One of the healthiest forms of exercise available is simply going for a run. It is inexpensive, available almost anywhere, and good for your heart, lungs, and circulatory system. By extension, it is a good exercise for your muscles and your overall well being.
However, there is certainly a slew of injuries associated with running, most of them, of course, associated with your legs and feet. Overdoing it can cause muscle strains and shin splints, which includes stress fractures. Tendons and ligaments can be injured by overuse or over-extension.
To keep injuries to a minimum it helps to understand the concepts of overpronation and underpronation and how those conditions can result in injuries down the line. Pronation, which can also be termed neutral pronation, is the word given to how much the arch of your foot collapses upon impact, which is to say when you walk or run.
Neutral pronation is the term given to arches that collapse a normal amount, while overpronation defines arches that collapse too much. Underpronation, also called supination, defines arches that do not collapse enough.
The arch of your foot does several things, but the primary purpose is to absorb some of the shocks that occur as your foot collides with the ground when you walk or run. It also provides a springing effect as you push off from the ground. Mostly, however, it provides for a cushion to protect your foot from the many, many times it strikes the ground.
Overpronation is also the term used for being flat-footed. In this case, the arch provides limited cushioning for the foot as it hits the ground. This can lead to shin splints, stress fractures, and over-use injuries to your knees, hips, ankle, and heel.
An overly excessively inward roll of the footmarks overpronation. Put another way, with overpronation, the impact of walking or running is concentrated unduly on the side of the foot that includes the big toe.
Underpronation or Supination
When the arch of the foot does not collapse enough (supination), this forces the foot to roll outward as you walk or run. In this situation, the foot strikes the ground first with the side of the foot that includes the smallest toe – the pinky toe. This can result in a loss of balance, which can lead to other injuries.
Testing Your Impact
There are several standard tests you can do yourself to figure out if your feet hit the ground at a neutral position or in one that is in an overpronation or supination position. One of these is called the Wet Test.
Take a dry piece of cardboard and lay it on the ground. Get your feet wet, but not dripping wet and walk on the cardboard. Look at the outline of the water you leave behind.
If your footprint is very thin in the portion of the arch – the portion between the ball of the foot and the heel — then this indicates a supination impact when you walk or run. If the middle section is especially thick, it indicates an overpronation impact.
You can do the same test by walking on a sandy beach or in a sandbox. First, smooth out the sand, then examine your footprints after you walk across it. Semi-firm, moist sand works best for this test.
The Wear Test
Another way to test your foot’s impact on the ground is to simply look at the bottom of your sneakers or shoes and examining the wear. Is most of the worn rubber or leather on the inside of the foot (supination) or the outside (overpronation) or evenly divided (neutral)?
When To Seek Help
Seek help anytime pain in the hip becomes acute when you lose the ability to walk or raise a leg, when you cannot bear the pain and when the hip looks misshapen or deformed.