The second lumbar vertebra is usually positioned in two ways: the first is to find the second lumbar vertebra through the fourth lumbar vertebra, which is located in the posterior midline of the body. The iliac crest is flat against the spinous process of the fourth lumbar vertebra, and after finding this position, count up two is the second lumbar vertebra. The second, touch the twelfth rib, the twelfth rib is located in the back of the body, you can feel the twelfth rib by counting down from the top of the back, and then there are no ribs down. The twelfth rib flat against the twelve thoracic vertebrae, the next twelve thoracic one is the lumbar one vertebrae, and then the next one is the lumbar two vertebrae, so it can be well positioned.