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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