WO2009069926A1

WO2009069926A1 - A midsoles for masai walking footwear

Info

Publication number: WO2009069926A1
Application number: PCT/KR2008/006940
Authority: WO
Inventors: Ki Tae Kim
Original assignee: Ryn Korea. Co., Ltd.
Priority date: 2007-11-26
Filing date: 2008-11-25
Publication date: 2009-06-04

Abstract

Masai walking footwear having a sensor disposed therein. The Masai walking footwear includes a midsole having a downwardly convex and circular arcuate shape going from a front edge to a rear edge, with a sensor area defined in a rear bottom portion thereof, a sensor provided on a bottom portion of the midsole including the sensor area, and having a convex and arcuate shape going from a front edge a rear edge, a shank provided inside the midsole, and having a plate-like shape that resembles a contour or a curved shape of a footwear sole, an insole attached to a top portion of the midsole, and an outsole attached to the bottom portion of the midsole in which the sensor is provided, and having a convex and circular arcuate shape going from a front edge to a rear edge.

Description

A MIDSOLES FOR MASAI WALKING FOOTWEAR

Technical Field

[1] The present invention relates to Masai walking footwear, and more particularly, to

Masai walking footwear having a sensor disposed therein. Background Art

[2] More and more modern people are developing obesity problems owing to an irregular diet, increased intake of fast food and insufficient exercise. This phenomenon is gradually spreading throughout the world, thereby becoming a cause of a variety of cancers and adult diseases.

[3] In order to solve this obesity problem, a balanced diet and regular exercise are necessary. While exercising to reduce fatness requires a great amount of time, many modern people have little time to steadily and regularly exercise due to leading busy lives.

[4] Recently, many people are seeking measures that can increase the effects of exercise without devoting time specifically to exercise. As one of the measures, functional footwear capable of providing the effects of exercise to a user when the user simply walks wearing the shoes is gaining attention.

[5] Various types of functional footwear capable of providing effects to a user when the user simply walks wearing the shoes are currently distributed in the market. These types of shoes are generally referred to as Masai Barefoot Technology (MBT) footwear or Masai walking footwear. Such a type of Masai walking footwear consists of an upper and a sole, which includes an insole, a midsole and an outsole. Inside the midsole, provided is a high elasticity shank. The shank acts to efficiently restore the original shape of the sole, which is frequently deformed by bending and stretching while walking, and to improve the safety of the walking.

[6] The Masai walking footwear has a downwardly convex and circular arcuate shape and no heel. Here, walking is carried out by repeating a three-phase process on the ground, which includes a heel contact phase, a heel-to-toe center-of-mass movement phase and a taking-off phase, in which the toe pushes against the ground and comes up off the ground.

[7] When a person wearing the Masai walking footwear walks according to the three- phase process, a sharp impact is not transferred to ankles or joints of the body or legs, and the wearer can feel good when striking the ground and can easily and smoothly walk. Furthermore, the Masai walking footwear can prevent diseases of the musculoskeletal system and maintain a correct spinal posture of a reverse S-shape by supporting the waist. In this manner, the Masai walking footwear can correct the improper gait of modern people. Disclosure of Invention

Technical Problem

[8] Due to the shank provided inside the midsole, the conventional Masai walking footwear can restore the original shape of the sole, which is frequently deformed by bending and stretching while walking, as well as promoting comfortable walking by adding a restoring force to the taking-off phase of walking.

[9] However, since the conventional shank is designed to move forwards and backwards, it may be a cause of preventing the midsole from smoothly moving through the heel contact, center-of-mass movement and taking-off phases in the three-phase walking process. In addition, the three-phase walking process may feel unnatural since the midsole may create a bouncing feeling.

[10] Accordingly, the present invention provides Masai walking footwear having a shank that can ensure easy and smooth three-phase walking consisting of heel contact, center- of-mass movement and taking-off phases without any bouncing feeling being imparted by the midsole. Technical Solution

[11] The inventors have found that Masai walking footwear, capable of achieving stable three-phase walking without a bouncing feeling, preventing decomposition by water and raising the effects of walking, can be provided by installing a connecting plate type shank or a spring type shank inside a midsole, providing a sensor on a bottom portion of the midsole, and providing side pads on both side surfaces of the sensor or a cap to cover the rear part of the sensor, and thereby completed the present invention based on these findings. Brief Description of Drawings

[12] FIG. 1 is a cross-sectional view illustrating Masai walking footwear having a sensor disposed therein according to a first embodiment of the present invention;

[13] FIG. 2 is a perspective view illustrating the Masai walking footwear having a sensor disposed therein according to the first embodiment of the present invention;

[14] FIGS. 3 through 7 are views illustrating the Masai walking footwear having a sensor disposed therein according to the first embodiment of the present invention;

[15] FIG. 8 is a cross-sectional view illustrating Masai walking footwear having a sensor disposed therein according to a second embodiment of the present invention;

[16] FIG. 9 is a perspective view illustrating the Masai walking footwear having a sensor disposed therein according to the second embodiment of the present invention; and

[17] FIGS. 10 through 14 are views illustrating the Masai walking footwear having a sensor disposed therein according to the second embodiment of the present invention. Best Mode for Carrying out the Invention

[18] The present invention provides Masai walking footwear including a midsole, an insole and an outsole. Mode for the Invention

[19] The present invention relates to Masai walking footwear, which includes a soft sensor having a convex and arcuate shape from the front edge to the rear edge, wherein the soft sensor is provided on the bottom portion of a midsole. Specifically, the sensor is provided in a sensor area defined in the rear bottom portion of the midsole, which has a downwardly convex and circular arcuate shape going from the front edge to the rear edge.

[20] The present invention also provides Masai walking footwear, which includes side pads attached to both side surfaces of the sensor. Preferably, the side pads can be attached to all the side surfaces of the sensor having a convex and arcuate shape from the front edge to the rear edge or be selectively attached to both side surface portions of the sensor occupied in the sensor area.

[21] In addition, the present invention also provides Masai walking footwear, which includes a cap covering the rear part of the sensor. The cap can be open at one side, the size thereof corresponding to that of the sensor.

[22] Furthermore, the present invention also provides Masai walking footwear, which has a connecting plate type shank or a spring type shank. The connecting plate type shank may include a front shank, a rear shank and a connecting shank connecting the front and rear shanks with each other. The spring type shank may include a front shank, a rear shank and at least one spring connecting the front and rear shanks with each other.

[23] Hereinafter, the present invention is described more fully with reference to the accompanying drawings, in which exemplary embodiments thereof are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[24] FIG. 1 is a cross-sectional view illustrating Masai walking footwear having a sensor disposed therein according to a first embodiment of the present invention, and FIG. 2 is a perspective view illustrating the Masai walking footwear having a sensor disposed therein.

[25] As shown in the drawings, the Masai walking footwear 400 includes a midsole 440, which has a downwardly convex and circular arcuate shape going from the front edge to the rear edge so as to realize the heel contact of a Masai walking method. In the rear bottom portion of the midsole 440, provided is a sensor area. The Masai walking footwear 400 also includes a sensor 450, which has a convex and arcuate shape from the front edge to the rear edge including the sensor area, and side pads (not shown) attached to both side surfaces of the sensor. A shank is provided inside the midsole, in the form of a plate or board that resembles the contour and curved shape of the footwear sole. An insole 420 is attached to the top portion of the midsole, and an outsole 460 having a convex and circular arcuate shape going from the front edge to the rear edge is attached to the bottom portion of the midsole 440.

[26] Referring to FIGS. 3 through 7, details of the Masai walking footwear according to the first embodiment of the present invention will be described in detail.

[27] FIG. 3 is a representation of the midsole of the present invention. The midsole 440 has a downwardly convex and circular arcuate shape going from the front edge to the rear edge, with the angle of inclination of the heel ranging from 25 to 45 degrees, so as to realize the heel contact of a Masai walking method. The sensor area is provided in the rear bottom portion of the midsole 440. The midsole is made of polyester or polyurethane, with the hardness thereof ranging from 40 to 60.

[28] If the hardness of the midsole does not exceed 40, the midsole is too soft to properly act as a support. In contrast, if the hardness of the midsole is the same as or greater than 60, the midsole is too hard to properly act as an elastic body.

[29] FIG. 4 is a representation of the midsole and the sensor attached to the bottom portion of the midsole. The sensor 450 extends from the rear part including the sensor area through the middle part to the forward part of the midsole, and is tapered with a thickness decreasing towards the forward part. The sensor 450 is made of soft polyester sponge or soft polyurethane sponge, with the hardness thereof ranging from 15 to 30.

[30] If the hardness of the sensor does not exceed 15, the sensor is too soft to properly act as a support. In contrast, if the hardness of the sensor is the same as or greater than 30, the sensor is too hard to properly act as an elastic body.

[31] The sensor 450 is attached to the bottom portion of the midsole 440 to increase elasticity and restoring force.

[32] FIG. 5 is a representation of the sensor 450 and the side pads 451 attached to both sides of the sensor 450. The side pads 450 may be attached to all side surfaces of the sensor, and have a shape the same as the side elevation shape of the sensor. Alternatively, the side pads 450 may be attached to both side surface areas of the sensor which are in the sensor area.

[33] FIG. 5 (a) illustrates the side pads attached to both the side surface areas of the sensor which are in the sensor area, and FIG. 5 (b) illustrates the side pads attached to all the side surfaces of the sensor with a shape the same as the side elevation shape of the sensor.

[34] The side pads 451 are made up of one material selected from the group consisting of a polyol coating layer, a polyol fabric combined layer, a polyester pad and a polyurethane pad, with the hardness thereof ranging from 40 to 60. The side pads prevent the sensor 450 from being decomposed by water.

[35] FIG. 6 is a representation of the shank 430 provided inside the midsole 440. The shank 430 is provided in the shape of a plate or board that resembles the contour and curved shape of the footwear sole.

[36] Specifically, referring to FIG. 6 (a), the shank 430 can be preferably made of synthetic resin in the shape of a plate or board that resembles the contour and curved shape of the footwear sole. However, these are not intended to limit the present invention, but the shank 430 can be made of materials of any shape. In more detail, a plurality of slits 431 extend from predetermined points to the leading edge of a forward part of the shank, which has a relatively large bending angle in walking. The slits 431 divide the forward part into a plurality of portions such that the toe part can easily bend. Bead-shaped ribs 432 are formed in a waist part, extending in the longitudinal direction, to reinforce the waist part, and a plurality of through-holes 433 are formed to facilitate the flowing of molding resin in the manufacturing of the midsole.

[37] Referring to FIG. 6 (b), the shank 430 includes a front shank 430a, which has a plurality of slits 431 extending from predetermined points to the leading edge of a forward part and a plurality of through-holes 433 formed on both sides of the slits 431, a rear shank 430b and a connecting plate 430c connecting the front and rear shanks 430a and 430b with each other. The shank 430 can be of a unitary structure in which the front and rear shanks 430a and 430b are integrally connected with each other by the connecting plate 430c, or a separate structure in which the front shank can be connected with the rear shank using fixing members 433c. The connecting plate 430c is made of a material the hardness of which is smaller than that of the front and rear shanks 430a and 430b. Preferably, the connecting plate 430c is made of a thin flexible metal sheet or flexible thin synthetic resin.

[38] Referring to FIG. 6 (c), the shank 430 includes a front shank 430a, a rear shank 430b and at least one spring 434 connecting the front and rear shanks 430a and 430b with each other. In other words, the shank can be configured using the spring 434 in place of the above-described connecting plate. Preferably, in this case where the front and rear shanks are connected with each other using the spring 434, the front shank 430a has a plurality of front spring hooks 434a attached to the rear edge thereof, and the rear shank 430b has a plurality of rear spring hooks 434b attached to the front edge thereof. The front and rear shanks 430a and 430b are made of polyvinyl chloride. Preferably, the spring 434 can be covered with a sheath 435.

[39] With the shank 430 provided inside the midsole according to the present invention, the rolling movement of Masai walking can be naturally coordinated. The front and rear shanks bend in the vertical direction with respect to the connecting plate, which in turn acts as an elastic body during walking. Owing to the elastic function of the connecting plate, the rolling of Masai walking is carried out easily and smoothly.

[40] In addition, the shank 430 ensures easy and smooth elastic rolling from the heel to the toe without a bouncy feeling coming from the sole and perfectly maintains the original shape of the sole and the footwear.

[41] FIG. 7 is a representation of the insole and the outsole. The insole 420 is attached to the top portion of the midsole and is made of nonwoven cloth the hardness of which ranges from 25 to 30.

[42] If the hardness of the insole does not exceed 25, the insole is too soft to properly act as a support. In contrast, if the hardness of the insole is the same as or greater than 30, the insole is too hard to properly act as an elastic body.

[43] The outsole is attached to the bottom portion of sensor, which is provided on the bottom portion of the midsole, and has as a characterizing feature a convex and circular arcuate shape going from the front edge to the rear edge. The outsole 460 is made of polyester or polyurethane, with the hardness thereof ranging from 70 to 80.

[44] If the hardness of the outsole does not exceed 70, the outsole is too soft to properly act as a support. In contrast, if the hardness of the outsole is the same as or greater than 80, the outsole is too hard to properly act as an elastic body.

[45] The outsole 460 has an inclined and curved arcuate shape, with the main angle of inclination of the heel with respect to the ground ranging from 25 to 45 degrees. If the main angle of inclination does not exceed 25 degrees, the rolling movement of the Masai walking footwear is not possible. In contrast, if the main angle of inclination is the same as or greater than 45 degrees, the inclination is too steep for a user to adopt a stable posture when wearing or standing in the footwear.

[46] FIG. 8 is a cross-sectional view illustrating Masai walking footwear having a sensor disposed therein according to a second embodiment of the present invention, and FIG. 9 is a perspective view illustrating the Masai walking footwear having a sensor disposed therein.

[47] As shown in the drawings, the Masai walking footwear 600 includes a midsole 640, which has a downwardly convex and circular arcuate shape going from the front edge to the rear edge so as to realize the heel contact of a Masai walking method. In the rear bottom portion of the midsole 640, provided is a sensor area. The Masai walking footwear 600 also includes a sensor 650, which has a convex and arcuate shape going from the front edge to the rear edge including the sensor area, and a cap (not shown) covering the rear part of the sensor. A shank is provided inside the midsole, in the form of a plate or board that resembles the contour and curved shape of the footwear sole. An insole 620 is attached to the top portion of the midsole, and an outsole 660 having a convex and circular arcuate shape going from the front edge to the rear edge is attached to the bottom portion of the midsole 640.

[48] Referring to FIGS. 10 through 14, details of the Masai walking footwear according to the second embodiment of the present invention will be described in detail.

[49] FIG. 10 is a representation of the midsole of the present invention. The midsole 640 has a downwardly convex and circular arcuate shape from the front edge to the rear edge, with the angle of inclination of the heel ranging from 25 to 45 degrees, so as to realize the heal contact of a Masai walking method. The sensor area is provided in the rear bottom portion of the midsole 640. The midsole is made of polyester or polyurethane, with the hardness thereof ranging from 40 to 60.

[50] If the hardness of the midsole does not exceed 40, the midsole is too soft to properly act as a support. In contrast, if the hardness of the midsole is the same as or greater than 60, the midsole is too hard to properly act as an elastic body.

[51] FIG. 11 is a representation of the midsole and the sensor attached to the bottom portion of the midsole. The sensor 650 extends from the rear part including the sensor area through the middle part to the forward part of the midsole, and is tapered with a thickness decreasing towards the forward part. The sensor 650 is made of soft polyester sponge or soft polyurethane sponge, with the hardness thereof ranging from 15 to 30.

[52] If the hardness of the sensor does not exceed 15, the sensor is too soft to properly act as a support. In contrast, if the hardness of the sensor is the same as or greater than 30, the sensor is too hard to properly act as an elastic body.

[53] The sensor 650 is attached to the bottom portion of the midsole 640 to increase elasticity and restoring force.

[54] FIG. 12 is a representation of the cap attached to the sensor. The cap 651 is shaped to surround the rear part of the sensor 650. FIG. 12 (a) shows the state in which the sensor 650 and the cap 651 are separated from each other, and FIG. 12 (b) shows the state in which the cap 651 is attached to the sensor 650. Preferably, the cap 651 is open at one side, the size thereof corresponding to that of the sensor.

[55] The cap 651 is made up of one material selected from the group consisting of a polyol coating layer, a polyol fabric combined layer, a polyester pad and a polyurethane pad, with the hardness thereof ranging from 40 to 60. The cap 651 prevents the sensor 650 from being decomposed by water.

[56] FIG. 13 is a representation of the shank 630 provided inside the midsole 640. The shank 630 is provided in the shape of a plate or board that resembles the contour and curved shape of the footwear sole.

[57] Specifically, referring to FIG. 13 (a), the shank 630 includes a front shank 630a, which has a plurality of slits 631 extending from predetermined points to the leading edge of a forward part and a plurality of through-holes 633 formed on both sides of the slits 631, a rear shank 830b and a connecting plate 630c connecting the front and rear shanks 630a and 630b with each other. The shank 630 can be of a unitary structure in which the front and rear shanks 630a and 630b are integrally connected with each other by the connecting plate 630c, or a separate structure in which the front shank 630a can be connected with the rear shank 630b using fixing members 633c. The connecting plate 630c is made of a material the hardness of which is smaller than that of the front and rear shanks 630a and 630b. Preferably, the connecting plate 630c is made of a thin flexible metal sheet or flexible thin synthetic resin.

[58] Referring to FIG. 13 (b), the shank 630 includes a front shank 630a, a rear shank

630b and at least one spring 634 connecting the front and rear shanks 630a and 630b with each other. In other words, the shank can be configured using the spring 634 in place of the above-described connecting plate to connect the front and rear shanks 630a and 630b with each other. Preferably, in the case where the front and rear shanks are connected with each other using the spring 634, the front shank 630a has a plurality of front spring hooks 634a attached to the rear edge thereof, and the rear shank 630b has a plurality of rear spring hooks 634b attached to the front edge thereof. The front and rear shanks 630a and 630b are made of polyvinyl chloride. Preferably, the spring 634 can be covered with a sheath 635.

[59] Referring to FIG. 13 (c), the shank 630 includes a plurality of slits 631 extending from predetermined points to the leading edge of a forward part of the shank, so as to divide the forward part into a plurality of portions such that the toe part can easily bend, bead-shaped ribs 632 formed in a waist part extend in the longitudinal direction so as to reinforce the waist part, and a plurality of through-holes 633 that facilitate the flowing of molding resin in the manufacturing of the midsole.

[60] FIG. 14 is a representation of the insole and the outsole. The insole 620 is attached to the top portion of the midsole 640 and is made of nonwoven cloth the hardness of which ranges from 25 to 30.

[61] If the hardness of the insole does not exceed 25, the insole is too soft to properly act as a support. In contrast, if the hardness of the insole is the same as or greater than 30, the insole is too hard to properly act as an elastic body.

[62] The outsole is attached to the bottom portion of the sensor, which is provided on the bottom portion of the midsole 640, and has as a characterizing feature a convex and circular arcuate shape going from the front edge to the rear edge. The outsole 660 is made of polyester or polyurethane, with the hardness thereof ranging from 70 to 80.

[63] If the hardness of the outsole does not exceed 70, the outsole is too soft to properly act as a support. In contrast, if the hardness of the outsole is the same as or greater than 80, the outsole is too hard to properly act as an elastic body. [64] The outsole 660 has an inclined and curved arcuate shape, with the main angle of inclination of the heel with respect to the ground ranging from 25 to 45 degrees. If the main angle of inclination does not exceed 25 degrees, the rolling movement of the Masai walking footwear is not possible. In contrast, if the main angle of inclination is the same as or greater than 45 degrees, the inclination is too steep for a user to adopt a stable posture when wearing or standing in the footwear. Industrial Applicability

[65] The Masai walking footwear of the present invention can improve elasticity and restoring force and prevent decomposition by water thereof and can be applied to the development of Masai walking footwear of excellent functionality.

Claims

[I] A Masai walking footwear comprising: a midsole having a downwardly convex and circular arcuate shape going from a front edge to a rear edge, with a sensor area defined in a rear bottom portion thereof; a sensor provided on a bottom portion of the midsole including the sensor area, and having a convex and arcuate shape going from a front edge a rear edge; a shank provided inside the midsole, and having a plate-like shape that resembles a contour or a curved shape of a footwear sole; an insole attached to a top portion of the midsole; and an outsole attached to the bottom portion of the midsole in which the sensor is provided, and having a convex and circular arcuate shape going from a front edge to a rear edge. [2] The Masai walking footwear according to claim 1, wherein the midsole has a convex curved arcuate shape, with an angle of inclination of a heel ranging from

25 to 45 degrees. [3] The Masai walking footwear according to claim 1, wherein the midsole is made of polyester or polyurethane. [4] The Masai walking footwear according to claim 1, wherein the midsole has a hardness ranging from 40 to 60. [5] The Masai walking footwear according to claim 1, wherein the sensor is made of soft polyester sponge or soft polyurethane sponge. [6] The Masai walking footwear according to claim 1, wherein the sensor has a hardness ranging from 15 to 30. [7] The Masai walking footwear according to claim 1, further comprising side pads attached to both side surfaces of the sensor.

[8] The Masai walking footwear according to claim 1, wherein the side pads are selectively attached to both side surface portions of the sensor which is in the sensor area. [9] The Masai walking footwear according to claim 7 or 8, wherein the side pads are made of polyester or polyurethane. [10] The Masai walking footwear according to claim 7 or 8, wherein the side pads have a hardness ranging from 40 to 60.

[I I] The Masai walking footwear according to claim 1, wherein the shank includes a front shank, a rear shank and a connecting plate connecting the front and rear shanks with each other.

[12] The Masai walking footwear according to claim 1, wherein the shank includes a front shank, a rear shank and at least one spring connecting the front and rear shanks with each other. [13] The Masai walking footwear according to claim 11 or 12, wherein the front and rear shanks are made of polyvinyl chloride. [14] The Masai walking footwear according to claim 11, wherein the connecting plate of the shank is made of a thin flexible metal sheet or flexible thin synthetic resin. [15] The Masai walking footwear according to claim 12, wherein the spring of the shank is covered with a sheath. [16] The Masai walking footwear according to claim 1, wherein the insole is made of nonwoven cloth. [17] The Masai walking footwear according to claim 1, wherein the insole has a hardness ranging from 25 to 30. [18] The Masai walking footwear according to claim 1, wherein the outsole is made of polyester or polyurethane. [19] The Masai walking footwear according to claim 1, wherein the outsole has a hardness ranging from 70 to 80. [20] A Masai walking footwear comprising: a midsole having a downwardly convex and circular arcuate shape going from a front edge to a rear edge, with a sensor area defined in a rear bottom portion thereof; a sensor provided on a bottom portion of the midsole including the sensor area, and having a convex and arcuate shape going from a front edge a rear edge; a cap covering a rear part of the sensor; a shank provided inside the midsole, and having a plate-like shape that resembles a contour or a curved shape of a footwear sole; an insole attached to a top portion of the midsole; and an outsole attached to the bottom portion of the midsole, in which the sensor is provided, and having a convex and circular arcuate shape going from a front edge to a rear edge. [21] The Masai walking footwear according to claim 20, wherein the midsole has a convex curved arcuate shape, with an angle of inclination of a heel ranging from

25 to 45 degrees. [22] The Masai walking footwear according to claim 20, wherein the midsole is made of polyester or polyurethane. [23] The Masai walking footwear according to claim 20, wherein the midsole has a hardness ranging from 40 to 60. [24] The Masai walking footwear according to claim 20, wherein the sensor is made of soft polyester sponge or soft polyurethane sponge. [25] The Masai walking footwear according to claim 20, wherein the sensor has a hardness ranging from 15 to 30. [26] The Masai walking footwear according to claim 20, wherein the cap is open at one side, with a size thereof corresponding to that of the sensor. [27] The Masai walking footwear according to claim 20, wherein the cap is made of polyester or polyurethane. [28] The Masai walking footwear according to claim 20, wherein the cap has a hardness ranging from 40 to 60. [29] The Masai walking footwear according to claim 20, wherein the shank includes a front shank, a rear shank and a connecting plate connecting the front and rear shanks with each other. [30] The Masai walking footwear according to claim 20, wherein the shank includes a front shank, a rear shank and at least one spring connecting the front and rear shanks with each other. [31] The Masai walking footwear according to claim 29 or 30, wherein the front and rear shanks are made of polyvinyl chloride. [32] The Masai walking footwear according to claim 29, wherein the connecting plate of the shank is made of a thin flexible metal sheet or flexible thin synthetic resin. [33] The Masai walking footwear according to claim 30, wherein the spring of the shank is covered with a sheath. [34] The Masai walking footwear according to claim 20, the insole is made of nonwoven cloth. [35] The Masai walking footwear according to claim 20, wherein the insole has a hardness ranging from 25 to 30. [36] The Masai walking footwear according to claim 20, wherein the outsole is made of polyester or polyurethane. [37] The Masai walking footwear according to claim 20, wherein the outsole has a hardness ranging from 70 to 80.