Correlation of clinical examination characteristics with three sources of chronic low back pain.

BACKGROUND CONTEXT: Research has demonstrated some progress in using a clinical examination to predict discogenic or sacroiliac (SI) joint sources of pain. No clear predictors of symptomatic lumbar zygapophysial joints have yet been demonstrated.

PURPOSE: To identify significant components of a clinical examination that are associated with symptomatic lumbar discs, zygapophysial joints and SI joints.

STUDY DESIGN: A prospective, criterion-related concurrent validity study performed at a private radiology practice specializing in spinal diagnostics.

PATIENT SAMPLE: The sample consisted of 81 patients with chronic lumbopelvic pain referred for diagnostic injections.

OUTCOME MEASURES: Contingency tables were constructed for nine features of the clinical evaluation compared with the results of diagnostic injections. Statistical analysis included chi-squared test for independence, phi and odds ratios with confidence intervals.

METHOD: Patients received blinded clinical examinations by physical therapists, and diagnostic injections were used as the criterion standard.

RESULTS: Significant relationships were found between discogenic pain and centralization of pain during repeated movement testing, and pain when rising from sitting. Lumbar zygapophysial joint pain was associated with absence of pain when rising from sitting. Sacroiliac joint pain was related to three or more positive pain provocation tests, pain when rising from sitting, unilateral pain and absence of lumbar pain.

CONCLUSIONS: Significant correlations exist between clinical examination findings and symptomatic lumbar discs, zygapophysial and SI joints. The strongest relationships were seen between SI joint pain and three or more positive pain provocation tests, centralization of pain for symptomatic discs and absence of pain when rising from sitting for symptomatic lumbar zygapophysial joints.