Shoe sole and shoe including the same

Abstract

A shoe sole includes a cushion layer, an upper-side plate, and a lower-side plate. The cushion layer includes: a first region configured to support a metatarsophalangeal (MP) joint of a foot of a wearer; and a second region included in a portion located on a rear side with respect to the first region and located on a front side with respect to the rearfoot portion. The second region includes: a third region located in a central portion in a left-right direction; a fourth region located in a medial foot-side end portion in the left-right direction; and a fifth region located in a lateral foot-side end portion in the left-right direction. The fourth region and the fifth region are lower in compression rigidity than the first region, and the third region is lower in compression rigidity than the fourth region and the fifth region.

What is claimed is: 
     
         1 . A shoe sole including: a forefoot portion configured to support a toe portion and a ball portion of a foot of a wearer; a midfoot portion configured to support an arch portion of the foot of the wearer; and a rearfoot portion configured to support a heel portion of the foot of the wearer, the forefoot portion, the midfoot portion, and the rearfoot portion being connected in a front-rear direction corresponding to a foot length direction of the foot of the wearer, the shoe sole having: an upper-side surface configured as a supporting surface for supporting a bottom of the foot of the wearer; and a lower-side surface configured as a ground contact surface, the shoe sole comprising:
 a cushion layer located to extend in the forefoot portion, the midfoot portion, and the rearfoot portion;   an upper-side plate located close to the supporting surface with respect to the cushion layer to cover an upper-side surface of the cushion layer, the upper-side plate being located to extend in at least the forefoot portion and the midfoot portion; and   a lower-side plate located close to the ground contact surface with respect to the cushion layer to cover a lower-side surface of the cushion layer, the lower-side plate being located to extend in at least the forefoot portion and the midfoot portion, wherein   the cushion layer includes
 a first region configured to support a metatarsophalangeal (MP) joint of the foot of the wearer, and 
 a second region included in a portion located on a rear side with respect to the first region in the front-rear direction and located on a front side with respect to the rearfoot portion in the front-rear direction, 
   the second region includes
 a third region located in a central portion in a left-right direction corresponding to a foot width direction of the foot of the wearer, 
 a fourth region located in a medial foot-side end portion in the left-right direction, and 
 a fifth region located in a lateral foot-side end portion in the left-right direction, 
   the fourth region and the fifth region are lower in compression rigidity than the first region, and   the third region is lower in compression rigidity than the fourth region and the fifth region.   
     
     
         2 . The shoe sole according to  claim 1 , wherein
 the cushion layer includes
 a first cushion member disposed at least in a portion of the cushion layer to form the first region, the portion of the cushion layer being configured to support the MP joint of the foot of the wearer, and 
 a second cushion member disposed to at least extend in a portion included in the midfoot portion of the cushion layer and a portion included in the rearfoot portion of the cushion layer to form the second region, 
   the second cushion member has a shape bifurcating forward in the front-rear direction, the shape including
 a medial foot-side branch portion extending to the medial foot-side end portion on the front side with respect to the rearfoot portion in the front-rear direction, and 
 a lateral foot-side branch portion extending to the lateral foot-side end portion on the front side with respect to the rearfoot portion in the front-rear direction, 
   the fourth region is formed of the medial foot-side branch portion of the second cushion member,   the fifth region is formed of the lateral foot-side branch portion of the second cushion member, and   the third region is formed of a gap portion provided between the medial foot-side branch portion and the lateral foot-side branch portion in the second cushion member.   
     
     
         3 . The shoe sole according to  claim 2 , wherein
 the first cushion member is formed of a three-dimensional structure made of resin or rubber, the three-dimensional structure including a unit structure body having a three-dimensional shape formed by a wall having an outer shape defined by a pair of parallel flat or curved surfaces, the three-dimensional structure being formed of a plurality of the unit structure bodies repeatedly arranged to be adjacent to each other, and   the second cushion member is configured of a plate-shaped or block-shaped member formed of a foam material made of resin or rubber.   
     
     
         4 . The shoe sole according to  claim 3 , wherein the unit structure body is formed by adding a thickness to each of divided structure units obtained by dividing a structure unit into two structure units in one of orthogonal three-axis directions, the structure unit being formed of a plurality of flat surfaces disposed to intersect with each other so as to be hollow inside. 
     
     
         5 . The shoe sole according to  claim 4 , wherein the structure unit has one of a Kelvin structure, an octet structure, a cubic structure, and a cubic-octet structure. 
     
     
         6 . The shoe sole according to  claim 3 , wherein the unit structure body is formed by adding a thickness to each of divided structure units obtained by dividing a structure unit having a triply periodic minimal surface into two structure units in one of orthogonal three-axis directions. 
     
     
         7 . The shoe sole according to  claim 6 , wherein the structure unit has one of a Schwartz P structure, a gyroid structure, and a Schwartz D structure. 
     
     
         8 . The shoe sole according to  claim 1 , wherein
 a first rib extending along a medial foot-side edge portion of the shoe sole is provided in a portion included in a medial foot-side end portion of the midfoot portion on a lower-side surface of the lower-side plate, and   a second rib extending along a lateral foot-side edge portion of the shoe sole is provided in a portion included in a lateral foot-side end portion of the midfoot portion on the lower-side surface of the lower-side plate.   
     
     
         9 . The shoe sole according to  claim 8 , wherein each of the first rib and the second rib is formed by forming the lower-side plate to be locally thicker than other portions. 
     
     
         10 . The shoe sole according to  claim 1 , wherein at least one of a portion included in the forefoot portion of the upper-side plate and a portion included in the forefoot portion of the lower-side plate has a curved shape having a central portion bulging downward with respect to the medial foot-side end portion and the lateral foot-side end portion in the left-right direction. 
     
     
         11 . The shoe sole according to  claim 1 , wherein
 the lower-side plate is a spike plate provided with spikes, and   a lower-side surface of the lower-side plate forms the ground contact surface.   
     
     
         12 . A shoe comprising:
 the shoe sole according to  claim 1 ; and   an upper provided above the shoe sole.