What causes pain when sitting?

Causes of Pain When Sitting

Pain when sitting is commonly caused by nonspecific low back pain, lumbar disc herniation, spinal stenosis, poor sitting posture, or specific spinal conditions such as ankylosing spondylitis. 1

Common Causes of Sitting-Related Pain

Nonspecific Low Back Pain

• Accounts for approximately 85% of all back pain cases presenting to primary care 1
• Often exacerbated by prolonged sitting, especially in poor postures 2
• May be related to muscle fatigue, soft tissue strain, or minor disc issues without specific identifiable pathology 1

Radiculopathy and Disc Herniation

• Herniated discs (especially at L4/L5 and L5/S1 levels) can cause pain while sitting 1
• Characterized by back and leg pain in a typical lumbar nerve root distribution (sciatica) 1
• Positive straight-leg-raise test (reproduction of sciatica between 30-70 degrees of leg elevation) has high sensitivity (91%) but modest specificity (26%) for diagnosing herniated disc 1

Spinal Stenosis

• Narrowing of the spinal canal causing compression of nerve roots 1
• Presents with neurogenic claudication - leg pain when walking/standing that is relieved by sitting or spinal flexion 1
• However, some patients with spinal stenosis may actually experience increased pain with sitting, particularly in certain positions 3

Postural Factors

• Slumped sitting posture significantly increases loads on cervico-thoracic and lumbosacral joints compared to upright or lordotic postures 4
• Prolonged slumped sitting causes higher activity in upper and lower trapezius muscles, potentially leading to neck and back pain 2
• Sitting without proper lumbar support increases back and referred leg pain compared to sitting with lumbar support maintaining lordosis 3

Other Specific Spinal Conditions

• Ankylosing spondylitis (prevalence 0.3-5% in primary care patients) can cause alternating buttock pain and pain when sitting 1
• Vertebral compression fractures (4% of cases) may cause positional pain including when sitting 1
• Patellofemoral pain syndrome can cause knee pain during prolonged sitting with knee flexion (affects over 54% of patients with this condition) 5

Biomechanical Factors

• Joint moments and anterior-posterior reaction forces at cervico-thoracic and lumbosacral joints are significantly greater in slumped sitting postures 4
• Head flexion angle strongly correlates with cervico-thoracic joint loads (r>0.86) 4
• Trunk flexion angle strongly correlates with lumbosacral joint loads (r>0.77) 4
• Arm position affects joint loads - arms forward position increases cervico-thoracic loads compared to arms-on-chest position 4

Psychosocial Factors

• Psychosocial factors and emotional distress are stronger predictors of low back pain outcomes than physical examination findings or pain severity/duration 1
• Factors that may predict poorer outcomes include depression, passive coping strategies, job dissatisfaction, higher disability levels, disputed compensation claims, and somatization 1
• Reduced movement (fewer spine fidgets) during sitting is associated with increased pain development 6

Clinical Pearls and Pitfalls

• Pain while sitting may not always correlate with observable biomechanical differences - a study found no significant differences in posture or muscle activity between pain developers and non-pain developers during sitting 6
• Patients with stenosis or spondylolisthesis may have symptoms aggravated by lumbar rolls or supports that increase lordosis, contrary to most other back pain conditions 3
• Sitting-induced pain appears to be related to micro-movement strategies, with pain developers showing fewer spine fidgets than non-pain developers 6
• Slumped sitting postures create joint loads comparable to or exceeding those experienced during more dynamic activities like sit-to-stand transitions and walking 4

Recommendations for Assessment

• Conduct a focused history and physical examination to classify patients into one of three categories: nonspecific low back pain, back pain potentially associated with radiculopathy/spinal stenosis, or back pain potentially associated with another specific spinal cause 1
• Assess for red flags suggesting serious pathology: history of cancer, unexplained weight loss, failure to improve after 1 month, age >50 years, fever, recent infection, or intravenous drug use 1
• Evaluate for neurological deficits including motor weakness, sensory changes, and reflex abnormalities that may indicate nerve root compression 1
• Consider psychosocial factors that may contribute to pain persistence and disability 1