What Really Happens When You Crack Your Knuckles

Many of you crack your knuckles often, even though it’s been said for years that it could eventually lead to problems like arthritis, for example. This bad habit gives people a kind of pleasure when they do it, and some people crack their knuckles all the time without ever thinking about the potential consequences.

What are the risks of cracking your knuckles?

A joint is a location where two bones meet. All joints are made up of an area known as a joint capsule, which is what protects the joint and contains a natural lubricant known as synovial fluid that’s necessary for healthy joint movement.

It’s precisely this lubricant that’s responsible for the infamous “cracking” sound, because there is dissolved air inside the joint capsule that’s released when force is applied to the knuckles. Small air pockets escape quickly, and the characteristic sound occurs.

After you crack your knuckles it’s not possible to repeat it immediately, because the joint has to settle back to its normal position and more air must dissolve into the synovial fluid. But after about fifteen minutes, it’s possible to crack the same knuckles again.

Why do so many people enjoy cracking their knuckles?

Most experts think that knuckle cracking is a nervous habit. But it can also be a pleasurable habit because by stretching the joints, the nerves are stimulated in that area. It’s been estimated that between 25% and 54% of people have this habit, and that it’s more commonly seen in men than in women.

What happens to your knuckles when you crack them?

Lots of people crack their knuckles constantly, even though it can irritate or even cause discomfort for the people around them. Studies have suggested that cracking your knuckles can actually lead to arthritis, instability in the joints, and a loss of strength or mobility in the hands. From a scientific point of view, cracking your knuckles over the course of many years can damage the cartilage that protects the joint. However, there’s still not enough evidence to show that this habit can eventually damage your hand motion.

One well-known study won the 2009 Ig Nobel award (an alternative award for unconventional scientific research). Donald Unger, and California physician, cracked the knuckles of his left hand for 60 years, at least twice a day. He never did the same to his right-hand knuckles and concluded that, after six decades, he had no signs of arthritis.

Another study that was conducted in Detroit in the 1990s analyzed the hands of 300 people over the age of 45, and found that 84% of them with inflammation in the joints used to crack their knuckles. They couldn’t find a direct relationship between the habit and the inflammation, however.

In any event, it’s curious to find that only people who formerly cracked their knuckles frequently have later experienced discomfort and inflammation.

For those who practice osteoarthritic medicine, that characteristic cracking sound is a sign that joint manipulation is being performed correctly, and even that a bone has been repositioned correctly.

The findings of various studies throughout the years are divided between those that argue that the habit can eventually damage the joints, and those that say it does not. The truth is that more research is needed to link knuckle cracking with arthritis later in life, because it’s a disorder that’s also caused by many other factors including genetics and age. Many hard years of scientific work remain.
How could that knuckle “crack” really be dangerous?

Aside from the unknown relationship between cracking your knuckles and the onset of arthritis, this habit can cause other damage, such as ligament tears, finger sprains, and thumb injuries – to name a few.