Labor pain is caused by contracture of the uterine muscle tissue. The criss-crossed muscle fibers wrap the pear-shaped uterus extremely tenaciously. This layer-by-layer arrangement allows the uterus to contract to the maximum extent under the control of hormones, and the direction of force can be appropriately adjusted, so that enough force can be used to push the baby out of the body. Generally speaking, the uterine muscles are the main source of labor pain. In addition, the pelvis