People who like to work out or run regularly can’t afford to compromise on shoes. Shoes don’t just provide comfort; properly-fitting footwear is a critical component to avoiding injury and having an efficient stride. Just as running strides differ from person to person, running shoes differ in how they help the foot contact the ground and progress through the gait cycle. Matching your stride to your shoes is one of the most important aspects of getting shoes that fit properly. That is why knowing whether you over-pronate, under-pronate, or run neutrally is essential to avoiding issues in your ankles, knees, hips, and lower back.
Understanding how your feet land when you run is not particularly hard. In fact, if you don’t know how you land, just looking at the bottom of a well-used pair of your shoes can tell you a great deal. Arm yourself with this knowledge, and you’ll be that much smarter when investing in your next pair of shoes.
What Is Pronation?
Sports podiatrists, veteran runners, coaches, and running store staff say it all the time: “pronation.” A lot of people assume that running is a simple physical act which involves putting your one foot in front of the other foot. However, it isn’t this simple—running is a complex bio-mechanical process involving:
- Striking the ground with your foot, whether with your toes, forefoot, or heel
- The rest of the foot contacting the ground, usually rolling slightly inwards as it meets the surface. This downwards and inwards rotation is known as “pronation”
- Toe-off, in which the foot leaves the ground and provides the force to propel the runner forward
Pronation is a normal part of running mechanics, as it will help your legs and feet absorb all the shock. It is simply part of each stride, and a matter of how your muscles and joints mechanically move you forward. But, as with any aspect of motion, different bodies do it in different ways. Some people’s feet pronate the normal amount—they are “neutral” runners. Others see an excess of pronation, meaning that their feet roll in too much.
At the other end of the spectrum, although not as frequent, is under-pronation. Here, the foot either doesn’t roll in at all, or rolls slightly outward. Runners with high arches are more likely to have under-pronation (also known as “supination”). The end result is a stride that pushes off of the outer toes more than the big toe, and lessens the foot’s ability to absorb shock.
Determining Pronation from Shoe Wear
It is important to note that about 15% pronation is ideal for a runner. This allows your foot to evenly distribute impact, which maximizes your foot’s ability to act as shock absorber. You can determine whether you under- or over-pronate by looking at how the bottoms of your shoes are worn down.
When you go for a regular run, your heel will strike the pavement a little on the outside (lateral) edge, which is why the soles on that part of the shoe will usually be more worn. If you find the shoe’s soles more worn right in the middle of the heel area, or on the inside (medial) edge, then the chances you over-pronate is high.
These wear patterns will be easier to notice on older running shoes that have rubber soles, as they tend to wear down more quickly. Also, bear in mind that wear to the extreme outside of the shoe’s rear (posterior) sole may indicate way too much rigidity on the arch or in the ankle. This signals significant under-pronation, or supination.
Determining Pronation Without Shoes
You can also easily determine pronation without looking at your shoes.
A. Space Underneath the Foot
You can estimate your degree of pronation by checking the space that is present underneath the foot.
- Begin by standing upright. There should be some amount of space present between the floor and your arch. Ideally, you should be able to insert a finger easily in this gap.
- Grab a friend and ask them to insert their finger in that space while you stand upright. If they are able to insert a single finger in that gap without difficulty or causing you discomfort, then you most likely have normal arches and pronation.
- If there isn’t any space at all to insert your finger, then it is highly possible that you have flat feet. This may indicate over-pronation.
When you do this at home, be sure that you are doing this barefoot while on a firm floor (hardwood or tile). But remember: just because your arches appear to be normal when you stand does not guarantee that you also have normal pronation when you run. In the same way, just because you have flat feet does not necessarily indicate that you will definitely over-pronate.
B. Using Cardboard
Another quick and straightforward way to determine pronation is by wetting your feet and walking on cardboard.
- Start by wetting or dampening the bottom of your feet with water.
- Place some cardboard on the floor and walk over it. Check to make sure that your wet footprint is clearly visible on the cardboard.
- Once you get a clear, wet print of your feet on the cardboard, carefully examine the prints of both feet.
A good arch with a reasonable amount of pronation will show your heel connected to your forefoot through a strip that would be about half the width of your foot on the outside of your sole. If you over-pronate, it will be very evident as your entire foot will be seen on the cardboard.
Knowing whether you over- or under-pronate will help you find shoes that best fit your needs, keep your feet and legs healthy, and keep you out on the road logging miles. Most running stores will be able to help you assess your stride, but with a couple simple tests you can do at home, you can show up at the store better informed of your own needs.