Cracking of knuckles is a common habit among many people. It is observed mainly in the small joints of the hand. According to one study, between 25% and 54% people crack their knuckles. Of the percentage, a vast majority of them are males. Do you crack your joint? Have you ever paused for one day to wonder why you do that? Well, researchers believe that most people crack their joints for many different reasons. But then, people do it chiefly because it helps them to relax (relieves tension), and they see it as fun (thanks to the sound!). While the reason for cracking the knuckles may vary, does it not harm the joints? You will get to find out shortly.
Pains after Cracking Knuckles
Human body has synovial fluid in the joint that lubricates the joints, thus reducing the friction and preserving the cartilage. The noise of the crackling knuckles is due to the following reasons:
Nitrogen bubbles burst out from synovial fluid by a typical cracking or popping sound. The nitrogen bubbles within the synovial fluid usually take 20 minutes to re-form in your joints before they can crack again
The movement of ligaments around the joint can also cause a popping sound.
Feeling good after cracking knuckles is a psychological experience. Knuckle cracking itself does no harm to the fingers, neck, ankles, or other joints that pop and crack throughout the day. If there is pain and discomfort after cracking, then it is due to preexisting conditions.
Cracking Children’s Knuckles
Habitual knuckle cracking in children has been considered a cause of arthritis. A survey of a geriatric patient population with a history of knuckle cracking failed to show a correlation between knuckle cracking and degenerative changes of the metacarpal phalangeal joints. The data failed to support evidence that knuckle cracking leads to degenerative changes in the metacarpal phalangeal joints in old age. The chief morbid consequence of knuckle cracking would appear to be its annoying effect on the observer1.
A Mathematical Model for the Sounds Produced by Knuckle Cracking concluded that, that helped to confirm that the noise comes from collapsing gas bubbles2.
A 2011 study published in the Journal of American Board of Family Medicine found that there was no difference in the rates of arthritis between people who cracked their knuckles frequently and those who did not3.
Every finger has three joints. Funnily enough, some people crack one or two of them while others crack them all. On top of that, these people crack their knuckles for different reasons. But then, why do you crack yours? Regardless of the reason behind this common habit, you should know that cracking your knuckles is NOT bad unless you are suffering from preexisting pathology.
Swezey RL, Swezey SE. The consequences of habitual knuckle cracking. West J Med 122:377-379, May 1975
V. Chandran Suja , A. I. Barakat. A Mathematical Model for the Sounds Produced by Knuckle Cracking, Nature, Scientific REPORTS | (2018) 8:4600 | DOI:10.1038/s41598-018-22664-4