Understanding Lower Back Pain: A Physiotherapy Guide

Anatomy of the Lower Back

The lower back, or lumbar spine, consists of five vertebrae (L1–L5) that bear the majority of the body's weight. These vertebrae are separated by intervertebral discs — gel-filled cushions that absorb shock and allow spinal movement. The lumbar spine is supported by a complex network of muscles, ligaments, and tendons, including the erector spinae, multifidus, and transversus abdominis.

The spinal cord terminates at approximately the L1–L2 level, giving rise to a bundle of nerve roots called the cauda equina. These nerve roots exit through openings (foramina) between the vertebrae and supply sensation and motor function to the lower limbs. Understanding this anatomy is critical because many causes of lower back pain relate to mechanical dysfunction or irritation of these structures.

The sacroiliac joints, which connect the base of the spine to the pelvis, also play a role in lower back function. Dysfunction in these joints can mimic or contribute to lumbar pain, making accurate assessment by a physiotherapist essential.

Common Causes of Lower Back Pain

Muscle Strain and Ligament Sprain

The most common cause of acute lower back pain is a strain or sprain of the muscles and ligaments surrounding the lumbar spine. This often occurs with heavy lifting, sudden movements, or prolonged poor posture. Research shows that the majority of these injuries resolve within six to eight weeks with appropriate management, though recurrence rates are high without addressing underlying contributing factors.

Disc Herniation

Intervertebral disc herniation occurs when the soft inner portion (nucleus pulposus) of a disc protrudes through the outer fibrous ring (annulus fibrosus). This can compress adjacent nerve roots, causing radicular pain — commonly referred to as sciatica when it affects the sciatic nerve distribution. Evidence suggests that disc herniations are present on MRI in many asymptomatic individuals, emphasising the importance of correlating imaging findings with clinical presentation.

Sciatica

Sciatica refers to pain that radiates along the path of the sciatic nerve — from the lower back through the buttock and down the back of the leg. It is a symptom rather than a diagnosis, and can be caused by disc herniation, spinal stenosis, or piriformis syndrome. The hallmark features include shooting or burning pain, numbness, tingling, or weakness in the affected leg.

Spinal Stenosis

Lumbar spinal stenosis is a narrowing of the spinal canal that compresses the nerve roots. It is more common in adults over 50 and is often associated with degenerative changes such as osteoarthritis. Symptoms typically include pain, heaviness, or cramping in the legs that worsens with walking (neurogenic claudication) and improves with sitting or leaning forward.

Facet Joint Dysfunction

The facet joints are small paired joints at the back of the spine that guide and limit spinal movement. Degeneration, inflammation, or mechanical dysfunction of these joints can cause localised lower back pain that may refer into the buttock or thigh. Facet joint pain is often aggravated by extension (arching backwards) and rotation movements.

Sacroiliac Joint Dysfunction

The sacroiliac joint connects the sacrum at the base of the spine to the ilium of the pelvis. Dysfunction in this joint can cause pain in the lower back, buttock, and groin. It is particularly common in pregnant and postpartum women due to hormonal ligament laxity and altered biomechanics.

When to See a Physiotherapist

While many episodes of lower back pain improve on their own within a few weeks, certain situations warrant prompt assessment by a physiotherapist or medical professional:

• Pain that persists beyond four to six weeks despite rest and self-care
• Pain that radiates into the leg, particularly below the knee
• Numbness, tingling, or weakness in the legs or feet
• Pain following a significant injury or fall
• Recurrent episodes of back pain
• Pain that disrupts sleep or daily activities

Physiotherapy Assessment

A thorough physiotherapy assessment for lower back pain typically includes a detailed history of your symptoms, aggravating and easing factors, and functional limitations. The physical examination assesses spinal range of motion, muscle strength, neurological function (reflexes, sensation, and power), and specific provocation tests to identify the pain source.

Your physiotherapist may also assess posture, movement patterns, hip mobility, and core muscle activation. This comprehensive assessment allows for an accurate clinical diagnosis and a targeted treatment plan tailored to your specific presentation.

Evidence-Based Treatment Approaches

Manual Therapy

Manual therapy techniques — including spinal mobilisation, manipulation, and soft tissue massage — are commonly used by physiotherapists to reduce pain and improve mobility. A systematic review published in the Journal of Orthopaedic & Sports Physical Therapy found that manual therapy combined with exercise produces superior outcomes for lower back pain compared to either intervention alone.

Exercise Therapy

Exercise is the cornerstone of evidence-based lower back pain management. Research consistently demonstrates that structured exercise programmes improve pain, function, and quality of life. Effective approaches include:

• Core stabilisation exercises: Targeted activation of the deep stabilising muscles (transversus abdominis, multifidus, pelvic floor) to improve spinal support and control.
• General strengthening: Exercises for the gluteals, hip muscles, and trunk extensors to distribute load more effectively across the kinetic chain.
• Flexibility and mobility: Stretching of the hip flexors, hamstrings, and thoracic spine to address common restrictions that contribute to lumbar overload.
• Aerobic conditioning: Walking, swimming, or cycling to improve overall fitness, reduce pain sensitivity, and support recovery.

Education and Self-Management

Patient education is a critical component of back pain management. Understanding that back pain is common, usually non-serious, and modifiable helps reduce fear-avoidance behaviours that can contribute to chronicity. Evidence suggests that patients who understand their condition and actively participate in their rehabilitation have better long-term outcomes.

Dry Needling and Acupuncture

Some physiotherapists use dry needling or acupuncture as an adjunct treatment for lower back pain. These techniques may help reduce muscle tension and modulate pain pathways. While the evidence base is still evolving, some clinical trials have shown short-term benefits when combined with exercise therapy. Learn more in our guide to dry needling.

Cognitive and Psychosocial Approaches

For persistent lower back pain, addressing psychosocial factors — such as catastrophising, fear of movement, stress, and low mood — is essential. Physiotherapists trained in cognitive functional therapy (CFT) integrate behavioural strategies with movement retraining to address both the physical and psychological dimensions of chronic pain.

Exercise Rehabilitation Programme

A structured rehabilitation programme for lower back pain typically progresses through several stages:

Phase 1: Pain Management (Weeks 1–2)

• Gentle range of motion exercises (pelvic tilts, knee rolls)
• Diaphragmatic breathing and pelvic floor activation
• Supported walking for short durations
• Avoiding prolonged bed rest — evidence strongly discourages rest beyond the first 48 hours

Phase 2: Motor Control and Stabilisation (Weeks 2–6)

• Transversus abdominis and multifidus activation exercises
• Bridging progressions
• Bird-dog (quadruped arm and leg extension)
• Side plank modifications
• Gradual return to normal daily activities

Phase 3: Strengthening and Functional Restoration (Weeks 6–12)

• Progressive resistance training (deadlifts, squats, lunges)
• Gym-based strengthening programme
• Sport-specific or occupation-specific movements
• Aerobic conditioning progression

Phase 4: Maintenance and Prevention (Ongoing)

• Independent home exercise programme
• Regular physical activity (150 minutes of moderate-intensity exercise per week, as per Australian physical activity guidelines)
• Ergonomic modifications for work and home
• Periodic physiotherapy review if symptoms recur

Prevention Strategies

Preventing recurrence of lower back pain is just as important as treating the initial episode. Evidence-based prevention strategies include:

• Regular exercise: Maintaining strength and flexibility through consistent physical activity is the single most effective prevention strategy.
• Ergonomic workstation setup: Ensure your desk, chair, and monitor are positioned to support neutral spinal alignment. Take regular breaks from prolonged sitting.
• Lifting technique: Use your legs to lift, keep loads close to your body, and avoid twisting under load.
• Weight management: Excess body weight, particularly around the abdomen, increases load on the lumbar spine.
• Stress management: Chronic stress contributes to muscle tension and pain sensitisation. Strategies such as mindfulness, adequate sleep, and regular relaxation can help.
• Smoking cessation: Smoking is associated with increased rates of back pain and poorer recovery outcomes, likely due to reduced blood flow to spinal structures.

For more information on related conditions, see our guides on knee pain physiotherapy, neck pain treatment, and shoulder pain physiotherapy.