The sword extension

Definition - What is the sword extension?

The sword extension - also called "Processus Xyphoideus" - is the lowest part of the breastbone.
The breastbone (sternum) can be divided into three parts. It looks like a sword on the whole. Above, between the collarbones, is the handle (manubrium sterni). The middle part, to which the second to sixth ribs attach via cartilage, is called the body (corpus sterni). The lowest part, on which no ribs are attached and which tapers downwards, is the sword extension.

Anatomy of the sword process

The breastbone (sternum) is one of the flat bones. Strictly speaking, the sternum is made up of three individual parts that are still connected to one another by cartilage in childhood. These connections ossify over time. Listed from top to bottom are the three parts of the sternum handle (manubrium sterni), the sternum body (corpus sterni) and the sword extension (processus xyphoideus).

The sword extension sits at the lowest end of the sternum and, like the whole sternum, lies directly under the skin. Its shape is usually pointed downwards, but it can also be split or perforated.

The heavy process forms with the lowest costal arches and the 12th thoracic vertebral body the lower limit of the chest. The inside of this lower boundary of the chest, including the back of the sword extension, is the attachment surface for the diaphragm.
The rectus abdominis muscle, the straight abdominal muscle, also adheres to the sword process with a few fibers. On the outside there is only skin with the associated fatty tissue over the sword process.
The diaphragm is attached to the inside of this lower boundary of the chest. It forms a dome inside the body and separates the trunk into the chest and abdominal cavity.

Further information can be found at: Sternum

What is the function of the sword extension?

The sternum is, so to speak, the keystone in the chest. This is where the right and left ribs meet. As a result, the sensitive organs, lungs and heart, are protected by the bones. Ribs no longer attach to the sword extension itself. It forms the last small bone plate that protrudes towards the abdomen.

This could also be of interest to you: Costal arch

Illustration of the sword extension

Figure sword extension
  1. Sword extension -
    Xiphoid process
  2. Sternum handle -
    Manubrium sterni
  3. Sternum body -
    Corpus sterni
  4. Fiber cartilage -
    Symphysis xiphosternalis
  5. White line -
    Linea alba
    (Interweaving of
    Tendon plate)
  6. Straight Abdominal Muscle -
    Rectus abdominis muscle
    Sternum -


You can find an overview of all Dr-Gumpert images at: medical illustrations

Pain and swelling at the process of the sword

  • Surgical interventions involving opening of the chest can lead to swelling of the sword extension. Excessive physical exertion also occasionally leads to swelling of the sword process or swelling of the sternum. This is based on micro-fractures in the bones.
  • If there is pain in the sternum area, a heart attack, angina pectoris and other organs such as the esophagus should also be considered.
  • The swelling can be seen from the outside with a reddening in the area of ​​the chest and ribs. Swelling of the sternum is primarily characterized by pain when inhaling and exhaling and an increased pulse. Those affected speak of a "burning pain" in the chest area and a feeling of heat. Middle-aged people are often affected, with the symptoms getting worse with age. But sternum swelling can also occur in children.
  • If there is a fracture of the breastbone, this is always an indication of other injuries.
  • Pain in the sternum area can also be projections from other organs. For example, angina pectoris, a heart attack or diseases of the esophagus cause pain behind the sternum. But the pain of a stomach ulcer can also spread to the sternum.
  • Another cause is what is known as costochondritis, in which the cartilage between the ribs and the breastbone is inflamed. Costochondritis is rather rare and usually occurs in the course of systemic diseases (for example Reiter's disease) on.
  • Some babies have a congenital hole in the sternum, most of which is on the right side.
  • The so-called funnel breast is one of the pathological changes in the sternum. In this case, the cartilage connections between the ribs and the sternum change and the front part of the chest sinks.
  • Another deformation is the keel or chicken breast. Here the sternum is arched like a keel, which is especially psychologically stressful for those affected. The cause of this is suspected to be strong cartilage growth, which causes the sternum to bulge.
  • If the breastbone is twisted in the longitudinal axis, one speaks of a Harrenstein deformity. The ribs protrude above the breastbone on one side, but are lowered on the other side.

The diagnosis of swelling of the sternum is usually made using a pressure test. Therapy is treated with painkillers, which can also be injected directly into the spinal cord if the pain is severe. Acupuncture, physiotherapy, and muscle-relaxing medication are other treatment options for relieving pain. Heat or cold therapy can also help.

Also read our topic: Sternum fracture

Cracking at the sword extension

A cracking in the area of ​​the sternum can have various causes.

  • Incorrect posture: someone who sits a lot and works on the PC and often uses his elbows to support himself or herself will train himself to adopt an incorrect posture. In this way, the sternum is improperly stressed. If you stretch yourself after sitting for a long time, the sternum cracks. By stretching, the rib and sternum joints are stretched again and the muscles also pull on the ribs and sternum.
  • A blockage in the cervical or thoracic spine is also an option for the cracking in the sternum. Here, too, the cracking occurs after prolonged incorrect posture, when suddenly the position is changed. Most of the time, the cracking also relieves the pressure in the sternum and the pain.
  • If this feeling of pressure does not go away despite the cracking in the sternum, you should consult a physiotherapist or an osteopath.

What is Tietze Syndrome?

Tietze syndrome is a rare disease of the breastbone. This leads to swelling in the area of ​​the rib attachment to the sternum. In this area is the costal cartilage, which connects the ribs and sternum as a joint. This swelling can be palpable and visible and is often painful.
The cause of this swelling is not yet clear.

Often the pain occurs spontaneously for no immediately apparent reason. Usually, however, the pain increases with physical activity and stress. This can be explained by the fact that physical exertion leads to increased and deeper inhalation and the costal cartilage is more stressed.

Since the upper 3 ribs are most frequently affected in Tietze syndrome, the syndrome is not associated with pathological changes in the sword process.

Read more about this at: Tietze syndrome