A midsole system for a running shoe or foot prosthesis have a sole spring, a heel spring and/or a forefoot spring stores energy of foot impact and releases it during the running cycle. A preferred embodiment provides bending beam sole systems for shoes or foot prostheses comprising a bending beam heel...http://www.google.co.uk/patents/US6029374?utm_source=gb-gplus-sharePatent US6029374 - Shoe and foot prosthesis with bending beam spring structures
