Myth or Fact, (2)

The knuckle (MDs call it the metacarpo-phalangeal joint) is surrounded by the synovial fluid, a clear liquid that lubricates the joint. This fluid contains about 15 percent carbon dioxide in solution. When you crack your knuckles, you tug or twist the finger or toe with a steady effort, creating a low-pressure zone within the synovial fluid. According to the most likely hypothesis (Unsworth, Dowson, and Wright, 1971), the low pressure draws CO2 and water vapor out of solution, creating a bubble. (This process is called cavitation.) This collapses almost instantly, and the fluid crashing in from all sides makes the noise.

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http://www.straightdope.com/classics/a2_305b.html
Very fascinating actually. Something I never knew till now anyhow.
HAPPY POSTINGS FROM GRANDPA BOB!!~

I've wondered about this one! Somehow it just doesn't seem like it would be good for the joints! Of course most people lose interest in doing it after awhile, so maybe that's what helps!

Well, you are in a teaching mood this morning.. I hope we can learn more from you as time goes by.. Have a great day, By the way, I do not pop my knuckes and don't have arthritis either..

My grandma used to tell me that myth after I was taught by my brother to crack my knuckles. I stopped, because she had arthritis and her poor hands were all gnarled and knobby.

I've always said that, but my dad doesn't listen. So I have just gotten to where I don't crack them around him.

It is tough to ignore but there are exercises that can help arthritis when it does set in! Most people cracked their fingers and arthritis is common!

hiccup, this is an interesting fact. When I was small, grandma always tell me that cracking knuckles is a bad bad way. Your fingers joint may lose and fall off if you did this regularly. which of course I know now is a myth cause i do it everyday, and I still can type here in mylot.

Sometimes I do wonder where does this myth came from?

Popping knuckes is a most disgusting sound. I don't know why people do it deliberately!

It's reassuring to know that it doesn't contribute to arthritis though, as my knees crack all the time. I sound like such an old woman! I wonder why some people are prone to cracking and popping joints but not others.

I have heard this myth before! Unfortunately, I do crack my knuckles. They will start to feel cramped and painful. After cracking them, the pressure seems to be relieved.