What really happens when you crack your knuckles?

Finally, science shows what happens when we crack our knuckles. Photo: AFP

For the first time, scientists have proved that the notorious popping sound is the formation of a cavity inside your joint.

To settle what had become a fiery debate among scientists, highlights of which include a vapour bubble formation theory penned in 1947, a team of international researchers pulled fingers under magnetic resonance imaging (MRI) scanners.