ULTIMATE FLEXIBILITY FOR YOUNG FEET The Nike Free 5.0 (3.5y-7y) Girls' Running Shoe features a flexible outsole and a breathable mesh upper for freedom to move and total comfort wherever you go. Freedom to Move Nike Free flex grooves along the length and width of the midsole allow for full range of motion and unrestricted comfort during activity. Comfortable Fit Flywire technology wraps the midfoot and arch from underneath the foot up through the laces for an adaptable, glove-like fit for your foot. Ventilation Ultra-breathable mesh on the upper provides ventilation for extra comfort. More Benefits Easy-entry tongue contruction for easy on and off Strategically placed no-sew overlays for durability and support Asymmetrical lacing system for reduced pressure on the top of the foot Abrasion-resistant rubber under the heel for durability Waffle pistons in the outsole to absorb impact and provide traction 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.