The sternum (breast bone) is the central point of the chest wall where the clavicle (collarbone) and ribs attach. There are joints at the points where these bones meet. Unusual sounds emanating from bones usually arises from the joints rather than the bones itself. Some of the more common joints noises from the sternal joints is popping, clicking or cracking in nature.
The ribs do not connect directly with the sternum. Instead it connects to costal cartilages which in turn connect to the breastbone. There are three set of joints in this area:
- Sternocostal joints where the costal cartilages connect to the sternum.
- Costochondral joints where the costal cartilages connect to the ribs.
- Sternoclavicular joints where the sternum connects to the clavicle (collarbone).
Clicking, cracking or a popping sound around the region of the sternum most likely arises from one of the joints. It may also be accompanied by other symptoms such as breastbone pain, tenderness, redness and/or swelling of the chest wall.
Reasons for Joint Popping Sound
The exact reason why the joints discussed above may pop, crack or click is unclear. It is believed that these sounds from the joints may be due to either ligaments that stretch and release suddenly (snapping) or due to nitrogen bubbles becoming compressed within the joint spaces. These possible explanations of joint sounds should only be considered in healthy joints. However, there can also be other possible reasons for joint popping, cracking or clicking sounds.
For example, inflammation of the joint (arthritis), erosion of the joint structures or dislocation (partial or complete) could account for unusual joint sounds. Usually these conditions are accompanied by other symptoms like pain and swelling. The sternocostal, costochondral and sternoclavicular joints do not have the same range of motion as some of the other joints, like the finger joints. However, it can also be strained by actions like breathing deeply, when lifting heavy objects with the arms or stretching the arms widely.
These sounds may be audible only to the person while at other times the sound can even be heard by others nearby. It is important to determine whether there is actually a popping sound or just a sensation of popping. Sometimes people imagine hearing a sound when the experience a popping sensation.
Causes of Popping Sternum-Rib Sounds
There are many possible causes of popping sounds from the sternum and ribs. However, the exact cause of these abnormal joint sounds may not always be known.
- Trauma to the chest wall, bones (sternum, ribs, clavicle) and/or joints specifically may arise for a number of different reasons. This may include a blow to the chest as may be seen with an assault, fall or car accident injuries where the chest wall is struck by an airbag or steering wheel.
- Strain is another common cause of abnormal joint sounds. Acute strain can cause joint inflammation and dislocation while chronic strain can cause joint damage and osteoarthritis. With regards to the sternal joints, acute strain can occur with actions requiring the use of the arms in particular like weight lifting.
- Costochondritis is a condition where the costal cartilages become inflamed. While pain and tenderness is quite pronounced, there is little to no swelling evident on the chest wall. Costochondritis may be caused by repeated minor trauma as well as strain. Major surgery to the chest wall can also cause it.
- Tietze’s syndrome usually affects ribs slight higher up than costochondritis. The two conditions are very similar but with Tietze’s syndrome there is pain, tenderness and prominent swelling evident on the chest wall. As with costochondritis, Tietze’s syndrome is due to strain and minor trauma that occurs repeatedly. Persistent coughing and vomiting can cause it.
- Dislocation occurs when the ends of the bones in the joint spaces slips out of the position where it articulates. This may be either partial or complete. Sometimes the popping occurs when the bone slips back into place. Dislocation is usually associated with trauma but certain diseases can increase the likelihood of the bone slipping even with slight trauma.
- Arthritis is the term for joint inflammation. Rheumatoid arthritis occurs when the immune system attacks the joint structures and causes inflammation. Osteoarthritis is where there is degeneration of the joint structures and sometimes the ends of the bones as well. This could affect the small joints between the sternum and ribs.
Sometimes the sensation of popping of the sternum and ribs does not arise from these structures. It may be due to other chest wall structures like muscles. Spasm of the chest wall muscles can limit movement in the sternum-rib joints which may feel like the joint is under strain. Similarly chest wall injury even without any involvement of the joints may result in reduced movement and pain upon movement. This is sometimes mistaken for a problem with the sternum-rib joints.
Remedies for a Popping Sternum
A popping sternum should always be investigated by a medical professional and the prescribed treatment should be followed. However, a few simple lifestyle changes may help with minimizing the popping and associated pain.
- Avoid carrying heavy weights until the problem subsides. Strenuous physical activity like push-ups and bench pressing (weight lifting) can cause and worsen a popping sternum and should be discontinued at least for a period of time.
- Hot and cold therapy can be helpful. Cold therapy like applying an ice pack should be used for about 2 days after acute injury or strain. Heat is useful if the pain persists for 2 days after the injury and this can be done by placing a hot water bottle on the chest.
- Topical applications like muscle rubs can help with muscle strain and inflammation. The rubbing action or massaging can also help with easing pain particularly where muscle spasm is the problem.
- Stretching exercises may help ease and prevent muscle spasm especially when the hands and chest muscles are overworked. It should always be done before exercise routines involving activities such as push-ups and bench presses.
- Do sleep on the tummy for long periods as this can hamper normal movement of the chest wall during breathing and worsen any injury to the chest wall.