Up to half the population crack their knuckles, with men more likely to do so than women.

On hearing the ‘pop’ of someone cracking their knuckles, most  will not only feel an urge to wince in annoyance, but also to tell the offender to cease for their own good. “That behaviour will give you arthritis, don’t you know,” is a likely response when the noisy faux pas is committed (although they never quote their sources).

Despite this common belief, studies have all shown that cracking your knuckles does not give you arthritis.

A young Donald Unger from California was one of the people who proved his mother, aunts and mother-in-law wrong by self-experimenting. He proceeded to crack the knuckles of only his left hand for 50 years, and left the right alone as a control. After an approximate 36,500 crackings, the results were in. He found “no arthritis in either hand and no apparent differences between the two hands”. Similar studies have been published in several academic journals, namely The Western Journal of Medicine and Annals of the Rheumatic Diseases, which reach the same conclusion: it has no effect on arthritis.

So what happens when knuckles are cracked? When a finger is extended through normal movement, the pressure decrease in the lubricating fluid surrounding the joints causes dissolved gases such as carbon dioxide to form bubbles. Pulling the fingers creates an increase in pressure and the bubbles audibly burst. This also explains why the joints can’t be cracked again immediately, as it takes around 20 minutes for the gas to re-form bubbles. So fear not, you are free to crack your knuckles with reckless abandon. Or, maybe not, as at least one paper has shown that chronic joint popping may cause inflammation and a weakened handgrip.

But, as one study concluded, “The chief morbid consequence of knuckle cracking would appear to be its annoying effect on the observer.”