The Lumbar Spine

The sacrum is a flat triangular bone located below the lumbar spine. It functions as a wedge between the 2 hip bones on either side of it, stabilizing the entire pelvic area. Many nerves exit out holes on each side of the sacrum, including the sciatic nerve, which is the source of pain for sufferers of sciatica.

The spinal curve reverses at the sacrum. The sacral curve is a kyphosis.