A footwear sole construction has a cavity. The footwear sole construction includes pods disposed on the medial and lateral sides of the heel region of the sole. The pods may be formed independent from the sole or integral with the sole. In addition, the pods may be disposed on the forefoot region...http://www.google.fr/patents/US5797199?utm_source=gb-gplus-shareBrevet US5797199 - Sole construction for footwear
