I must do it more often than I thought! In the last week, two patients asked, a little suprised; 'did you just crack your knuckles'? 'doesn't that cause arthritis'?
Despite what most people think, there is no evidence that cracking your knuckles causes or leads to arthritis.
For over six decades, a Californian doctor put his body on the line to test this assumption. He cracked the knuckles on his left hand at least twice a day. His efforts won him the Ig Noble Prize in 2009 for showing that after 60 years of cracking one hand only, there was no arthritis in either hand. Various larger scale scientific studies have also found no link.
So what causes the cracking, and why was this myth created? When you crack your knuckles, you are increasing the joint space between the bones by stretching your fingers. This increase in joint space casues a decrease in pressure within the joint, and brings the disolved gasses out of solution with a 'pop'
When your parents don't want you to stare at the TV all day they may have told you that your eyes will go square, or if you pull an unattrative face and the wind changes...you know the rest.
I suspect that this knuckle cracking myth follows along these same lines.
I should end with a word of caution however; even though there is no evidence to support the link, I would still only crack in moderation - just in case. I should also add that cracking your own back is a different story and should be left to the professionals - but more on that in a future Blog.....