JPS58165801A - Athletic shoes - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to athletic shoes, and more particularly to athletic shoes for running and other sports of the type having an open sole of single cell polymeric foam.

Currently, slip-last and board-last running (or jogging) shoes, as well as other types of athletic shoes, typically rest on a flexible outsole with a unicellular polymeric foam intermediate layer bonded to it. Laminated sole structures with soles have been manufactured. Sliplast shoes differ from boardlast athletic shoes primarily in that they do not have an insole, but instead have a closed knitted sole that completely wraps around the foot like a slipper. In boardlast type footwear, the upper has an open sole closed by a midsole board that rests on the midsole. Foam midsoles are used in both types because of their light weight and shock absorbing properties that cushion the wearer's feet from impact.

Sliplast athletic shoes are generally preferred over boardlast athletic shoes because they are typically more comfortable to wear. However, due to the lack of a midsole board, sliplast athletic shoes are typically less stable than boardlast athletic shoes. This is because concentrated stress occurs in the foam midsole during running, leading to uneven deterioration of the foam midsole to an undesirable extent. Foamed intermediate soles therefore significantly lose their effectiveness as shock absorbers due to uneven deterioration.

Deterioration of the foamed midsole occurs due to continuous stress caused by the periodically repeated deformation and restoring of the midsole during running. This deterioration may manifest itself in the form of permanent compressive deformation of the midsole, ie, compressive sag. Further, in areas where single cells within the foamed intermediate sole are destroyed, deterioration may occur without compression set.

Midsole deterioration is often localized due to concentration patterns caused by a certain runner's running style. For example, localized deterioration may occur at the rear outer edge of the shoe, at the rear of the heel. Midsole degradation also occurs throughout the shock absorbing portion of the midsole as a result of compressive forces that cause the midsole to expand outwardly of the shoe.

Localized midsole deterioration on the inside center of the shoe and localized midsole deterioration on the outside of the shoe both tend to cause the shoe to tilt and lose its stability when the runner's foot hits the ground.

This is particularly troublesome. Runners may adjust their running style to compensate for this instability, which can in turn injure their feet and ankles. Moreover, since deterioration of the intermediate sole often occurs before the life of the outsole is over, the problem of intermediate sole deterioration is magnified.

The foam midsoles of boardlast shoes also deteriorate as a result of use, but this deterioration is not as uneven as the midsoles of sliplast athletic shoes. This is because the midsole of a boardlast type athletic shoe disperses the force acting on the midsole to some extent unless the midsole board itself deteriorates.

Midsole boards also disperse forces acting on the foam midsole to some extent, but if the midsole board were made stiff enough to distribute the forces across the foam midsole, the athletic shoe would become too stiff and the wearer's It makes it very uncomfortable to wear. On the other hand, a low-strength midsole board that satisfies the wearer's wearing comfort is susceptible to deterioration, and even in boardlast type athletic shoes, the midsole deteriorates extremely unevenly.

The general object of the invention is to improve the stability of an athletic shoe without making the shoe uncomfortably stiff and without using components that reduce the foot storage volume of the upper. The object of the present invention is to provide a novel structure that reduces deterioration of the midsole and increases anatomical support for the wearer's foot. A more unique object of this invention is to avoid relying on the midsole board;
Another object of the present invention is to provide a new structure that sufficiently reduces uneven deterioration of the midsole of slip-last type athletic shoes without impairing the comfort of the slip-last type athletic shoes. This is done to stiffen the surface of a pre-selected part of the midsole.
This is usually accomplished by bonding the foam midsole with a special layer in the portion underlying the upper side of the midsole. In the embodiment shown, this special layer is in the form of a thin, stiff, almost inextensible layer, a so-called stiffening board, which has two stiffening boards between the upper and lower surfaces of the midsole. between and bonded to the intermediate bottom layer. The stiffening board has sufficient stiffness to effectively distribute the forces acting on the shoe over the area covered by the board in order to more evenly distribute the forces acting on the shoe. I need to be there.

Its geometry is particularly important since the stiffening board of the invention effectively stiffens the foam midsole support under the foot. In the illustrated embodiment, the stiffening boards are located on the lower part of the wearer's rear foot or heel, and in the front, the stiffening boards are generally first, second, second, and so on, and also under the medial arch of the foot.
It is shaped so that it extends to the third metatarsal head but does not extend to the outside of the wearer's mid-foot arch.

Since only selected areas are covered with the stiffening board, the interpolation board and the interpolation board do not interfere with the flexibility required by the shoe. Therefore, the interpolation board may be made as stiff as possible without becoming too stiff and brittle.

By distributing the forces acting on the midsole, the interpolation board of the present invention clearly reduces harmful and uneven midsole deterioration and greatly extends the service life of the shoe. The fact that the interpolation board is glued to the opposing midsole layer has the effect of itself restraining the outward expansion of the midsole due to compressive forces, thereby preventing deterioration of the midsole due to this outward expansion. Reduce. This deterioration due to the outward expansion of the intermediate sole is manifested in the destruction of the cell due to shear forces acting on the intermediate sole.

By providing the interpolation board of the present invention at a position midway between the upper and lower surfaces of the midsole and using a boardless midsole (i.e., a slip last structure without a midsole board), there is an advantage that the foot support portion can be lowered. .

The foam intermediate sole layer below the interpolation board serves only to absorb the force due to the impact of the foot on the ground.

The midsole layer above the interpolation board also acts as a shock absorber and also cushions the wearer's feet, so the shoe does not feel stiff due to the interpolation board. Furthermore, the foam midsole layer above the interpolation board in the rear foot area of the wearer is thick enough to snugly conform to the shape of the wearer's heel, thereby making the shoe comfortable to wear. Increase comfort.

By stiffening the foam midsole as described above, the extent to which a runner's foot sinks into the midsole is advantageously reduced as the stiffness of the midsole material is selectively increased.

By extending the interpolation board to a portion of the midsole below the medial arch or central arch supporting portion, the interpolation board and foam midsole also work well as a comfortable dynamic arch support. This feature of the invention eliminates the need for conventional arch support inserts, such as treadlocks, which disadvantageously reduce the foot storage volume of the shoe upper. 1 The midsole interpolation layer of the present invention advantageously allows podiatrists and orthopedic surgeons to modify existing running shoes to compensate for leg and foot asymmetries or solve other problems. It can be manufactured separately from the shoe as a custom item so that it can be modified and used. Various shoe inserts have traditionally been used for this purpose, such as heel cushions, arch supports, and other so-called muscular and indirect reinforcement restoration devices. All of them had the common disadvantage of creating some degree of discomfort by encroaching on the shoe's foot storage space.

In contrast to these conventional shoe inserts, the interpolation layer of the present invention is within the midsole and not within the upper so that the volume within the upper remains completely intact to comfortably cover the wearer's foot. be able to.

With the foregoing in mind, it is a further object of the present invention to interpolate a foam midsole by including an interpolation layer between the upper and lower surfaces of the foam midsole along a preselected surface of the underfoot portion. An object of the present invention is to provide athletic shoes with a new intermediate sole structure.

Yet another object of the present invention is to provide an athletic shoe with a novel midsole structure in which a special layer is bonded to the foam midsole body to reduce or slow down the harmful uneven deterioration of the foam midsole. The goal is to provide the following.

Yet another object of this invention is to provide a novel midsole construction athletic shoe with dynamic arch support.

Another object of the invention is to provide an athletic shoe with a new and economical midsole structure that is easy to manufacture and achieves the above objectives.

Another object of this invention is to provide a new, custom-made layer for modifying existing athletic shoes to accommodate the wearer's unique anatomy and asymmetries.

Another object of this invention is a novel method of utilizing the above-described custom shoe modification layer to compensate for weight differences and leg length differences.

In this specification, "hindfoot" refers to the part of the heel of the foot that includes the calcaneus, and "midfoot" refers to the part adjacent to the hindfoot that together forms the beginning of the arch of the foot. It refers to the middle part of the foot that includes five bones, and the "forefoot" refers to the part of the foot that is adjacent to the midfoot and includes the metatarsal bones.

In the illustrated embodiment, the intermediate sole interpolation layer of the present invention is incorporated into a slip-last type athletic shoe;
It is understood that the principles of the invention also apply to competitive running shoes having a midsole board made sufficiently flexible so that the midsole board does not impair the functionality of the special interpolation layer of this invention. Good morning.

The present invention will be described in detail below with reference to the drawings.

Referring to FIGS. 1 and 2, a competition running shoe incorporating the principles of the present invention includes a flexible slip last upper 10 and a sole 12 beneath the upper 10. , flexible and easy-to-bend Islip last type midsole 13
(See Figure 2). The upper 10 has a closed fabric sole 1'5'' which extends completely around the foot in the usual manner.

The midsole 13 extends into the upper 10 and overlies the textile sole 15.

The carapace 10 may have any suitable structure, and the one shown has a toe portion 14, a muddy portion 16, a heel portion 18, and a moon-shaped portion 20 surrounding the back of the heel portion. , a throat 22 for fastening with a string 24 that is open along the muddy part 16, a padded tongue 26 along the throat 22, and a padded edging part 28 around the opening for inserting the foot into the shoe. Contains.

The sole 12 is a laminated structure having a flexible outsole 32 in contact with the ground and a shock-absorbing midsole 33 overlying and bonded to the outsole 32.

Outsole 32 may be of any suitable construction and may be made of synthetic or natural rubber. Preferably, the tread surface of the outsole 32 has a suitable tread pattern 36.

The intermediate sole 33 has approximately the same shape as the outer sole 32. Carapace 1
0 is fastened to the intermediate sole 33 along the fabric sole 15 by gluing or other suitable method.

The midsole 33 is formed from a suitable single cell polymeric foam shock absorbing material. For example, midsole 33 is made from a mixture of ethylene vinyl acetate and polyethylene, cross-linked with peroxide during molding. The foam material preferably has a density of about 0.2 grams per cubic centimeter, or is slightly less dense and light.

The midsole 33 is thickest at the rearfoot or heel portion 39 of the shoe, which is under the heel or rearfoot of the shoe wearer. In the illustrated embodiment, the heel portion 39 of the midsole is of generally uniform thickness. As shown in FIGS. 1 and 2, the heel portion 39
There is a follower taper going to the middle part of the front.
Wedge-shaped. This wedge portion may be made separately from the intermediate sole 33, and may be located above or below the intermediate sole.

In the illustrated embodiment, the intermediate bottom interpolation layer of the invention is a thin, rigid, flat, flat-sided layer 37;
It is called a supplement board. This supplement board 37 is formed separately from the foamed midsole 33.

It is incorporated into the intermediate sole in a manner described in detail later.

In the illustrated embodiment, the midsole 13 is a soft, flexible flat cushion liner 3 for the wearer's sock.
It is made up of 8. The liner 38 has a woven sole 1 with an upper 10
5 and may be made of any suitable flexible material such as foam or terry cloth. A feature of the midsole 13 is that it does not have a midsole board.

As shown in FIGS. 1 to 5, the replenishment board 37 is located within the midsole 33 within a gap 42 between the upper and lower surfaces of the midsole that partially divides the midsole 33 into an upper layer 44 and a lower layer 46. inserted. The supplement board 37 is adhered to the lower surface of the upper layer 44 of the intermediate sole and the upper surface of the lower layer 46 of the intermediate sole by adhesive or other suitable method.

Any suitable adhesive may be used to adhere the supplement board 37 to the upper and lower layers 44 and 46 of the midsole.

The adhesive is applied to the entire contact surface between the supplementary board 37 and the intermediate sole upper layer 44, and is also applied to the entire contact surface between the interpolation board K7 and the intermediate sole lower layer 46.
It is desirable to apply the coating to the entire contact surface.

The split 42 is parallel, or at least generally parallel, to the outsole 32 when the sole is straight and unbent.

The rearmost end of the heel of the intermediate sole may be tapered as shown in FIG. 2, but other than this, the intermediate sole lower layer 46 has a generally uniform thickness over the entire length and width of the crack 42. . The rear foot portion of the midsole upper layer 44, which lies beneath the wearer's rear foot or heel, also has a generally uniform thickness.

The crack 42 is formed in the intermediate sole 33 at the center or slightly below the upper and lower ends of the rear foot portion of the intermediate sole.

In any case, the location of the crack 42 is such that there is sufficient thickness in the upper layer of the midsole to prevent the wearer's foot from being pushed up by the supplementary board during the maximum expected impact on the midsole. must be low. The thickness and other dimensions of the midsole 33 may be any conventional and suitable values currently used in the shoe industry for manufacturing running shoes.

At the wearer's rear foot, or below the center of the heel, the total thickness of the midsole 33 is, for example, approximately 19%
11J)), the height of the crack 42 is approximately % above the lower surface of the intermediate bottom.
inch (811JI).

As shown in FIGS. 1 to 3, the shape of the crack 42 and
The circumference matches the shape and circumference of the supplement board so that the supplement board 37 fits snugly into the hole. The split 42 extends across the entire rearfoot or heel portion of the midsole 33 so as to open completely to the rear and both sides of the midsole rearfoot.

From the rearfoot portion of the midsole 33, the cleft 42 extends forward and opens at the medial or mid-heel portion of the shoe, below the medial arch of the wearer and approximately at the head of the first metatarsal bone.

The supplement board 37 may be assembled to the intermediate sole by any suitable method. For example, make a crack 42 in the middle bottom and use the supplement board 37.
After applying adhesive to both sides of the board, the supplement board is fully inserted into the crack 42. Next, the upper and lower layers 44 and 46 of the middle layer
Then, the supplementary material board 37 is pressed and adhered to the upper and lower layers of the intermediate sole.

The filler board 37 is formed from a suitable, durable, generally non-extensible material. For example, poly)
The amount of ester resin and glass fiber is approximately 2 by volume of the sheet.
A rigid composite sheet consisting of 5% woven or shredded glass fibers.

The minimum bending modulus of the supplementary board required to sufficiently distribute the forces acting on the midsole 33 depends on the thickness of the supplementary board. The thickness of the supplement board 37 is typically at least about 0.1 mm thick.
inch (1,:l1m) is required, preferably about 0.0
Six inches (1,5111) (approximately % inches) is preferred.

The required bending modulus for a 0.06 inch (1.5 wh) thick filler board is at least 1,000,000 psi (70
000 psi/d), preferably about 2,000,000 psi
(140000Kt/1tlt) is more desirable.

As shown in FIG. 3, the supplement board 37 extends from the entire rearfoot portion of the sole to the outer edge of the heel and from one side of the midsole to the other. From the rear of the midsole 33, the supplement board 37 extends forward along the medial or medial edge of the shoe to a location 50 proximal to the head of the wearer's first metatarsal. From here, the edges, or perimeter, of the supplement board 37 are the second and third
An arc is drawn posterolaterally along a line 51 proximal to the head of the metatarsal bone. The edge of the replenishment board is further marked by a line 5 extending in the longitudinal direction.
2 to the bottom of the wearer's cuboid bone, and then arcs in the opposite direction at 53 to the longitudinal axis of the shoe at the upper end of the rearfoot or heel 39 of the midsole. It follows a generally perpendicular line 54 to the outer edge of the sole.

With the construction described above, the supplement board 37 extends forward over the entire rear foot of the wearer along the central edge until it is below the medial side of the wearer's foot, but on the outside of the wearer's arch.
That is, the first. It is clear that the forefoot extends anteriorly to the second and third metatarsal heads. Since the supplementary board 37 only covers a specific area, it does not interfere with the flexibility required for running shoes. Therefore, it can be made as stiff as desired as long as it does not become brittle.

When the wearer steps on the sole of the shoe, the edge of the replenisher board does not give the wearer the feeling that its stiffness has suddenly changed, so the replenisher board 37 is installed as shown at 56 in FIG. It is desirable to taper the thickness along the curved leading edge (see line 51-54). In addition, the rear lateral or outer corners 58 (see FIG. 3) are also designed to avoid stress concentrations in the area where the heel most commonly strikes the ground and to accommodate the supplementary board 37. The same can be done diagonally to eliminate or greatly reduce accelerated and harmful sole wear.

The midsole underlayer 46 only functions as a shock absorber to absorb the forces resulting from the impact of the runner's foot as it strikes the ground. The midsole upper layer 44 also acts as a shock absorber to absorb this force, but in addition to this, the supplementary board 37 cushions the wearer's feet so that the shoe does not feel stiff. In addition, the wearer's rear foot or heel portion of the midsole upper layer 44 closely conforms to the shape of the wearer's heel, or is designed to conform itself to the shape of the wearer's heel, for added comfort. It has sufficient thickness.

By supplementing the midsole 33 as described above, the present invention advantageously reduces the extent to which the runner's foot sinks into the upper layer of the midsole overlying the supplementary board 37, compared to conventional shoes without a restraint. greatly reduced. The initial deformation and auxiliary effect as the wearer's foot sinks into the midsole upper layer 44 is multiplied by the presence of the auxiliary board 37, so that energy is absorbed at approximately twice the rate of a normal shoe. The maximum force will be greater than a new normal shoe, but still within acceptable limits.

In addition, it is known that regular shoes often lose about half of their energy absorbing properties due to continuous use, such as when running marathon distances.

Reducing the degree to which the hindfoot sinks into the midsole 33
This has the advantageous effect of allowing the runner to have greater control over the movement of the hindfoot.

This increases rearfoot stability without significantly compromising the shock absorbing properties of the midsole 33.

By extending the supplementary board 37 to the inside or below the arch of the runner's foot, the combined effect of the intermediate sole 33 and the supplementary board 37 located below the inside of the arch of the foot provides comfort to the wearer. Provides arch support. This arch support is dynamic in the sense that it is only felt when significant force is applied. For this reason, so-called arcuate keys and conventional anti-step support inserts are not required. These have the disadvantage of being placed within the upper of the shoe and reducing the volume that the foot enters within the upper of the shoe.

The supplementary board 37 serves to reduce intermediate layer degradation in two ways. First, it has sufficient stiffness to effectively distribute the forces acting on the midsole 33 across the auxiliary board, thereby distributing the forces acting on the midsole 33 evenly over the auxiliary board portion. ing. The supplementary board 37 thus eliminates or significantly reduces the pattern of high concentration caused by the runner's unique running style, thereby reducing uneven deterioration of the midsole 33.

Second, the supplementary board 37 has intermediate bottom and upper layers 44 and 46
Due to its adhesion to and its inherently inextensible nature, it has the effect of restraining the midsole 33 from expanding outwardly under the influence of compressive forces.

The foam parapet tensile properties of the midsole in contact with the adhesive surface therefore also serve to restrain outward expansion under the influence of compressive forces. Although this compressive force causes some midsole expansion, the outward expansion within each midsole layer 44 and 46 is still much less than that which would occur without the complementary layer of the present invention. Therefore, the deterioration of the midsole due to this outward expansion is correspondingly reduced by the present invention.

From the foregoing structure, it is important to realize that the supplementary board 37 has the effect of greatly improving the stability of a new running shoe without midsole deterioration. In this regard, supplementary board 37 has the effect of distributing eccentric or unbalanced forces caused by unique running styles. Such dispersion creates a repositioning force that counteracts the imbalance or eccentricity of one landing, such as when a runner lands on the outside edge rather than landing flat. In addition, the supplemental board 37 uses the midsole upper layer 44 as a cushion that comfortably conforms to the shape of the wearer's heel during running, and also provides dynamic arch support for the medial or central portion of the runner's arch. This results in improved foot support while running. In addition to the above, the supplementary board 37 greatly reduces the uneven deterioration of the midsole, greatly improves the stability of running juice over a long period of time, and greatly extends the trouble-free life of the shoe.

It is precisely because the outward expansion of the midsole is constrained by the inextensible or tensile nature of the supplement board 37 and by its adhesion to the midsole top and bottom layers 44 and 46 that this midsole This outward expansion is achieved by using a flexible, mostly non-stretchable layer in place of the filler board 37, and by substituting this non-stretchable flexible layer into the midsole 44. This may be alleviated by adhering to and 46.

Instead of being formed in one piece and later being split to fit the filler board 37, the midsole 33 may be manufactured from the beginning as two separate foam layers, the two layers having different densities. It might be something.

The interpolation layer of the present invention allows different foams not previously considered suitable for midsole to be used in the production of running juice.

The replenishment board 37 does not have to be installed horizontally as shown in FIGS. 1-5. Rather than being horizontal, it is tilted in either direction about the longitudinal axis, as shown in FIGS. 6 and 7. In other words, it may rotate.

In FIG. 6, the supplemental board 37 is positioned so that the lateral edge of the supplemental board is in the center of the sole at the lateral edge of the sole to compensate for the forces that occur when the runner's foot is significantly pronated. Or, it is inclined in a direction that is lower than the side edge at the inner end. In FIG. 7, the supplement board 37 is designed so that the side edges of the supplement board are on the outside of the sole at the center or medial edge of the sole to compensate for the forces that occur when the runner's foot is significantly supinated. Tilt it in the opposite direction so that the wood at one end is lower than the opposite edge of the supplement board.

The midsole interpolation layer in this invention need not be planar or flat as in the case of the supplement board 37. The supplement board 37 may therefore be replaced by an interpolation layer of a different shape. For example, the interpolation layer may have a curved shape or may be formed using a masonry mold. Furthermore, various elements related to the present invention may be modified as appropriate depending on the circumstances.

For example, the thickness of the interpolation layer, the stiffness of the layer, the geometric range and area covered by the interpolation layer, the height of the interpolation layer, etc., will vary depending on each running style, asymmetry of the legs and feet, and weight. May be modified to suit.

It will also be appreciated that the interpolation layer of the present invention avoids the difficult and costly attempt to modify the support geometry of a running shoe by using different elastic materials for the midsole foam. .

Furthermore, the intersolation layer of the present invention advantageously compensates for leg and foot asymmetries and other problems, as well as for making the shoe custom-tailored to the individual. It can be manufactured separately from the running juice as a custom product for use by a medical doctor or orthopedic surgeon who modifies the ready-made, ie fully constructed, shoe after its manufacture. For example, the midsole interpolation layer of the present invention can be used to compensate for differences in leg length, but also has the advantage that nothing needs to be inserted into the shoe upper itself. The main steps in this method of using interpolated shoulders are: first, creating a crack or gap in the foam midsole of the ready-made shoe to accommodate the interpolating layer;
Then, a specially prepared interpolation layer is inserted into the crack or gap and the interpolation layer is glued to the midsole.

It goes without saying that each part of the competitive running juice for the right leg is completely symmetrical to each part of the running juice for the left leg described so far.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the left foot of a competitive running 8-use according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the competitive running juice shown in FIG. 1. FIG. 3 is a horizontal cross-sectional view taken generally along line 3--3 of FIG. 2, illustrating the shape of an interpolation layer according to one embodiment of the invention. FIG. 4 is a longitudinal section taken approximately along line 4--4 of FIG. FIG. 5 is a longitudinal section taken along line 5--5 of FIG. FIG. 6 is a longitudinal section similar to FIG. 4, but shows one of the variations applicable to runners whose feet are significantly pronated. FIG. 7 is a longitudinal section similar to FIG. 4, but shows one of the other variations applicable to runners whose feet are highly supinated. 10... Shell 12... Bottom 13... Insole 15
...Bottom 33...Intermediate bottom patent applicant Colgate-Palmolive Company (4 others) Fig, 3 Fig, ε Fig7 Procedural amendment (method) Date of 1920, Showa 3G /-No. 7 Untiy Maru 6, Relationship with the case of the person making the amendment Applicant's address-Zi';
・Goun? \)-4, Agent

Claims (1)

[Scope of Claims] (1) having an upper and a bottom, the upper overlying and attached to a portion of the bottom, and the bottom having a flexible outsole; a flexible shock-absorbing midsole overlying and secured thereto, the midsole being formed from a foamed polymeric material; formed separately from said midsole for stiffening along preselected portions of the surface;
An athletic shoe comprising a layer that joins the midsole by a preselected surface portion below the wearer's foot and intermediate the upper and lower surfaces of the midsole. (2. In the athletic shoe according to claim 1, the above layer is located at least under the wearer's heel, but not under the wearer's foot plate, and at least under the wearer's heel. (3) In the athletic shoe according to claim 2, the layer extends from the bottom of the wearer's heel forward to the center arch of the wearer. (4) In the athletic shoe of claim 1, the layer is worn from the edge of the middle portion of the sole. extending inwardly along a curve near the heads of the wearer's first, second, and third metatarsals, then further curving and extending posteriorly to the medial base beneath the wearer's cuboid bones; It extends only to the portion of said intermediate sole in front of the boundary line which extends laterally along said intermediate sole and extends to the lateral edges of said intermediate sole, said intermediate sole being further than said boundary line. The midsole is adapted to be stiffened by a layer extending over the entire rear part. (5) In the athletic shoe of claim 1, the layer is below the heel of the wearer. Across the midsole, extending forward from the midsole to below the mid-arch of the wearer's foot, but laterally to the wearer's foot, i.e., the wearer's first, second, and third metatarsal heads. (6) In the athletic shoe according to claim 1, the upper is a slip having a knitted sole bonded to the intermediate sole. (7) Claims The athletic shoe according to any one of Items 1 to 6, wherein the layer has an interpolation layer that is located between the upper and lower layers of the intermediate sole and is bonded thereto. In the athletic shoe according to any one of Items 1 to 6, the shoe has an intermediate sole, at least a portion of which is divided into an upper layer and a lower layer, and the layer is located between the upper layer and the lower layer and is adhered to the upper layer and the lower layer. The upper layer is at least under the wearer's heel to cushion the heel, and the insole is at least below the wearer's heel when the wearer's foot touches the ground. (9) Any one of claims 1 to 6 which is sufficiently flexible to compress the upper layer under the load of the wearer's heel to conform to the shape. In the athletic shoe of item 1, the layer is a single, almost inextensible board bonded to and between the upper and lower layers of the intermediate sole, and the board is a board that is attached to the foot of the running sling wearer. generated by the impact when the board touches the ground, and which has sufficient stiffness in said part of the board to disperse the forces acting on said midsole and to distribute the forces acting on said part more evenly. (10) In the athletic shoe according to any one of claims 1 to 6, the intermediate sole is at least partially divided into an upper layer and a lower layer, and the above layer is the above layer. It has an interpolation board that is located between the upper and lower layers and connects them, and the board is approximately parallel to the outsole when the outsole is straight and not bent, so that the feet of the running bag wearer are in contact with the ground. the force resulting from the impact of the impact acting upon the midsole of said section of the board, said board having sufficient stiffness to distribute said force more evenly over said section; The board has almost no extensibility and is bonded to the upper and lower layers to resist the intermediate sole from expanding laterally when subjected to the above forces. a shell having a shell and a bottom, the shell overlying and attached to a portion of the bottom, and the bottom being fixed to the top over and above a flexible outsole; In athletic shoes for running and other sports, the midsole is formed from a foamed polymeric material, and the midsole is formed from a foamed polymeric material, and has a flexible, shock-absorbing midsole that is resistant to stress generated in the midsole by the wearer during running. An athletic shoe characterized in that, in order to reduce uneven deterioration of the midsole, a layer is provided which is formed separately from the midsole and joins the midsole at a preselected location outside the epithelium. (121 The process of cutting the midsole to create a space between the upper and lower layers of the midsole for the layer, the step of inserting a rigid skin along a pre-selected plane to interpolate the midsole, and the layering of the midsole. A method for modifying an existing running or other sports athletic shoe having a polymeric foam midsole, the method comprising: adhering the foam to the midsole.