Isolated Effects of Footwear Structure and Cushioning on Running Mechanics in Habitual Mid/Forefoot Runners

The true differences between barefoot and shod running are difficult to directly compare 2 because of the concomitant change to a mid/forefoot footfall pattern that typically occurs 3 during barefoot running. The purpose of this study was to compare isolated effects of footwear 4 structure and cushioning on running mechanics in habitual mid/forefoot runners running shod 5 (SHOD), barefoot (BF), and barefoot on a foam surface (BF+FOAM). Ten habitually shod 6 mid/forefoot runners were recruited (male=8, female=2). Repeated measures ANOVA 7 (α=0.05) revealed differences between conditions for only vertical peak active force, contact 8 time, negative and total ankle joint work, and peak dorsiflexion angle. Post hoc tests revealed 9 that BF+FOAM resulted in smaller vertical active peak magnitude and instantaneous vertical 10 loading rate than SHOD. SHOD resulted in lower total ankle joint work than BF and 11 BF+FOAM. BF+FOAM resulted in lower negative ankle joint work than either BF or SHOD. 12 Contact time was shorter with BF than BF+FOAM or SHOD. Peak dorsiflexion angle was 13 smaller in SHOD than BF. No other differences in sagittal joint kinematics, kinetics, or ground 14 reaction forces were observed. These overall similarities in running mechanics between SHOD 15 and BF+FOAM question the effects of footwear structure on habituated mid/forefoot running 16 described previously