Back Pain: From Assessment to Action (Part 1)

Back pain is a common yet complex presentation in Australian primary care GP and ED. Understanding acute vs chronic pain, the underlying mechanisms, and evidence-based management strategies is key—especially when differentiating between specific and non-specific causes.

Here’s a clinical reasoning-based summary 👇

🔍 Pathophysiology & Classification

Most back pain is non-specific, meaning no clear structural cause is identified. It often relates to mechanical strain, poor conditioning, or psychosocial factors.

However, don't miss the specific causes:

🚩 Malignancy

🚩 Infection (e.g. vertebral osteomyelitis, discitis)

🚩 Fracture

🚩 Inflammatory (e.g. axial spondyloarthritis)

🚩 Neurological compromise (e.g. cauda equina syndrome)

Use your red flags! 

Duration also matters:

🟢 Acute <6 weeks

🟠 Subacute 6–12 weeks

🔴 Chronic >12 weeks – may involve central sensitisation, fear avoidance, and functional impairment.

🖼️ Imaging Guidelines (RACGP / Choosing Wisely)

❌ Do not image non-specific low back pain unless red flags are present.

✅ Use imaging if:

• Trauma
• Suspected malignancy/infection
• Neurological deficits
• Suspected fracture
• Failed conservative therapy >6 weeks

📌 Plain X-ray: Limited utility unless suspicious of acute fracture

📌 MRI: Best for neuro signs, suspected malignancy or infection

📌 CT: Reserved for trauma or when MRI unavailable

💊 Pharmacological Management (Therapeutic Guidelines: Pain / eTG)

First-line for most patients with acute non-specific LBP:

• NSAIDs – short-term, lowest effective dose

→ Avoid in renal impairment, GI risk, or elderly

If NSAIDs contraindicated:

• Consider paracetamol, though evidence for LBP is weak

Second-line:

• Short-course opioids only if severe pain impairs function AND all else fails

→ Taper early, avoid long-term use

Chronic LBP?

• Avoid opioids long-term

• Antidepressants (e.g. amitriptyline, duloxetine) may help in selected patients with central sensitisation

• Anticonvulsants (e.g. pregabalin) not recommended for non-specific LBP

🧘 Non-Pharmacological Management: The Core of Care

• Education & reassurance – pain ≠ harm
• Activity continuation – avoid bed rest
• Exercise therapy – physiotherapy, graded movement
• Multidisciplinary care – especially for chronic pain
• Psychological therapies – CBT, pain neuroscience education
• Manual therapies – e.g. spinal manipulation (limited but acceptable as adjunct)

❗Passive treatments alone (e.g. massage, acupuncture) may provide acute pain relief but offer limited long-term benefit.

🩺 Clinical vignette: When to investigate back pain

James, a 52-year-old landscaper, presents with lower back pain that started suddenly 10 days ago after lifting heavy pavers. He describes it as a dull, constant ache across the lumbar region, worse with movement but improving with rest. No leg weakness, no saddle anaesthesia, and no changes to bowel or bladder.

He’s otherwise well. No fevers, weight loss, or cancer history. He smokes occasionally and takes no regular medications.

On exam:

• Vitals normal
• No neurological deficits
• Mild paraspinal tenderness
• Straight leg raise negative

🧠 Your task:

Would you image this patient?

What initial management would you recommend?

✅ Key reasoning:

• This is acute, non-specific back pain
• No red flags → No imaging needed
• First-line: NSAIDs (short course) + keep active + provide reassurance
• Imaging only if symptoms persist or worsen after 6 weeks

To read more - 

💬 Stay tuned for Part 2, where we cover chronic back pain, yellow flags, and red flag scenarios every med student should recognise.