Patent ID: 8590179

Claim:
An article of footwear that extends in a longitudinal direction between a heel region and a forefoot region of the footwear and in a transverse direction between a medial side and a lateral side of the footwear, the article of footwear comprising: (a) a first sole portion, said first sole portion including: (i) a bottom surface; and (ii) a plurality of recesses which are recessed from the bottom surface; and (b) a second sole portion, said second sole portion including: (i) a plurality of securing portions which are secured in the recesses of the first sole portion; and (ii) a plurality of hollow tread members extending between adjacent securing portions, wherein each hollow tread member includes an inner surface and an outer surface, the inner surface of each hollow tread member at least partially defining a hollow cavity within the article of footwear such that the plurality of hollow tread members at least partially define a corresponding plurality of separate hollow cavities, and the outer surface of each hollow tread member at least partially defining a ground contacting surface of the footwear, and wherein each hollow cavity of the plurality of hollow cavities extends between a first opening facing in a direction towards a medial side of the footwear and a second opening facing in a direction towards a lateral side of the footwear such that the ends of the hollow cavity are open to the outside of the article of footwear.