footwear, aging, barefoot, minimalist shoes, standard running shoes

This study aimed to compare impact loading among four groups of preschool children (crucial period of running skill development) and one group of young adult people (A) in three footwear conditions (B-barefoot, M-minimalist, SRS-standard running shoes). Sixty healthy participants (32 males/28 females) performed simple running game in three standardized footwear conditions (BM- SRS). Participant were divided into 5 age groups (3-4-5-6-yr-old children and 20-24-yr-old adults). There were 12 participants in each group. Six recorded running trials for each participant were included into the 3-D biomechanical analysis. A two-way mixed ANOVA (5x3) was performed on vertical instantaneous loading rate (VILR). Consequently, a one-way ANOVA was used for each footwear separately to compare mean values of VILR among age groups followed by post hoc pairwise comparisons. An interaction was found between age and footwear condition in VILR (P=0.010). There were clear descending trends of VILR with increasing age in both shod conditions. No differences were found when B (3yr= 175, 4yr= 184, 5yr= 165, 6yr= 143 and A= 134 BW/s; P=0.254). Pairwise comparisons showed significant differences in M between 3yr-A (P=0.019), 4yr-A (P=0.023); and in SRS between 3yr-6yr (P=0.012), 3yr-A (P=0.001), 4yr-6yr (P=0.023), 4yr-A (P=0.001), 5yr-A (P=0.002) and 6yr-A (P=0.014). Three and four-year-old children should use minimalist and running shoes gradually with cautious, at least during introduction to running on hard surfaces. It is in accordance with previous study (4) which showed that 3 and 4 had lower VILR in barefoot than in shod condition, on the contrary running shoes in the current study significantly reduced VILR in adults. It seems that barefoot running could be safely used in preschool age with relative less loading than during minimalist and standard shod running.