US Patent 7644517 Modular article of footwear

An article of footwear includes an upper and a sole structure and at least two elements that join to form the upper and the sole structure. The elements each form a portion of the upper and a portion of the sole structure. With regard to the upper, the elements each form a strap portion that, in combination, secures a foot to the footwear. With regard to the sole structure, the elements each form a portion of the foot-supporting surface and the ground-engaging surface. The elements may be joined through a snap-fit system involving protrusions and apertures, or adhesives may be used.