The term "lumbar regions" generally refers to the lower back area, specifically the region between the rib cage and the pelvis. There are several synonyms for this anatomical area, including lumbosacral region, lumbar spine, lower back, and the lumbar vertebrae. The lumbosacral region is the portion of the back that consists of five vertebrae in the lower spine, which extend into the sacrum. The lumbar spine is the section of the vertebral column that is located between the thoracic and sacral regions. Lower back refers to the part of the back that lies below the ribcage and above the hips. The lumbar vertebrae are the five individual bones that make up the lower part of the spine.