Low back pain: the AU general practice approach to acute, chronic and radicular

What low back pain is and why it matters

Low back pain — pain between the costal margins and the gluteal folds, with or without leg radiation — is the leading cause of years lived with disability in Australia. About 80% of Australians experience back pain at some point in their lives, with approximately 4 million living with chronic back problems at any time (AIHW back problems). Annual healthcare costs exceed $4.8 billion, not including the far larger indirect costs from lost productivity, reduced work capacity, and disability payments.

The most important shift in understanding low back pain over the past two decades is this: most low back pain does not arise from structural pathology that imaging reveals, and imaging findings correlate poorly with pain in the majority of presentations. Disc bulges, facet arthrosis, and degenerative changes are extraordinarily common in pain-free adults. Routine imaging for uncomplicated low back pain generates nocebo effects — knowledge of incidental findings makes pain worse and drives unnecessary downstream procedures.

The ACSQHC Low Back Pain Clinical Care Standard 2022 and RACGP guidance establish the framework for Australian general practice: systematic red-flag exclusion, no routine imaging for uncomplicated presentations, reassurance that hurt does not equal harm, staying active, and first-line NSAIDs over opioids or bed rest.

A. Core clinical — the AU general-practice framework

Classification

Duration is the primary management determinant:

• Acute: under 6 weeks
• Sub-acute: 6–12 weeks
• Chronic: 12 weeks and over

Mechanism guides the clinical approach:

• Non-specific low back pain — approximately 90–95% of presentations; no identifiable specific pathological cause; mechanical and multifactorial
• Radicular pain — pain with or without sensory or motor signs in a nerve root distribution (L5: dorsum of foot, great toe extension weakness; S1: lateral foot, plantar flexion weakness, reduced ankle reflex)
• Spinal canal stenosis — neurogenic claudication worsened by walking or standing, relieved by sitting and lumbar flexion
• Inflammatory spondyloarthritis — insidious onset under age 40, morning stiffness over 30 minutes, improved by exercise not rest, alternating buttock pain
• Serious specific pathology — fracture, malignancy, infection, cauda equina syndrome

Red-flag assessment

Red flags require immediate action and must be systematically screened at every presentation:

Cauda equina syndrome — saddle anaesthesia, urinary retention or incontinence, faecal incontinence, bilateral leg weakness, sexual dysfunction → emergency MRI within hours plus spinal surgery assessment; do not delay

Spinal fracture — significant trauma, age over 65 with minor trauma, prolonged corticosteroid use, known osteoporosis, sudden severe pain → plain X-ray initially, MRI or CT if neurological involvement or persistence

Malignancy — age over 50 with new back pain, prior cancer history, unexplained weight loss, night pain unrelieved by rest, no improvement at 4–6 weeks → MRI plus bloods (FBC, ESR, CRP, calcium, ALP, PSA in men, immunoglobulins, urine Bence-Jones protein, LDH)

Spinal infection — fever, intravenous drug use, immunocompromise, recent spinal procedure, severe progressive night pain → urgent MRI plus inflammatory markers and blood cultures

Inflammatory back pain — age under 40, insidious onset, morning stiffness over 30 minutes, improves with exercise not rest, alternating buttock pain, family history of spondyloarthritis → ESR, CRP, HLA-B27, sacroiliac joint MRI, rheumatology referral

Severe or progressive neurological deficit — foot drop, rapidly worsening motor weakness, multilevel radiculopathy → urgent MRI plus spine surgery assessment

History

• Pain location and radiation — central, paraspinal, sacroiliac, gluteal, or leg; dermatomal radiation to foot implies nerve root involvement
• Onset — sudden or traumatic versus insidious and gradual
• Duration and prior episode history — first episode versus recurrent
• Aggravating and relieving factors — flexion (disc), extension (facet or stenosis), prolonged walking (stenosis), rest
• Red-flag screen — systematically excluded at every presentation regardless of clinical confidence
• Functional impact — work capacity, sleep, activities of daily living, mood
• Yellow-flag screen — psychosocial risk factors for chronicity: fear-avoidance beliefs, pain catastrophising, low recovery expectations, depression, anxiety, compensation status, occupational dissatisfaction, poor self-efficacy for activity. The STarT Back screening tool (Hill, BMJ 2008) formalises this into low, medium, and high risk

Examination

• Gait, posture, inspection for deformity or scoliosis
• Lumbar spine range of movement — flexion, extension, lateral flexion, rotation
• Neurological examination of lower limbs — power (L1–S2 myotomes), sensation (dermatomal), reflexes (knee L3–4, ankle S1, plantar response)
• Straight-leg raise (positive 30–70° → L4–S1 nerve root irritation); crossed straight-leg raise (more specific for disc herniation)
• Saddle sensation and rectal tone if cauda equina is clinically possible
• Hip examination to exclude hip joint as the primary pain source (groin pain, restricted internal rotation)
• Sacroiliac joint provocation tests if inflammatory spondyloarthritis is suspected

Investigations

RACGP Choosing Wisely — Imaging in acute low back pain and ACSQHC LBP Clinical Care Standard 2022: imaging is not indicated for uncomplicated acute low back pain.

Image when: a red flag is present; fracture, malignancy, infection, or inflammatory pathology is suspected; cauda equina is suspected (urgent MRI); persistent radicular pain beyond 4–6 weeks with surgical candidacy being considered; or severe or progressive neurological deficit.

Relevant bloods when red flags present: FBC, ESR, CRP, UEC, calcium, ALP, PSA (men), immunoglobulins, urine Bence-Jones protein, LDH, HLA-B27 (if inflammatory suspected).

B. What works and what to avoid — the evidence

Acute low back pain (first 6 weeks)

Reassurance and education — the therapeutic value of explanation is often underestimated. Telling patients that hurt does not equal harm, that most episodes resolve within 4–6 weeks, and that imaging routinely shows changes unrelated to pain, directly influences outcomes. This is not dismissing the pain; it is correcting the nocebo narrative.

Staying active and returning to normal activity — the strongest evidence-based intervention for acute non-specific low back pain. Structured activity prevents the fear-avoidance cycle from becoming entrenched.

NSAIDs as first-line analgesia — per eTG Pain: Low back pain: ibuprofen 400 mg three times daily, naproxen 250–500 mg twice daily, or diclofenac 50 mg three times daily; shortest effective course; counsel patients about gastrointestinal, renal, and cardiovascular risks; use with a proton pump inhibitor in higher-risk patients.

Paracetamol — the PACE trial (Williams, Lancet 2014) demonstrated paracetamol is no better than placebo for acute low back pain on primary recovery or pain outcomes. It remains acceptable as an adjunct for those who cannot take NSAIDs, but should not be presented as first-line on efficacy grounds.

Physiotherapy — exercise prescription and manual therapy as an adjunct to active management. No single exercise modality is superior; the best exercise is the one the patient will actually do. RACGP Best practice care for acute LBP (AJGP 2024) supports physiotherapy referral from early in the episode for most patients.

What to avoid:

• Opioids — the SPACE trial (Krebs, JAMA 2018) showed opioids provide no functional benefit over non-opioid analgesia for chronic back, hip, and knee pain, with significant dependence and harm potential; reserve for very short-term use (≤1 week) in severe acute cases with a clear plan and scheduled review
• Bed rest beyond 48 hours — delays recovery, promotes deconditioning and fear-avoidance
• Routine imaging — no benefit; increases downstream interventions and nocebo effects
• Gabapentinoids for non-radicular pain — Mathieson, NEJM 2017 demonstrated pregabalin was not effective for sciatica; misuse risk is clinically significant; Choosing Wisely Australia recommends against
• Traction, therapeutic ultrasound, long-term lumbar supports — no evidence of benefit for non-specific low back pain

Chronic low back pain (12+ weeks) — biopsychosocial framework

Chronic low back pain is a biopsychosocial condition, not a structural problem amenable to imaging or injection. The ACSQHC Clinical Care Standard emphasises multidisciplinary care over escalating analgesia:

• Sustained exercise — walking, swimming, yoga, Pilates, tai chi, and resistance training all show equivalent benefit in chronic low back pain (Saper, Ann Intern Med 2017); the most important factor is long-term adherence, not modality selection
• CBT and mindfulness-based stress reduction (MBSR) — Cherkin, JAMA 2016 demonstrated MBSR is non-inferior to CBT, both superior to usual care for chronic low back pain; accessed via Better Access Mental Health Care Plan (MHCP)
• Pain neuroscience education — understanding that pain does not equal tissue damage addresses fear-avoidance and catastrophising, which are stronger predictors of chronicity than any imaging finding
• Multidisciplinary biopsychosocial programmes — physiotherapist plus psychologist plus medical input; superior to usual care for disabling chronic low back pain; accessed via Pain Australia service directory and GP Management Plan allied health referrals
• Duloxetine — off-label for chronic low back pain; modest effect size; requires Authority for PBS reimbursement; useful when comorbid depression is present
• Avoid long-term opioids — Faculty of Pain Medicine ANZCA position: opioids should not be used for chronic non-cancer pain except in highly selected cases with a clear plan, regular SafeScript or equivalent monitoring, and multidisciplinary support

STarT Back stratification

High-risk patients on the STarT Back tool (Hill, Lancet 2011) — those with high psychosocial risk of chronicity — benefit from combined physical and psychological treatment from the outset of a sub-acute episode, rather than waiting for chronicity to develop. This stratified approach produced significantly better outcomes than usual care in the landmark Keele trial.

C. Radicular pain, stenosis and specific pathology

Radicular pain management

Most radicular pain follows the same general approach as non-specific low back pain — active management, NSAIDs, reassurance, physiotherapy. Additional considerations when nerve root involvement is confirmed:

• Neuropathic agents — evidence is limited; Mathieson, NEJM 2017 showed pregabalin was no better than placebo for sciatica; reserve gabapentinoids for chronic radicular pain not responding to other measures; PBS Authority Required (Streamlined) for neuropathic pain indication
• Epidural corticosteroid injection — modest short-term pain benefit for radicular flares; specialist-administered; does not change long-term outcomes or surgical rates; reasonable as a bridge before surgical decision
• Surgical assessment — if disabling radicular pain persists beyond 6–12 weeks despite conservative care, or if progressive motor deficit occurs; spine surgery opinion warranted

Spinal canal stenosis

Neurogenic claudication is the hallmark — lower limb pain or heaviness with walking or standing, relieved by sitting or lumbar flexion. Manage with NSAIDs, physiotherapy (flexion-based exercises), and activity modification. Epidural steroid injection for short-term flare management. Surgical decompression for severe or progressive cases unresponsive to conservative measures.

Vertebral compression fracture

Common in osteoporotic women over 70 and men on prolonged corticosteroid therapy. Acute analgesia, brief activity modification if pain is severe, early physiotherapy. Investigate for underlying osteoporosis — bone densitometry (MBS item 12306), calcium, vitamin D, PTH — and manage per current osteoporosis guidelines. Falls clinic referral for secondary prevention.

D. Australian operations

MBS item numbers

Standard consultations use general practice items 23, 36, or 44 by duration. Additional items from MBS Online:

• Lumbar spine X-ray — items 58106 / 58108
• CT lumbar spine — items 56220 / 56223
• MRI lumbar spine — item 63154 range (restricted MBS rebate; specialist referral generally required; GP referral pathway exists for selected indications — verify current eligibility before requesting)
• Bone densitometry — item 12306 (fracture or osteoporosis suspicion)

GPCCMP (items 965/967) applies for chronic low back pain — providing access to 5 allied health sessions per year (10 for ATSI patients), including physiotherapy, exercise physiology, and psychology. Plan elements: written self-management strategy, exercise prescription, psychological intervention if yellow flags identified, return-to-work goals, opioid review if applicable.

Mental Health Care Plan (items 2715/2717) — when chronic low back pain coexists with depression, anxiety, or pain catastrophising; accesses Better Access psychology sessions for CBT or mindfulness-based stress reduction.

PBS analgesic landscape

Per PBS:

• Paracetamol, NSAIDs (ibuprofen, naproxen, diclofenac, meloxicam, celecoxib) — general schedule; most available OTC
• Codeine — Schedule 8 since February 2018; prescription required
• Oxycodone, tapentadol, buprenorphine — restricted; most require Authority for chronic non-cancer pain; SafeScript monitoring
• Pregabalin — Authority Required (Streamlined) for neuropathic pain
• Gabapentin — Authority Required (Streamlined) for refractory neuropathic pain after pregabalin trial
• Duloxetine — Authority Required for chronic pain conditions; off-label for non-specific chronic low back pain

Workers compensation and occupational context

Low back pain is one of the most common WorkCover and TAC claims. Document mechanism of injury, functional limitations, treatment plan, and return-to-work goals. Set realistic capacity certificates; involve physiotherapy, exercise physiology, and occupational therapy. DVA Gold Card covers comprehensive rehabilitation. Return-to-work planning with modified duties is preferred over prolonged absence.

E. Special populations

Older adults (over 65). Higher baseline risk of serious pathology — malignancy, osteoporotic fracture, spinal stenosis. Maintain a lower threshold for investigation. NSAIDs require careful assessment — renal function, cardiovascular risk, gastroprotection. Falls risk assessment is warranted given gait impairment and neurological implications.

Workers in manual occupations. Disproportionate burden of chronic low back pain. Ergonomic workplace assessment and modification are evidence-based interventions. Multidisciplinary return-to-work planning — with a physiotherapist, occupational therapist, and WorkCover liaison — reduces long-term disability.

Pregnant women. Low back pain affects approximately 50–70% of pregnant women. Manual therapy, aquatic exercise, and pelvic girdle support are safe and evidence-based options. NSAIDs are generally avoided after 20 weeks; paracetamol remains the first-line analgesic option in pregnancy despite its limited efficacy for back pain specifically.

Adolescents. Most low back pain in adolescents is non-specific and responds to reassurance and activity. Be alert to inflammatory spondyloarthritis presenting in teenagers — morning stiffness, enthesitis, HLA-B27, family history of psoriasis or inflammatory bowel disease — as it is often missed at this age.

People with significant depression or anxiety. Yellow flags — particularly catastrophising, kinesiophobia (fear of movement), and low self-efficacy — are stronger predictors of chronicity than any imaging finding. Early psychological intervention from the sub-acute phase, particularly for high-risk patients on STarT Back, reduces rates of chronic disabling pain significantly more than continuing purely analgesic escalation.

When to escalate

Refer urgently (emergency department or same-day):

• Cauda equina syndrome — saddle anaesthesia, urinary or bowel dysfunction, bilateral leg weakness → emergency; do not wait
• Severe progressive neurological deficit — rapidly worsening foot drop, multilevel motor deficits
• Suspected spinal infection or malignancy with systemic compromise — fever, haemodynamic instability

Routine referral:

• Persistent radicular pain beyond 6–12 weeks — spine surgery opinion for disc herniation with correlated deficit
• Spinal canal stenosis with disabling neurogenic claudication — surgical decompression assessment
• Suspected inflammatory spondyloarthritis — rheumatology; early DMARD therapy reduces long-term damage
• Disabling chronic low back pain — multidisciplinary pain clinic; Pain Australia maintains a national service directory; PainHealth (UWA) provides validated self-management resources
• Osteoporotic compression fracture requiring specialist management — orthopaedic or spinal surgery

What this article is and is not

This is general health information drawn from current Australian guidelines — ACSQHC Low Back Pain Clinical Care Standard 2022, RACGP guidance, Therapeutic Guidelines, Australian Medicines Handbook, and Faculty of Pain Medicine ANZCA opioid position. It is not personal medical advice and does not create a doctor–patient relationship. Decisions about imaging, analgesia, referral, and return to work are made with your own GP, taking your complete clinical and occupational picture into account.

For consumer-facing resources: HealthDirect — Back pain, Better Health Channel — Back pain, Pain Australia, PainHealth (UWA), ACSQHC patient fact sheet.

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Sources cited

1. ACSQHC — Low Back Pain Clinical Care Standard 2022
2. RACGP — Imaging in adults with acute low back pain (Choosing Wisely)
3. RACGP — Best practice care for acute low back pain (AJGP 2024)
4. Therapeutic Guidelines (eTG) — Pain: Low back pain
5. Australian Medicines Handbook
6. Faculty of Pain Medicine ANZCA — opioid position statements
7. Pain Australia
8. PainHealth (UWA / WA Health)
9. AIHW — Back problems
10. Choosing Wisely Australia
11. MBS Online
12. PBS
13. HealthDirect — Back pain
14. Better Health Channel — Back pain
15. Williams et al. — PACE trial (Lancet 2014)
16. Krebs et al. — SPACE trial (JAMA 2018)
17. Mathieson et al. — Pregabalin for sciatica (NEJM 2017)
18. Hill et al. — STarT Back screening tool (BMJ 2008)
19. Hill et al. — STarT Back stratified care RCT (Lancet 2011)
20. Cherkin et al. — MBSR vs CBT for chronic LBP (JAMA 2016)
21. Saper et al. — Yoga vs physiotherapy for chronic LBP (Ann Intern Med 2017)