Raul Topan / Shutterstock

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.

Heel spurs usually happen on the sole of the foot, though, and would not create a visible bulge. Spurs are deposits of calcium that protrude at the points where ligaments attach to bone. The most common heel spurs extend from the calcaneus (which is the bone that forms the human heel), and they come off of the front of that bone, at the point where the plantar fascia attaches to the calcaneus.

Spurs can sometime grow upward from the calcaneus at the point where the Achilles tendon attaches. This tends to happen in older people with rheumatic diseases and in serious athletes. Larry Bird played for a season with spurs at the Achilles insertion—some blame his poor performance agains the Pistons in the 1988 conference finals on the spurs—before undergoing surgical removal later that year.

Trump played high-school basketball, but he would’ve been an extremely rare case to have been debilitated by spurs at 22, especially of the sort that required no surgical intervention (he admits to having none) nor any other discernible treatment (according to his medical record).

Much more plausibly, as Trump also admitted to the Times, the spurs were a “minor” problem.

There is a tradition of avoiding the Vietnam draft among recent American presidents, so this would not itself set Trump apart. What would set him apart is having done so and then criticized the contributions of veterans and their families—of John McCain and Humayan, Khizr, and Ghaala Khan—while claiming to have sacrificed himself in a different way, by building a real estate empire.

The case of the heel spur only calcifies the case that, as Warren Buffet said yesterday, “Trump and his family have sacrificed nothing.”

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.