Footwear structure and method of forming the same

1. 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

a base portion including portions defining at least one receptacle therein, and

at least one insert disposed in said at least one receptacle.

2. A footwear structure according to claim 1 , said structure comprising a plurality of said receptacles and a plurality of said inserts, each of said plurality of said inserts being disposed in an associated one of said plurality of said receptacles.

3. A footwear structure according to claim 1 , wherein said base portion and said at least one insert are formed from different materials.

4. A footwear structure according to claim 1 , wherein said insert is removably disposed in said receptacle.

5. A footwear structure according to claim 1 , wherein said at least one receptacle is in a heel area of said base portion.

6. A footwear structure according to claim 1 , wherein an interior surface of said upper has a bottom portion and an exterior surface of said upper has a bottom portion, said bottom portion of said exterior surface being disposed against said top surface of said outsole, and said bottom surface of said midsole being disposed against said bottom portion of said interior surface of said upper.

7. A footwear structure according to claim 1 , wherein said bottom portion of said upper extends along an entire length and width of said midsole.

8. A footwear structure according to claim 1 , wherein said midsole is removably disposed in said cavity.

9. A footwear structure according to claim 1 , wherein said shank interlock portion of said outsole comprises a continuous arc.

10. A footwear structure according to claim 1 , wherein said structure further comprises a shank component disposed between a bottom surface of said outsole and a top surface of said midsole.

11. A method of forming a footwear structure comprising:

providing an outsole having a top surface with a shank interlock portion;

providing an upper, said upper being separate from said outsole and comprising: a top portion, and a separate a bottom portion secured to said top portion, said bottom portion having an upper shank interlock portion,

securing said upper shank interlock portion to said shank interlock portion of said top surface of said outsole, said upper at least partially defining a cavity for receiving a foot;

providing a midsole having a bottom surface with a midsole shank interlock portion which mates with said upper shank interlock portion, said midsole comprising

a base portion including portions defining at lease one receptacle therein, and

at least one insert disposed in said at least one receptacle; and

positioning said midsole in said cavity with said bottom portion of said upper disposed between said midsole and said outsole.

12. A method according to claim 11 , said structure comprising a plurality of said receptacles and a plurality of said inserts, each of said plurality of said inserts being disposed in an associated one of said plurality of said receptacles.

13. A method according to claim 11 , wherein said base portion and said at least one insert are formed from different materials.

14. A method according to claim 11 , wherein said insert is removably disposed in said receptacle.

15. A method according to claim 11 , wherein said at least one receptacle is in a heel area of said base portion.

16. A method according to claim 11 , wherein an interior surface of said upper has a bottom portion and an exterior surface of said upper has a bottom portion, said bottom portion of said exterior surface being disposed against said top surface of said outsole, and said bottom surface of said midsole being disposed against said bottom portion of said interior surface of said upper.

17. A method according to claim 11 , wherein said bottom portion of said upper extends along an entire length and width of said midsole.

18. A method according to claim 11 , wherein said midsole is removably disposed in said cavity.

19. A method according to claim 11 , wherein said shank interlock portion of said outsole comprises a continuous arc.

20. A method according to claim 11 , wherein said method further comprises:

providing shank component; and

positioning said shank component between a top surface of said midsole and a bottom surface of said outsole.