An article of footwear is disclosed that includes an upper and a sole
structure secured to the upper. The sole structure has a midsole element
that defines a void, and the void may extend substantially vertically
through a central area of the midsole element. The void may also extend
between an upper surface and a lower surface of the midsole element to
define an interior surface. A plurality of bores are also defined in the
midsole element. The bores may extend substantially horizontally through
the midsole element, and the bores may extend between an exterior surface
of the midsole element and the void.