To Prove His Mother Wrong, Dr. Donald Unger Cracked the Knuckles of Just One Hand for 50 Years—And Ended a Worldwide Medical Myth
Most of us have heard it since childhood. “Stop cracking your knuckles—you’ll get arthritis!” It’s one of those warnings that’s passed down with absolute certainty, like sitting too close to the TV will ruin your eyes, or going outside with wet hair will give you a cold. But while these things are said with love, not all of them are based in actual science.
That’s what pushed Dr. Donald L. Unger to conduct one of the quirkiest—and most dedicated—personal experiments in modern medical history.
Tired of hearing his mother, his aunts, and basically every adult around him scold him for his knuckle-cracking habit, Dr. Unger decided he wasn’t just going to ignore the warning—he was going to test it. Himself.
He didn’t need a lab. He didn’t need a team of researchers or a clinical trial. He just needed his hands, time, and one heck of a stubborn spirit.
So he chose his left hand. That would be the one he cracked. Every single day. Twice a day. Just the left. Never the right.
For over 50 years, Dr. Unger kept this up. That’s not an exaggeration. He started in his early adult life and didn’t stop until decades had passed. He kept count. He estimated a total of 36,500 knuckle cracks on the left hand alone. Meanwhile, his right hand remained quiet—untouched, uncracked, a perfect control subject.
Now, imagine the commitment that takes. Through every life event, every move, every cold morning when your joints feel stiff—he kept at it. Every crack on the left was a tiny act of rebellion, of curiosity, of science.
And after half a century?
No arthritis.
That’s right. A full medical examination revealed no difference in joint health between the two hands. No pain. No swelling. No stiffness. And more importantly—no arthritis.
A Funny Award with a Serious Message
Dr. Unger didn’t do it for fame. He wasn’t trying to publish in prestigious journals or win a Nobel Prize. But in 2009, he did win something that may be even more delightful in its own way—the Ig Nobel Prize in Medicine.
For those unfamiliar, the Ig Nobel Prizes are a satirical spin on the real Nobel Prizes. They’re awarded each year to studies or researchers whose work “first makes people laugh, and then makes them think.” And Dr. Unger’s lifelong experiment certainly fit the bill.
There’s something wonderfully human about it. One man, cracking one hand, for 50 years—not out of ego or profit, but because he genuinely wanted to know. Is what everyone keeps saying actually true?
And that’s the heart of it. His work didn’t involve huge budgets or complicated technology. But it got people talking. And thinking. How many other things do we accept as truth without proof? How many “facts” are passed down more out of habit than science?
In interviews, Dr. Unger joked that he didn’t set out to win a prize—he just wanted to “silence” a myth that had annoyed him since childhood. And honestly, who among us hasn’t wanted to do the same?
After his story spread, people took to the internet to share their appreciation. One user wrote, “This man deserves a statue made of knuckles.” Another said, “The ultimate ‘I told you so’—50 years in the making.”
But beyond the humor was real impact. His quirky study encouraged people—especially younger science fans—to question everyday assumptions. It showed that curiosity doesn’t always have to be complicated. Sometimes, science starts with a simple idea and a whole lot of patience.
Dr. Unger’s legacy is now more than just arthritis-related. It’s about the spirit of questioning, of asking “why?” when others just say “because.” And it’s a perfect reminder that science doesn’t always wear a lab coat. Sometimes, it just wears a stubborn grin.
So, should you crack your knuckles?
Well, according to Dr. Unger’s hands—go ahead.