The lumbar spine is the lower part of the spine, consisting of five vertebrae labeled L1 to L5. It is located between the thoracic spine above and the sacrum below. This region supports much of the body's weight and allows for a range of movements, including bending and twisting. The lumbar spine is crucial for maintaining posture and stability. It houses the spinal cord and nerves that extend to the lower body, playing a vital role in mobility and sensation. Conditions affecting the lumbar spine, such as herniated discs or sciatica, can lead to pain and discomfort.