L5-S1 is the exact spot where the lumbar spine ends and the sacral spine begins. The lumbosacral joint connects these bones.

Three lesions are created at each sacral level at 2 ... which included studies for cervicogenic headaches, cervical brachial neuropathy and lumbar radiculopathy, as well as studies with PRFA ...

The L5- S1 refers to specific vertebrae in the spine, spanning from the end of the lumbar to the sacral region ... the number ...