When you crack your knuckles, what makes your knuckles crack?
452186
There are gasses dissolved in the fluid. When you stretch the joint the volume increases and therefore the pressure in that volume decreases. This allows to gas to come out of the liquid. It makes a noise like opening a bottle of soft drink. This is also the same principle that gives divers the bends if they come up too quick. \nThere is a name for the law, it is to do with dissolving gasses in a liquid under pressure. I am suffering a mental block, err henry's law?? russels?? errr.. some plain name like that anyway
793826
i never used to crack my fingers, until my best friend did it so i just took it up as a habit since we always hung out. it was really hard to stop b/c my fingers would get cramped up so that the only form of relief was to crack them. whenever i got the urge to crack them i just really had to have a lot of self discipline and just NOT do it. my b/f helped though too b/c he would always be like stop that! if he caught me doing it without me knowing. my dad also was always like dont crack your fingers, or else they'll get all fat lol. good luck
32001
Tendons don't "crack". Any popping is usually a bubble of nitrogen in the joints that is being expelled. It should not result in any damage.
335127
THATS A FLUID BUILD UP WHEN YOU HEAR THE CRACKING. ITS NATURAL HOWEVER YOU CAN REDUCE YOUR SODIUM INTAKE AND TRY TO ALLEVIATE SOME.WHEN IT BEGINS TO HURT IS PROBLEM..
1050667
If you squeeze, you make your muscles tense up and as a result, you feel weaker. Try not to squeeze or tense up so much. Use the strength in your biceps not so much on your fingers/hands.
61582
askin the doctor is a good idea but i also play the guitar and have broken knuckles and moderate arthritis  i usally just streach my fingers and keep them warm. also take just reg asprin  but thats just me (stop cracking you knuckles) even though it seems to help them form hurting when you play its temp.   pEACE
1034926
I can crack pretty much everything very loud and joint cracking is not linked to developing arthritis - it's a myth. However it is often linked to having more flexible joints (hypermobile) - maybe you are someone who can bend your fingers back a long way or put the palms of your hands on the floor. It's normal to hear a crack if a joint moves beyond where it would normally move. \n\nHere's a very good summary: http://www.studentbmj.com/back_issues/1201/life/477.html
6467
I know exactly what you mean.  My ankle does the same thing.  I can do it over and over again just by rolling it.  It is not like cracking your knuckles that you have to wait a while before you can do it again.  I do not know why it happens but it drives my wife crazy when I sit and do it.  I just wanted you to know that you are not the only one with that condition.
1161772
The knuckles on your hands.
1156087
Do you mean like cracking your knuckles or other joints in your body?
665822
cracking your knuckles doesnt do jack sh*t to cause arthritis.  my grandmother cracked her knuckles for years and her hands were tiny and her fingers were slim..no arthritis.  i have been cracking mine for over 10 years and my hands are the same way.
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.
29043
A single event is not enough to cause damage to the joint, although it is possible that prolonged joint stress due to cracking knuckles may eventually lead to a higher risk of joint damage. The long-term consequences of this practice have not been studied thoroughly, and the scientific evidence is inconclusive. However, the common parental advice "Cracking your knuckles gives you arthritis" may be simply a device to deter children from this practice, which many people find annoying because of the sound it makes. In actual fact, study by Castellanos and Axelrod showed that arthritis was not a product of knuckle cracking. They evaluated 300 consecutive outpatients at Mount Carmel Mercy Hospital to determine whether habitual knuckle cracking is a risk factor for hand dysfunction. They found no relation with osteoarthritis, but noted that 'knuckle crackers were more likely to have hand swelling and lower grip strength'
707386
No, that's just a myth.  No amount of cracking them is going to make them larger.  I've cracked mine for years and still have small hands and knuckles.  I have read that there are negative repercussions in the long run though not related to making them larger.  I'd try to make an effort not to crack them.
306363
Not exactly. There are two types of arthritis. Rheumatoid arthritis is when a person’s own immune system attacks the joints and causes pain. Cracking knuckles won’t cause this but it could definitely make it more painful! This habit could worsen the symptoms of osteoarthritis, however. Osteoarthritis, sometimes called degenerative joint disease, is caused when the cartilage between bones starts to wear away and the bones rub together. The repetitive motion of cracking your knuckles may contribute to the pain felt by people with osteoarthritis.
500452
I haven't heard of that one before, but I have heard that it increases your chances of getting arthritis in your hands/knuckles.
219427
The answer already given by Grant Master G is probably the closest to being correct.  Indeed when you do this, gases are entering the joint spaces of your knuckles.  However, there is no proof that this leads directly to arthritis or other problems with your fingers later on.\n\nI don't recommend doing it often, simply because it can be seen as a form of dislocation, although very minor.  I don't personally do it because I already have very mild arthritis in at least two fingers - both ring fingers coincidentally.  Women are more prone to getting arthritis of the hands/fingers in later life than men.  But then again, I see more men who "crack" their knuckles than women.