What Is Pronation and Why Does It Matter?
Search for the term ‘pronation,’ and it’s easy to be confused. You can overpronate, and you can underpronate. You can even pronate your hands. Does pronation bring to mind barefoot tribes and ultra-athletes or flat feet and fallen arches? Is it good or bad? In this article, you’ll learn what pronation is and what it means for your running.
What Is Pronation?
Pronation refers to the rolling movement of the foot at the ankle so that weight is transferred toward the inside edge of the foot (the big toe side). Imagine your ankle pushing inward.
Supination is when the foot rolls in the opposite direction, with weight transferred toward the outside edge of the foot (the little toe side). Imagine your ankle pushing outward.
To better understand the movement, try standing on one leg and shifting your weight from left to right. As your foot rolls to maintain balance, it pronates and supinates.
Although pronation has negative connotations, a certain degree of pronation is normal and healthy when walking and running. It is only insufficient or excessive amounts of pronation that cause problems with our feet. Too little (under-pronation) or too much (over-pronation) is detrimental to joint health and running performance.
Like so many things, pronation is best in moderation. Pronation that enhances shock absorption and running performance as part of a natural running style is known as neutral pronation.
In neutral pronation, our feet are rotated slightly inward (supinated) on ground contact – meaning that the outside edge of the foot hits the ground first.
As our bodyweight moves forward over the foot, the foot rotates downward and outward so that the whole foot is in contact with the ground – this is pronation. At this point in mid-stance, the foot is now in a neutral position – neither pronated nor supinated and flat to the ground.
This movement from a supinated position on ground contact to a neutral position at mid-stance is a natural part of the gait cycle. This is referred to as neutral pronation – essential for effective shock absorption during running.
For some, the foot rotates outward too much. This is overpronation, and it is more common than underpronation. Excessive or overpronation transfers weight to the inside edge of the foot, including the big and second toe. As the foot rotates outward in overpronation, the arch of the foot flattens. Over time, this can cause or exacerbate flatfootedness. This affects weight transfer and balance during running and power transfer during toe-off.
Overpronation can cause injury by increasing the risk of heel spurs (bony structures that grow under your foot from the heel) and plantar fasciitis (pain and inflammation in the band running from heel to front foot). A flatter foot is less rigid, placing more stress on other joints and muscles, including the tibialis anterior. Straining this muscle can cause shin splints. Overpronation also alters the rotation of the tibia (shin bone), which can cause various types of knee injuries through overloading.
A smaller group of people are ‘underpronators,’ also known as ‘supinators.’ In other words, their feet are rotated inwardly, placing pressure on the outside (little toe) edge of the foot. Runners who underpronate usually have a pronounced high arch.
The problem with underpronation is that forces are not distributed through the whole foot-on-ground contact as with neutral pronation. Instead, ground contact forces are absorbed by smaller and weaker structures in the foot, such as the little toe. This type of running gait puts additional strain on the plantar fascia, tibia, and knee, increasing the risk of common running injuries.
How Do I Know if I Overpronate or Underpronate (Supinate)?
Now to the important question. What is my foot type? Am I a pronator or a supinator? Here are two simple methods to help determine whether you over- or under- pronate.
The Wet Footprint Test
Walk across a flat, dry surface with wet feet. Dry concrete or cardboard works well for this. Your footprints show which parts of your foot contact the ground. If the footprint is broad/oval with no obvious dry area where the arch of your foot should be, this indicates overpronation and flatfootedness.
If the footprint shows a curved connection between the heel and ball of the foot, this indicates a neutral/normal amount of pronation, with a normal arch.
If the footprint shows little to no connection between the heel and forefoot, this indicates underpronation (supination) and a high arch that does not contact the ground.
The Wear and Tear Test
The next test you can do to determine if you under- or over- pronate is to check the wear and tear on the sole of your shoes.
Wear on the inside edge of the heel and the big toe indicate overpronation. Wear on the outside edge of the foot from heel to little toe indicates underpronation, aka supination. For neutral pronation, wear shows in an s-shape, from the outside heel to the big toe.
Running Gait Analysis
For the best results, professional gait analysis gives you accurate pronation feedback when running. Running gait analysis is usually performed by capturing slow-motion footage of treadmill running from different angles. Motion analysis software is used to calculate joint angles and distances to provide accurate data.
With the right guidance, gait analysis can help you adjust your running technique and choose the right running shoe. Running gait analysis is becoming increasingly available and is often a free service that comes with shoe fitting.
You can perform your own gait analysis with the help of video analysis apps – though be sure to corroborate your conclusions with a professional before making big changes.
How Do I Correct Overpronation or Underpronation (Supination)?
In most cases, over- and under- pronation can be corrected non-invasively and inexpensively.
Well-fitting shoes with arch support can help achieve neutral pronation. A wide variety of shoe inserts and insoles are available to correct pronation problems. These can help alleviate pain and improve heel alignment when walking and running. Kinesiology tape to brace the foot is also an effective way of controlling foot pronation.
Simple foot strengthening exercises and barefoot running can help correct overpronation by strengthening the arch of the foot. Try the exercises below as part of your training routine:
‘Crunch’ or flex your foot to bring heel and toes together. Hold this position for two seconds. Repeat for eight reps and three sets.
In a standing position, raise your heels off the ground and hold for two seconds. Repeat for eight reps and three sets.
In more severe cases, overpronation and flatfootedness may require custom orthotics, pain medication, ice, physical therapy, and, as a last resort, surgery. This may be the case if you have had foot problems for a long time or if injury and scar tissue have affected the mobility of your foot.
Which Shoes Are Best for Overpronation and Underpronation (Supination)?
Shoe choice is a big deal for runners. Running shoes are simultaneously believed to be the root of poor performance and injury and the source of success and healing. Barefoot evangelists preach zero cushioning and ‘natural’ techniques. Podiatrists prescribe arch support and corrective orthotics. Both agree that achieving neutral pronation alleviates pain, reduces injury, and improves performance.
One popular way to achieve neutral pronation is to wear shoes that actively encourage it. These usually incorporate motion control features such as arch support to prevent overpronation or lateral support to prevent underpronation (supination).
While these features may alleviate pain in the short term, it is not clear if they reduce injury in the long term. In some studies of motion control footwear, injury rates were reduced(3 4), while in others, they were unchanged(5,6) or potentially increased.(7) To complicate things further, one study found that pronators wearing neutral shoes without motion control had the lowest injury rates.(8)
A criticism of cushioned, supportive shoes is that they dull sensitivity to the running surface and weaken the foot by providing support in place of bones, muscles, and connective tissue. This is counterproductive from an injury perspective.
An alternative solution is to wear shoes with less cushioning or run barefoot. This can help strengthen the arch of the foot and correct overpronation naturally. Unfortunately, there is very little evidence to show whether this results in fewer injuries.
The conflicting evidence does prove one thing; the relationship between foot type, performance, and injury is complex. There are no ‘one-size-fits-all’ solutions to problems of pronation. Except perhaps for the ‘comfort filter’.
Recent evidence suggests that runners intuitively select footwear best suited to injury prevention and performance based on comfort.(7,8) After all, discomfort is a good indicator of when something isn’t right.
So until there is a definitive answer, choose shoes that feel comfortable while still permitting sensitivity to the running surface.