An article of footwear, comprising: a sole having a top portion and a bottom portion , at least a portion of a periphery of each of the top and bottom portions being separate from the other of the top and bottom portion in at least a midfoot region ; and an upper ; wherein the top portion of the sole is attached to the upper , thereby allowing rotational freedom between the top and bottom portions of the sole in a peripheral location where the top and bottom portions are separated; wherein the top and bottom portions of the sole are separate from one another on both a lateral side and a medial side of the sole , and wherein the separation of the top and bottom portions of the sole on each of the lateral side and the medial side defines a lateral recess and a medial recess , characterized in that a lateral width of the lateral recess increases from a first lateral width at a forefoot region to a higher second lateral width at the midfoot region and decreases from the higher second lateral width to a third lateral width at a heel region , wherein the lateral width is defined as a distance generally perpendicular to a longitudinal axis of the sole from the periphery to a lateral attachment boundary spaced from the periphery in a particular location along a length of the sole and wherein the lateral attachment boundary is spaced from the periphery in the midfoot region , and in that a medial width of the medial recess increases from a first medial width at the forefoot region to a higher second medial width at the midfoot region and decreases from the higher second medial width to a third medial width at the heel region , wherein the medial width is defined as a distance generally perpendicular to the longitudinal axis of the sole from the periphery to a medial attachment boundary spaced from the periphery in a particular location along the length of the sole and wherein the medial attachment boundary is spaced from the periphery in the midfoot region . a sole having a top portion and a bottom portion , at least a portion of a periphery of each of the top and bottom portions being separate from the other of the top and bottom portion in at least a midfoot region ; and an upper ; wherein the top portion of the sole is attached to the upper , thereby allowing rotational freedom between the top and bottom portions of the sole in a peripheral location where the top and bottom portions are separated; wherein the top and bottom portions of the sole are separate from one another on both a lateral side and a medial side of the sole , and wherein the separation of the top and bottom portions of the sole on each of the lateral side and the medial side defines a lateral recess and a medial recess , characterized in that a lateral width of the lateral recess increases from a first lateral width at a forefoot region to a higher second lateral width at the midfoot region and decreases from the higher second lateral width to a third lateral width at a heel region , wherein the lateral width is defined as a distance generally perpendicular to a longitudinal axis of the sole from the periphery to a lateral attachment boundary spaced from the periphery in a particular location along a length of the sole and wherein the lateral attachment boundary is spaced from the periphery in the midfoot region , and in that a medial width of the medial recess increases from a first medial width at the forefoot region to a higher second medial width at the midfoot region and decreases from the higher second medial width to a third medial width at the heel region , wherein the medial width is defined as a distance generally perpendicular to the longitudinal axis of the sole from the periphery to a medial attachment boundary spaced from the periphery in a particular location along the length of the sole and wherein the medial attachment boundary is spaced from the periphery in the midfoot region . <EOS>