without Positive SLR

• Radicular pain pattern extending below the knee in sciatic distribution 1
• Dermatomal sensory changes corresponding to specific nerve root 1
• Motor weakness in nerve root distribution 1
• These findings establish sciatica diagnosis even with negative SLR 1

Critical Pitfalls to Avoid

• Do not rely solely on SLR: Its modest 26% specificity means many positive tests are false positives, and negative tests can occur with true pathology 1
• Do not confuse hip pathology with sciatica: Perform FABER and FADIR tests to exclude hip joint pathology 3
• Do not assume dermatomes are reliable: Dermatomal patterns are unreliable for precise localization 4
• Do not order immediate imaging based on positive SLR alone: Imaging is indicated only for severe/progressive neurological deficits or symptoms persisting beyond 4-6 weeks despite conservative management 1, 3