Emerging Evidence On Footstrike Patterns In Running
However, directly contradicting the findings of the study by Lieberman and colleagues, a more recent study by Hatala and coworkers in 2013 showed that when another group of habitually barefoot Kenyans ran at a much slower and more common recreational running speed of 3.3 m/sec (8:08 mile pace), 72 percent of these barefoot runners were rearfoot strikers, 24 were midfoot strikers and only 4 percent were forefoot strikers during running.7,8Therefore, the idea of Lieberman and coauthors that our ancestors who ran barefoot were predominantly forefoot strikers and were not rearfoot strikers seems unlikely. In addition, the speculation that forefoot striking running is a more “natural” form of running than rearfoot striking or midfoot striking running is not supported by the scientific research literature.
What The Research Reveals: Rearfoot Striking Preferred By Majority Of Runners
In order for the clinician to better understand the footstrike pattern debate and the scientific research on the subject, it is important first to review some of the most significant running research studies involving footstrike patterns.
In 1980, Cavanagh and Lafortune published the first modern scientific study of footstrike patterns of runners.9 In their study, 17 people ran over a force plate to classify their running footstrike patterns. The researchers divided the anterior-posterior length of the shoe sole into equal thirds with those people who first contacted the ground with the proximal third of the shoe being labelled as rearfoot strikers, those contacting in the middle third being midfoot strikers and those contacting in the distal third of the shoe sole being forefoot strikers. At a 4.5 m/sec (5:58 mile pace) running velocity, 12 of the study participants were rearfoot strikers, five were midfoot strikers and none of the runners were forefoot strikers. In 1987, the term “strike index” first arose within the scientific literature to describe the percentage of the running shoe sole length, from anterior to posterior, where the runner first contacted the ground at footstrike.10
In regard to the footstrike patterns of the running population as a whole, there have been seven research studies to date that have measured footstrike patterns in large numbers of runners. Kerr and colleagues measured the footstrike patterns of 753 runners in 10 km and marathon distance races, and found that 81 percent were rearfoot, 19 percent were midfoot and 0 percent were forefoot strikers.11 Hasegawa and coauthors studied the footstrike patterns of 283 elite half-marathoners and found that 74.9 were rearfoot, 23.7 percent were midfoot and only 1.4 percent were forefoot strikers.12 Larson and colleagues measured 936 half-marathon runners and found that 88.9 percent were rearfoot, 3.4 percent were midfoot, 1.8 percent were forefoot and 5.9 percent were asymmetrical foot strikers.13
Out of 903 novice runners, Bertelsen and coworkers found there were 98.1 percent rearfoot, 0.2 percent midfoot, 0.4 percent forefoot strikers and 1.2 percent asymmetrical foot strikers.14 Kasmer and colleagues studied 1,991 runners in a marathon and found that 93.7 percent were rearfoot strikers.15 In a 50 km trail race, Kasmer and coauthors also determined that 85.1 percent of 165 runners were rearfoot strikers.16 Finally, Almeida and coworkers showed that in 514 recreational runners, 95.1 percent were rearfoot strikers, 4.1 percent were midfoot strikers and 0.8 percent were forefoot strikers.17
Of the 5,545 runners who had their footstrike measured in these seven research studies, 90.8 percent (5,034) were rearfoot strikers (see “Seven Studies Show Rearfoot Striking Preferred Form In Runners” below).11-17 This conclusively demonstrates that the preferred footstrike pattern for the vast majority of runners is rearfoot striking.