coccyx

Eva Rudolf-Müller is a freelance writer in the medical team. She studied human medicine and newspaper sciences and has repeatedly worked in both areas - as a doctor in the clinic, as a reviewer, and as a medical journalist for various specialist journals. She is currently working in online journalism, where a wide range of medicine is offered to everyone.

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The tailbone (Os coccygis) is the lowest, last section of the spine. It is viewed as a rudiment of the vertebrate tail vertebrae that have receded over the millennia and grown together to form a vertebral block. Basically, the coccygeal bone no longer has any function in humans, but it can certainly cause discomfort. Read everything you need to know about the tailbone!

What is the tailbone?

The tailbone (os coccygis) is the last section of the spine. It consists of four to five vertebrae, which in adults usually have grown together to form a single bone that is slightly bent forward. Movements in the tailbone are only possible forwards and backwards.

The individual coccyx vertebrae are partly only rudiments of the normal shape of the vertebrae, i.e. they are strongly regressed:

The first vertebra of the coccyx still has a vertebral body, transverse processes and remnants of articular processes that point upwards - towards the sacrum. The vertebral arch is absent in the first coccyx vertebra as well as in all those below. The vertebral arches are replaced by ligaments. The remaining three to four vertebrae of the coccyx consist only of remnants of the vertebral bodies: they have receded into rounded pieces of bone.

Fusion of vertebrae

Similar to the border between the lumbar spine and sacrum, where the last lumbar vertebra can be fused with the first sacral vertebra (upper sacralization), what is known as sacralization (lower sacralization) can also occur at the border between the sacrum and the coccyx. In most cases, these assimilation or transition vortices go unnoticed and without symptoms.

The individual vertebrae of the coccyx are connected to one another by fiber cartilage. An articulated cartilaginous connection often remains between the sacrum and the first and second coccyx vertebrae (especially in women). In old age, the tailbone usually grows together with the sacrum - earlier in men than in women.

The longitudinal ligaments of the spine

The anterior longitudinal ligament of the spine (ligamentum longitudinal anterius), which runs along the entire spine and is firmly connected to the vertebral bodies, stabilizes the spine and limits its backward movement. It is lost on the front of the sacrum and only reappears on the tailbone.

The posterior longitudinal ligament of the spine (ligamentum longitudinal posterius), which is firmly connected to the intervertebral discs and, together with the anterior longitudinal ligament, serves to stabilize the spine, connects the coccyx to the sacrum.

What is the function of the tailbone?

The tailbone serves as a starting point for various ligaments and muscles of the pelvis, the pelvic floor and the hip joints. Since the pelvis is open at the bottom, the ligaments and muscles in this area are important in keeping the organs in place.

The articulated connection between the sacrum and the first two vertebrae of the female coccyx is important during childbirth: when the child's head passes through the birth canal, the pressure causes the tip of the coccyx to move back about two centimeters, thereby expanding it Pelvic exit, which facilitates the passage of the child.

Where is the tailbone?

The tailbone (Os coccygis) forms the lowest section of the spine, so it follows the sacrum.

What problems can the tailbone cause?

As in all parts of the spine, congenital or acquired changes (deformities, malformations, etc.) can also occur in the coccyx.

A fracture of the tailbone, which occurs mainly in the event of a fall on the buttocks, or the less common dislocation, leads to the end piece of the tailbone kinking forward. Pain from a fracture or dislocation is particularly common when sitting or sneezing when the pelvic muscles are tensed (coccygodynia). Other causes of pain in this area can include difficult delivery. Sometimes they are also psychogenic.

As in all bone areas, osteoporosis also leads to a fracture more easily in the coccyx if the person concerned falls.

If the connection between the coccyx and sacrum is solidified, this can be an obstacle to childbirth.

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