If there’s one thing you probably feel like you’ve got down after a lifetime of practice, it’s walking. After all, it’s something you’ve been doing for a really long time, and honestly, you don’t even think about it.

Walking, though, is a more delicate (and complex) operation than you might first think. Consider a single step. You extend one leg forward, plant your heel on the ground, then roll forward on your arch. When you do, your arch rolls inward in a process called pronation, which brings you to the ball of your foot, and then to your toes so you can push off and take that next step.

Here’s the problem: some people’s arches don’t roll inward sufficiently, which is known as “underpronation,” which essentially means that your feet aren’t providing the proper shock absorption for the rest of your body. Long term, this can lead to chronic pain in your back, bulging discs, sciatica, and other disorders, all of them painful.

People who are prone to underpronate tend to have high arches in their feet that aren’t very flexible, and in that case, then you want to find shoes that have plenty of padding and cushioning to help absorb the shocks your feet aren’t absorbing naturally.

At the other end of the spectrum are those who overpronate. You’ve heard the phrase “flat-footed,” and this is exactly the problem for those who overpronate. In these cases, you want a shoe that offers excellent arch support to help stabilize your gait.

In both cases, wearing the proper shoe can have a big impact on your level of comfort, so if you’ve been walking around wondering why your feet and back are in near-constant pain, wonder no longer! Odds are that you’re not wearing the “right” kind of shoes for your feet!