In A Nutshell
It’s a habit that some people find relief in, and others find annoying. Everyone who’s done it has probably been told that they’re increasing their risk for arthritis, but there’s absolutely no medical evidence to support this claim. There are, however, other dangers such as dislocated fingers associated with obsessive knuckle-cracking, so many medical experts recommend you still don’t do it.
The Whole Bushel
It’s an often-recited admonishment: Cracking your knuckles will increase your chances of developing arthritis down the road. Fortunately for those that habitually crack their knuckles, there’s absolutely no medical evidence to support the claim. In fact, one study showed a reverse correlation between cracking knuckles and arthritis; the more that those surveyed did it, the less likely they were to develop arthritis.
Unfortunately, there are other dangers associated with habitual knuckle-cracking, so it’s still not necessarily a habit that’s healthy for your hands.
There have only been a handful of actual studies done on the correlation between arthritis and knuckle-cracking, and the first was a 60-year commitment made by a single doctor who was apparently really, really tired of being told he was giving himself arthritis by cracking his knuckles. So for 60 years, he committed to cracking the knuckles of his left hand twice a day, while leaving his right hand uncracked. At the end of six decades, there was no difference between the condition of his hands.
More formalized studies were also done, in the form of surveying elderly patients who either had or had not developed arthritis whether or not they had cracked their knuckles when they were younger. In one such study, done in 1975, it was discovered that those who had been habitual knuckle-crackers were less likely to have arthritis in their old age.
Several other, more recent studies have confirmed the findings that it doesn’t even matter how often you crack your knuckles (you can do it about every 15 minutes): It’s still not more likely that you’ll give yourself arthritis from doing it.
But there are other dangers associated with the habit.
Knuckles pop because when the space between the joint is increased, tiny bubbles in the fluid between the joints form larger bubbles, which is then popped by the extra fluid the body floods the joint with to fill the space.
While that might not cause arthritis, it can cause damage to the ligaments that secure the joint in the first place. It’s not unheard of for people to tear ligaments while cracking their knuckles, or cause enough damage to the ligaments that they end up dislocating fingers. Long-term knuckle-cracking can also lead to a noticeably reduced strength in a person’s hands. It’s also been associated with changes in a person’s skin and development of pads or calluses over the joints.
So what does cause arthritis? Studies suggest that there’s a genetic component to how likely you are to develop one of the different types of arthritis. It’s not always an age-related disease, either, and can be brought on by the extra strain put on joints by obesity or repetitive activity such as job-related strain. Women are also more likely to develop arthritis, and joints that have been exposed to injuries can be more susceptible to becoming arthritic.
And the presence of arthritis in a joint can make it more likely that a joint will be damaged by habitual knuckle-cracking, and joints may be more likely to crack on their own because of the damage that’s been done by the arthritis.
Show Me The Proof
Johns Hopkins Arthritis Center: Knuckle Cracking Q and A
BBC Future: Does cracking your knuckles cause arthritis?
Providence Health Services: Ask an Expert: Knuckle cracking and arthritis
Centers for Disease Control: Arthritis