Why Do You Get Lumbar Spinal Stenosis? Commonly called your lower back, the lumbar spine is comprised of the 5 largest vertebrae of the 12 that make up your spinal column. These vertebrae are referred to as L1 – L5, and require some of the largest of the body’s muscles to support them. Separating each vertebrae are discs, which help absorb the shock and pressure placed on your spine every day. The spinal canal runs ...