Fact or Fiction: Cracking Your Knuckles Gives You Arthritis
If you are a knuckle cracker, like me, you’ve probably been told to stop cracking your knuckles as it can cause arthritis. But is there any truth to this claim, or is it something we’re told by people who don’t like the sound?
To knuckle crackers, the audible ‘pop’ as knuckles are stretched and squeezed is the sound of relief and comfort. But to non-crackers, that ‘pop’ is often followed by a shudder of discomfort. In fact, that infamous popping sound is often associated with pain, so many people believe joint disorders will follow. As such, children are often told to stop cracking their knuckles.
Why Do Knuckles Crack?
The characteristic pop of a cracked knuckle is caused by tiny bubbles of gas.
In our bodies, synovial fluid helps to lubricate our joints. This fluid acts as a cushion to help our joints move smoothly.
When you crack your knuckles, you pull the joint apart, which reduces the pressure in the synovial fluid. The reduction in pressure allows bubbles to form. When the joint is returned to its normal size, the pressure increases again, and the bubbles pop.
Does Cracking Knuckles Cause Arthritis?
It would make sense for knuckle cracking to cause arthritis – repeated pushing and stretching of the joints can be painful and affect joint function. But to date, no studies have observed a connection between cracking knuckles and arthritis.
In fact, one scientist was so convinced that cracking knuckles would not lead to arthritis, he was willing to sacrifice his own hands for science.
Donald Unger cracked the knuckles in his left hand every day for 50 years. He did not crack his knuckles at all in his right hand. This way, he could directly compare how cracking his knuckles affected the health of his joints.
Unger found there was no difference in the health of his joints – neither hand had arthritis, or any joint issue. Unger won the Ig Nobel Prize in Medicine in 2009 for his work (the Ig Nobel Prize is awarded to research which “makes people laugh and then think”).
But even though cracking your knuckles won’t cause arthritis, there are still some negative side-effects.
Knuckle crackers have more swelling in their hands, and have a weaker grip compared to those who don’t crack their knuckles. This may be a result of the changing pressure in synovial fluid. Swelling may not cause pain, but it can be uncomfortable.
People who crack their knuckles may also injure themselves whilst they are cracking their knuckles: Pushing and stretching knuckles may lead to pain, swelling, immobility of the joint, and in extreme cases, dislocations.
So, although cracking you knuckles won’t give you arthritis, you may still want to consider giving up the habit.