What does percussion of the thoracic and lumbar spine detect?

• A. Positive pain with trauma, infection, tumors
• B. Pain only with muscle strain
• C. No abnormal findings expected
• D. Sensory loss in the lower limbs

Answer: (A)

Percussion of the thoracic and lumbar spine is used to uncover pathology in the vertebral bones themselves. When you tap over the spinous processes, if there is a fracture, osteomyelitis, infection, or a tumor, the vibration can provoke pain from the affected bone or periosteum. A positive percussion test points to underlying bony or infectious or neoplastic processes in the spine, rather than a purely soft-tissue issue.

This test isn’t about muscle strain, which is soft tissue and typically won’t produce focal pain with tapping on the vertebral spinous processes. Nor is it a test that reliably detects sensory loss in the lower limbs—that’s determined by a neurological exam. And while a normal percussion exam is reassuring, it doesn’t rule out all pathology; it mainly helps identify acute bony involvement.