What is the recommended evaluation and management for acute or sub‑acute low back pain in a military service member?

Evaluation and Management of Low Back Pain in Military Service Members

For acute or subacute low back pain in military personnel, initiate a focused assessment for red flags, maintain activity rather than bed rest, and start with nonpharmacologic treatments (superficial heat, spinal manipulation, or massage) as first-line therapy, adding NSAIDs only if pharmacologic treatment is specifically desired. 1

Initial Clinical Assessment

Conduct a targeted history and physical examination focusing on red flag identification rather than comprehensive evaluation 1:

Red flags requiring immediate imaging and specialist referral include:

• Cauda equina syndrome (saddle anesthesia, bowel/bladder dysfunction) 1
• History of cancer with unexplained weight loss 1
• Fever suggesting infection 1
• Significant trauma or history of osteoporosis (risk for vertebral compression fracture) 1
• Progressive neurologic deficits 1

Perform a focused neurological examination:

• Straight leg raise test between 30-70 degrees (91% sensitivity for herniated disc) 2
• Motor strength testing of ankle dorsiflexion and plantarflexion 2
• Ankle reflexes and sensory distribution assessment 2
• Midline tenderness evaluation (may indicate vertebral compression fracture or infection) 1

Screen for psychosocial risk factors using the STarT Back tool at 2 weeks, as these factors are stronger predictors of outcomes than physical findings in military populations 1, 3:

• Depression and anxiety 1, 3
• Fear-avoidance beliefs and catastrophizing 1
• Job dissatisfaction 1
• Passive coping strategies 2

Military-specific considerations include concomitant psychological trauma, heavy combat load requirements, and the constraints of training environments that make seeking care challenging 4, 5.

Diagnostic Imaging Strategy

Do not order routine imaging for acute or subacute low back pain without red flags, even in the presence of radiculopathy or midline tenderness. 1, 2 This is critical because:

• Most acute LBP with radiculopathy is self-limiting and improves within the first month regardless of imaging 2
• Disc abnormalities are found in 29% of asymptomatic 20-year-olds and 43% of asymptomatic 80-year-olds 2
• Routine imaging provides no clinical benefit and exposes service members to unnecessary radiation 1, 2

Order immediate MRI or CT only if:

• Red flags are present (cauda equina syndrome, severe/progressive neurologic deficits, suspected serious underlying condition) 1
• Symptoms persist beyond 4-6 weeks without improvement despite conservative management 1, 2

Plain radiography may be considered at 4-6 weeks for persistent symptoms or in patients with risk factors for vertebral compression fracture 1.

First-Line Management Algorithm

Nonpharmacologic Treatment (Primary Approach)

Advise the service member to remain active and avoid bed rest, as maintaining activity within pain limits reduces disability and improves outcomes more effectively than rest 1, 2, 6:

Initiate these evidence-based nonpharmacologic interventions immediately:

• Superficial heat application using heating pads (moderate-quality evidence) 1, 2, 6
• Spinal manipulation by appropriately trained providers (low to moderate-quality evidence) 1, 2, 6
• Massage therapy (low-quality evidence) 1, 2
• Acupuncture (low-quality evidence) 1, 2

Provide self-care education and reassurance about the favorable natural history of acute LBP 1, 2.

Pharmacologic Treatment (If Specifically Desired)

NSAIDs are the first-line pharmacologic choice, providing approximately 10 points greater pain relief on a 100-point visual analogue scale compared to acetaminophen (moderate-quality evidence) 1:

• Use the lowest effective dose for the shortest duration 1
• Assess cardiovascular and gastrointestinal risk factors before prescribing 1
• Consider co-administration with a proton-pump inhibitor in higher-risk patients 1
• Monitor for renal toxicity, especially in patients with pre-existing kidney disease 1

Acetaminophen (up to 4g daily) is an appropriate alternative if NSAIDs are contraindicated, though slightly less effective 1, 6.

Skeletal muscle relaxants can be added if NSAIDs alone are insufficient (moderate-quality evidence) 1.

Medications to Avoid

Do not prescribe:

• Systemic corticosteroids (ineffective, good evidence demonstrating no benefit over placebo) 1, 6
• Benzodiazepines as first-line (high sedation rates) 1
• Opioids for initial management (reserve as last resort after all other options have failed, with time-limited courses and careful monitoring) 1, 2

Risk-Stratified Management Using STarT Back Tool

At 2 weeks from pain onset, use the STarT Back tool to direct resources appropriately 1:

Low-risk patients (minimal psychosocial barriers):

• Continue activity maintenance and self-care 1
• Reassurance about favorable prognosis 1

Medium-risk patients:

• Refer to physiotherapy 1
• Develop patient-centered management plan 1
• Consider additional nonpharmacologic treatments (massage, acupuncture, spinal manipulation) 1

High-risk patients (anxiety, depression, catastrophizing, fear-avoidance beliefs):

• Refer for comprehensive biopsychosocial assessment by physiotherapy 1
• Review no later than 12 weeks 1
• Consider psychological interventions if psychosocial factors are prominent 1

This stratification is particularly important in military populations, where LBP has been shown to negatively impact participation in training, academics, and interpersonal relationships, and where approximately three-quarters of spine-area pain involves low back pain 4, 5.

Follow-Up and Reassessment Protocol

Reevaluate at 4-6 weeks if symptoms persist without improvement 1, 2:

• A 2-5 point improvement on the Roland-Morris Disability Questionnaire represents moderate and clinically significant change 1
• Changes less than 1 point are generally not clinically relevant 1

Consider earlier reassessment for:

• Severe pain or functional deficits 2
• Older service members 1
• Signs of radiculopathy or spinal stenosis 1
• Worsening neurologic symptoms 1, 2

At the 4-6 week reassessment, if no improvement:

• Consider MRI or CT to evaluate for disc herniation or nerve root compression 2
• Refer for physical therapy or more intensive rehabilitation 1
• Consider intensifying nonpharmacologic therapies 1

If symptoms persist beyond 3 months minimum with no response to standard noninvasive therapies, consider referral or consultation for progressive neurologic deficits or persistent functional disabilities 1.

Common Pitfalls to Avoid

Critical errors that worsen outcomes in military populations:

• Ordering routine imaging in the first 4-6 weeks without red flags increases healthcare costs without improving outcomes and may lead to unnecessary interventions 2
• Prescribing bed rest is inferior to activity maintenance for recovery 2, 6
• Starting opioids as initial therapy should be avoided 2
• Failing to reassess patients with persistent symptoms after 1 month 2
• Failing to assess psychosocial factors that contribute to delayed recovery, which are particularly prevalent in military populations with deployment-related injuries 1, 3
• Prescribing prolonged bed rest 1
• Overreliance on opioid medications for pain management 1

Note that adherence to clinical practice guidelines for physical therapy in military settings remains below 50%, highlighting the importance of systematic implementation of evidence-based care 7.