The Influence of Heel Fit on Rearfoot Motion in Running Shoes

Prior research into eversional control in running has reported the occurrence of calcaneal slipping, defined as the difference between calcaneal and heel counter eversion within the shoe. Inadequate heel fit has been proposed to explain the observed slippage. Therefore, the purpose of the current study was to investigate whether eliminating excess space around the calcaneus by narrowing the heel counter or by introducing heel inserts could minimize eversional slipping of the calcaneus within the shoe and, in so doing, improve eversion control of the calcaneus. Three-dimensional rearfoot kinematics of 20 subjects running on a treadmill at 3.8 m · s−1 were recorded using a three-camera Vicon movement analysis system. ANOVA analyses of the angular displacement data revealed a significant (p < .05) reduction in maximal eversion of the calcaneus in shoes with a narrower heel fit though the heel counter of the same shoes displayed more eversion than their wider counterparts. Calcaneal eversion in the shoes with a wider heel counter, however, could be reduced significantly (p < .05) using heel inserts. Maximal relative eversion (referenced to the value at heel strike) and eversional velocity were only affected by the heel inserts, the latter, however, not significantly. All these results show that heel fit affects the eversional behavior of the calcaneus during ground contact and that running shoes equipped with a rigid heel counter will improve rearfoot control, thus only reducing the risk for overload injuries if a snug heel fit used.