Effect of Footwear on Running Impact Loading in the Preschool Years

Abstract

Background Previous research indicated that running barefoot or in minimalist shoes led to lower impact loading in an adolescent and adult population. Running as fundamental locomotor skill significantly develops during early childhood (preschool age). However, no study has focused on effect of footwear condition on lower limb impact loading during running in this age. Therefore, the purpose of this study was to assess effect of footwear conditions (barefoot, minimalist and standard running shoes) on running impact loading in the preschool years. Methods Fourty-eight habitually shod preschool children were divided into 4 age groups. Children performed simple running game in 3 different footwear conditions (random counter-balanced order), 3-dimensional biomechanical analysis were carried out during overground running. The key dependent variables included vertical ground reaction force (VGRF) and vertical instantaneous loading rate (VILR). Statistical parametric mapping was performed to reveal possible differences in VGRF and one-way repeated measures ANOVA in VILR. Results Three-year-old children displayed significantly lower impact peak of VGRF in barefoot condition compared to minimalist (3-7% stance, P = 0.012) and standard running shoes (7-11% stance, P = 0.009). Furthermore, in 3-year-old in minimalist shoes had higher loading than in standard running shoes (0-4% stance, P = 0.007). There were also differences in VILR, where 3-year-old had lower loading in barefoot than in minimalist (P = 0.010, d = 1.19) or standard running shoes (P = 0.045, d = 0.98). No differences were found in older children. Conclusion Running in minimalist shoes did not imitate barefoot running and did not lower impact forces compared to standard running shoes in 3-year-old children. On the contrary, increased loading was observed in minimalist shoes in early running developmental stages. Professionals who work with children should consider effect of minimalist shoes on impact loading (running on hard surfaces).