NIKE, Inc.
Footwear with reactive layers

Abstract:

An article of footwear includes an upper defining an opening for receiving a foot of a wearer and a sole structure affixed to an under side of the upper. The upper has a throat opening provided between a medial side of the upper and a lateral side, and further includes a forward portion for receiving a forefoot of the foot, a rearward portion for receiving a heel of the foot, and an intermediate portion between the forward portion and the rearward portion. The intermediate portion comprises a reactive material extending between the sole structure and the throat opening on both the medial side and on the lateral side of the upper. The reactive material has a negative Poisson's ratio and is bounded on either side by materials that have a positive Poisson's ratio.