The Larson Test is used to identify which condition?

• A. Lumbar radiculopathy due to facet arthropathy
• B. Internal Disk Disruption
• C. Spondylolysis
• D. Piriformis syndrome

Answer: (B)

This test targets discogenic pain from internal disk disruption. It provokes the lumbar disc by applying loading to the spine in a way that stresses the posterior annulus, so if the disc is disrupted you’ll reproduce deep, axial low-back pain. A positive result supports internal disk disruption as the pain source because the pain pattern is centered in the back and not primarily radicular. This helps differentiate it from nerve-root–mediated radiculopathy, which would typically present with leg pain following a dermatomal pattern and possible neuro signs, and from facet joint pain, which tends to show a pain pattern linked to extension or specific facet-loading movements. Spondylolysis involves a pars interarticularis defect and is usually identified with imaging and specific stress tests like single-leg extension, while piriformis syndrome causes buttock or posterolateral thigh pain with hip movements and does not centralize on disc-loading provocation.