Abstract: A running shoe having a sole structure that includes an outsole extending from the toe to the heel and having a thickened section extending the full width of the sole structure and positioned to underlie the ball of the foot. The thickened section is appreciably thicker than the portions of the outsole that underlie the remainder of the foot. A plurality of parallel slots are cut in the thicker section across the full width of the outsole and extend from the bottom surface or tread, upwardly to just short of the top surface of the outsole to form hinges which allow it to readily flex. The slots may be partially bridged by struts which do not interfere with the hinge action at each of the slots but which provide added strength to the outsole at that region.

Abstract: A running shoe having a sole structure that includes an outsole extending from the toe to the heel and having a thickened section extending the full width of the sole structure and positioned to underlie the ball of the foot. The thickened section is appreciably thicker than the portions of the outsole that underlie the remainder of the foot. A plurality of parallel slots are cut in the thicker section across the full width of the outsole and extend from the bottom surface or tread, upwardly to just short of the top surface of the outsole to form hinges which allow it to readily flex. The slots may be partially bridged by struts which do not interfere with the hinge action at each of the slots but which provide added strength to the outsole at that region.