The L1 vertebra is located in the spinal column of the lumbar (lower back) region inferior to the T12 vertebra and superior to the L2 vertebra.
Video Transcript. The lumbar region of the spine, more commonly known as the lower back, consists of five vertebrae labeled L1 through L5. The lumbar region is situated between the thoracic, or chest, region of the spine, and the sacrum.
They are thicker in the front than the back. The large size and bone strength is necessary because these vertebrae support more weight than the upper two segments of the backbone. The L1 vertebra is level with the ninth rib and the connection between the stomach and the small intestine.