Why do bones crack and pop?

[kddani]

Somehow the GCers can always answer my random questions....

What causes bones to crack/pop? Example- when your knuckles crack. I've noticed this happening to me with various other joints too......

[Tom Earp]

Maturity

[ThetaPrincess24]

Cuz that's what happens when you get old

[sigmagrrl]

I've heard it's because air is trapped b/w the joints and that's the sound you hear.

Also, I've heard that when cartilidge wears away, the bones start to grind against each other a bit more...

[rainbowbrightCS]

from Kidsworld.com

What's really happening when you "crack" your knuckles is that you are either pushing the joint back into or out of its normal position. Joints are the meeting points of two separate bones which are held together by connecting tissues and ligaments. A thick, clear lubricant (made mostly of carbon dioxide and some nitrogen) called synovial fluid is found between the bones. When you stretch or pull your finger to get that desired popping noise, you are causing the bones to pull apart. Pressure is reduced on the synovial fluid and bubbles form that quickly expand and then burst - which is why you get that noise

[MeLikey]

Yeah my ankles used to crack when I walked, so I asked my doctor... he said not to be concerned about it... it doesn't really happen anymore. He may have told me to drink more milk (?), but I forget, it was a while ago. I often crack my knuckles... I've known this isn't the best thing to do since I was a kid, but I couldn't help it. I just went for my annual checkup and asked my doctor about it, who said that I should really try not to crack them so much because it could lead to arthritis... since then, I have fought the urge to crack them, only now and then do I do it, but not nearly as much as I used to. This guy I know, happens to be a Phi Delt, he cracks EVERYTHING, ie, his toes, neck, back (he actually had me walk on his back so that it would crack).

I'm one of those who cracks everything... either on purpose or accidentally.

At most recent count, my neck, shoulder, clavicle, wrists, back, hip, knees, feet and toes crack. The only ones I do on purpose are my neck and my back. Everything else just happens whenever.

I do have to crack my back every morning before I get out of bed though, otherwise I have trouble moving. In my case, it's because the cartilage is wearing away... but it really freaks people out!

[DigitalAngel126]

My bones crack allllll the time. My boyfriend doesn't even say "goodnight" when we're in bed until he know's I've cracked all my bones...Heh.

[Betarulz!]

http://www.orthop.washington.edu/art...eral/joints/05

Purposefully cracking your knuckles WILL NOT lead to arthritis, although arthritic joints will pop and crack. Since artritis is the break down of cartilage and is esentially bone rubbing on bone, popping your knuckles is not a cause of arthritis. People that do pop their knuckles will happen to notice that their knuckles are bigger, and this is due to the fact that if you pop them regularly you are stretchign the tendons and ligments out. They adjust by getting bigger so that you can pop away but still have a decent grip. I've read that popping your knuckles does lead to reduced grip strength.

[Senusret I]

I can crack my knuckles and my ankles, and it feels sooooooo good.

I can also crack my pelvis (or whatever joint that is).

[MeLikey]

And when I was falling asleep in class, I'd crack my knuckles and ankles just to stay awake... usually worked, but all you'd hear is me cracking away.

[MoxieGrrl]

My chiropractor said most of the time it's just air trapped in the joints, and it especially happens with people who are active. He said that you should start to worry when they don't pop anymore (I have no clue why).

[Peaches-n-Cream]

My right ankle has cracked since I was a child. I was told that it was due to arthritis although I have never received an official diagnosis. Sometimes you can hear me walking around my home: step, crack, step, crack, step, crack. I am used to it now.