A modern running shoe is a piece of high-tech athletic equipment. Advances in technology and increased competition among manufacturers have increased the speed and safety of this type of shoe. The outsole absorbs the energy when the runner's foot strikes the ground and reduces supination and pronation. The heel wedge is a flexible platform that absorbs shock to prevent Achilles tendon injuries. The midsole provides both shock absorption and energy return.
Arch support is provided by the insole.
Holding the soles on the runner's foot and providing ventilation are the functions of the shell. Today's shoe balances the needs for decreased injuries and for increased speed. It includes an exploded diagram showing all parts of the construction.