Sports shoes for training physical strength which are divided into the uppers, middle layer of a shoe sole, and the bottom sole, including: a rubber seat inserted at both sides and the back of the uppers; a high-elastic sponge adhered at bottom surface of the middle layer thereof; and, a plurality of...http://www.google.es/patents/US6397498?utm_source=gb-gplus-sharePatente US6397498 - Sports shoes for training physical strength
