A midsole insert for use with a shoe is provided. The midsole insert includes a
heel portion, a midfoot portion, and a
forefoot portion, and a plurality of grid systems located on the midsole insert, where each
grid system includes a plurality of openings
cut into the midsole insert forming a lattice pattern. The plurality of grids may be located on at least one of the
heel portion, the midfoot portion, and the
forefoot portion, constructed to provide energy return features. The midsole may further be constructed and arranged to attach directly to an upper during a manufacturing step, to secure the shape of the upper on a last. By attaching directly to the upper, the midsole insert eliminates the need for a stroble board, which is typically used to secure the upper to the last. By eliminating the stroble board, the present invention places the midsole insert and the energy return
grid system closer to the foot, which maximizes reaction time and performance. The midsole insert may be formed of at least two materials having different hardnesses, such that the
heel portion has a greater
hardness than the
forefoot portion.