Plantar Fasciitis Is Everywhere Right Now. Could It Be Your Shoes?

Injuries often appear in clusters. In the running group I coach, we’ve had the year of the ankle (lots of sprains), the year of the owl (multiple owl attacks), the year of the hip, and even the year of pneumonia. Now, the injury du jour is plantar fasciitis. “It seems to be everywhere,” a colleague told me.

Figuring out causes, however, can be tricky. The year of the ankle was probably a reflection of a statistical construct called the Poisson distribution that explains why random events sometimes appear in clusters. Other clusters have obvious causes. The year of the owl was related to the increasing presence of highly territorial barred owls. That was the year we realized we had to take them seriously and be on alert. Popular training patterns can also produce injury clusters. Iliotibial band (ITB) problems, for example, are known to be related to running on slanted surfaces. If everyone’s favorite long run is suddenly on a trail that’s always on a sidehill, a surge in ITB problems wouldn’t be a surprise.

So, when it comes to plantar fasciitis, has something changed? Or is it just the Poisson distribution doing its thing?

A deeper dive into plantar fasciitis

Plantar fasciitis is pain in the thick band of tissue, called the plantar fascia, that connects the ball of your foot to your heel. It’s usually viewed as an inflammatory problem, but a 2003 study found that it is actually a degenerative condition with no inflammation. Either way, it usually manifests as heel pain, both when running and when first stepping out of bed in the morning. It can also be really frustrating because it can take up to a year to resolve.

“Nine to 12 months is not abnormal,” says Matt Klein, an assistant professor of physical therapy at George Fox University, Newberg, Oregon, who specializes in, among other things, plantar fasciitis.

The biggest risk factors other than overtraining, Klein says, are tight calves, stiff feet, and limited ankle mobility. But changes in shoe design may be playing a role. “What’s happening in the running industry right now,” Klein says, “[is that] footwear has gotten way stiffer. Even though not every shoe has a carbon plate, they have really increased the stiffness of a lot of shoes, and we know that excessive [shoe] stiffness can contribute to stiffness in the ankle.”

Is it the shoes? It’s gotta be the shoes. 

Today’s shoes also feature a lot of rocker, meaning they have a curved base that allows your foot to roll forward, akin to the way you roll forward in a rocking chair. This itself isn’t bad, Klein says, because research says it can take pressure off the sole of your foot, including the plantar fascia. But the rocker is often produced by designs that curve the toes upward—a feature called toe spring, which can angle the toes up by as much as 30 degrees.

This can speed you up in a race by letting you roll forward more easily, but it may come with costs if you always use shoes that incorporate it. “Toe spring reduces how much work the intrinsic foot muscles have to do to maintain stability at the MTP joint (the joint between the toes and the forefoot),” Harvard University researcher Daniel Lieberman (famous for his role in the book Born to Run) told Outside Run in 2020. Habitual use of them will mean that these muscles won’t be as well conditioned and will be less able to protect other tissues in the foot, such as the plantar fascia.

Portland, Oregon, sports podiatrist and minimalist-footwear advocate Ray McClanahan adds that toe spring keeps the toe-controlling muscles of the arch constantly stretched, additionally preventing them from buffering stresses to the plantar fascia. Furthermore, McClanahan says research dating back to 1905 shows that in cultures that habitually wear shoes with rigid toe springs, toes remain elevated even after the shoes are taken off.

Goldilocks shoes

Also important is that the shoe that works for one runner may not work for another. Benno Nigg, the now-retired co-director of the Human Performance Laboratory at the University of Calgary, Alberta, has found that when given a choice of footwear, runners’ “comfort filter” can be relied on to steer them toward the shoe least likely to cause injuries.

But that only works if there is a wide enough range of shoes for them to try out.

“There’s still decent diversity in the racing world, but a lot of trainers are starting to look the same and feel the same,” Klein says. Yes, there are exceptions, but for the most part, “everything has gotten stiffer, firmer.” Which is a problem, he says, because the shoe that works best for you is the one that works best with your own personal biomechanics. “It shouldn’t be too stiff or too flexible,” he says. “It should feel just right.”

Breaking the plantar fasciitis cycle

If you are one of those struggling with plantar fasciitis, the first thing to realize is that you’re not alone. One study found it to be the third most common running injury. Recovering from it may involve a lot of experimentation. One of my best friends, a hiker, not a runner, struggled with it for nearly a year, then, with a hiking vacation looming, got eight acupuncture treatments. They worked, and she went from being unable to walk more than 2 miles to doing 11-mile hikes.

Klein approves. There is good evidence that treatments like acupuncture and dry needling can work, he says.

That said, dealing with plantar fasciitis can be complex. The current best-practice guidelines, he says, include the following:

• Keep moving. “You should keep moving as much as you can,” Klein says. “You are not doing tissue damage.” Not that this means you should ignore the pain and run a marathon or a fast 5K. As always, discretion is important.
• Try an arch support. It might work; it might not. “You don’t know until you try it,” Klein says.
• Seek physical therapy for reducing stiffness in the calf and the big toe. Either of these can apply tension to the plantar fascia.
• Realize that not all heel pains are plantar fasciitis. “Everything in that area gets labeled as plantar fasciitis,” Klein says, [but] there are actually several things that could cause those kinds of symptoms.” I.e., what you think is plantar fasciitis might actually be a nerve pinch or a tendon issue. “Make sure someone can actually diagnose you,” he says. “A nerve is not going to respond [to treatment] the same way as a tendon or the plantar fascia.”

And, of course, consider changing your footwear (or strengthening your feet). Minimalist-style footwear shows 10% strengthening of the intrinsic muscles of the foot, McClanahan says, “and should be one of the areas of focus during recovery.”

How to prevent plantar fasciitis altogether

Scott Christensen, head of coaching instruction for USA Track & Field, suggests there may be ways to train yourself to become more resistant. Plantar fasciitis in distance runners, he says, is tied to too much running straight ahead, especially in a narrow range of paces. The solution, he says, is to diversify your training to include not just race-pace speed work, but sprints, strength, agility, and coordination work.

“Distance runners should be skipping rope, running flying 30 meters in sets at maximum velocity, [doing] lots of deep body squats and step lunges, frequent jumping, side-to-side jumps, backward hops, etc.” People who do this, he says, “don’t get plantar fasciitis.”