Compressible structure secured to an upper of an article of footwear

Abstract

An article of footwear has an upper and a compressible structure secured to the upper. The compressible structure can include one or more materials with physical properties that singly or in vertical aggregate, generally conform to those of a spring, following Hooke's Law, F=−kx, whereby the ratio of k/kideal approaches a value of 1.0, wherein the ideal k value is defined as kideal=Fimpulsexs-max, for a compressible structure region located adjacent to the corresponding region of the foot that generates the force impulse.

1 .- 18 . (canceled) 
     
     
         19 . A running shoe tuned to a running speed of a runner wearing the shoe, the shoe consisting of (a) an upper that secures the foot to the shoe, and (b) a compressible sole structure under the upper that compresses in proportion to the amount of pressure applied during the gait cycle of the runner to no more than the limit of elasticity and decompresses when pressure is decreased and removed from the compressible sole structure during the ground contact phase of the gait cycle of the runner, the shoe characterized in that:
 i) the gait cycle of the runner to which the shoe is tuned consists of: first, a time when the shoe initially contacts the ground; second, a time during which gravity and the runner's leg muscles apply increasing force to the shoe; third, a time of maximum application of force to the shoe, fourth, a time of application of decreasing force to the shoe until the force applied to the shoe is zero but the shoe remains in contact with the ground; fifth, a time when the shoe is removed from contact with the ground; sixth, a time when the shoe is moved forward before again contacting the ground,   ii) the compressible sole layer compresses to no more than its limit of elasticity upon application of increasing force to the shoe during the initial stage of the stride,   iii) the compressible sole layer decompresses in response to decreasing force during the time after the maximum application of force to the shoe and until the shoe leaves the ground.   
     
     
         20 . The running shoe of  claim 19 , wherein the compressible sole layer decompresses substantially completely during the time after the maximum application of force to the shoe during the contact period of the runner and before the shoe leaves the ground during the gait cycle of the runner. 
     
     
         21 . The running shoe of  claim 19 , wherein the compressible sole layer decompresses at least 90% during the time from after the maximum application of force to the shoe during the contact period of the runner and before the shoe leaves the ground during the gait cycle of the runner. 
     
     
         22 . The running shoe of  claim 19 , wherein the compressible sole layer decompresses at least 50% during the time from after the maximum application of force to the shoe during the contact period of the runner and before the shoe leaves the ground during the gait cycle of the runner. 
     
     
         23 . The running shoe of  claim 19 , wherein the compressible sole layer consists of a plurality of regions, each region of the compressible sole layer below a corresponding region of the foot and tuned to the forces applied to that region of the compressible sole layer by the corresponding region of the foot. 
     
     
         24 . The running shoe of  claim 23 , wherein each of the plurality of regions of the compressible sole layer decompresses substantially completely during the time after the maximum application of force to that region of the compressible sole layer during the contact period of the runner and before the corresponding portion of the outer sole leaves the ground during the gait cycle of the runner. 
     
     
         25 . The running shoe of  claim 23 , wherein each of the plurality of regions of the compressible sole layer decompresses at least 90% during the time from the maximum application of force to that region of the compressible sole to the time when the shoe leaves the ground. 
     
     
         26 . The running shoe of  claim 23 , wherein each of the plurality of regions of the compressible sole layer decompresses at least 50% during the time from the maximum application of force to that region of the compressible sole to the time when the shoe leaves the ground. 
     
     
         27 . The running shoe of  claim 23 , wherein the regions of the foot consist of (a) the heel of the runner's foot, (b) the ball of the runner's foot, (c) the arch of the runner's foot, (d) the toes of the runner's foot. 
     
     
         28 . The running shoe of  claim 23 , wherein the regions of the foot consist of any subregion of the plantar surface of the runner's foot that may exert a differential force onto an adjacent subregion of the compressible layer. 
     
     
         29 . An article of footwear having an upper and a compressible structure secured to the upper, the compressible structure providing cushioning and energy return to the wearer by means of first compression of the compressible structure followed by expansion of the compressible structure. 
     
     
         30 . The article of footwear as in  claim 29 , wherein the cushioning and energy return are maximized for a running speed zone by tuning the ratio of k/k ideal  to approach a value of 1.0. 
     
     
         31 . The article of footwear as in  claim 29 , wherein the compressible structures are tuned to a progression of runner speeds and allow for distinct versions of the footwear differentiated by runner speed zone. 
     
     
         32 . The article of footwear as in  claim 31 , wherein the runner is matched to a particular footwear version according to the runner's intended running speed. 
     
     
         33 . The article of footwear as in  claim 31 , wherein the runner's intended running speed has a midpoint speed and a range of +/−0.3 m/s. 
     
     
         34 . The article of footwear as in  claim 31 , wherein the runner's intended running speed has a midpoint speed and a range of +/−1 m/s. 
     
     
         35 . The article of footwear as in  claim 31 , wherein the runner's intended running speed has a midpoint speed and a range of +/−2 m/s. 
     
     
         36 . The running shoe of  claim 19 , further comprising a midsole element formed from polyurethane or ethylvinylacetate. 
     
     
         37 . The article of footwear as in  claim 31 , further comprising a midsole element including at least one of (a) a plate formed from a semi-rigid polymer material, (b) a combination of a plate and foam material, or (c) a plurality of foam-based and semi-rigid structures.