The invention relates to a sliding element for a shoe sole. The sliding element includes an upper sliding surface and a lower sliding surface, wherein the lower sliding surface is arranged below the upper sliding surface so as to be slideable in at least two directions. The upper sliding surface can...http://www.google.co.uk/patents/US20040055182?utm_source=gb-gplus-sharePatent US20040055182 - Full bearing 3D cushioning system
