If you’re human (as we know you are), it’s a good bet that you, or someone close to you, is a habitual knuckle-cracker.
It’s also a good bet that you, or the knuckle-cracker you know, has often been warned, usually by a parent or grandparent, that the habit could be bad for you. But is it true? Can cracking your knuckles do you harm?
According to numerous articles and research we’ve read, the answer is, in short, nope! There does not seem to be any research to indicate a correlation between pain, arthritis or any other condition and cracking knuckles. In fact, several studies have proven the contrary.
To crack or not to crack…
Just what is the source of the cracking sound when one cracks one’s knuckles? This question has been up for debate for many years. (Who cares about this enough to debate it, we wonder?) The received wisdom is that, the pulling apart of the knuckle joint causes vacuum pressure on synovial fluid surrounding the joint. In turn, that pressure pulls gases out of the fluid to form a gas bubble which “pops” to create that magical cracking sound.
Just this year, however, a study in the journal, PLOS | One, seemed to show something different. MRI images showed that it is the formation of the gas bubble, itself, that causes the knuckle to seem to crack, not the popping of the bubble. That would also explain why it takes 20 minutes or so to create another cracking sound – to allow the gas from the bubble to absorb back into the synovial fluid. Fascinating!
What proof, sir?
Back to the question of whether cracking your knuckles is harmful, a study published in the Journal of the American Board of Family Medicine in 2010 found that, in a population of 215 respondents between 50 and 89, arthritis was prevalent in about 18 percent of the people who crack their knuckles and in 21.5 percent who don’t crack their knuckles – not a significant difference.
Probably the most amusing study on the subject is by Dr. Donald Unger who, inspired by his mother’s warnings as a child about getting arthritis by constantly cracking his knuckles, spent more than 60 years cracking only the knuckles on his left hand at least twice a day (the right hand was the control). His finding, published in a letter to the journal, Arthritis & Rheumatism, found that there was no discernible sign of arthritis in his left hand, as opposed to his right. Fittingly, he received the Ig Nobel Prize (a popular parody of the Nobel Prize) in 2009 for this observation.
To crack or not to crack…
If the urge to crack your knuckles comes over you, go ahead and crack – chances are, it won’t harm you. However, there is widespread evidence to indicate, it will most definitely inspire anger and a mildly queasy feeling in many of those around you! The choice is yours…