What is the appropriate initial management for low back pain, including red‑flag assessment and treatment recommendations?

Initial Management of Low Back Pain

For most patients with acute low back pain, advise staying active, prescribe NSAIDs or acetaminophen as first-line medication, and avoid routine imaging unless red flags are present. 1

Red Flag Assessment

Immediately evaluate for serious underlying conditions that require urgent intervention:

High-priority red flags requiring immediate MRI and specialist consultation: 2, 1

• Cauda equina syndrome (saddle anesthesia, new bowel/bladder incontinence or urinary retention, loss of anal sphincter tone) 3
• Severe or progressive motor/sensory deficits 2, 4
• History of cancer (especially metastatic to bone) 4, 3
• Suspected spinal infection (fever with back pain, recent infection, IV drug use) 2, 5

Moderate-priority red flags warranting consideration of imaging: 1, 3

• Significant trauma relative to age (major fall/motor vehicle crash in young patients; minor fall in elderly or osteoporotic patients) 3
• Unexplained weight loss 2, 5
• Age >50 with new-onset pain 1
• Prolonged corticosteroid use 5
• Midline tenderness with osteoporosis risk factors (suggests compression fracture) 1

If red flags are present: Obtain urgent MRI (preferred over CT due to superior soft tissue visualization and no radiation exposure) and arrange specialist consultation. 1, 4 Do not delay imaging in these cases, as outcomes worsen with delayed diagnosis. 4

Initial Treatment for Uncomplicated Low Back Pain

Patient Education and Activity Modification

Provide evidence-based reassurance and activity guidance: 2, 1

• Inform patients that 90% of acute episodes resolve within 6 weeks regardless of treatment 6
• Strongly advise patients to remain active and continue ordinary activities within pain limits 2, 1, 6
• Explicitly discourage bed rest, which causes deconditioning and worsens disability 1, 7, 6
• Encourage early return to work, which reduces long-term disability 6
• Recommend superficial heat application (heating pads) for symptomatic relief 1, 7

First-Line Pharmacologic Management

NSAIDs are the most effective first-line medication option, providing approximately 10 points greater pain relief on a 100-point visual analogue scale compared to acetaminophen. 7 However, assess cardiovascular and gastrointestinal risk factors before prescribing, and use the lowest effective dose for the shortest duration. 7

Acetaminophen (up to 4g daily) is a reasonable alternative with a more favorable safety profile and lower cost, though slightly less effective. 7 Consider this for patients who cannot tolerate NSAIDs. 7

Skeletal muscle relaxants (cyclobenzaprine, tizanidine, metaxalone) can be added for short-term relief if muscle spasm contributes to pain. 2, 7

Avoid these medications: 1, 7

• Systemic corticosteroids (ineffective, no benefit over placebo) 7
• Opioids for initial management (reserve only for severe, disabling pain uncontrolled by NSAIDs/acetaminophen, with time-limited courses) 1, 7
• Benzodiazepines as first-line (high sedation rates) 7

Non-Pharmacologic Therapies

For acute low back pain (<4 weeks): 2, 1

• Spinal manipulation by appropriately trained providers 2, 1
• Massage therapy 2, 1
• Acupuncture 2, 1

For chronic or subacute low back pain (≥4 weeks): 2, 1

• Exercise therapy (most effective with individual tailoring, supervision, stretching, and strengthening components) 2, 7, 8
• Intensive interdisciplinary rehabilitation 2
• Cognitive-behavioral therapy 2, 1
• Yoga or tai chi 1, 8
• Progressive relaxation 2

Imaging Decisions

Do not routinely order imaging for uncomplicated acute low back pain, even with midline tenderness, if no red flags are present. 1, 7 This exposes patients to unnecessary radiation without clinical benefit and increases healthcare costs. 1, 7

Consider plain radiography only if: 1, 6

• Risk factors for vertebral compression fracture are present 1
• Symptoms persist after 4-6 weeks of conservative management 1, 6

Order MRI (preferred) or CT if: 2, 1

• Severe or progressive neurologic deficits develop 2, 4
• Serious underlying condition is suspected based on red flags 2, 1
• Patient is a potential candidate for surgery or epidural steroid injection for suspected radiculopathy 2

Follow-Up and Reassessment

Reevaluate at 1 month if symptoms persist without improvement. 1 Consider earlier reassessment for: 1

• Patients over 65 years old 1
• Signs of radiculopathy or spinal stenosis 1
• Worsening symptoms 1

At 2 weeks from pain onset, use the STarT Back tool to risk-stratify patients and direct resources appropriately. 1 This improves cost-effectiveness and outcomes. 1

If symptoms persist beyond 4-6 weeks despite conservative management: 1, 7

• Consider imaging if not previously performed 1
• Refer for physical therapy or more intensive rehabilitation 1
• Intensify non-pharmacologic therapies 1
• Evaluate psychosocial factors (depression, catastrophizing, fear-avoidance beliefs, job dissatisfaction) that predict chronicity 1

Common Pitfalls to Avoid

• Do not order routine imaging for uncomplicated cases—this leads to unnecessary interventions without improving outcomes 1, 7
• Do not prescribe prolonged bed rest—this worsens disability through deconditioning 1, 7, 6
• Do not fail to assess psychosocial factors that contribute to delayed recovery 1
• Do not overrely on opioid medications for pain management 1
• Do not use extended medication courses without clear ongoing benefit 7