Posterolateral view of the lumbar spine

Bones of the Lumbar Spine and Pelvis

The low back is defined by the lumbar spine, composed of 5 vertebrae, named L1-L5. The pelvis is defined by the bones of the pelvic girdle.

herniated disc with compression of the spinal nerve in the intervertebral foramen

Pathologic Disc Conditions of the Neck

The danger with a disc bulge or herniation is that the disc can compress the spinal nerve within the intervertebral foramen, causing a pinched nerve.