Sole for a shoe, in particular for a running shoe

Abstract

A shoe sole includes a midsole and an outsole having discrete outsole elements. The midsole has on the side facing the outsole a multiple of flex grooves crossing each other and creating pads in the midsole. A curved forefoot flex groove emanates from the medial side of the arc and essentially follows a path over one or more of the cuneiform bones and continues between the third and fourth metatarsal phalanges, over the third proximal phalange and continues between the first and second metatarsal phalanges in a direction towards the heel. Both the outsole elements and the pads are arranged to follow an essentially spiral curve around the curved forefoot flex groove. The sole reduces the risk of injury during running, and gives the foot increased compensation possibilities for correcting imbalances especially after heel strike.

1 .- 14 . (canceled) 
     
     
         15 . A sole for a running shoe for a foot of a wearer having cuneiform bones and a plurality of metatarsal phalanges, the sole comprising:
 a midsole having a heel portion, an arch portion, and a forefoot portion, the midsole having:
 a foot facing surface, and 
 an outsole facing surface including:
 a plurality of flex grooves that extend into a material of the midsole, the plurality of flex grooves crossing each other and creating a plurality of discrete pads in the midsole, such that each pad is separated from other pads by at least one flex groove, and 
 a curved forefoot flex groove extending into the material of the midsole in a direction towards the foot facing surface, the curved forefoot flex groove having a first terminal end on a medial side of the arch portion and being oriented such that, when the wearer is wearing a shoe with the sole, the curved forefoot flex groove follows an uninterrupted path towards the forefoot portion over one or more of the cuneiform bones and continuing between a third metatarsal phalange and a fourth metatarsal phalange of the wearer, thereby providing an increased flexibility in the forefoot portion of the shoe, and the curved forefoot flex groove being further oriented to continue towards a second terminal end in the forefoot portion; and 
 
   an outsole including a plurality of discrete outsole elements separated from each other by at least one flex groove,   wherein the plurality of discrete pads in the midsole and the plurality of discrete outsole elements are arranged to follow a spiral curve and arranged to be adjacent to the curved forefoot flex groove.   
     
     
         16 . The sole according to  claim 15 , wherein the curved forefoot flex groove is continued from a start of proximal phalanges over a third proximal phalange and is continued between a first metatarsal phalange and a second metatarsal phalange in a direction towards the heel portion. 
     
     
         17 . The sole according to  claim 16 , wherein the curved forefoot flex groove has a straight portion in the arch portion and runs parallel to a straight reinforcement bar in the midsole. 
     
     
         18 . The sole according to  claim 16 , wherein the heel portion of the midsole has a curved heel flex groove emanating from a medial side of the heel and stretching to a lateral side of the heel portion. 
     
     
         19 . The sole according to  claim 18 , wherein the plurality of discrete outsole elements are directly attached to respective midsole pads. 
     
     
         20 . The sole according to  claim 18 , wherein the curved heel flex groove is between 1.5 and 3 times wider than the plurality of flex grooves, respectively. 
     
     
         21 . The sole according to  claim 18 , wherein the curved heel flex groove has a depth of more than 50 percent of a thickness of the heel portion. 
     
     
         22 . The sole according to  claim 15 , wherein the forefoot portion of the midsole in a transverse direction from a medial side thereof towards a lateral side thereof includes at least a first additional flex groove following a path along the joints between the plurality of metatarsal phalanges and a plurality of proximal phalanges and crossing the curved forefoot flex groove. 
     
     
         23 . The sole according to  claim 22 , wherein the forefoot portion of the midsole includes a second additional flex groove which follows a path along joints between the plurality of proximal phalanges and a plurality of medial phalanges, respectively. 
     
     
         24 . The sole according to  claim 15 , wherein the curved forefoot flex groove runs in a longitudinal direction from the medial side of the arch portion to an apex point in a metatarsal zone of the foot. 
     
     
         25 . The sole according to  claim 21 , wherein the curved forefoot flex groove continues in an opposite direction from the apex point in a direction facing the heel portion of the midsole. 
     
     
         26 . The sole according to  claim 15 , wherein the midsole is injection-molded and bonded on the foot facing surface with an upper and on the outsole facing surface with the plurality of discrete outsole elements. 
     
     
         27 . The sole according to  claim 15 , wherein a shank is placed in or on the midsole, which shank extends in a longitudinal direction into a medial forefoot region and/or a lateral forefoot region. 
     
     
         28 . The sole according to  claim 15 , wherein an intermediate flexible layer of thermoplastic polyurethane (TPU) is placed between the plurality of discrete outsole elements and the midsole, the intermediate flexible layer being between 0.5 and 2 millimeters thick and following a shape of the plurality of flex grooves and the plurality of discrete pads of the midsole. 
     
     
         29 . The sole according to  claim 15 , wherein the plurality of discrete pads of the midsole have a larger surface area than the plurality of discrete outsole elements. 
     
     
         30 . The sole according to  claim 15 , wherein the curved forefoot flex groove has a width corresponding to between one and two times a distance between the third metatarsal phalange and the fourth metatarsal phalange.