exactly what is the noise when you crack your knuckles or a joint pops?  what's going on in there?
415179
When you pull the joint, you create negative pressure in the synovial sac (fluid sac in the joint that allows movement without the bones rubbing on each other). Nitrogen is a gas dissolved in the synovial fluid (and blood and interstitial fluid) which is pulled out of the fluid to balance the negative pressure (essentially a vacuum) created. (This is because the physical force of the vacuum is greater than the opposing chemical force keeping it in solution.) The rush of nitrogen makes the popping sound.\n\nKids having chest Xrays often have little bubbles of nitrogen visible in the shoulder joints, from having their arms held up out of the way of the Xray. It's not harmful.
404241
It's like cracking your knuckles. It's cardon dioxide released from your joints. Totally harmless.
454635
I spoke to a Dr. recently about this and he gave me am article about it............NO it is not it is an old myth, about arthritis and knuckles getting larger, the cracking sound that is heard is only gasses in the joint and by cracking them it just releases the gas...and then when the gas refills the joint it can be popped again
111682
ah!  such a great question.\n\nThe threats that your mother gave you (that cracking your knuckles will cause arthritis, will cause enlarged joints, will cause numbness) are all not true.  An article by Swezey and Swezey way back in 1975 disproved the knuckle-cracking-and-arthritis threat.\n\nHowever, it is not completely safe. First, there are case reports of acute injury to the hands and of knuckle pads associated with cracking, but these are only case reports.  The better studies show a couple of things:  The amount of force needed to crack a knuckle is greater than that needed to damage articular cartilage, and knuckle cracking HAS been associated with decreased grip strength when you get older.  \n\nSo, if you get arthritis, it's not because you cracked your knuckles.  If you can't grasp things very hard, it probably is.
14672
This is a mental thing.  You've told yourself that you will feel relaxed after you pop your knuckels, so you do.  It is not a proven way to relax, and it doesn't relax me.  It gives me anxiety to hear someones knuckles pop.  \n\nThe sound is produced by air trapped inbetween you knuckles, and when you pull it releases the air.  Also, a common misconception is that cracking your knuckles will cause arthritus.  It actually does not.  Your just releasing the oxygen inbetween your knuckles.
622228
The initial noise comes from the superheated air surrounding a bolt of lightning moving at high speeds, creating a fairly high pitched CRACK.  The "rolling" thunder sound is caused by that superheated air "pushing" (via air pressure in case you were wondering) the air around it.  Kinda cool to think that all we are hearing is friction of air molecules at different speeds, huh?
949476
We call it cracking but you are not really cracking ..you see your body prduces gases and that "crack" you hear is actually nitrogen that has built up between the  joint being released ..and it's not a bad thing but it's not a good thing to do all the time..if you find yourself "having to crack " all the time try soaking your hands in some warm water ..and look up some hand stretching exercises to help with this problem
667529
OK Peeps, there is no adhesive seal between joints, and "cracking your knuckles" is not an unhealthy thing to do. There's no reason to believe it causes arthritis (the inflammation of a joint caused by the degradation of the hyaline cartilage surfaces of the bones) as "cracking" doesn't really cause abnormal joint movement. The pop heard may be caused in two different ways. Pops you can't repeat right away are caused by the release of gas which, while soluble in body fluids, has accumulated in a joint. Second, pops which can be repeated right away are caused by a ligament or tendon moving over a bony protuberance. Neither are bad, especially if done with moderation.
674124
eat a few baking soda crackers, I have heard that they prevent that sound because your stomach has them to "chew" on. That sound is the entrance and exit to your stomach opening and closing on nothing, so if you put some crackers in there it won't make that sound.
233628
Getting arthritis from popping your knuckles is just an old myth that most people still buy into.  There are no adverse effects ... other than possibly annoying people around you who hear you doing it.
845296
sounds like a pinched nerve
1031366
as long as there is no pain dont worry \n\nair can build up in joints including the spine and the popping noise is simply that air escaping - it is normal and not anything  to worry about
533337
Yes... it can really cause harm to u. It weakens your bones. Whenever u crack your knuckles, hydrogen sulphide H2S gas is released. If you do it very often, your bones will soon get weaken and within a short span of time, you will observe that even if you do not crack your knuckles yourself, it will be cracked by just a little move.
219212
The proper term is adjust. Your vertebra become misaligned and when they are put back into place air is released which causes that cracking sound. See a chiropractor for a "real" adjustment. You won't regret it!
727596
Try resting it and seeing a doctor!  A month is a long time to be in pain and if its not getting better then the exercise is NOT helping.  The popping could be due to a loose ligament, you need medical advice!!!  Get it before you do any serious damage to the joint.
220534
The snap noise is from your finger hitting the palm of your hand.
1035906
According to two different doctors, Chiropractor and a physician, cracking your joints is nothing more than the sound the fluid makes when it passes through, cerebro-spinal fluid I believe but don't quote me on that.  The only harm that comes from 'cracking' your knuckles and other joints is when you must force them to get a 'crack'.  Otherwise it's relatively harmless.