What components should be included in the physical examination of a 55‑year‑old patient with chronic low‑back pain, intermittent neurogenic claudication, and suspected lumbar radiculopathy?

Physical Examination of Lumbar Spinal Stenosis with Radiculopathy

The physical examination must include straight-leg-raise testing, a focused neurological assessment of L4, L5, and S1 nerve roots (motor strength, reflexes, and sensory distribution), gait observation with a walking test, and screening for psychosocial risk factors that predict chronic disability. 1

Core Neurological Examination Components

Nerve Root-Specific Testing

The examination should systematically evaluate each potentially affected nerve root 1:

• L4 nerve root: Test knee extension strength and patellar reflex 1
• L5 nerve root: Assess great toe dorsiflexion and foot dorsiflexion strength 1
• S1 nerve root: Evaluate foot plantarflexion strength and ankle (Achilles) reflexes 1
• Sensory examination: Map the distribution of sensory symptoms along dermatomes corresponding to each nerve root 1

Straight-Leg-Raise Testing

The straight-leg-raise (SLR) test has 91% sensitivity but only 26% specificity for disc herniation, making it useful for ruling out radiculopathy when negative but less helpful when positive. 1

• A positive SLR is defined as reproduction of the patient's sciatica between 30 and 70 degrees of leg elevation 1
• The crossed straight-leg-raise test (pain in the affected leg when raising the contralateral leg) is more specific at 88% but only 29% sensitive, making it highly suggestive of disc herniation when positive 1

Spinal Stenosis-Specific Assessment

Walking Test and Gait Observation

A walking test with gait observation is one of three core diagnostic items recommended by international consensus for lumbar spinal stenosis. 2

• Observe for neurogenic claudication symptoms that worsen with walking and improve with rest or forward flexion 1, 3
• Downhill treadmill testing showing symptom changes has the highest positive likelihood ratio (3.1) for spinal stenosis 1

Clinical Features with Diagnostic Value

The following findings have modest predictive value 1:

• Age older than 65 years: Positive likelihood ratio of 2.5 for spinal stenosis 1
• Radiating leg pain: Positive likelihood ratio of 2.2 1
• Pseudoclaudication symptoms: Positive likelihood ratio of 1.2 1
• Pain relieved by sitting: Variable predictive value 1

Critical Red Flag Assessment

Screen for severe or progressive neurologic deficits and serious underlying conditions that require immediate imaging rather than conservative management. 1

Absolute Emergency Indicators

Assess for cauda equina syndrome 1:

• Bladder, bowel, or sexual dysfunction
• Saddle anesthesia or perianal numbness
• Bilateral lower extremity weakness or absent reflexes

Other Red Flags Requiring Prompt Evaluation

Look for 1:

• Rapidly progressive motor weakness
• History of cancer (strongest predictor of malignancy with spinal cord compression)
• Fever, recent infection, or intravenous drug use (suggesting vertebral infection)
• History of osteoporosis or chronic steroid use (risk for compression fracture)
• Age >50 years with new-onset pain and unexplained weight loss

Psychosocial Risk Factor Assessment

Psychosocial factors are stronger predictors of low back pain outcomes than physical examination findings or pain severity, and must be systematically evaluated. 1

Screen for 1:

• Depression
• Passive coping strategies
• Job dissatisfaction
• Higher baseline disability levels
• Disputed compensation claims
• Somatization

Common Pitfalls to Avoid

Individual physical examination tests have poor diagnostic accuracy when used in isolation, with most failing to reach clinically useful likelihood ratios. 4, 5

• The SLR test in isolation has high sensitivity but poor specificity, leading to many false positives 4
• Motor weakness, sensory deficits, and reflex changes show poor diagnostic performance individually 4, 5
• Combining multiple positive findings increases specificity and improves diagnostic accuracy 4
• An overall clinical evaluation integrating multiple examination findings performs better than individual tests alone 5

Clinical Decision Algorithm

For patients with positive examination findings suggesting radiculopathy or spinal stenosis, imaging with MRI (preferred) or CT is only indicated if the patient is a potential candidate for surgery or epidural steroid injection. 1

• If red flags are present: Obtain immediate MRI 1, 6
• If severe or progressive neurologic deficits: Obtain immediate MRI 1, 6
• If persistent symptoms after 6 weeks of conservative therapy in a surgical candidate: Consider MRI 1, 6
• If mild symptoms without red flags: Continue conservative management and reassess at 1 month 1