Is spondylolisthesis worse with flexion or extension?

Spondylolisthesis Symptoms Worsen with Extension, Not Flexion

Spondylolisthesis symptoms are typically worse with extension (backward bending) rather than flexion (forward bending), and flexion-based exercises are the recommended conservative treatment approach. 1

Biomechanical Rationale

The fundamental biomechanics of spondylolisthesis explain why extension worsens symptoms:

• Extension increases anterior displacement of the affected vertebra in typical cases, exacerbating neural compression and pain 2
• Flexion typically reduces the slip by decreasing the shear forces at the affected segment, though paradoxical motion can occur in 15% of cases 2
• The forward slippage is normally resisted by posterior facets, the neural arch, and the intervertebral disc—structures that are compromised in spondylolisthesis 3

Evidence-Based Conservative Management

Flexion Exercises Are Superior

Flexion-based exercise programs demonstrate significantly better outcomes than extension exercises for symptomatic spondylolisthesis:

• At 3-month follow-up: only 27% of flexion exercise patients had moderate-to-severe pain versus 67% in the extension group 1
• At 3-year follow-up: only 19% of flexion patients had moderate-to-severe pain versus 67% in the extension group 1
• Recovery rates: 62% for flexion exercises versus 0% for extension exercises at 3 years 1
• Flexion exercise patients were less likely to require back supports, job modifications, or activity limitations 1

Recommended Flexion Exercise Protocol

The effective flexion program includes:

• Abdominal curl-ups to strengthen anterior core musculature 1
• Posterior pelvic tilts to reduce lumbar lordosis 1
• Seated trunk flexion exercises 1
• Avoidance of maximal forward flexion despite the flexion-based approach 3

Additional Conservative Measures

• Strengthening of abdominal and paraspinal muscles, especially thoracic paraspinals 3
• Instruction in proper body mechanics and posture 1
• Deep-heat therapy for symptom relief 3
• Epidural steroid injections may provide short-term relief 4
• Minimum 3-4 month trial of conservative treatment before considering surgery 3

Important Clinical Caveats

Paradoxical Motion Pattern

Be aware that 15% of patients with L5-S1 spondylolytic spondylolisthesis demonstrate paradoxical motion where flexion reduces the slip and extension increases anterior translation—the opposite of typical biomechanics 2:

• Paradoxical motion is associated with significantly higher slip angles 2
• These patients may have low sacral slope and increased lumbosacral lordosis 2
• Patients without anterolisthesis during flexion may still have paradoxical instability 2

When to Consider Surgical Intervention

Surgery becomes appropriate when:

• Conservative treatment fails after 3-4 months of comprehensive management 3
• Patients have stenosis with spondylolisthesis and evidence of instability 5
• Neurogenic claudication persists despite appropriate conservative care 4
• Fusion is recommended when decompression is needed in the presence of spondylolisthesis to prevent iatrogenic instability 5

Clinical Algorithm

1. Initial assessment: Confirm spondylolisthesis grade and assess for instability on flexion-extension radiographs 2
2. Conservative trial (3-4 months minimum): Implement flexion-based exercise program with abdominal strengthening, posterior pelvic tilts, and seated trunk flexion 3, 1
3. Avoid extension-based exercises: These worsen outcomes in 67% of patients at 3 years 1
4. Monitor for paradoxical motion: If symptoms worsen with flexion, obtain dynamic radiographs to assess for paradoxical instability pattern 2
5. Surgical consideration: Reserve for failed conservative management with documented instability or progressive neurological symptoms 5, 4