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Why does it hurt so much to hit your funny bone?

Why does hitting your funny bone hurt?
Why does hitting your funny bone hurt? 02:21

MINNEAPOLIS — The funny bone is anything but funny. So why does it hurt so bad when it gets hit? It turns out there's a "humerus" answer.

WCCO spoke with Dr. L. Pearce McCarty III, who specializes in elbows.

"Well, a lot of people already know the funny bone is not a bone. It's a nerve," McCarty said. "Right between those bony points runs the ulnar nerve, that's the funny bone."

It's a nerve cleverly named for its proximity to the humerus bone.

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WCCO

"So the nerves are super close together in this intersection which is an elbow. It's all right there," he said. "So nerves are like electric cables. If you smash a nerve, it discharges its energy."  

He says there's an activation, like a shock. There are three nerves in the elbow, with the ulnar nerve located directly beneath the skin's surface, making it extra sensitive.

McCarty says if funny bone pain lasts a while or you experience numbness in your fingers, see your doctor.

But 99% of the time, the pain doesn't last much longer than a curse word.

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