A sole for footwear comprises an outer sole (12; 22; 31) housing a plurality of pressure-stimulation elements (15; 24; 33) movable perpendicularly, relative to the bearing surface of the outer sole, through the thickness of the outer sole and, in the absence of stresses, extending below the bearing surface...http://www.google.co.uk/patents/US6082024?utm_source=gb-gplus-sharePatent US6082024 - Sole for footwear
