REACTIVE SHOE
This invention relates generally to footwear and methods for making the same, and more particularly to an athletic shoe with a reactive midsole. In one aspect of the invention, the midsole provides a continuously increasing offset between a heel center of pressure and a ball-of-foot center of pressure between the loading and a toe off gait phases.
1 . An article of footwear comprising:
an upper attachable to a foot of a user; and
a midsole connected to the upper comprising a first portion proximate a heel of the foot and a second portion proximate a ball-of-foot of the foot, the heel of the foot having a heel center of pressure imparted to the first portion and defining a first distance between the heel center of pressure and the ground, and a ball-of-foot center of pressure imparted to the second portion and defining a second distance between the ball-of-foot center of pressure and the ground, wherein a distance offset of the first distance minus the second distance is increased between a loading gait phase and a toe off gait phase.
2 . The article of footwear of claim 1 , wherein the first portion is generally of constant thickness and the second portion is generally of decreasing thickness along a longitudinal axis of the midsole from the heel to the ball-of-foot.
3 . The article of footwear of claim 2 , wherein the first portion is 30-50% of a total distance of the longitudinal axis of the midsole.
4 . The article of footwear of claim 3 , wherein the first portion is interconnected to the second portion.
5 . The article of footwear of claim 2 , wherein the decreasing thickness generally forms a French curve.
6 . The article of footwear of claim 1 , wherein the distance offset is always positive between the loading gait phase and the toe off gait phase.
7 . The article of footwear of claim 1 , wherein the distance offset at the toe off gait phase is at least 40 mm.
8 . The article of footwear of claim 1 , wherein the distance offset of the first distance minus the second distance is continuously increased between the loading gait phase and the toe off gait phase.
9 . The article of footwear of claim 1 , wherein a foot center of pressure imparted to the midsole continuously increases between the loading gait phase and the toe off gait phase.
10 . A method of manufacturing an article of footwear comprising:
forming an upper attachable to a foot of a user; and
forming a midsole connected to the upper comprising a first portion proximate a heel of the foot and a second portion proximate a ball-of-foot of the foot, the heel of the foot having a heel center of pressure imparted to the first portion and defining a first distance between the heel center of pressure and the ground, and a ball-of-foot center of pressure imparted to the second portion and defining a second distance between the ball-of-foot center of pressure and the ground, wherein a distance offset of the first distance minus the second distance is increased between a loading gait phase and a toe off gait phase.
11 . The method of claim 10 , wherein the first portion is generally of constant thickness and the second portion is generally of decreasing thickness along a longitudinal axis of the midsole from the heel to the ball-of-foot.
12 . The method of claim 10 , wherein the first portion is 30-50% of a total distance of the longitudinal axis of the midsole and the first portion is interconnected to the second portion.
13 . The method of claim 10 , wherein the distance offset is always positive between the loading gait phase and the toe off gait phase.
14 . The method of claim 10 , wherein the distance offset at the toe off gait phase is at least 40 mm.
15 . The method of claim 10 , wherein the distance offset of the first distance minus the second distance is continuously increased between the loading gait phase and the toe off gait phase.
16 . The method of claim 10 , wherein a foot center of pressure imparted to the midsole continuously increases between the loading gait phase and the toe off gait phase.
17 . The method of claim 10 , wherein the midsole is manufactured using injection molding.
18 . An athletic shoe, comprising:
an upper attachable to a foot of a user; and
a midsole connected to the upper comprising a first portion generally of constant thickness proximate a heel of the foot and a second portion generally of decreasing thickness along a longitudinal axis of the midsole from the heel to the ball-of-foot and proximate a ball-of-foot of the foot, the first portion 30-50% of a total distance of the longitudinal axis of the midsole and interconnected to the second portion, the heel of the foot having a heel center of pressure imparted to the first portion and defining a first distance between the heel center of pressure and the ground, and a ball-of-foot center of pressure imparted to the second portion and defining a second distance between the ball-of-foot center of pressure and the ground, wherein a distance offset of the first distance minus the second distance is continuously increased between a loading gait phase and a toe off gait phase and is always positive between the loading gait phase and the toe off gait phase.
19 . The article of footwear of claim 18 , wherein a foot center of pressure imparted to the midsole continuously increases between the loading gait phase and the toe off gait phase.
20 . The article of footwear of claim 18 , wherein the distance offset at the toe off gait phase is at least 40 mm.
21 . An article of footwear comprising:
an upper attachable to a foot of a user;
a midsole connected to the upper comprising a first portion proximate a heel of the foot and a second portion proximate a ball-of-foot of the foot; and
an outsole connected to the midsole comprising a central portion, a medial portion and a lateral portion, the medial portion and the lateral portion forming a substantially non-smooth surface, the central portion forming a substantially smooth surface with a curvilinear edge.
22 . The article of footwear of claim 21 , wherein the heel of the foot having a heel center of pressure imparted to the first portion and defining a first distance between the heel center of pressure and the ground, and a ball-of-foot center of pressure imparted to the second portion and defining a second distance between the ball-of-foot center of pressure and the ground, wherein a distance offset of the first distance minus the second distance is increased between a loading gait phase and a toe off gait phase.
23 . The article of footwear of claim 21 , wherein the central portion is of a first material and the medial and lateral portions are of a second material.
24 . The article of footwear of claim 21 , wherein the central portion extends over and is integral to at least one of a toe portion and a heel portion of the article of footwear.