Synonym: short: coccyx; Latin: Os coccygis
Introduction
The coccyx is a slightly forward curved section of the spine, which is formed by the fusion of 2-4 vertebrae. It is the lowest (caudal) section of the spinal column, which is connected to the sacrum via the cartilaginous sacrococygeal joint.
Anatomy
The coccygeal vertebra no longer shows a classic vertebral structure. Only the first vertebra is still recognizable as a vertebra due to its short transverse processes. The remaining vertebrae are approximately square, with the last appearing conical.
The individual vertebrae are not connected by intervertebral discs as in the rest of the spinal column, but are fused together as bones. This is called synostosis (ossification). In some cases, however, the individual vertebrae are also connected by cartilage plates (synchondroses).
This already shows that the development of the coccyx vertebrae can be very variable. No nerves emerge from the coccygeal vertebra except for the coccygeal nerve, which emerges from the spinal column at the connection between the sacrum and the coccygeal vertebrae. Since the coccyx is the lowest part of the spinal column, the ligaments Ligamentum longitudinale anterius and posterius (the long anterior ligament and the long posterior ligament), which span the entire spinal column, end here.
There is also a ligamentous connection between the sacrum and the coccygeal vertebra, the so-called Ligamentum sacrococcygeum. In addition to these ligaments, many muscles of the pelvic floor attach to the coccyx, for example the Musculus pubococcygeus or the Musculus iliococcygeus. The pelvic floor generally serves as a holding apparatus for the sexual organs (e.g. uterus), the rectum and the urethra.
Overexertion of this holding apparatus can lead to pain in the coccyx. This is due to the fact that the muscles that hold the rectum in place, for example, are overstrained and irritated by increased pressing. This can lead to inflammation in the muscle, which then spreads to the sensitive periosteum of the coccyx.
This is also often the case after birth. The coccyx is thus exposed to permanent stress. This is intensified if one sits too long and too often on hard surfaces (for example, in the office at a desk). Because of its slightly forward facing shape and its connection to the muscles of the pelvic floor, the coccyx is only relieved when you stand upright.
