Patent ID: 7997012

Claim:
An article of footwear having an upper and a sole structure secured to the upper, the sole structure comprising: a midsole element formed from a polymer foam material and having an upper surface and an opposite lower surface, the midsole element extending substantially through a forefoot region, a midfoot region, and a heel region of the sole structure and from a lateral side to a medial side of the sole structure, the midsole element defining a plurality of substantially vertical bores extending through the polymer foam material and from the upper surface to the lower surface; a first upper sheet secured to the upper surface and extending over at least a first portion of the bores, the first upper sheet being positioned in the heel region; a second upper sheet secured to the upper surface and extending over at least a second portion of the bores, the second upper sheet being positioned in at least one of the midfoot region and the forefoot region, and the second upper sheet being positioned adjacent the lateral side; a third upper sheet secured to the upper surface and extending over at least a third portion of the bores, the third upper sheet being positioned in the forefoot region, and the third upper sheet being positioned adjacent the medial side; and at least one lower sheet secured to the lower surface and extending under the first portion, the second portion, and the third portion, wherein the first upper sheet, the second upper sheet, the third upper sheet, and the lower sheet seal a fluid within the first portion, the second portion, and the third portion of the bores, and a fourth portion of the bores are not sealed.