Mechanical Low Back Pain

Orthopedics

Non-specific low back pain without red flags or radiculopathy; 90% improve within 6 weeks.

History taking

  • • Onset (acute / subacute), trigger (lifting, posture)
  • • Site, radiation, severity, what makes it better/worse
  • • Red flags: night pain, weight loss, fever, neurological deficit, bladder/bowel symptoms

Examination

  • • Inspection: posture, scoliosis
  • • Palpation: paraspinal spasm, midline tenderness
  • • Range of movement
  • • Neurological screen lower limbs
  • • SLR (positive at <60° suggests radiculopathy)
  • • Saddle sensation + anal tone if cauda equina concern

Red flags

  • • Age <20 or >55, trauma, cancer history
  • • Thoracic pain, night pain, systemic features
  • • Saddle anaesthesia, bladder/bowel dysfunction (cauda equina — emergency MRI)
  • • Bilateral neurology, progressive weakness

Differential diagnosis

  • • Disc prolapse with radiculopathy
  • • Spinal stenosis
  • • Vertebral fracture
  • • Ankylosing spondylitis (inflammatory features)
  • • Malignancy / infection

Recommended investigations

  • • No imaging in first 6 weeks if no red flags
  • • MRI lumbar spine if red flags or radiculopathy >6 weeks
  • • Bloods (FBC, CRP, ALP, myeloma screen) if systemic features

Diagnosis

  • • Clinical: mechanical pattern, no red flags, no neurology

Initial treatment / management

  • • Stay active — bed rest worsens outcomes
  • • Heat / cold packs, posture advice
  • • Physiotherapy if persistent >2 weeks
  • • Stepped analgesia

Drug therapy

  • • Paracetamol + topical NSAID first line
  • • Add oral NSAID (ibuprofen 400 mg TDS or naproxen 250–500 mg BD) with PPI cover
  • • Short course weak opioid (codeine 30 mg QDS) if needed
  • • Avoid benzodiazepines and routine muscle relaxants

Lifestyle advice

  • • Maintain activity, ergonomic advice
  • • Lose weight if BMI elevated
  • • Smoking cessation

Prescription examples

  • • Ibuprofen 400 mg PO TDS × 7 d + omeprazole 20 mg OD
  • • Paracetamol 1 g PO QDS PRN
  • • Physiotherapy referral

Follow-up advice

  • • Review in 2–4 weeks; sooner if red flags emerge
  • • Re-evaluate work modification, mental health

Patient counselling

  • • Reassure: most resolve in 6 weeks
  • • Importance of returning to normal activity
  • • Avoid passive treatments alone (manipulation, traction without exercise)

Referral criteria

  • • Urgent MRI / neurosurgery: cauda equina syndrome, progressive neuro deficit, suspected malignancy / infection
  • • Pain clinic / spinal surgery if persistent >12 weeks

Clinical pearls

  • • Yellow flags (fear avoidance, low mood, work issues) predict chronicity — address early

References

  • • NICE NG59 Low back pain 2016/2020
  • • BMJ Best Practice

Educational outpatient guide — verify against local guidelines before clinical use.

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