Hard or Soft Ground?
What struck me so paradoxically, in Gina Kolata’s column ”For Runners, The Soft Ground Can Be Hard On The Body” (http://www.nytimes.com/2011/07/19/health/nutrition/19best.html?_r=1&ref=personalbest), was not the inconclusive responses to the question at hand – Is it better to run on hard or soft ground? – but rather Ms. Kolata’s comment about her own running dilemma: “every time I push off of on a soft surface, I twist my ankle.”
Although Ms. Kolata was clearly just adding a personal anecdote to bolster the story, it undoubtedly echoed the views of University of Texas at Austin exercise physiologist Hirofumi Tanaka who “aggravated” his knee injury and “sprained his ankle” when using a dirt path during his rehab. To him, the “soft and irregular surface” was the culprit. Kolata did her editorial diligence, interviewing several experts, including her coach Tom Fleming. Still, it seems odd to me that modern man is so ill-prepared to run on anything outside the most tempered surfaces, while our less civilized ancestors mucked around for years in nothing more than a leather sandal or bare foot. And even stranger are the controversies and misinformation buzzing around the subject.
When did we lose the ability to just go outside and run? At a time when our technology and problem-solving seem so far-reaching, why are we still in a quandary over how to perform the most fundamental of human tasks? The answer is simple, yet lurking outside the radar: gravity.
What befuddles scientists, coaches, athletes and runners, like Kolata, is the understanding that the propulsive impetus in running is gravity-driven. Gravity (plus friction) holds the landing foot in place while the body has the opportunity to rotate over this axis (imagine holding a pencil upright then letting it fall towards the table). If the fulcrum created by the foot remained, the body would topple rapidly towards the ground. However, it’s this resultant pull of gravity forward and downward, coupled with the removal of the foot from ground support, that allows our bodies to move horizontally. This process (repeated over and over, from foot to foot), is the true definition of running. A timely spring-release of the foot from any stretch of grass/dirt/asphalt/track, therefore, becomes the primary responsibility of the runner and, most importantly, the clue to assessing our injury-proness.
Kolata may feel it interesting to examine the effect of surface type on impact forces and injury potential, but I think this drastically misses the point. With regards to a soft, undulating surface, the angle of our footstrike and the time it takes for us to remove that foot is essential (I often train my form by running on ice). The conventional wisdom offered by Dr. Stuart J. Warden, director of the Indiana Center for Translational Musculoskeletal Research at Indiana University, to “get a pair of comfortable shoes and run on whatever surface they prefer” seems illogical considering the scope of the questions posed in the article.
It took many years for a forefoot strike to become common knowledge (although the photo accompanying the article suggests otherwise). I guess it’ll take more time for that push-off, regardless of the terrain, to be deemed unnecessary as well.