Foot strike pattern in preschool children during running: sex and shod-unshod differences

Purpose: This study aims to determine the foot strike patterns (FSPs) and neutral support (no inversion [INV]/eversion [EVE] and no foot rotation) in preschool children, as well as to determine the influence of shod/unshod conditions and sex. Methods: A total of 1356 children aged 3-6 years (673 boys and 683 girls) participated in this study. A sagittal and frontal-plane video (240Hz) was recorded using a high-speed camcorder to record the following variables: rearfoot strike (RFS), midfoot strike (MFS), forefoot strike (FFS), inversion/ eversion (INV/EVE) and foot rotation on initial contact. Results: There were no between-sex significant differences in both shod and unshod conditions in RFS. In the unshod condition, there was a significant reduction (p<0.001) of RFS prevalence in both boys (shod condition=44.2% vs. 34.7% unshod condition) and girls (shod condition=48.5% vs. 36.1% unshod condition). As for neutral support, there were no between-sex differences in both shod and unshod conditions or in the shod-unshod comparison. Conclusion: In preschool children, no between-sex differences were found in relation to prevalence of RFS and neutral support (no INV/EVE). Shod running alters FSP of running barefoot, producing a significant increase of RFS prevalence.