Running Surfaces

By Brian Crispell, DPM / Photography By Laurence Kelly

gravel running

Once you gather enough motivation to lace up your running shoes and get out the door, your next choice is where to run. There are many choices out there with plenty of ups and downs, literally and figuratively. You could go to the track and run in circles, which can be boring, but is also flat, soft, and consistent. Head to the gym, hop on the treadmill, and look at the clock every thirty seconds, or the hottie you’ve been checking out on Facebook. Hit the bike path, climb up and down the rugged single track, click off intervals around the soccer field, or enjoy the sunset along the beach. All of these surfaces have different qualities that should be taken into account along with your injury history, body type, and foot structure. Here is a look at several of the most common surfaces, which have been ranked according to their overall abilities to cause or prevent running injuries.

1. Cinder/Crushed Stone Paths – This surface is ranked number one for several reasons. Small amounts of internal/external rotation occur around the tibia during the toe-off portion of the gait cycle. This can be seen on some people who rotate excessively by looking at the bottom of their shoes. A giant circular wear pattern will be seen in the ball of the foot. Cinder paths allow this rotation to occur where the shoe meets the surface. Other surfaces, such as pavement, don’t allow much of this rotation, thanks to friction between the shoe and the surface. This rotation then occurs in the ankle, knee, and hip joints which can damage them over the long term. The surface is fast, usually flat, and very consistent. There aren’t many bad things one can say about this surface. Most runners will tolerate loads of mileage on this surface.

2. Single track/Trail – Overuse injuries on this surface have a very low incidence. This type of surface is very inconsistent with steep hills, rocks, roots, fallen trees, and streams. This forces every step you take to be slightly different, reducing the chance of overusing one muscle, bone, or joint. This type of surface is very inconsistent, which causes an increased incidence of traumatic injuries including sprains, fractures, and lacerations. Runners who aren’t nimble on their feet, have high or low arches, are generally stiff or clumsy, or have an unstable foot type, will have trouble on this surface.

3. Treadmill – Most treadmills have a shock absorbing platform. You can see this in action if you watch the platform each time your foot strikes. It will move up and down about half an inch. Depending on your mood, treadmills can be very monotonous. Some people tend to run much faster on a treadmill than they should be running. Being in the company of others at the gym can inadvertently cause the pace to increase. Be aware of this. Running on the treadmill at zero percent incline requires a lower aerobic effort than running outside on a flat surface. If you want to equalize the effort to a flat outside surface, the incline should be raised to about 1%.

4. Synthetic Rubber Track – Rubber tracks can also be monotonous. Who wants to run in circles? A rubber track is the most consistent surface you can run on. Every lap will require the same effort and the distance is very measureable. This gives you the greatest degree of reliable performance feedback. Tracks are great for quality workouts to gauge your fitness level. The shock absorption is moderate. In colder weather the surface stiffens, reducing shock absorption. Constant left hand turns can lead to injury over long distances. If you’re running a long distance on the track, reverse your direction every 10 minutes or so. If you’re a pace monger, the speed can get out hand. If you are worried about your pace, run in lane 8 where the distance is not as measureable.track running

5. Grass – This surface has very good impact absorption. Small divots, however, are concealed by the grass, which makes it a very inconsistent surface. Great for running intervals, grass is a much slower surface than pavement or track, but is the best surface to run barefoot. Grass is a fantastic running surface, it is just very difficult to find enough grass to make an entire run. There are only so many soccer fields and baseball diamonds you can string together.

6. Pavement/Concrete – The human body was simply not designed to run on hard rock. Roads and sidewalks are the hardest and most unforgiving surfaces that one could run on. These surfaces have zero shock absorption. Friction between the shoe and the surface is very high causing a higher degree of rotational motion to occur within the hip, knee, and ankle joints. These rotational forces cause a higher frequency of overuse injuries. Many roads are “crowned,” or sloped sideways, to facilitate drainage. This small slope can cause higher impact on either leg which can lead to injuries. All this to deal with, plus traffic. Try to stay just off the shoulder on the gravel border. On sidewalks, try to stay on the edge of grass where available.

7. Sand/Snow – Running on sand and snow has been shown to increase the incidence of Achilles tendonitis by ten times. The extreme softness of the surface causes you to over-push during the toe-off part of the gait cycle. This engages the Achilles to a high degree and causes overuse of the tendon. If you’re aware of this you can mentally compensate by slowing your pace, staying off your toes, and running flat-footed. Many beaches are steeply sloped. Avoid running on these beaches. When possible run on the beach at low tide and stay on the hard, wet sand closest to the water.

Dr. Brian CrispellDr. Brian Crispell is a board qualified foot & ankle surgeon. He has his own practice located in Media, PA. He specializes in sports medicine and running injuries. He is a competitive runner and cyclist himself, having run a 2:36 marathon and a 54:19 10-mile. To learn more about Dr. Crispell visit