A footwear structure including an upper and a separate midsole having interlocking shank portions. The upper has an upward extending arc in the shank area which defines a shank interlock portion therein. The midsole has a corresponding arc which defines a shank interlock portion on a bottom surface thereof...http://www.google.co.uk/patents/US6701643?utm_source=gb-gplus-sharePatent US6701643 - Footwear structure and method of forming the same
