Back Pain — Overview

Low back pain (LBP) is one of the most prevalent and burdensome musculoskeletal conditions in Australia, affecting approximately 4 million Australians at any given time and representing the leading cause of disability-adjusted life years (DALYs) in the country. It is the most common reason for GP consultations in musculoskeletal medicine and a major driver of work absenteeism, healthcare utilisation, and early retirement.

Australia's National Pain Strategy and the Australian Evidence-Based Guidelines for the Management of Low Back Pain (2021) emphasise the central role of active, self-management-focused approaches, avoidance of unnecessary imaging, and discouragement of passive, medicalised care for non-specific LBP.

The lumbar spine consists of five vertebrae (L1–L5), intervertebral discs, facet joints, ligaments, and paraspinal musculature. Pain can arise from any of these structures, and in most non-specific LBP, the precise pain generator cannot be identified. Proposed mechanisms include:

Non-Specific LBP Mechanisms

• Intervertebral disc degeneration: Loss of disc height, annular tears, and nucleus pulposus protrusion — stimulate nociceptors in the annulus fibrosus and posterior longitudinal ligament
• Facet joint pain: Synovial joint inflammation, cartilage degeneration — can refer pain to buttocks and proximal thigh
• Paraspinal muscle spasm: Protective response to injury; perpetuates pain cycle
• Central sensitisation: In chronic LBP, altered spinal and cortical pain processing amplifies pain disproportionate to tissue pathology — explains poor correlation between imaging findings and pain severity
• Psychosocial factors ("yellow flags"): Fear-avoidance behaviour, catastrophising, low self-efficacy, depression, and anxiety are major drivers of chronification and disability

Specific LBP Mechanisms

• Disc herniation: Nucleus pulposus extrusion compresses nerve roots — causes radiculopathy (dermatomal pain, neurological deficit)
• Spinal stenosis: Narrowing of spinal canal or neural foramina from osteophytes, ligamentum flavum hypertrophy, disc protrusion — neurogenic claudication
• Spondylolisthesis: Forward slippage of vertebral body — degenerative (L4/5 most common in adults) or isthmic (pars interarticularis defect, common in young athletes)
• Vertebral fracture: Osteoporotic compression fracture (acute pain in older adults), traumatic fracture, or malignant pathological fracture
• Inflammatory LBP (spondyloarthropathy): Enthesitis at sacroiliac joints and vertebral attachments — ankylosing spondylitis, axial spondyloarthritis, psoriatic arthritis
• Infection: Discitis, vertebral osteomyelitis — haematogenous spread; immunosuppressed patients, IVDU, recent spinal procedure
• Malignancy: Primary bone tumours (rare) or metastatic disease (prostate, breast, lung, kidney, thyroid) — pathological fracture risk

A thorough history and physical examination are the cornerstone of LBP assessment. The primary clinical objective is to differentiate non-specific LBP (the vast majority) from specific LBP with identifiable pathology or serious underlying disease.

Red Flag Screening

History Features

• Onset and duration: Acute (often precipitated by activity), insidious (inflammatory), or after trauma
• Character: Localised dull ache (mechanical), sharp shooting (radicular), band-like (referred), deep boring (serious pathology)
• Radiation: Below knee (L4–S1 root compression), to groin (renal/ureteric), to buttocks only (somatic referred/facet)
• Aggravating/relieving factors: Worse with flexion (disc); worse with extension (stenosis, facet); worse at rest/night, better with exercise (inflammatory); worse with walking improved by sitting (neurogenic claudication)
• Morning stiffness: >1 hour suggests inflammatory disease; <30 minutes typical of mechanical LBP
• Neurological symptoms: Paraesthesia, weakness, bladder/bowel dysfunction
• Psychosocial assessment: Depression, anxiety, work stress, litigation, fear-avoidance beliefs (STarT Back Tool or Örebro screening recommended)

Physical Examination

• Inspection: Posture, scoliosis, kyphosis, gait, list
• Range of motion: Flexion (disc/mechanical), extension (facet/stenosis), lateral flexion
• Palpation: Midline tenderness (fracture, infection), paraspinal tenderness (muscle spasm), sacroiliac joint tenderness
• Neurological examination: Lower limb reflexes (L3/4 — knee jerk; L5/S1 — ankle jerk), sensation (dermatomal map), power (hip flexion L2, knee extension L3/4, ankle dorsiflexion L4, great toe extension L5, plantarflexion S1)
• Straight leg raise (SLR): Positive (<60°, reproduces radiating leg pain) — sensitive for L4–S1 disc herniation; crossed SLR highly specific
• FABER/FADIR: SI joint provocation; hip pathology exclusion
• Schober test: Reduced lumbar flexion in ankylosing spondylitis

Routine imaging for acute non-specific LBP is NOT recommended. Imaging does not improve outcomes and increases the risk of medicalisation, incidental findings, and unnecessary intervention. Imaging is indicated only when red flags are present or when symptoms persist beyond expected recovery.

• Inv-Essential
  No Imaging (Acute Non-Specific LBP)

  Clinical reassurance preferred. Imaging findings (disc degeneration, facet arthropathy, disc bulges) are present in asymptomatic populations and do not predict prognosis or guide management.
• Inv-Essential
  Plain X-Ray — Lumbar Spine

  Indicated for: suspected fracture (trauma, osteoporosis), suspected ankylosing spondylitis (sacroiliac joints — AP pelvis), significant deformity, or persistent pain >4–6 weeks. Limited sensitivity for disc pathology, infection, early malignancy.
• Inv-Essential
  MRI — Lumbar Spine

  Gold standard for neural compression, disc herniation, cauda equina, infection (discitis/osteomyelitis), malignancy, and inflammatory disease. Indicated urgently if cauda equina syndrome suspected. For radiculopathy not resolving after 4–6 weeks of conservative treatment.
• Inv-Recommended
  CT — Lumbar Spine

  Superior bone detail. Useful for: bony stenosis, spondylolysis/spondylolisthesis, fracture characterisation, pre-surgical planning. Second-line to MRI for soft tissue pathology.
• Inv-Essential
  Full Blood Count + ESR + CRP

  When red flags present (infection, malignancy, inflammatory). Elevated ESR/CRP may suggest infection or inflammatory arthropathy. Normal values do not exclude malignancy.
• Inv-Recommended
  HLA-B27

  If inflammatory LBP suspected (age <45, insidious onset, morning stiffness >1 hour). Positive in ~85–90% of ankylosing spondylitis patients; not diagnostic alone.
• Inv-Recommended
  Bone Scan / SPECT-CT

  Detect occult fractures, bony metastases, active inflammatory enthesitis (spondyloarthropathy). Increasing use of SPECT-CT for facet joint pain localisation.
• Inv-Specialist
  Dual-energy X-Ray Absorptiometry (DXA)

  Bone mineral density assessment in patients with suspected osteoporotic vertebral fracture, prolonged corticosteroid use, or multiple vertebral fractures.

Risk stratification identifies patients likely to develop chronic LBP, guiding early intervention. The STarT Back Screening Tool (9-item questionnaire) is the most validated tool in Australian primary care, stratifying patients into low, medium, and high psychosocial risk.

STarT Back Screening Tool Stratification

Yellow Flag Assessment (Psychosocial)

• Beliefs: Belief that pain means serious harm; expectation of passive treatment
• Behaviours: Fear-avoidance, catastrophising, reduced activity
• Compensation and litigation: Workers' compensation claims associated with worse outcomes
• Diagnosis and treatment issues: Multiple previous investigations and treatments; passive approaches
• Emotions: Depression, anxiety, irritability
• Family and work: Overprotective family; poor job satisfaction or physical demands

Cauda Equina Syndrome — Emergency Risk

The evidence-based approach to non-specific LBP prioritises active self-management, patient education, and exercise over passive treatments and pharmacotherapy. The 2021 Australian Commission on Safety and Quality in Health Care (ACSQHC) guidelines align with this approach.

Core Non-Pharmacological Treatments

• Patient education and reassurance: Explain benign natural history; 90% of acute LBP resolves within 6 weeks. Avoid nocebo messaging ("your back is damaged", "avoid all activity")
• Stay active: Activity and return to normal function faster than bed rest. Bed rest is NOT recommended.
• Exercise therapy: Most effective intervention for chronic LBP. Supervised exercise (general, McKenzie, core stabilisation, yoga, aquatic) reduces pain and disability. Type of exercise is less important than adherence.
• Physiotherapy: Manual therapy (spinal manipulation, mobilisation) has modest short-term benefit in acute LBP. Most effective as part of multimodal physiotherapy.
• Psychological therapies: Cognitive behavioural therapy (CBT) and acceptance and commitment therapy (ACT) are effective for chronic LBP with significant psychosocial contributions.
• Multidisciplinary pain rehabilitation: For chronic, disabling LBP — combines physical, psychological, and social interventions. Most effective approach for reducing disability in chronic LBP.
• Weight management: Obesity associated with higher LBP prevalence and severity — support weight loss where indicated.

Pharmacotherapy

Interventional procedures and surgery are reserved for patients with specific pathology (disc herniation with radiculopathy, spinal stenosis, spondylolisthesis) who have failed adequate conservative management, or for urgent indications (cauda equina syndrome, unstable fracture, spinal infection, malignant cord compression).

Interventional Procedures

• Epidural corticosteroid injection (ECI): Short-term relief (4–8 weeks) for radiculopathy from disc herniation or spinal stenosis. Not effective for non-specific LBP. Risks: infection, bleeding, nerve injury, short-lived benefit.
• Facet joint injection / medial branch block: Diagnostic and therapeutic for suspected facet-mediated pain. Short-term benefit; radiofrequency ablation of medial branch nerves provides longer-lasting relief (6–18 months).
• Sacroiliac joint injection: For suspected SI joint pain confirmed by provocation tests; fluoroscopy- or CT-guided corticosteroid injection.
• Trigger point injection: For myofascial pain with palpable trigger points; limited evidence.

Surgical Indications

• EMERGENCY surgery: Cauda equina syndrome — immediate decompression within hours
• Disc herniation with radiculopathy: Discectomy if severe or progressive neurological deficit, or persistent radiculopathy after 6–12 weeks of conservative management
• Spinal stenosis: Decompression (laminectomy) for neurogenic claudication limiting function, after failure of conservative management
• Spondylolisthesis: Spinal fusion if high-grade or associated with neurological deficit
• Vertebral fracture: Vertebroplasty/kyphoplasty for symptomatic osteoporotic compression fracture; stabilisation for traumatic fracture with instability
• Spinal infection: Surgical debridement if neurological compromise, instability, or failure of antibiotic therapy
• Malignant cord compression: Surgical decompression + stabilisation (if surgically fit) or radiotherapy

Inflammatory low back pain (inflammatory LBP) requires a distinct approach from mechanical LBP. The hallmark features — insidious onset before age 45, morning stiffness >1 hour, improvement with exercise, nocturnal pain, buttock pain — suggest axial spondyloarthropathy (axSpA) including ankylosing spondylitis (radiographic axSpA) and non-radiographic axSpA.

Assessment of Inflammatory LBP

• HLA-B27 testing and CRP/ESR
• AP pelvis X-ray (sacroiliitis — grading per modified New York criteria)
• MRI sacroiliac joints (active bone marrow oedema — most sensitive for early non-radiographic axSpA)
• Rheumatology referral — initiation of biological therapy requires specialist assessment

Treatment of Inflammatory LBP / axSpA

• NSAIDs: First-line; continuous use may slow radiographic progression in ankylosing spondylitis. Naproxen or indomethacin preferred.
• Physiotherapy and exercise: Essential — hydrotherapy, extension exercises, breathing exercises
• TNF inhibitors (adalimumab, etanercept, infliximab): PBS-listed for active ankylosing spondylitis (radiographic axSpA) failing ≥2 NSAIDs over ≥4 weeks — requires rheumatologist prescription
• IL-17 inhibitors (secukinumab, ixekizumab): PBS-listed alternative to TNF inhibitors for radiographic axSpA; preferred in patients with comorbid IBD (caution — TNF preferred for IBD)
• JAK inhibitors (tofacitinib, upadacitinib): Emerging role in axSpA; growing PBS indications

Monitoring of LBP focuses on functional recovery, pain control, medication safety, and psychological wellbeing. Regular reassessment prevents over-medicalisation and identifies patients failing to improve as expected.

NSAID Monitoring

• Renal function (eGFR) if using NSAIDs >2 weeks or in at-risk patients (CKD, heart failure, elderly)
• Blood pressure — NSAIDs raise BP and can precipitate cardiac failure
• GI symptoms — add PPI (omeprazole 20 mg daily) in patients with GI risk factors, age >65, or concurrent anticoagulant/antiplatelet use
• Avoid NSAIDs in eGFR <30, heart failure, active peptic ulcer disease, third trimester pregnancy

🤰 Pregnancy

LBP affects up to 70% of pregnant women. Management is largely non-pharmacological.

• Exercise and physiotherapy: Safe and effective — water-based exercise, pelvic floor physiotherapy, stabilisation exercises
• Paracetamol: First-line analgesic — use at lowest effective dose for shortest duration; emerging concerns about prolonged use
• NSAIDs: AVOID after 20 weeks gestation (premature closure of ductus arteriosus, oligohydramnios); acceptable with caution before 20 weeks if essential
• Opioids: Avoid — risk of neonatal abstinence syndrome, growth restriction
• Sacropelvic belt: May reduce pelvic girdle pain; safe and inexpensive

👶 Paediatrics and Adolescents

• LBP in children <10 years is uncommon and should always prompt investigation for serious pathology (infection, malignancy, spondylolysis)
• In adolescents, spondylolysis (pars stress fracture) is common in young athletes — oblique X-ray ± SPECT-CT; managed with rest and physiotherapy
• NSAIDs are appropriate in adolescents; avoid opioids; paracetamol first-line
• Screen for juvenile idiopathic arthritis / enthesitis-related arthritis in adolescents with inflammatory features

👴 Elderly Patients

• Osteoporotic vertebral compression fractures are a major cause of acute severe LBP in older adults — always consider in postmenopausal women and men >70
• Spinal stenosis and multilevel degenerative disease increasingly prevalent with age — neurogenic claudication distinguished from vascular claudication (no relief sitting in vascular)
• NSAIDs: use with extreme caution in elderly (GI, renal, cardiovascular risks); prefer short duration with PPI; consider topical NSAIDs as alternative
• Opioids in elderly: heightened fall risk, cognitive impairment, constipation — avoid or use at lowest dose if essential
• Ensure DXA scan and osteoporosis management if vertebral fracture identified

🛡️ Patients on Anticoagulation

• Avoid NSAIDs — increased bleeding risk; worsen anticoagulant effect (especially warfarin)
• Paracetamol first-line; short-course low-dose opioid if severe acute pain
• Spinal procedures (injections, surgery) — discuss anticoagulant management with treating physician; bridge therapy planning required

💼 Workers' Compensation

• Return-to-work is a therapeutic goal — evidence shows longer time off work predicts worse long-term outcomes
• Involve occupational physician or occupational physiotherapist early
• Avoid unnecessary sick certificates for non-specific LBP beyond 2–4 weeks
• Psychosocial factors particularly important in compensation settings — address fear-avoidance beliefs actively

Stewardship in LBP management focuses on reducing low-value care: unnecessary imaging, inappropriate opioid prescribing, passive treatments, and unnecessary spinal interventions. The ACSQHC Choosing Wisely Australia recommendations specifically address LBP.

Opioid Stewardship

• Opioids for LBP should only be considered for severe acute pain, for the shortest possible duration (<1 week), at the lowest effective dose
• Document opioid risk assessment before prescribing — AUDIT-C for alcohol, ORT (Opioid Risk Tool) for addiction risk
• Use state-based prescription drug monitoring programs (SafeScript VIC, NarxCheck NSW) to identify high-risk patients
• Avoid concurrent opioid + benzodiazepine prescribing (fatal overdose risk)
• If transitioning to chronic opioid therapy, establish clear goals, regular review (3-monthly), and an exit strategy

Most acute LBP resolves within 6 weeks without specific treatment. Follow-up is targeted at patients at risk of chronification or with persistent symptoms.

Prevention

• Exercise: Regular aerobic exercise and core strengthening reduces LBP recurrence
• Weight management: Maintain healthy BMI — reduces lumbar load
• Workplace ergonomics: Ergonomic workstation assessment, manual handling training for physical workers
• Smoking cessation: Smoking impairs disc nutrition and healing
• Osteoporosis prevention: Calcium, vitamin D, and antiresorptive therapy where indicated to prevent vertebral fractures
• Avoid prolonged sitting: Encourage movement breaks

• 01
  Hartvigsen J, et al. What low back pain is and why we need to pay attention. Lancet. 2018;391(10137):2356–2367.
• 02
  Foster NE, et al. Prevention and treatment of low back pain: evidence, challenges, and promising directions. Lancet. 2018;391(10137):2368–2383.
• 03
  Maher C, Underwood M, Buchbinder R. Non-specific low back pain. Lancet. 2017;389(10070):736–747.
• 04
  Chou R, et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147(7):478–491.
• 05
  Australian Commission on Safety and Quality in Health Care (ACSQHC). Evidence-Based Care in Musculoskeletal Conditions: Low Back Pain. Sydney: ACSQHC; 2021.
• 06
  Buchbinder R, et al. Low back pain: a call for action. Lancet. 2018;391(10137):2384–2388.
• 07
  van Tulder M, et al. European guidelines for the management of acute nonspecific low back pain in primary care. Eur Spine J. 2006;15 Suppl 2:S169–S191.
• 08
  Koes BW, van Tulder M, Lin CW, Macedo LG, McAuley J, Maher C. An updated overview of clinical guidelines for the management of non-specific low back pain in primary care. Eur Spine J. 2010;19(12):2075–2094.
• 09
  Urquhart DM, et al. Antidepressants for non-specific low back pain. Cochrane Database Syst Rev. 2008;(1):CD001703.
• 10
  Australian Rheumatology Association. Recommendations for the Management of Axial Spondyloarthritis in Australia. Sydney: ARA; 2022.
• 11
  Artus M, van der Windt D, Jordan KP, Hay EM. Low back pain symptoms show a similar pattern of improvement following a wide range of primary care treatments. Rheumatology. 2010;49(12):2346–2356.
• 12
  Graves JM, et al. Opioid-related adverse drug events in low back pain: a population-level study. Pain Med. 2018;19(10):2073–2083.
• 13
  Royal Australian College of General Practitioners (RACGP). Prescribing drugs of dependence in general practice — Part C2: The role of opioids in pain management. Melbourne: RACGP; 2020.