Patent ID: 8381416

Claim:
A footwear structure comprising: an outsole comprising a top surface having shank interlock portion; an upper, said upper being separate from said outsole and being secured to said outsole to at least partially define a cavity for receiving a foot, said upper comprising: a top portion, and a separate a bottom portion secured to said top portion, said bottom portion having a corresponding shank interlock portion which mates with said shank interlock portion of said outsole; and a midsole at least partially disposed within said cavity with said bottom portion of said upper disposed at least partially between said top surface of said outsole and a bottom surface of said midsole, said bottom surface of said midsole having a midsole shank interlock portion which mates with said corresponding shank interlock portion of said upper, said midsole comprising multiple separate layers of differing rigidity, said multiple separate layers of differing rigidity comprising a rigid layer disposed between first and second cushioning layers, said first and second cushioning layers being less rigid than said rigid layer.