The sudden sensation of the chest popping during a stretch can be concerning, but in most cases, it is not a serious event. The feeling—and noise—is actually the sternum popping, and is a common occurrence. The sound is similar to that heard when purposely cracking the knuckles, or when bending at the knees. All of these incidents are normal, but if severe pain follows the popping of the chest, medical attention may be required.
The cracking noise and sensation of shifting within the chest cavity may occur during deep breathing exercises or when simply stretching the arms out wide to the sides.
What Is the Sternum?
The sternum is commonly known as the flat, T-shaped breastbone. Located in the middle of the chest, the sternum has three main sections.
The trapezoid-shaped manubrium is the upper portion of the sternum. The top of the manubrium has a concave notch at its highest point, visible as a depression at the bottom of the neck. The sternal angle joins the manubrium to the “body” portion of the sternum.
The body is the long middle section of the sternum. It is also referred to as the gladiolus and forms notches for cartilage attachment for the third to sixth ribs. The body narrows at the bottom for the xiphoid process.
The xiphoid process forms the lower section of the sternum bone. Its thin, pointed shape gives it its name, a Greek word for sword-shaped.
The sternum protects the lungs, heart, and blood vessels as it forms the front portion of the ribcage.
A popping sternum produces sound from the sternoclavicular joint region in the chest, located between the collarbone and the sternum. It may also originate from the sternocostal joints between the first seven ribs and the sternum.
Causes of Sternum Popping
While there is no direct cause for the popping in the chest, researchers believe the sound may be linked to several factors.
An injury to the chest from a motor vehicle accident or fall may cause sternum popping pain. This may be due to small cracks or fractures within the bone, as seen when the chest is forced against a hard surface such as the vehicle steering wheel.
This form of trauma may also be caused by the degenerative disease known as osteoporosis. With this condition, the density of the bones decreases and makes the bone susceptible to fractures. This may be heard as popping in chest.
Treatment for trauma to the sternum revolves around basic care and prevention from further injury.
- Rest the body and refrain from activity that uses the chest muscles during the recovery period of two to three months.
- Use an ice compress for the first three days for any pain and swelling. This should happen in 20-minute intervals every two hours.
- Severe injuries may require prescribed pain medication as the trauma may lead to breathing difficulty and coughing. These upper-respiratory issues could develop into An injured chest may also result from a collapsed lung or broken ribs. Anti-inflammatory and narcotic medications may be necessary.
- Surgery is considered for trauma cases where the bones have been displaced or breathing has become obstructed. Doctors may remove any broken bone fragments and connect the remaining bone with metal plates or wires.
2. Ligament Injuries
Injury to ligaments attaching the sternoclavicular joint to the breastbone is uncommon, but may occur with extreme overextension. This may also occur in ligaments that are overused and become damaged.
The sternum pops when stretching these ligaments by moving or lifting heavy objects like weights, which also may displace the joints and even the sternum itself. This dislocation is referred to as subluxation.
The popping noise may result due to ligament injuries, since the ligaments suddenly shift.
Treatment is similar to the management plan of major trauma to the sternum.
- Rest is the best medicine for a pulled or strained ligament anywhere in the body but especially in the chest region. These ligaments are used for movement in all positions.
- Avoid exercises that use the chest such as running, swimming, and biking.
- Apply ice compresses to treat the swelling that also causes the pain. Do this in 15-minute intervals once an hour, over the first several hours of the injury.
- Keep the chest motionless with the use of a compression wrap to address swelling and pain.
- Elevate the side of the chest affected by the injured ligament to promote proper blood flow and reduce inflammation and swelling.
The sensation of the sternum cracking may be caused by the condition costochondritis. This involves inflammation of the cartilage in the rib cage by trauma, strain, tumors, arthritis, or infection of the upper respiratory system.
Costochondritis is commonly seen in the cartilage of the costosternal joint, located at the point where the sternum attaches to the upper portion of the rib cage. Cartilage inflammation hinders the movement of the ribs and allows for physical contact of the ribs against the cartilage.
Treatment of costochondritis may involve both medical and natural remedies.
- Rest the body by refraining from activities that worsen the pain.
- Use hot and cold compresses to treat pain.
- Over-the-counter pain relievers may be necessary for persistent pain.
- Prescription medications such as potent nonsteroidal anti-inflammatory drugs, antidepressants, narcotics, or anti-seizure drugs may be essential for excruciating pain.
- Physical therapy including targeted stretches and electrical nerve stimulation may work to alleviate pain.
- Corticosteroid injections in the affected joint may be used to treat severe cases.
4. Tietze’s Syndrome
Not to be confused with costochondritis, Tietze’s syndrome is another condition with rib cartilage swelling from inflammation. With this condition, the inflammation may be due to a chest infection, in addition to any straining of the chest muscles that occurs with violent coughing or gagging.
Treatment for Tietze’s syndrome is similar to that of costochondritis. Rest, corticosteroid injections, and anti-inflammatory drugs may be used alone or as combined therapy. Other treatments may work to alleviate the swelling, pain, and damage to the afflicted area.
- Physiotherapy with stretching, strengthening, massage, and breathing exercises may be recommended. Some practitioners use electrotherapy and cryotherapy with ice to intercept pain signals from the nerves.
- Hydrotherapy uses warm water to ease and strengthen sore muscles, alleviate pain, and promote good blood circulation.
- Balance exercises may help with maintaining core strength and improve muscle and joint proprioception, as overextension may cause a loss in conception of joint placement.
- Range-of-movement exercises may help to increase range of motion in an affected joint that has become stiff. These exercises are done with and without the use of mechanical devices.
- Manipulation and mobilization exercises target movement of a joint.
5. Sternal Instability
Sternal instability, also known as sternal non-union, occurs with an injured sternum that does not heal. It is seen with surgical procedures such as coronary artery bypass grafting, during which the sternum is purposely split or cracked open. Movement of the sternum at this stage causes the wires connecting the segregated sternum to break through the sternum.
Conditions that may lead to sternal instability after a surgical procedure include obesity, chronic coughing, loss of bone density, a large chest size, or medications such as steroids and beta-adrenergic agonists. Health conditions like diabetes, renal failure, or osteoporosis may also cause the sternum to split further.
This condition presents severe and constant pain and popping noises in the sternum. The pain can impair daily activities because it may affect the ability to use the torso and upper extremities.
Treatment for sternal instability may focus on improved mobility in the arms with exercises of bilateral means. This may be accomplished through physical therapy exercises using both arms at once.
Deep breathing and coughing exercises are done with precise and careful planning so as not to further damage the sternum.
6. Synovial Gas
Popping of the chest has yet to be linked to a direct cause; however, there are a number of factors that appear to lead to the sound when pressure in the synovial fluid drops.
Synovial fluid lubricates the ends of the bones that form the joints to protect against wear and tear. The fluid has carbon dioxide, oxygen, and nitrogen gasses. The pressure of the fluid decreases as the surrounding connective tissue stretches when the body is extended. A low pressure produces bubbles within the synovial fluid from the existing gases. These bubbles bursting may cause the cracking sound, known as crepitus in medical terms.
Treatment for synovial gas issues is not required, as this is a natural occurrence with some movements. Rest and compresses may help with inflammation. Alternative measures such as acupressure or acupuncture may help by promoting proper blood flow.
When to See a Doctor
A sternum popping sound with pain, swelling, and a tightening in the chest may require medical attention. This is especially vital with chest popping after a hard fall or direct blow to the chest region.
See a doctor for sternum pain accompanied by visible swelling of the chest, fever, chest redness, persistent heartburn, or infection. The popping of the breastbone with radiating pain in the back or arms, excessive sweating, or with jaw pain or breathing difficulty may be signs of a heart attack.
As a popping sternum may be caused by an underlying health condition, any sudden, odd symptoms accompanying or following the cracking noise should be checked.
If you are still searching for answers to “why my sternum pops,” certainly seek medical advice. A popping sternum may be a natural response to overstretching the tendons and ligaments in the chest region. It may also be a sign of damage, and as such, require rest and abstention from activities for a short time.
Sternum popping needs further investigation only if pain is present. The breastbone sits in close proximity to the heart, lungs, and delicate blood vessels. Sudden and unexplained pain with crackling sounds and severe swelling or a tightness sensation may signal a serious condition.
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