FREE TO MOVE IN ALL DIRECTIONS The Nike Free 5.0 (3.5y-7y) Girls' Running Shoe features a flexible outsole and a mesh upper with Flywire technology for lightweight, breathable comfort and freedom to move wherever you go. Flexibility Hexagonal flex grooves are hot-knife cut into the outsole and wrap around the sidewall, allowing the foot to move more naturally in every direction. Support and Breathability The woven mesh upper provides lightweight ventilation to help keep feet cool. Flywire in the midfoot offers durability without added weight and an adaptive, supportive fit that moves with you. Natural Stride The rounded heel mimics the shape of your foot, rolling with the ground to promote natural movement and extended range of motion. More Benefits Low-profile, Phylite midsole provides a resilient ride and is tough enough to double as an outsole No-sew overlays for support and durability without added weight Dynamic Fit technology is integrated with the laces for an adaptive, supportive fit Sections of solid rubber under the toe for traction and durability in this high-wear area Nike Free Origins After learning that Stanford athletes had been training barefoot on the university's golf course, three of Nike's most innovative and creative employees set out to develop a shoe that felt natural and weightless, similar to bare feet. In 2002, they examined a group of men and women with pressure-measuring insoles taped to their feet, using high-speed cameras to capture images of each foot in motion. The team spent eight years studying the biomechanics of shoeless running. The results yielded a profound understanding of the foot's natural landing angle, pressure and toe position, allowing Nike designers to build an unconventional and flexible running shoe from the inside out.