Shoe Sole Having Diagonal Groove

Abstract

A shoe sole including: an outsole having a tread surface to be in contact with a road surface; and a midsole arranged on the outsole, wherein: the midsole is exposed in a central section of a rear foot section and an arch section; in the central section and a lateral side section of the rear foot section of the shoe sole, a diagonal groove is formed extending in a diagonal front-rear direction in the rear foot section to an outer edge of a lateral side of the rear foot section; an angle β, formed between a virtual center line of the diagonal groove and a longitudinal axis connecting between a center of a heel and a middle point between a big-toe ball and a little-toe ball, is set in a range of 12° to 35°; and a virtual intersection point between the longitudinal axis and the center line is set within a range of 21% to 43% of a full length of the longitudinal axis of the shoe sole from a posterior end of the shoe sole, the diagonal groove extending to a point anterior and medial to the intersection point.

Description

TECHNICAL FIELD[0001]The present invention relates to a shoe sole having a diagonal groove.BACKGROUND ART[0002]Shoe soles having a diagonal groove are known in the art. (the first patent document)CITATION LISTPatent Literature[0003]First Patent Document: JP 2008-620 A (FIG. 4, FIG. 10(b))[0004]Second Patent Document: JP H07-236503 ASUMMARY OF INVENTION[0005]As is well known in the art, a shoe sole is required to be light in weight, be capable of suppressing eversion of the heel area, and serve to absorb the impact on the heel area.[0006]However, these functions cannot be realized sufficiently only by forming a diagonal groove in a shoe sole.[0007]It is therefore an object of the present invention to form an appropriate diagonal groove so as to realize these functions.[0008]The present invention in one aspect is a shoe sole including:[0009]an outsole 1 having a tread surface to be in contact with a road surface; and a midsole 2 arranged on the outsole 1, wherein:[0010]in a central se...

AI Technical Summary

Benefits of technology

[0019]Eversion of the heel area occurs as the foot is rotated (twisted) about the subtalar joint axis A1. The subtalar joint axis A1 is diagonally inclined, in the horizontal plane, with respect to the anatomical longitudinal axis A2 of the foot section. According to V. T Inman (1969), the inclination angle is 23° on average, and varies over a range of about ±11° due to individual differences. Therefore, for suppressing eversion of the heel area, it is important to keep the torsional rigidity of the sole so as to reduce the rotation about the subtalar joint axis A1, which is inclined by 23°±11°.

[0030]Since the outsole 1 has a U shape in which the central section Rc of the rear foot section R is cut out, the weight is reduced also because of the cutting out of the central section Rc. Now, the diagonal groove 4 is formed in the midsole 2 in the central section Rc. This also reduces the weight of the midsole 2 while the midsole 2 still contributes to the torsional rigidity.

Problems solved by technology

However, these functions cannot be realized sufficiently only by forming a diagonal groove in a shoe sole.

Images