What is the purpose of physical therapy (PT) for patients with chronic back pain?

Purpose of Physical Therapy for Chronic Back Pain

Physical therapy serves as a cornerstone first-line treatment for chronic back pain, with the primary purpose of reducing pain intensity and improving physical function through structured exercise programs, manual therapies, and patient education to restore mobility and prevent deconditioning. 1, 2

Primary Therapeutic Goals

Physical therapy for chronic back pain aims to achieve several interconnected objectives:

• Pain reduction: Exercise therapy produces moderate improvements in pain intensity, typically reducing pain scores by approximately 10 points on a 100-point scale, with effects sustained from 2 to 18 months. 1, 3

• Functional restoration: Physical therapy moderately improves disability scores and physical function, though effects on function are generally smaller than effects on pain. 2, 4

• Prevention of deconditioning: A critical purpose is maintaining activity levels and preventing the physical deterioration that occurs with bed rest or inactivity, which worsens outcomes. 2, 4

• Restoration of neuromuscular control: Motor control exercises specifically target coordination, control, and strength of spinal-supporting muscles, addressing biomechanical dysfunction. 2, 3

Evidence-Based Components

The American College of Physicians strongly recommends physical therapy as part of a multimodal strategy, incorporating: 1

• Structured exercise programs: The specific type of exercise matters less than patient adherence, though individualized, supervised programs incorporating stretching and strengthening produce the best outcomes. 2, 3

• Manual therapies: Including massage, myofascial release, and spinal manipulation, which provide small to moderate short-term benefits when combined with exercise. 1, 2

• Heat therapy: Superficial heat application moderately improves pain at 5 days and disability at 4 days, with greater benefits when combined with exercise. 2, 4

• Patient education: Teaching proper body mechanics, activity modification, and self-management strategies to prevent future episodes. 5

Comparative Effectiveness

Physical therapy demonstrates important advantages over other interventions:

• Superior to usual care alone: Moderate-quality evidence shows multidisciplinary rehabilitation (which includes physical therapy) moderately reduces short-term pain intensity and disability compared with usual care. 1

• Comparable to psychological therapies: Low-quality evidence shows no difference between psychological therapies and physical therapy for pain intensity, suggesting they address different aspects of the pain experience. 1

• More cost-effective than multidisciplinary programs: While multidisciplinary rehabilitation shows slightly better outcomes, physical therapy alone provides substantial benefit at lower cost, reserving intensive programs for non-responders. 1, 6

Mechanism of Benefit

Physical therapy works through multiple mechanisms:

• Biomechanical correction: Restoring proper movement patterns and reducing mechanical stress on pain-sensitive structures. 7

• Neurophysiological effects: Exercise produces analgesic effects through endogenous opioid release and central pain modulation. 7

• Psychological benefits: Supervised exercise provides reassurance, reduces fear-avoidance behaviors, and improves self-efficacy. 8

• Prevention of chronicity: Early physical therapy intervention can prevent acute episodes from transitioning to chronic disability. 5

Critical Implementation Considerations

Physical therapy must be active rather than passive: The American College of Physicians recommends against passive modalities like TENS and lumbar supports, which show no clear benefits. 2, 4

Avoid common pitfalls:

• Do not prescribe bed rest, as it leads to deconditioning and worsens outcomes. 2, 4
• Avoid relying solely on passive treatments like ultrasound, which shows no difference compared to sham treatment. 1
• Do not delay exercise therapy while pursuing extensive imaging or interventional procedures, as these do not improve outcomes for nonspecific back pain. 2, 4

Integration with Multimodal Care

Physical therapy serves as the foundation upon which other treatments are built:

• First-line nonpharmacologic approach: The American College of Physicians recommends beginning with exercise and heat therapy before adding pharmacologic interventions. 2, 4

• Enhanced by combination therapies: Adding psychological interventions like cognitive-behavioral therapy or mindfulness-based stress reduction addresses psychosocial factors that complicate chronic pain. 1, 2

• Platform for medication optimization: Physical therapy allows for lower medication doses and reduces reliance on opioids by providing alternative pain control mechanisms. 1

Realistic Outcome Expectations

Physical therapy produces clinically meaningful but not complete resolution:

• The magnitude of pain benefits is typically small to moderate, with most patients experiencing some residual pain and disability despite treatment. 2, 6

• Large reductions in pain and disability are possible with exercise, suggesting it should play a major role in management, though the problem of chronic low back pain is far from solved. 6

• Adapted physical exercise, physical agent modalities, and multidisciplinary approaches represent the most effective strategies to reduce pain and disability based on network meta-analysis. 7