The lumbar spine is located under the 12th thoracic vertebral body from the 1st to the 5th vertebrae, and is the largest of the vertebrae, totaling 5 vertebrae. The lumbar spine has a total of 5 vertebrae and can be palpated in the prone and sitting positions. The 1st vertebra under the 12th thoracic vertebra is the 1st lumbar vertebra; the largest and longest transverse process palpable on either side of the lumbar vertebra is the 3rd lumbar transverse process, which is at the same level as the 3rd lumbar vertebra; the 4th lumbar vertebra is located above the horizontal line of the apexes of the posterior supraspinatus of the iliac bones on each side; and the 5th lumbar vertebra is located at a line of the iliac crests on each side, i.e., the highest point of the pelvis. The lumbar vertebrae are located in the center of the posterior lumbar region, and their position can be determined by the position of the 1st lumbar vertebrae or the 5th lumbar vertebrae. If there is injury to the lumbar spine, it is recommended that the exact location be clarified by CT or MRI.