Emerging Evidence On Footstrike Patterns In Running
Given the popularity and perceptions associated with barefoot running and minimalist shoes, this author takes a closer look at the research on foot striking patterns in runners and finds that rearfoot striking is not only far more prevalent but may be more efficient as well.
Much of the relatively recent increase in the popularity of running in America can be traced back to the “running boom” of the early 1970s when United States distance runner Frank Shorter won the marathon in the 1972 Munich Olympic Games.1 With the “running boom” came increased demand for a wider range and number of better running shoes. Now, in the U.S. alone, running shoe sales total over $3 billion and over 50 million Americans currently participate in running as a recreational activity.2
One of the most interesting trends or fads in running since the “running boom” started has been the surge of interest in barefoot running, minimalist running shoes and running footstrike patterns over the past five years. The surge in interest in barefoot and minimalist shoe running and footstrike patterns was at least partially due to the popularity of a 2009 book, Born to Run, by Christopher McDougall.3 Throughout his book, McDougall made claims that because our ancestors ran barefoot, modern humans should also be running barefoot or least be running in thinner-soled shoes that mimic barefoot running and allow a more “natural” running form. In his book, McDougall also claimed that there was no evidence that the modern, thicker-soled, cushioned running shoe, which became popular in the 1970s, actually prevented running injuries.
As a result of believing McDougall’s claims, many runners became captivated by the idea of “natural running.”3 Many of these runners began to try barefoot running or running in thin-soled “minimalist” running shoes with the most popular minimalist shoe for a time being the five-toed Vibram FiveFingers shoe. Even though there were many anecdotal accounts within the popular media that these five-toed shoes helped decrease running injuries, there were also reports within the medical literature that these shoes actually caused injury in some runners.4,5 In fact, in a 2013 study, runners who underwent a 10-week transition period of running in Vibram FiveFingers shoes showed significant increases in foot bone marrow edema versus those runners who trained only in traditional thick-soled running shoes.6 (For a related News and Trends article on the recent Vibram class action settlement, see http://www.podiatrytoday.com/june-2014 .)
Countering The Notion That Forefoot Striking Is More ‘Natural’
Along with the interest in barefoot and minimalist running shoes, there have been suggestions within the popular media that running with a forefoot striking pattern was more “natural” and better than running with a midfoot or rearfoot striking pattern. The most referenced article that seemed to support the idea that forefoot striking running was the “most natural” way to run came from a 2010 study by Lieberman and colleagues, who showed that there were reduced impact forces in habitually barefoot Kenyan runners who ran with a forefoot striking pattern.7 Researchers measured the Kenyan runners’ footstrike patterns at a relatively fast running speed of 5.5 m/sec (4:52 mile pace). In their study conclusion, Lieberman and coworkers maintained that “Forefoot and midfoot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact related injuries now experienced by a high percentage of runners.”7