Articulated sole structure with sipes forming hexagonal sole elements

An article of footwear comprising:

• an upper;
• and
• a footwear sole structure attached to the upper comprising:
• a spanning portion extending longitudinally along a length of the footwear sole structure and transversely between medial and lateral sides of the footwear sole structure,
• an articulated portion located below the spanning portion, and
• a curved sipe extending sideward into a side of the footwear sole structure and extending continuously along the side of the footwear sole structure through at least a portion of a heel region, through a midfoot region, and through at least a portion of a forefoot region of the footwear sole structure;
• wherein the curved sipe permits the spanning portion to separate from the articulated portion in response to tension on the upper;
• and
• wherein the curved sipe forms opposing contoured surfaces in the footwear sole structure that abut against each other in response to twisting of the footwear sole structure and resist the twisting of the footwear sole structure.