Management of Sudden Lower Mid Back Pain Without Visible Injury
Start with NSAIDs (naproxen 500 mg twice daily) combined with superficial heat application and explicit instructions to remain active—avoid imaging unless red flags are present. 1
Immediate Assessment for Red Flags
Before initiating treatment, rapidly screen for conditions requiring urgent intervention:
- Cauda equina syndrome: Ask about urinary retention, fecal incontinence, saddle anesthesia, or bilateral leg weakness 2, 1
- Progressive neurologic deficits: Assess for worsening motor weakness, sensory loss, or loss of reflexes 2, 1
- Infection/malignancy indicators: Fever, unexplained weight loss, history of cancer, immunosuppression, or intravenous drug use 2, 1
- Fracture risk: Age >50 years, significant trauma, prolonged corticosteroid use, or osteoporosis 2, 1
If any red flags are present, obtain urgent MRI and specialist consultation immediately. 2, 1 If red flags are absent, proceed with conservative management without imaging. 2, 1
First-Line Treatment Protocol
Pharmacologic Management
NSAIDs are the first-line medication with moderate-quality evidence showing superior pain relief compared to other oral medications. 1, 3
- Prescribe naproxen 500 mg twice daily or ibuprofen 600-800 mg three times daily 1, 3
- Acetaminophen is an alternative if NSAIDs are contraindicated, though less effective 2
- Consider adding a muscle relaxant (cyclobenzaprine 5 mg three times daily) for the first 3-7 days if muscle spasm is prominent, though drowsiness is common 4
Nonpharmacologic Management
Heat therapy provides moderate pain relief at 5 days and should be applied for 15-20 minutes several times daily. 1, 3
Explicitly instruct the patient to avoid bed rest and remain as active as pain permits—this is critical for recovery. 2, 1 Bed rest leads to deconditioning and worsens outcomes. 3
Provide evidence-based reassurance that acute low back pain typically improves substantially within the first month, with or without treatment. 2, 1
Follow-Up Timeline and Escalation
Arrange follow-up in 1-2 weeks, as most patients improve rapidly in the first month. 1
At 1-2 Week Follow-Up:
- If improving: Continue current management and encourage gradual return to full activity 1
- If no improvement: Refer for physical therapy with a supervised exercise program 1, 3
At 4-6 Week Follow-Up:
- If pain persists beyond 4-6 weeks, obtain plain radiographs and refer to primary care or physiatry for comprehensive chronic pain management 1
- Consider MRI only if the patient becomes a candidate for surgery or epidural steroid injection (for suspected radiculopathy) 2
What to Avoid: Critical Pitfalls
Do not obtain routine imaging for nonspecific low back pain without red flags—imaging does not improve outcomes and incurs unnecessary costs. 2, 1
Avoid epidural injections, facet joint injections, radiofrequency ablation, and trigger point injections for nonspecific axial spine pain—these procedures do not improve morbidity, mortality, or quality of life. 3
Do not prescribe prolonged bed rest, as it worsens deconditioning. 2, 3
Additional Considerations for Persistent Pain
If pain persists beyond 6 weeks despite initial management, evidence-based options include:
- Exercise therapy: Individualized, supervised programs incorporating stretching and strengthening provide moderate pain relief (10 points on 100-point scale) 1, 3
- Spinal manipulation: Provides small to moderate short-term benefits when administered by appropriately trained providers 2, 3
- Yoga or tai chi: Moderate-quality evidence for sustained benefits at 26 weeks 1, 3
- Massage therapy: Moderate effectiveness for chronic low back pain 2, 3
- Cognitive-behavioral therapy: Consider if psychological factors (depression, fear-avoidance, catastrophizing) are present 1, 3
For medication escalation in persistent pain, duloxetine is the preferred second-line agent when NSAIDs provide inadequate response, particularly if neuropathic pain components exist. 3