Sternum popping, collar bone cracking, or joint cracking in general is not considered harmful; and if you go see your doctor about it, he/she will probably tell you not to worry.

This is a natural occurrence and, though we are still unsure why it happens, we are fairly certain it does not pose any threat to your joint health (kinda weird we can make this claim when we don`t know the exact cause of it, don you think?).

Anyways, today we are here to talk about cracking in one specific area of our body – sternum. Before we go into the actual causes of joint popping, I think we should talk a little about the anatomy of the breastbone.

Sternum Anatomy

Sternum is a flat bone located  at the front of your chest. It consists of three parts: manubrium (upper part of the sternum), the body (mid section) and xiphoid process (pointy lower part of the sternum). One of its main functions is to protect the delicate structures located behind it and, at the same time, build up the chest (thorax).

As you can see on the image below, edges of the breastbone are quire jagged… this is because it articulates with both clavicle bones and cartilages of the first seven ribs. And this is where that clicking noise takes place. It is usually in the sternoclavicular joint (joint between the collarbone and sternum) or in any of the numerous sternocostal joints (joints between the ribs and the sternum).

Image 1: Sternum – back and side view

So Why Do These Joints Pop?

Sternum popping, and joint popping in general, usually happens spontaneously, on its own… of course, there are exception – like popping your back for instance. I, sometimes, like to pop my back after sitting at my computer for a long time. Other people like cracking their knuckles.

One thing is for sure, though, we still don`t fully understand exact causes and mechanisms which lead to joint popping. I know it sounds crazy, but its true! But, we can make some educated guesses:

  • Ligaments and tendons snapping – when we move our joints, other structures within the joint move as well, such as tendons and ligaments. Some researchers believe that these cracking noises are caused by these ligaments and tendons snapping into their original place
  • Gasses – no, not the ones that pop in mind first; I am talking about gas bubbles that get released from joint fluid as we move
  • Rough, uneven surfaces – this is especially common in arthritis sufferers where popping and cracking noise is caused by uneven edges of the bone. Of course, this is very painful and not common in healthy individuals
  • Partial dislocations, bones popping out of place etc

Sternum Popping When Stretching

I don`t know about you, but I notice these cracking noises in my breastbone only when I`m stretching, sometime I hear a pop when I take a really deep breath.

Once again, this is completely normal, especially if you are stretching yourself after longer period of inactivity (in the morning, for instance). But if you start experiencing pain, tenderness of soreness in the breastbone area, you should talk to your doctor.

Sternoclavicular Cracking When Doing Dips

I already touched this topic in one of my previous articles (Pain Around The Collarbone Area – Clavicle Pain). Doing dips is incredibly difficult (for most people), it`s an advanced exercise and it has to be done with extreme caution… especially if you are just a beginner, like me.

I tried doing dips several months ago and, when I finished my set, I was struck by an intense, sharp pain in area around my collarbone. I haven`t experienced cracking, but some of my friends did. So, what I did in this situation?

Well, at first I stopped doing them altogether… But, as the time went by, I started getting back to them but I only do 3,4 reps; no more because I know (fear) I will experience that same pain again and injure myself.

What advice I can give you? My first advice would be to find someone who knows what he`s doing. It doesn`t have to be a personal trainer, but make sure you find someone familiar with these types of exercises to show you the correct way of doing dips. And if the pain persists, consider visiting your doctor.

Most Common Causes Of Sternum Popping and Cracking

We still don`t know what mechanisms lead to joint popping but that doesn`t mean we can`t list some of it`s most common causes:

  • Physical injuries – sternum bruising and light injuries are common in some sports (like basketball, soccer, football etc.) and, even though they will heal quickly, they can cause these popping sounds. More severe traumas can also cause them – high speed collisions where you slam your chest against the steering wheel, for example
  • Muscle spasms -if the spasm is strong enough, it can cause partial dislocation of the ribs, as we mentioned above
  • Strenuous activity – any strenuous activity which puts additional pressure to the chest, can cause sternum popping. Activities such as weight lifting, doing dips and even push ups
  • Costochondritis – an inflammation of the cartilage of the ribs. This is a relatively harmless condition and it will usually go away on its own, without any treatment; but the sternum can be painful and tender to touch
  • Tietze syndrome – this is also an inflammation of the cartilage of the ribs but it differentiates from costochondritis because cartilage is usually swollen
  • Arthritis – arthritis can cause joint degeneration, rough and uneven surfaces which can cause clicking, popping and cracking noises when they rub against each other. The pain may vary depending on the severity of the degeneration, but it can be very painful

Can You Treat Breastbone Popping – When To Go See A Doctor?

If you are a healthy individual, and you experience breast bone joint popping from time to time, there is really no need to worry. This is normal and it happens to all of us, so there is really no need to “heal” it. In some cases it will go away on its own, and in others it may stuck with you for years.

But if you start experiencing pain, swelling, tenderness or a general feeling of discomfort, you should visit your doctor and see if there is some underlying condition which is causing these symptoms. It is usually nothing serious, but it is worth checking it out just for the peace of mind.


  • Image 1 – Source: Gray H. Anatomy of the human body, page 120