Runners have been fooled into believing that running on grass is safer for obvious reasons: its softer and natural compared to asphalt. But recent research suggests that running on grass, especially learning barefoot running on grass, causes inappropriate plantar pressure distribution and impact forces and that the body undergoes a shift in better foot strike mechanics when running on asphalt.
A study by Quinn, 2006 reported that natural surfaces such as grass and beaches are very uneven and can cause more injuries because plantar pressures and forces vary with each step during running which also cause the ankles, knees, and hips to constantly adjust to the surface irregularities.
- Additionally, the accompanying slope changes at foot strike when running on grass or a beach creates a dangerous off-center force on the ankles and feet, Quinn reported.
In support of this, a more recent study by Janakiraman et al. found that runners who ran on grass had increased intravenous hemolysis –rupturing of red blood cells and their contents– of the foot compared to runners who ran on asphalt.
- Other work presents evidence that injuries occur more on grass than on unnatural surfaces simply because the unevenness of grass amplifies the ground reaction force.
Although the unevenness of grass is great for ankle strength and our ancestors ran barefoot on rugged, uneven terrain, when it comes to learning a new running style such as barefoot running or forefoot running in minimalist shoes, stick to smooth surfaces, for now.
Likewise, the modern running shoe has long separated us from how our ancestors ran –our ankles and feet are very weak, making it challenging to maintain stability when learning barefoot running on uneven terrain.
More From Run Forefoot:
- Forefoot Running
- Why Most Running Shoes are Bad
- Heel Strike
- Don’t Let Running Burn a Hole in your Pocket: Deals on Running Shoes/Gear
References:
Fuller, C. W., Dick, R. W., Corlette, J., & Schmaltz, R. (2007). Comparison of the incidence, nature and cause of injuries sustained on grass and new generation artificial turf by male and female football players. Part 1: match injuries British Journal of Sports Medicine, 41(Suppl. 1), i20–i26.
Janakiraman et al. Intravascular haemolysis during prolonged running on asphalt and natural grass in long and middle distance runners. J Sports Med, 2011; 29(12): 1287-1292.
Quinn, E. (2006). Running on sand or grass may increase risk of injury. Retrieved from http://sportsmedicine.about.com/od/injuryprevention /a/runnersand.htm
Bretta Riches
BSc Neurobiology; MSc Biomechanics candidate, ultra minimalist runner & founder of RunForefoot. I was a heel striker, always injured. I was inspired by the great Tirunesh Dibaba to try forefoot running. Now, I'm injury free. This is why I launched Run Forefoot, to advocate the health & performance benefits of forefoot running and to raise awareness on the dangers of heel striking, because the world needs to know.
How much experience do you recommend before running barefoot on in fields or on trails? Thanks! 🙂