The lower back, also known as the lumbar region, is the part of the spine located between the rib cage and the pelvis. It consists of five vertebrae, labeled L1 to L5, which provide support and flexibility to the upper body. This area is crucial for various movements, such as bending and lifting, and plays a key role in maintaining posture. The lower back contains important structures, including muscles, ligaments, and nerves. Common issues in this region include lower back pain, which can result from strain, injury, or conditions like herniated discs. Proper care, including exercise and ergonomics, can help maintain lower back health.