What is the recommended physical assessment and management approach for a patient presenting with back pain, considering their age, medical history, and lifestyle factors?

Physical Assessment for Back Pain

Perform a focused history and physical examination to categorize the patient into one of three groups—nonspecific low back pain, radiculopathy/spinal stenosis, or serious underlying pathology—which determines all subsequent management decisions. 1, 2

History Taking Components

Pain Characteristics

• Document pain location (localized vs. radiating), frequency (constant vs. intermittent), duration, onset circumstances, and quality of pain 1, 2
• Ask specifically about leg pain distribution to identify sciatica, which suggests nerve root compression at L4/L5 or L5/S1 levels 1
• Inquire about pseudoclaudication symptoms (leg pain with walking that improves with sitting/forward flexion), which indicates spinal stenosis 2, 3
• Review previous episodes, treatments attempted, and their effectiveness 1, 2

Red Flag Screening (Requires Immediate Imaging)

• History of cancer (increases malignancy probability from 0.7% to 9%, positive likelihood ratio 14.7) 1, 2, 3
• Urinary retention (90% sensitivity for cauda equina syndrome) or new fecal incontinence 1, 4
• Unexplained weight loss (positive likelihood ratio 2.7) 1, 2
• Age >50 years (positive likelihood ratio 2.7) 1, 2
• Failure to improve after 1 month (positive likelihood ratio 3.0) 1, 2
• Fever, recent infection, or IV drug use (suggests spinal infection) 1, 3
• Significant trauma or corticosteroid use (suggests compression fracture) 1, 3
• Rapidly progressive or severe neurologic deficits affecting multiple levels 1, 4

Additional Historical Elements

• Screen for ankylosing spondylitis risk factors: younger age, morning stiffness improving with exercise, alternating buttock pain, awakening with back pain in the second half of the night 1
• Consider non-spinal causes: pancreatitis, nephrolithiasis, aortic aneurysm, endocarditis, viral syndromes 1, 2
• Assess psychosocial factors: depression, anxiety, job dissatisfaction, passive coping strategies (stronger predictors of chronicity than physical findings) 4, 3

Physical Examination

Neurologic Assessment

• Straight-leg-raise test: Reproduction of sciatica between 30-70 degrees indicates nerve root compression 1
• Motor strength testing by nerve root:
  • L4: Knee extension strength and patellar reflex 1
  • L5: Great toe and foot dorsiflexion strength 1
  • S1: Foot plantarflexion and ankle reflex 1
• Dermatomal sensory testing: Map exact distribution of numbness to distinguish dermatomal from non-dermatomal patterns 4
• Reflex examination: Patellar and Achilles reflexes to identify nerve root compression 4

Musculoskeletal Evaluation

• Perform appropriately directed musculoskeletal examination with attention to spine range of motion, palpation for tenderness, and postural assessment 1
• Evaluate for signs of spinal deformity or asymmetry 1

Diagnostic Categorization After Assessment

Nonspecific Low Back Pain (85% of cases)

• Localized pain without radicular symptoms, no red flags, no specific identifiable cause 2, 3
• Management: Reassurance about favorable prognosis, remain active, acetaminophen or NSAIDs first-line 4, 2
• No routine imaging indicated 4, 3

Radiculopathy/Spinal Stenosis

• Sciatica in dermatomal distribution with corresponding motor/sensory deficits 1, 3
• Management: Conservative care for 4-6 weeks; consider MRI if candidate for surgery or epidural injection 2

Serious Underlying Pathology

• Any red flags present require immediate MRI (preferred over CT for soft tissue visualization and no radiation) 4, 3
• Urgent laboratory studies if infection suspected: CBC, ESR, CRP 3

Critical Pitfalls to Avoid

• Never delay imaging when red flags are present—missing cauda equina syndrome causes permanent disability 3
• Do not routinely image nonspecific low back pain—this leads to incidental findings and unnecessary interventions 4, 3
• Lower threshold for imaging in elderly patients (>65-70 years) due to higher prevalence of serious pathology 4
• Do not ignore psychosocial factors—depression, somatization, and job dissatisfaction predict chronicity better than anatomical findings 4, 3

Follow-Up Strategy

• Reevaluate within 1 month if symptoms persist or worsen 4, 2
• Earlier reassessment warranted for severe symptoms, progressive deficits, or new red flags 4
• Consider cognitive behavioral therapy for patients with high psychosocial risk 4