Not too long ago, I took my oldest child and a gang of her friends to see “Jurassic World” and we all had a righteous good time. Really, what’s not to like about genetically mutant dinosaurs and people with guns and motorcycles all running amok in 3D on a tropical island? But what appealed the most to my (slightly off) sense of humor was the heroine, sprinting for her life through the jungle mud in a pair of immaculate stiletto heels throughout the entire movie. Pretty soon, I had the girls giggling about it too—during particularly intense scenes I heard them whispering, “Look, she’s still wearing the high heels!”

Why was this so funny? Because in real life this would never happen. Any woman with an ounce of sense would kick the high heels off and run for her life. We all know by now that no matter how cute they are, stilettos are uncomfortable, impractical, and bad for our feet, knees and backs, and not suited to any activity other than standing around at a party for a few hours. We would never hike in them, clean the house in them, do any errands in them (except maybe dash into the wine store en route to a soiree).

So what I find so interesting is that people turn up in my clinic starting around this time of year with aches and pains resulting from choosing equally impractical and unhealthy shoes as their primary footwear for the summer. And I think we all know that I’m talking about flip flops. The pattern that I have noticed over the years is that starting around now and continuing through mid-September, a wave of people with plantar fasciitis, Achilles and posterior tibialis tendinitis, neuromas and intrinsic foot pain, knee pain, and hip and low back pain will arrive. Most of them are smart and articulate enough to be able to trace their pain back to wearing flip flops constantly, but ignore their symptoms until they require some medical intervention. I call this phenomenon “Summer Shoe Syndrome.”

Summer Shoe Syndrome is mostly a girl thing, primarily, I think, because women tend to be more committed to their flip flops, and also probably because women tend to be encouraged to prioritize fashion over comfort. Before anyone yells at me for making rash generalizations, please realize that I am deriving these observations from the demographics of the summer injuries that walk (or limp) through my door. Dudes are just not appearing in the clinic quite as frequently at this time of year with these injuries, and when they do, it is more frequently due to something like increasing their running mileage from 0 to 6 miles per day in less than a month. And I will also say that men committed to their flip flops may have larger problems at hand, like getting a date (just saying).

I don’t blame people for wearing flip flops—I get it, I really do! They’re cute, they’re convenient—you just slide into them and take off—and here in Vermont, where we clomp around in heavy, unsexy boots for so much of the year, they feel amazing. For a few minutes. I own several pairs myself. But I limit wearing them to a few situations: In the pool locker room; in and out of the river or reservoir to avoid stepping on sharp rocks; to an occasion where I will primarily be standing and sitting for a few hours; or maybe on a quick car trip to drop off/pick up the kids. That’s pretty much it. But other people frequently take it to a new level. I had a client at the end of last summer who hiked all around Europe in the same cheap pair of flip flops. Ouch!

What’s the big deal? Why are flip flops so detrimental? There are two main reasons, the first being that most flip flops are very cheaply designed and made; check yours out. You are walking on a flat, thin, hard piece of plastic or rubber or faux leather that provides no arch support whatsoever and no attention to the natural gait cycle or the points where people most commonly put pressure on their feet. The completely flat foot bed, if we can call it a foot bed, is frequently too drastic a change and way too much of a stretch on the Achilles tendon for people who have spent the rest of the year in more supportive footwear, particularly for those with tight calves. People frequently tell me, “But I bought the really good kind of flip flops,” by which they mean something a little higher end with a cushioned and/or contoured foot bed, or even a little wedge heel. This really is just like saying, “But I smoke only the filtered cigarettes,” or “I snort only the organic cocaine,” that is to say that the supposedly higher end stuff may work out for you for a little while longer, but the end result will be the same nonetheless. Because you still have to contend with reason number two.

Reason number two for why flip flops do not agree with so many people is that they require you to alter your normal gait cycle because there is nothing to hold them on your feet. My passion is biomechanics, and I’ve spent hours walking in flip flops to the point of pain just to try to figure this one out. There are two adaptations we make to alter our gait just to hold the darn things on, and for these to make more sense, it helps to have an understanding of the normal gait cycle, and for an uncomplicated diagram to help clarify the next paragraph, click here.

Here is a simplified description of what should normally happen when you take a step (and you can try this out barefoot or wearing some good quality sneakers): 1) Your heel hits the floor in a “dorsiflexed,” or upwardly flexed position. 2) As you propel your weight forward, your foot naturally rolls from its outer border, or “supinated” position, to its inner border, or “pronated” position, until 3) your heel leaves the ground in a downward flexed, or “plantar flexed” position, with your toes extended until you push off the ground. Got it? Stay with me…

Back to the weird things we do just to make our flip flops stay on our feet: The first adaptation that we make is to shorten our steps and abandon the natural roll of our foot through the gait cycle. With flip flops, you do not heel strike; you decrease the amount of dorsiflexion at that point where your heel hits the ground because your foot is already sliding backwards out of the shoe, and instead land at the back of your arch, around the point of origin of the plantar fascia. Hello, plantar fasciitis! The roll from supination to pronation is then lost, as you are beginning your step almost mid-gait cycle, and you repeatedly slap your foot down on the same pressure point, generally around your third metatarsal head, which is a recipe for a nice met head bone bruise and/or neuroma with long-term flip flop wear. The lack of arch support and the generally crappy, overflexible sole further stretches your already stressed plantar fascia through this phase.

Now, the second thing that you unconsciously do for the sake of fashion occurs at this point: As you approach push off at the end of the gait cycle, you do one of two things to keep the shoes from flying off: You either flex your toes and push the front of the shoe down to force it back up against your foot, at the point where your toes should be extending; or, you dorsiflex your foot back up, at the point where it should be plantar flexing, and extend your toes upward to stop the forward slide of the shoe. The people who clench their toes are the ones who wind up with hammer toes, irritated bunions, and intrinsic muscle strains (the foot intrinsics are the deep muscles between your metatarsal bones in your feet). The dorsiflexion/toe extension people seem to wind up with Achilles tendinitis and shin splints. Both groups are prone to plantar fasciitis.

And it doesn’t end here: With hours of wear, your poor foot muscles get tired out and the stronger ones will take over. The muscles controlling your big toe, second, and third toes normally are a little stronger than the 4th and 5th toes, as these toes are used more during the push off phase. So your foot will roll in as toes 1 through 3 take over the action, and your tibias and then your hips will follow, causing knee and hip pain due to malalignment, and low back pain as your spine takes all the shock absorption because the joints closer to the ground are not as efficient due to malalignment. Who knew that $5 shoes from certain chain stores that shall remain nameless (except to say that I’m getting kind of Old to shop there and Navy uniforms are not sold there either) could cause such an exciting array of problems!

Also interesting is what happens to your skin. Frequently, the skin on your heels just can’t handle the pressure of the fat pad of your foot being smushed like a pancake against the hard surface of the flip flop with no counter pressure that is normally exerted by a shoe with a closed heel, so it cracks.

Please don’t come in and tell me Geronimo! You’ve figured out how to walk normally in flip flops! I promise you that you have not. These adaptations that your foot makes are reflexive and not something you can control with every step. Really. If you try to mimic while wearing flip flops the way you walk when you are not wearing flip flops, and this is not easy to do, the flip flops really do come flying off. One might even hit you in the forehead (that happened to me once). And in a perfect world, your footwear should adapt to your body. Not the other way around.

So what’s a girl to do? You could scream, moan, and curse me for sentencing you to a lifetime of unfashionable footwear, but really, it’s not that bad! Like I said, wearing of flip flops here and there for short periods when you are going to be doing very little walking is permitted. But if you’re to the point where you have developed pain, the first thing we need to do is get you out of the flip flops. There are plenty of adorable little hiking sneakers in fun colors that can work for home, work and outdoor activities, and we can add an over the counter arch support or orthotic, heel lift or cup, or metatarsal pad or if needed to help resolve your symptoms. There also are plenty of dressier shoes now that are basically disguised sneakers, and the styles may be more appropriate than hiking sneakers for a certain work situation or social event. I have a couple of pairs of Champion flats that I wear for work, and they are the most comfortable, supportive things ever. I could probably hike in them but don’t want to ruin them. There also are some cute, good quality sandals that higher end companies like Birkenstock and Dansko make, and women everywhere are pleased that these companies have figured out that supportive summer shoes do not also need to double as birth control. I recommend wearing a good, supportive shoe whenever you are up, even in the house. If this self-help measure alleviates your symptoms, try going barefoot in your home for short periods just to help your body find its natural gait cycle again, continue making the more supportive shoes your primary footwear. I am encouraging you to go shopping here, ladies, buy a few different pairs that you like and it will make the flip flop withdrawal much more fun! If your symptoms are not improving within two weeks, or are just not clearing up quickly enough, please see a doctor or physical therapist for additional guidance as soon as possible.

Kathleen Doehla, M.S. P.T.