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The anatomy of the human tailbone: where is looks like and what is needed

The Coccyx is the lower end of the spine, small bone structure is triangular in shape. Why would anyone need to know how is the coccyx? Normal location the body does not attract attention, but the pathology is in the coccyx cause serious problems.

Where is the coccyx in humans

the Coccyx and its structure

On the images you can see that it is composed of three to five fused vertebrae. A single structure, they begin to form upon the completion of puberty, usually by age 40 all the coccygeal vertebrae, except the first, are fused. The coccyx is movably connected to the sacrum via the sacrococcygeal joint (is a joint), so maybe its posterior deviation if necessary (for example, when the baby passes through the birth canal). Sometimes this connection can be fixed by fusion, which is more common in men.

the anatomy of the coccyx


Scholars believe that during the evolution the coccyx has become the part of the spine, which supported the tail. Currently a person the tail is not needed, and therefore the tailbone has lost its original role. Why this small section of the spine?

  1. Place of fixation of the muscles and ligaments involved in the work of the organs of the urinary system and colon.
  2. To it partially attaches to the gluteus Maximus.
  3. Nerve plexus which is located on the anterior surface of the coccyx gives branches to the pelvic organs.
  4. It represents an additional foothold necessary to tilt the seated person back, is responsible for the even distribution of the load between the anatomical structures of the pelvis.

so, having considered all the functions of the tailbone, you can understand why nature has completed the spine in this way. But all he made in the same way?

structure of the human tailbone

options Anatomical location coccygeal segments

normally, the coccyx is as follows: top down, forming an acute angle directed anteriorly from behind. Such a structure of the coccyx is about 70% of cases. There are also other kinds of the location of the coccyx, when its top has a different direction or the tailbone is tilted at another, more sharp angle (bending, curvature). This structure coccygeal spine can be congenital or acquired (injury, torn ligaments between the sacrum and the coccyx).

common variants of anomalous locations

  • about 15% of people the tip of the tailbone directed down to the fact that it is folded anteriorly stronger than usual;
  • sometimes there is an additional bend at a right angle between the first and second, less often between the second and third vertebrae;
  • in 10% of cases of congenital subluxation occurs anteriorly.

fracture of the coccyx CT-image

As a rule, abnormal anatomy of the coccyx does not bother the man and is detected accidentally on x-ray images. However, those who go to the doctor about coccygeal pain (coccygodynia), significantly more frequently detected atypical location of this spine. In addition, the bend of the coccyx anteriorly can complicate the course of childbirth, so women who have had an injury or pain in this area should be screened before pregnancy planning.

Pathological state

Fractureis most Often the result of trauma (a fall or a strong kick).• redness or swelling (further acquires a bluish color);
• pain (when pressed, the seat or alone);
• swelling, spread-
himself on sacrum;
• the sound of movement of bone fragments on palpation.
Dislocationusually occurs as a result of the fall of man, when the articular surface of coccygeal segment and the sacrum is displaced in relation to each other.• severe pain and swelling;
• difficulty during defecation;
• increased pain in the sitting position.
InjuryFall in the gluteal region, a blow of moderate force• bruising and swelling of tissues;
• pain of varying intensity (from mild to severe).
Osteochondrosisthe degeneration of joint cartilage and intervertebral discs. Cartilage prone to fluid loss and thinning, there are microfractures. These processes are accompanied by inflammation of the periosteum, whereby it expands, forming protrusions osteophytes. They can injure the surrounding tissues (muscles, nerve structures), causing pain.• discomfort and pain when moving, uncomfortable position,prolonged sitting (especially on soft surfaces).
• pain can extend-
Xia in the direction of the pelvic organs and legs.
Hernia of coccyxan Extreme manifestation of degenerative changes of the intervertebral disc. The herniation causes rupture of the fibrous ring of the disc as a result of trauma or high stress (e.g. during childbirth). As a result, a soft substance that fills the middle of the disk, it appears in the spinal canal and can compress the nerve structure.• the pain and violation of defense-
ti (numbness) of the perineum and coccyx; the
• may be present of violation of functions of pelvic organs (mocheispuskani-
tion, defecation).
Epithelial coccygeal course (pilonidal cyst)a Congenital disorder arising from incomplete reduction of tail muscles (normally they are laid in the prenatal period, then disappear). Parallel to the crease between the buttocks is a narrow tube epithelium, which communicates with the coccyx and the sacrum. Epithelial turn connects with the external environment through skin pin holes, stand out substance that produces the epithelium. Coccygeal cyst usually does not manifest itself if the skin holes are functioning normally. However, as a result of injury or infectious process they may get clogged, it causes inflammation and destruction of the cyst walls. Subcutaneous tissue is subjected to purulent fusion with the formation of abscess.• increased body temperature and symptoms of intoxication (General weakness, malaise, headaches);
• education of pineal form in the coccygeal region, the red skin color and swelling over the cyst;
• intense pain, worse when you try to sit down;
• the hole in the crease between the buttocks, through which the pus (if there samoproizvol
Noah opening the cyst).
Tumors of the pelvic bonesplots the Destruction of bone and cartilage as a result of tumor growth.Pain in the sacrum, hips, coccyx and pelvis, worse during walking, movement, and increasing in dynamics poorly amenable to medical therapy.
Prolapse and prolapse of the pelvic organsReducing muscle tone of the pelvic floor causes a disturbance of the location of organs: prolapse of the uterus and vagina, rectum and bladder.• disorders of defecation and urination is more often the type of incontinence;
• in women – painful sexual intercourse;
• pain in the perineum and in the projection of the coccygeal region.


  1. Vertebral lumbar pain: polipektomii the origin, symptomatology, principles of treatment. Grachev Y. V. Shmyrev VI, the Magazine “doctor”, 05/08;
  2. Kokcigodiniâ. Belenky A. G. Russian medical journal.
  3. Surgical treatment of epithelial coccygeal progress: clinical and anatomic aspects, A. I. Zhdanov, S. V. Crooked onosov and S. G. Brezhnev. Voronezh state medical Academy named after N. N. Burdenko, Voronezh, Russian Federation, journal of experimental and clinical surgery, volume VI, No. 3, 2013;
  4. Instability of the coccyx in coccydynia. J.-Y. Maigne, D. Lagauche, Doursounian L. The journal of bone and joint surgery.