Patent ID: 8191284

Claim:
An article of footwear, comprising: an upper; an upper sole portion including an upper sole portion body and a projecting portion, the upper sole portion body having a top side configured to be disposed proximate to a wearer's foot when inserted within the article of footwear and the upper sole portion body having a bottom side disposed opposite the top side, wherein the projecting portion extends outward from the bottom side of the upper sole portion body; the upper sole portion including at least one aperture extending through the upper sole portion from the bottom side to the top side; a lower sole portion including a first side configured to contact the bottom side of the upper sole portion body and a second side configured to contact a ground surface; the lower sole portion including a hole, the hole configured to extend through the lower sole portion from the first side to the second side and is further configured to receive the projecting portion of the upper sole portion; a compression chamber defined by a lower surface of the projecting portion, at least one wall of the hole extending through the lower sole portion, and a ground surface; the compression chamber having a first volume, the first volume being associated with a first distance between the lower surface of the projecting portion and a ground surface; wherein the compression chamber has a second volume after being compressed, the second volume being associated with a second distance between the lower surface of the projecting portion and a ground surface; wherein the change in the compression chamber from the first volume to the second volume forces air through the at least one aperture; and wherein the lower sole portion includes at least one channel in fluid communication with the compression chamber.