The exact location of the sacral foramen is at the dorsal notch of the 4th and 5th sacral vertebrae where it surrounds the coccyx. 1. The sacral canal is connected to the spinal canal at the upper end, and the split at the lower end is called the sacral cleft. There are sacral horns protruding downward on both sides of the foramen, and sacral anesthesia is often marked by the sacral horns. 2. The sacral cleft is located at the very bottom of the gluteal fissure, just behind the tailbone. 3. The patient can simply localize and palpate it as follows: palpate downward through the sacral crest. First, at the top of the gluteal fissure, that is, the buttock groove, gradually follow the posterior median line downward, and you will feel the sacral median ridge, that is, the prominence of the sacrum in the posterior median area, and when you feel downward along this area, your fingers will feel a depression in the middle, which is the sacral fissure. 4. The patient can find it by locating the tailbone. The patient can locate a small protruding bone behind the anus, which is the coccyx. Feeling upwards along the center of the coccyx, you will also feel a depression, with bony markings of sacral horn protrusions on either side of it. In its center is the sacral cleft.