Most of the real cowboys in America are dead, but in our memories they wear spurs off the backs of their boot heels, small torture devices for the horses that afforded these men their livelihoods.

So when terms like “heel spur” or “bone spur” are used in a medical context, they conjure something analogous—a spike of bone projecting backward like a talon. But that is not a thing. The human body does a lot of amazing things, but that’s not among them.

Today The New York Times has a thorough investigation into the military draft history of Republican presidential nominee Donald Trump. Publicly available documents show that after education deferments, Trump received a medical deferment due to a bone spur (or two, depending by varying accounts).

“I had a doctor that gave me a letter—a very strong letter on the heels,” Trump said in a recent interview with the Times. Today’s article also notes that in the 2015 biography The Truth About Trump, author Michael D’Antonio described Trump slipping off a loafer and displaying a tiny bulge on his heel.

Thirty-eight percent of people have a heel spur, according to a 2014 trauma-clinic study. In my time as a radiology resident, noting heel spurs on X-rays was routine. According to the American Academy of Orthopedic Surgeons, only about five percent of people with spurs have any pain at all.