Why Do My Knuckles Crack

There hasn’t been a lot of research on the effects of knuckle cracking, but the limited evidence shows it doesn’t harm your joints.

• How To Stop Cracking Knuckles
• Why Do My Knuckles Always Crack
• Why Do My Knuckles Crack And Bleed
• Why Do My Knuckles Crack In The Morning

Nov 08, 2014  While cracking your knuckles might not lead to arthritis, it does appear to have other consequences. In a study of 300 people aged 45 and older, habitual knuckle crackers were again not found to have an increased risk of arthritis in their hands.

• Apr 16, 2015  Sci-Tech Mystery solved: Why do knuckles crack? For the first time, an MRI video has been taken of cracking knuckles, answering once and for all what makes the audible pop.
• Oct 26, 2001  To understand what happens when you 'crack' your knuckles, or any other joint, first you need a little background about the nature of the joints of the body. The type of joints that you can most easily 'pop' or 'crack' are the diarthrodial joints. These are your most typical joints.
• May 18, 2015  A recent study has cracked, so to speak, the code behind popping your knuckles, revealing that the cracking sound happens as a result of an air bubble that forms when a.
• Mar 14, 2019  Cracking your knuckles may sound like it's doing damage to your joints, but the research shows that it doesn't negatively impact the joint or ligaments surrounding it. Here's how you can stop if.

One review in the Swiss Medical Journal found no evidence in any of the available studies that cracking your knuckles causes arthritis.

A doctor even showed this by experimenting on himself. He reported in Arthritis & Rheumatology that, over a 50-year period, he cracked the knuckles on his left hand two or more times a day but never on his right hand. At the end of the experiment, the knuckles on his left hand were no different than those on his right hand, and neither hand showed signs or symptoms of arthritis.

There’s also no good evidence that cracking your knuckles makes your joints larger or weakens the strength of your grip.

Studies show that as many as 54 percent of people crack their knuckles. They do it for a lot of reasons, including:

• Sound. Some people like hearing the sound knuckle cracking makes.
• The way it feels. Some people think cracking their knuckles makes more room in the joint, which relieves tension and increases mobility. However, although it may feel like there’s more room, there’s no evidence that there actually is.
• Nervousness. Just like wringing your hands or twirling your hair, cracking your knuckles may be a way to occupy your hands when you’re nervous.
• Stress. Some people who are stressed need to take it out on something. Cracking knuckles may allow for diversion and release without actually causing harm.
• Habit. Once you start cracking your knuckles for any of these reasons, it’s easy to keep doing it until it happens without even thinking about it. When you find yourself unconsciously cracking your knuckles many times a day, it’s become a habit. People who do it five times a day or more are called habitual knuckle crackers.

The reason the joint makes a popping or cracking sound when pulled is still not completely understood. For a long time, many people attributed the noise to nitrogen bubbles either forming or collapsing in the joint fluid. Others thought it came from movement of the ligaments around the knuckle.

In a 2015 study, researchers watched knuckles while they were cracked using an MRI. They found that a cavity formed due to the negative pressure created when the joint was pulled apart quickly. They determined that the sound was made by formation of the cavity. However, this couldn’t explain the loudness of the sound.

A 2018 study suggested that the sound was actually caused by the partial collapse of the cavity. A review of studies noted that it takes 20 minutes for the cavity to fully collapse so a new cavity could be formed. This may be why after you’ve cracked your knuckles, you’re not able to do it again right away.

Cracking your knuckles shouldn’t be painful, cause swelling, or change the shape of the joint. If any of these things happen, something else is going on.

Although it’s not easy, if you pull hard enough, it’s possible to pull your finger out of the joint or injure the ligaments around the joint.

If you notice your joints are painful or swollen while cracking your knuckles, it’s likely due to an underlying condition, such as arthritis or gout.

Although cracking your knuckles isn’t harming you, it may be distracting to people around you. You might find it difficult to stop if it’s become a habit.

Some tips that might help you break the habit:

• Think about why you crack your knuckles and address any underlying issues.
• Find another way to relieve stress, such as deep breathing, exercise, or meditation.
• Occupy your hands with other stress relievers, such as squeezing a stress ball or rubbing a worry stone.
• Become aware of each time you crack your knuckles and consciously stop yourself.
• Wear a rubber band on your wrist and snap it whenever you’re about to crack your knuckles.

Cracking your knuckles doesn’t cause harm, so it shouldn’t be painful, cause swelling, or change the shape of the joint. These are signs that something is wrong, and you should be evaluated by your doctor.

Injuring your finger by pulling very forcefully or moving it in the wrong direction is usually very painful. Your finger may look crooked or start to swell. If this happens, you should see your doctor right away.

If you notice your joints are painful or swollen while cracking your knuckles, it’s likely due to an underlying condition and should be evaluated by your doctor.

According to research, cracking your knuckles isn’t harmful. It doesn’t cause arthritis or make your knuckles larger, but it can be distracting or loud to people around you.

Breaking a habit like cracking your knuckles can be hard, but it can be done. Being aware of when you’re doing it and finding other ways to relieve stress are two things you can do to help you kick the habit.

What is it that makes that popping sound when you crack your knuckles? If you think it's vacuum cavities forming in the synovial fluid of the joint, give yourself a gold star: a team of researchers led by the University of Alberta Faculty of Rehabilitation Medicine have confirmed that that is precisely what it is.

How? By pulling the fingers of a test subject inside an MRI machine.

How To Stop Cracking Knuckles

'We call it the 'pull my finger study' -- and actually pulled on someone's finger and filmed what happens in the MRI,' said lead author of the study published in PLOS One, Professor Greg Kawchuk of the Faculty of Rehabilitation Medicine. 'When you do that, you can actually see very clearly what is happening inside the joints.'

The theory of bubbles in the joint was first floated in 1947: UK researchers JB Roston and R Wheeler Haines hypothesised that cracking the knuckles caused bubbles to form in the synovial fluid; this, they believed, caused the sound. In 1971, however, another study came along that proposed that it was not the formation, but the collapse of the bubble that produced the audible effect -- in other words, that it was the bursting of the bubble that made a noise.

Other hypothetical sources of the knuckle-cracking noise included stretching ligaments, or the adhesions in the joints snapping -- but the bubble idea has always been the strongest, since X-rays taken directly after cracking a joint show a gas bubble inside that joint. But whether or not it was the formation or collapse of the bubble had still been something of a mystery.

Why Do My Knuckles Always Crack

The idea for the study came from Nanaimo chiropractor Jerome Fryer, who approached Professor Kawchuk with a theory. Rather than beat around the bush, they decided to take a direct look using magnetic resonance imaging -- with champion knuckle-cracker Fryer as the guinea pig.

'Fryer is so gifted at it, it was like having the Wayne Gretzky of knuckle cracking on our team,' Professor Kawchuk said.

Fryer's fingers were inserted, one at a time, into a tube attached to a cable; this tube slowly pulled on each finger until the knuckle cracked. And, in each instance, it was absolutely the formation of the bubble in the synovial fluid that was associated with the popping sound, occurring within 310 milliseconds.

'It's a little bit like forming a vacuum,' Professor Kawchuk explained. 'As the joint surfaces suddenly separate, there is no more fluid available to fill the increasing joint volume, so a cavity is created and that event is what's associated with the sound.'

Solving a decades-old mystery was far from the team's only focus, though -- as fun as that was. The team believes studying joint cracking could help them better understand joint health -- such as the contradiction between the amount of force required to crack a joint (enough to cause damage to hard surfaces) and the fact that it doesn't appear to do long-term harm.

One thing they found, for instance, was a flash of white in the MRI just before the joint popped -- something no one had ever documented before. Professor Kawchuk believes it was water suddenly being drawn into the joint, and plans to use more advanced MRI to study what happens in the joint just before and after the pop.

'It may be that we can use this new discovery to see when joint problems begin long before symptoms start, which would give patients and clinicians the possibility of addressing joint problems before they begin,' he said.

Why Do My Knuckles Crack And Bleed

The 1971 team may have missed the mark on the cause of the sound, but they did get at least one thing correct.

Why Do My Knuckles Crack In The Morning

'The data fail to support evidence that knuckle cracking leads to degenerative changes in the metacarpal phalangeal joints in old age,' the study concludes. 'The chief morbid consequence of knuckle cracking would appear to be its annoying effect on the observer.'