Verywell Health on MSN

Lumbar spine anatomy and function

Medically reviewed by Jennifer Steinhoff, MD Key Takeaways The lumbar spine includes five vertebrae that help with mobility ...
Because each lumbar facet joint is innervated by two medial branches of the primary dorsal ramus, both must be anesthetized to completely block a single joint. For example, to block the L4-L5 facet ...