The coccyx is the most caudal part of the spinal column and is formed developmentally from 4 former vertebrae (caudal vertebrae). In contrast to the sacrum, these vertebrae no longer have vertebral foramen and no spinal nerves emerge. The coccyx is much smaller in width and height than the sacrum and is connected to it by a true joint (sacrococcygeal articulation) or a cartilaginous connection (sacrococcygeal synchondrosis). Several muscles attach to the coccyx, in addition to the gluteus maximus, especially pelvic floor muscles such as the levator ani, coccygeus and urogenital diaphragm,
