Because this race was part of a weekend-long barefoot running “festival”, many of those attending had participated in form clinics and barefoot running seminars on the day prior to the race. Thus, it is possible that some runners were consciously running according to how they had been taught the previous day. However, since both barefoot and minimally shod runners had the opportunity to attend the same form seminars, the comparisons between barefoot and minimally shod runners

in this race should not have been affected. It is possible that the overall frequency of midfoot and forefoot striking was inflated by subjects forcing their form to meet their perception of how they should run when barefoot or in minimal

footwear. It is for this reason that I chose to film in a discrete way 350 m from the starting line. The intent of this protocol was to allow AG-014699 purchase runners time to settle into the run and to minimize learn more the likelihood that they would notice that they were passing a camera. Despite this concern, it should be noted that frequency of forefoot and midfoot striking observed here are not inconsistent with results of other studies that have observed barefoot runners on hard surfaces.8, 9 and 27 It is also important to point out that this study only classified the initial contact point of the foot with the ground into three broad categories. It was not possible to examine the forces associated with ground contact or accurately assess kinematic variability within Dipeptidyl peptidase the discrete categories. Wide variation in initial contact position has been recognized for

a long time,28 and such variation may influence patterns of force application. For example, Logan et al.29 reported a high degree of variability in force measurements among rearfoot-striking runners in a comparison of gait mechanics between cushioned running shoes, racing flats, and distance spikes; they suggested individual differences in initial contact location as a possible explanation for this variation. Altman and Davis27 found that visually assessed midfoot strikers were often classified as forefoot or heel strikers by the strike index method. Recent research also suggests that runners who contact first on the heel exhibit variation in the location of maximal vertical impact loading, with as many as 25%–33% of runners who contact on the heel experiencing maximal vertical loading rate when the center of pressure is under the midfoot.30 Despite the potential for variation in force measurements within visually assessed foot strike categories, a recent laboratory study found that foot strike angle at contact correlates well with kinetic measures of foot strike such as the strike index.