Detailed guides to painful problems, treatments & more

Joints popping … like flashbulbs?

 •  • by Paul Ingraham
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Weekly nuggets of pain science news and insight, usually 100-300 words, with the occasional longer post. The blog is the “director’s commentary” on the core content of a library of major articles and books about common painful problems and popular treatments. See the blog archives or updates for the whole site.

Writing an article about joint popping is my oldest-ever untouched to-do list item. One of the first big articles I ever wrote about musculoskeletal medicine was about Epsom salts, and I remember thinking the night I started that one, “Well, it’s salt or cracking.” And when I finished the first edition of that one, I thought, “Time to get cracking on cracking!” This was in 2002 or something. I don’t know what happened. But I’ve been aware of it as something I’d like to write about ever since.

Because, clearly, there are some interesting mysteries in knuckle cracks. I’ve always thought there had to be more to it than the cavitation hypothesis, and now it looks like there probably is:

What we saw was a bright flash on ultrasound, like a firework exploding in the joint,” Boutin said. “It was quite an unexpected finding.”

It’s quite a bizarre finding, is what it is.