Heel flat sole

Abstract

To provide an insole maintaining a horizontal state of a heel of a foot put in a shoe having an inner bottom surface inclined outward, and not supporting an arch.SOLUTION: An outside height of an inclined shoe bottom surface is corrected such that a heel of a foot put in a shoe becomes horizontal with respect to the ground, inclination of an inner bottom of the shoe is corrected, an arch originally held by the foot is not supported from below, and a front inclination angle is not provided in consideration of necessity of various motions such as moving to in a rear, side, or diagonal direction, standing, seating, or stopping.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an insole that maintains the levelness of the heel of a foot in a shoe generally having an outwardly tilted inner sole, and does not support the arch. [Background technology]

[0002] The shapes of many pumps and other shoes currently on the market are designed to accommodate the plantar flexion and supination of the ankle, meaning that the toes point downward and the sole of the foot points inward. As a result, the inside of the shoe is not horizontal, with the inner sole tilted outward by 2 to 5 degrees. This naturally causes weight to be placed on the outside when wearing shoes, and when pushing down, the toes flex and supinate, meaning that the toes bend as if gripping the ground, the toes point downward, and the sole points inward, which is a state that is caused by the structure of the foot. The subtalar joint of the foot is everted, which makes it difficult to brace and causes forward slippage. In addition, the shape of the toes pushes the big toe and causes it to move inward, compressing the big toe and little toe, leading to hallux valgus and hallux varus, which means the little toe bends inward.

[0003] Also, when the subtalar joint is everted, more weight is placed on the outside, making it easier for shoes to come off. Regarding the shape of the shoe, the space for the heel is short and the whole shoe is tilted forward and outward. Considering the movement of the foot, it is better for the part where the heel rests to be flat. The effects of tilting outwards include foot pain due to slipping forward inside the shoe, foot fatigue due to the need to brace yourself more when slipping, the tendency to tip outwards and therefore shoes coming off more easily, as well as hallux varus deformity, i.e., deformation of the little toe due to the little toe bending inwards, and ankle inversion sprains, i.e., sprains and falls due to the ankle bending inwards. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5858450 Summary of the Invention [Problem to be solved by the invention]

[0005] In normal ankle movement, the lateral malleolus (the so-called two malleoli) is positioned more posterior and inferior than the medial malleolus, which naturally causes the toes to point downward and the foot to turn inward.Normal ankle plantar flexion results in eversion, meaning the toes point downward and the sole of the foot turns inward. Therefore, shoes made from a wooden mold that is modeled after the normal, resting foot position tend to have the toes point downward and the sole of the foot point inward, resulting in the ankle being in a supinated position and making sprains more likely. For this reason, shoes with a structure that keeps the ankle in a straight, plantar flexed position are preferable, especially when making high-heeled shoes. However, since such shoes are not currently manufactured, it is essential to develop an insole that corrects the inclination of the inner sole of the shoe.

[0006] In the above-mentioned prior art documents, insoles are made to fit the shape of the foot (arch and heel). Arch height is determined by the position of the bones, not the shape of the foot, so it cannot be determined by the shape of the foot. Furthermore, since the size and length of people's feet, as well as the amount of change in the arch, vary widely, there should be no standard for arch height. The shape that supports the heel is said to be a horizontal surface, but because the inside of the shoe is tilted, simply making it cup-shaped does not create a horizontal surface. Also, the heel tends to collapse inwards and outwards, so a cup shape would hinder this movement and put strain on other parts of the body, which is not desirable.

[0007] The major difference from the present application is that the present application does not support the arch portion, and that the present application does not have a front portion because the front portion where the toes rest varies greatly depending on the shoe. Furthermore, in this application, the shock-absorbing material is designed so that the foot itself can absorb shock, so cushions are not necessary, and we believe that the most important thing is to create an environment inside the shoe that allows the foot to perform its shock-absorbing function. The body's natural function is to allow the heel to collapse inward and the arch to collapse when weight is applied, so it is important not to interfere with this, and this invention was based on that idea. The outsole of a shoe absorbs the shock from the ground, which is sufficient, but if it absorbed even more shock, it would be like standing on a fluffy sponge, which would make the body tense up and tire more easily. This is clear from the fact that walking on tatami mats is easier than walking on sandy beaches.

[0008] What all insoles have in common is that many of them support the arch from below or use materials to absorb shock without considering the movement of the foot. Problems arise because the insoles are made to fit the shape of the foot, only considering the shape of the foot. The foot has the ability to change shape to fit the shape of the foot, allowing for complex movements. Insoles that fit only a certain shape of the foot will limit that movement. In fact, there are many patients who find that insoles made to fit the shape of their feet are too painful to wear. Many insoles on the market are manufactured without considering the current state of the shoes or the movement of the feet. In order to solve these problems, the inventors have completed the present invention through repeated trial and error. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the heel flat sole of the present invention is an insole that is inserted into a shoe insole having an inner bottom surface that is tilted outward on both the left and right sides relative to the ground, and its main feature is that it corrects the outer heights of the inner bottom surface of the shoe so that the heel of the foot inserted in the shoe is horizontal to the ground.

[0010] In order to solve the above-mentioned problems, the heel flat sole of the present invention is also characterized by its shape not supporting the arch from below, so as not to deform the arch that the foot naturally possesses and inhibit its function of absorbing shock.

[0011] In order to solve the above-mentioned problems, the heel flat sole of the present invention is not designed only for moving forward, but is designed without a forward tilt angle, taking into consideration that natural human foot movement requires a variety of movements such as moving backward, sideways, and diagonally, as well as standing, sitting, and stopping.

[0012] In order to solve the above-mentioned problems, the heel flat sole of the present invention has a layered structure or is integrally molded, which is composed of at least an upper part, a middle part, or a lower part.

[0013] In order to solve the above-mentioned problems, the heel flat sole of the present invention does not require excessive cushioning, and the material is not limited as long as it has a hardness of about 70-90, such as resin, high-resilience material, leather, etc. It is sufficient that the hardness is such that it will not lose its shape or deform even when used every day for six months or more.

[0014] In order to solve the above-mentioned problems, the heel flat sole of the present invention has a shape without a forefoot portion.

[0015] In order to solve the above-mentioned problems, the heel flat sole for pumps of the present invention has the following features: the length of the upper, middle and lower parts is 50% to 70% of the user's foot size, and the width of the upper part is 70% to 90% for external correction; the middle part is smaller than the upper part from the center to the heel and narrows in width toward the heel; and the lower part is 1cm to 2cm in size except for the center.

[0016] In order to solve the above-mentioned problems, the heel flat sole for sneakers of the present invention is composed of at least two parts, an upper part and a middle part, and in the case of a three-part composition, the middle part of the front bar (midfoot plate) is half the length of the upper part, and the lower part is 1 cm long.

[0017] The heel flat sole for sports shoes of the present invention has a shape that corrects the outward tilt to a greater height than sneakers, since general sports shoes have a raised medial longitudinal arch, and the more it is raised, the more severe the outward tilt of the insole of the shoe becomes. [Effects of the Invention]

[0018] Because the shoe itself is designed based on the shape of the human foot, the insole of the shoe is tilted outward by approximately 5 degrees. Correcting this tilt and leveling the insole with the ground allows the heel to move more easily and allows the foot muscles to be used more naturally, reducing forward slippage, preventing toe deformation, and reducing shoe slip-off. Furthermore, the arch is designed not to be supported from below, so as not to deform the arch and inhibit its shock-absorbing function. This collapses the natural arch of the foot, allowing it to perform its shock-absorbing function, reducing foot pain and fatigue while walking and ultimately reducing edema. Furthermore, because the front part of the shoe where the toes rest varies greatly depending on the shoe, a front part has been intentionally omitted. This makes the present invention versatile and usable with a wide range of shoes. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is an explanatory diagram showing an example of an upper part of an insole according to Example 1 of the present invention, with the names of the parts corresponding to the numbers enclosed in white frames. [Figure 2] FIG. 2 is an explanatory diagram showing an example of an inner part of an insole according to the first embodiment of the present invention, with the names of the parts corresponding to the numbers enclosed in white frames. [Figure 3] FIG. 2 is an explanatory diagram showing an example of a lower part of an insole according to the first embodiment of the present invention, with the names of the parts corresponding to the numbers enclosed in white frames. [Figure 4] FIG. 2 is an explanatory diagram showing the dimensions of each portion of the upper part of the insole according to the first embodiment of the present invention, indicated by straight lines. [Figure 5] FIG. 2 is an explanatory diagram showing the dimensions of each part of the middle part of the insole according to the first embodiment of the present invention, indicated by straight lines. [Figure 6] FIG. 2 is an explanatory diagram showing the dimensions of each portion of the lower part of the insole according to the first embodiment of the present invention, indicated by straight lines. [Figure 7] FIG. 1 is an explanatory view of the overall view of the insole of Example 1 of the present invention as seen from the back side, showing that the sizes of the middle part, lower part and upper part become smaller in order. [Figure 8] This is a cross-sectional view of a shoe with an insole attached and a foot inserted into the shoe, showing that the heel surface is corrected to be horizontal with respect to the ground. [Figure 9] 1 is a schematic explanatory diagram showing the positional relationship between the sole of the foot and the insole when the insole is attached to the shoe. FIG. [Figure 10] This is a projection of the footprint outline. [Figure 11] FIG. 1 is an explanatory diagram showing the bones of the foot. [Figure 12] FIG. 2 is an explanatory diagram showing the sections of the foot. [Figure 13] FIG. 10 is an explanatory diagram of the leg swing angle. [Figure 14] FIG. 1 is an explanatory diagram showing the bending positions of the foot and shoe. [Figure 15] FIG. 2 is an explanatory diagram showing the load position of the foot. [Figure 16] 1 is an explanatory plan view of an upper part showing one embodiment of an insole for sneakers of the present invention. FIG. [Figure 17] 1 is an explanatory plan view of a middle part showing one embodiment of a sneaker insole of the present invention. FIG. [Figure 18] FIG. 1 is an explanatory plan view of a lower part showing one embodiment of an insole for sneakers according to the present invention; [Figure 19] This is an explanatory diagram showing the entire back side of one embodiment of an insole for sneakers of the present invention, and shows that the middle part, lower part, is smaller in size than the upper part. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0020] An embodiment of the present invention will be described with reference to Figures 1 to 9. Figures 4-6 show the length of each part with numbers in circles. This length indication is also used in Table 2, which shows the size range below. However, since numbers cannot be displayed in circles in the specification, they are shown in parentheses. Figures 1 to 7 relate to an insole for the left foot of a pump. To accommodate the complex structure of the foot and defects in shoe structure, the insole of the present invention is basically constructed with a three-layer structure. The top part (Figures 1 and 4), middle part (Figures 2 and 5), and bottom part (Figures 3 and 6) are shown according to the position of each of the three layers, and Figure 7 shows the back side of the combined three layers. This is used by placing the top part upward under the insole already placed at the base of the shoe, with the heel resting on part 2, and the side of the Heat Flat Sole against the outside of the shoe, with the rear end set as far back as possible (see Figure 9). Each diagram identifies each part with a number and a white box, and the name and size of each part (white lines) are shown in Figures 4-6, but all parts are connected. Regarding the shape of the insole, pumps have a high heel and are designed to place the ankle in plantar flexion (toes pointing downward), so there is no need to consider the arch of the foot. Since the truss mechanism, which is the foot's shock-absorbing mechanism (the arch lowers when weight is applied to the sole, increasing the contact area and dispersing impact), is not used, there is no need to consider the fact that the arch is not supported to function naturally. Table 1 below shows the Japan Leather Goods Industry Association's 2021 Foot Size Measurement Project Report.

[0021] [Table 1] Lateral malleolus-heel distance ML-H Medial malleolus-heel distance MM-H Heel width 18% HM1-HL1 Heel width 16% HM2-HL2 Half foot width outside BL-PL Sotofubutocho BLーH

[0022] The lateral malleolus-heel distance (ML-H, see Figure 10) and lateral arch length (BL-H) from the above report were used as reference to determine the areas 2 and 3 (Figures 1-3) where the heel rests and the length supporting the lateral side (4). The width was set to support the lateral support mechanism, the cuboid and the fourth and fifth metatarsals (see Figures 11 and 12), rather than the length where only the heel rests. This width was also set to half the width where the metatarsals of the fourth and fifth toes rest, based on the half-foot width (BL-PL) from the Japan Leather Goods and Leather Products Association's 2021 Foot Size Measurement Project Report (mentioned above, "0021"). To make the width of the midfoot plate (5) the same as that of a Japanese foot, we set it based on the outside half-foot width. The outside half-foot width is the distance from the intersection of the vertical line connecting the heel and second toe (index finger) and the horizontal line connecting the base of the hallux (thumb) and little toe (pinky finger) to the base of the little toe (pinky finger) (Figure 10FM-BL). Additionally, shoes have a swing angle that swings outward by approximately 4° to 8° (arrow in the upper right direction in Figure 13). For this reason, this insole is designed to swing inward by 6° at 5° + 1° (diagonal line 69 in Figure 4-6). In order to wear the shoe and insole so that they face in the same outward direction, the surface on which the heel rests is tilted inward so that the foot faces straight ahead. If this direction is not correct, discomfort will occur in the sole of the foot. This is designed to align the shoe and foot to eliminate any discomfort in the sole of the foot. The heel stand on which the heel rests faces forward, the same direction as the foot.

[0023] The three-part insole shown in Figure 1-3 has the following characteristics: Rearfoot: The outside is designed to be higher and the inside lower to prevent calcaneus inversion, i.e., the heel tipping outward (heel movement during foot supination). Midfoot: The length is measured from the bottom up to the position that supports the cuboid bone and the fourth and fifth metatarsals (the front side of the base of the ring finger and little finger). Forefoot: The area where the toes go varies depending on the shoe, so we intentionally left out the forefoot (the area in front of the ball of the big toe and the ball of the little toe at the base of the foot). Figure 1 shows the upper part, and Figure 4 shows the length of each part with white lines and numbers. 1 is the midfoot plate, and 2 is the heel stand. 1 and 2 together support the left side of the foot with a width of approximately 20 mm and a length of approximately 130 mm, compensating for the outward tilt of the inner sole of the shoe. Considering stability when the ankle is in plantar flexion with the toes pointing downward while wearing the shoe, the shape must compensate for the height of the outer sole. The reason for not supporting the entire length of the foot to the little toe is that the arch of the foot ends at the base of the ball of the big toe and the little toe, and any longer would restrict the movement of the toes. Also, there are many different shoe toe shapes, and the length and height of the area in front of the ball of the big toe and the little toe vary depending on the shoe.

[0024] Next, element 2 is the heel rest, supporting the heel horizontally to the ground. However, unlike conventional insoles, it does not cover the entire heel width, but rather accounts for approximately 80% of the actual heel width, approximately 38mm to 62mm. By eliminating the medial support, the outward tilt of the shoe insole is corrected by increasing the correction on the lateral side and decreasing the correction on the medial side, ensuring that the heel is horizontal to the ground when the shoe is worn. Note that the width of element 2 can also be designed to cover the entire heel. The correction of the outward tilt is achieved by making the lower middle part smaller than the upper part, which creates the tilt. The vertical length of element 2's heel stand (heel length) is approximately 74mm to 86mm, covering most of the heel, in order to keep the heel horizontal. Because the heel tends to tip outward due to the inclination of the shoe, the middle part (3) in Figure 5 is slightly smaller than the upper part (3) in Figure 4 to make it easier to evertide (the heel tips inward) the subtalar joint (the joint formed by the calcaneus and heel). The reason for this size and shape is that the thickness is reduced as far inward as possible (about 70% to 90%), maintaining a firm height correction on the outside while gradually reducing the thickness near the inside, aiming to keep the heel level.

[0025] The lower part, shaped as shown in Figures 3 and 6, consists of a heel plate 2, which extends toward the heel and is the same width as the midfoot plate 1, and a support plate 3, which extends inward in the center. The function of this part is primarily to correct the lateral aspect. The support portion, with a heel length 5 (Figure 6) of approximately 10 to 16 mm, is the same width as the middle part. This acts as a bank to moderate the forward slope of the shoe and also creates a backward slope. This corrects the height of the midfoot, preventing forward slippage. Furthermore, by correcting the calcaneus in the middle position, the calcaneus is caught in the shoe, making it less likely to slip off. Combining these three differently shaped parts creates a slope that allows the shoe to be shaped to suit the movement of the foot, improving the fit between the shoe and the foot. This insole creates an environment that allows the foot to move naturally.

[0026] When designing each size of this Heat Up Sole, we first measured the heel height and inclination of pumps that are actually on the market, using a round level for the inclination. The results are as follows: Heel height: 2.5cm, tilt: outward tilt 2° Heel height: 4.0cm, tilt: outward tilt 2° Heel height: 4.5cm, tilt: outward tilt 2° Heel height: 6.5cm, tilt: outward tilt 3° Heel height: 9.5cm, tilt: outward tilt 3° This shows that when the heel height exceeds 4.5 cm, there is more outward tilt.

[0027] In order to correct this outward tilt, the thickness and tilt of the insole for pumps of the present invention are configured as follows. Outer thickness: 3mm, inclination: inward 2-3°←Heel height: 4.5cm or less Applies to pumps Outer thickness: 5mm, inclination: 3-4°inner ← heel height over 4.5cm Applies to pumps If the heel height is 4.5 cm or less, the outward tilt is 2°, so in that case, a heel flat sole with a 2-3° inward tilt should be used, with the heel tilted slightly inward from horizontal. In other words, if the heel flat sole in Figure 7 is turned upside down with the top part facing up and placed on a level surface with heel stand 2 supporting the heel facing forward, it will tilt inward. This is because the thickness of the middle and bottom parts is reduced as they go inward. This inward tilt offsets the outward tilt of the inner sole of the shoe, which tilts outward, and makes it level. If the heel height is over 4.5 cm, the outward tilt is 3°, so in that case, a heel flat sole with a 3-4° inward tilt should be used, with the heel tilted slightly inward from horizontal. When we tried a 6mm thickness, the insole tilted inward by 5 degrees, which caused the heel to tilt inward more, placing too much weight on the inside of the foot and causing some pain below the lateral malleolus (outer ankle) and in the sole (heel). When the thickness range was 7mm, the insole itself became too thick and the shoes tended to slip off easily. Therefore, it was found that anything over 6mm put strain on the foot and caused pain. The reason for adding 1 degree to the inner angle is to prevent weight from being placed on the outside when walking, and to make it easier to use the toes, making walking easier. For these reasons, the thickness and width should be 3mm to 6mm and the inclination should be 2° to 4°.

[0028] By offsetting the outward tilt of the shoe with the inward tilt of the insole, the calcaneus will evert from the middle position, meaning the heel will tilt inward from the middle, and the weight that was on the little toe side will now also be on the big toe side, resulting in a stable center of gravity. When the ankle is in plantar flexion, meaning the toes are pointing downward, the calcaneus goes from neutral to pronated, meaning the heel tilts inward from the center, allowing the weight to be distributed across the entire toe, preventing it from drifting outward. Furthermore, with the entire foot on the ground, the toes can be used, making it easier to brace. Of course, the boundaries between each part, or edge (perimeter thickness), can be chamfered to create a gradual, gradual increase in thickness rather than abruptly increasing it, in order to minimize any discomfort when inserted into the shoe midshaft.

[0029] The insole structure described above has a slight backward tilt because the middle and lower parts are carved into the back of the heel. The slightly gentler forward tilt reduces forward slippage. Also, because there is no insole in the front, the entire toe is in contact with the ground, allowing the toes to brace themselves, which also reduces forward slippage. The outward tilt makes it easier for the foot to turn inward (the sole of the foot facing inward and the top of the foot facing outward), and when the toes flex (bend) when pushing off, it becomes even more likely to turn inward. The course of the muscles that plantar flex the ankle (pointing the toes down) also causes supination (the toes point down and the sole of the foot point inward), which can lead to hallux varus (the little toe pointing inward) when the toes hit the shape of the toe of the pumps and are pushed inward. Therefore, eliminating the tilt reduces the physical burden on the little toe, which also helps prevent hallux varus (the little toe pointing inward).

[0030] Applying the above measurements and the shoe grading (pattern enlargement / reduction) principle, i.e., the total length increases by 0.5 cm and the width increases by 1.5 mm, the sizes of the heat flat sole of the present invention for each foot size are shown below. XS is (20.0 cm), S is (22.0 cm), M is (24.0 cm), L is (26.0 cm), XL is (28.0 cm). Since sizes are in 2 cm increments, the settings will enlarge or reduce each size by 6 mm. (1) to (8) correspond to the numbers indicating the length of each part in Figures 1 to 4 to 6. [Table 2] The material to be used can be any material with a similar hardness, such as high-resilience material or leather, that can withstand use as an insole for a certain period of time and does not deform even when walking with the entire body weight on it, and is suitable as an insole. Using EVA as an example, the following is assumed: EVA hardness: 60-90 Other materials with equivalent hardness can also be used. EVA hardness: 35 was too soft and did not provide support FIG. 8 is a vertical cross-sectional view illustrating the state of the shoe, insole, and heel in relation to the ground when the right foot is inserted into a pump equipped with the heel flat sole of the present invention. As shown there, when the heat flat sole of the present invention is attached, the inserted heel remains horizontal to the ground even though the shoe is tilted outward.

[0031] The following are the results of a survey conducted on people who are troubled by pumps not fitting their feet, especially those who have made their own insoles at great expense but are still unable to wear them due to the poor fit and pain, in which the heel flat sole of the present invention was tried out. The questions asked in the questionnaire concerned issues that many women worry about, such as how long they wear pumps, foot fatigue, pain, slipping off, slipping forward, etc. Without insoles, 50% wore pumps for less than 30 minutes, 25% for half a day (4-5 hours), and 25% for the whole day (6-8 hours). However, after wearing insoles, improvements were seen in 25% for less than 30 minutes and 75% for the whole day (6-8 hours). Regarding concerns, 75% of respondents said they felt tired, 50% said their feet hurt, 25% said their shoes slipped off, and 75% said their shoes slipped forward. However, after wearing the insoles, improvements were seen: 50% said they felt less tired, 25% said their feet hurt less, 75% said their shoes were less likely to slip off, and 50% said their shoes slipped forward less.

[0032] These problems were alleviated by flattening the heel's resting position and improving the outward tilt. The stable position of the foot in the pumps allowed for natural movement. By maintaining the calcaneus in a neutral position, increased muscle activity in the intrinsic muscles of the foot (muscles on the sole of the foot) increased, and the toes braced themselves, reducing forward slippage. This reduced the toes' tendency to hit the ground and pain. Furthermore, by preventing the heel from tilting outward, the ankle also did not tilt outward, preventing the opening of the shoe from widening, making it less likely for the shoe to slip off. As for fatigue, since foot movement plays a role, forward slippage, pain, and easy slipping off are likely due to factors that cause excessive tension in the feet. The reduction in these factors is thought to have reduced fatigue. The reduction in these problems led to longer wear of pumps. The improvement in the outward tilt improved the problems associated with wearing pumps and led to a higher quality of life. [Example]

[0033] This example is about sneakers. When comparing sneakers and sports shoes sold in Japan, sports shoes tend to have a stronger inclination of the inner sole. This is thought to be due to some reason during the design of the last, such as an error in the shoe's contact point with the ground (the line connecting the joint at the base of the big toe and the base of the little toe). In addition, many shoes are designed to absorb shock and are made of soft materials such as sponge, which can cause the shoes to become distorted.The current situation is that no consideration is given to the natural movement of the foot.

[0034] The line connecting the ball of the big toe and the ball of the little toe is the point where the shoe bends when walking. Shoes that bend at this point are said to be good shoes (D in Figure 14 is a good shoe). As the heel gets higher, the ground contact point moves forward. This is the same as standing on tiptoes, so the ground contact point moves forward from the line connecting the big toe and little toe. The shaded area in Figure 15 is the ground contact point. As the heel gets higher, this position moves forward. However, almost all shoes on the market (sneakers, pumps, leather shoes) are designed so that the heel touches the ground just before the line connecting these two points. In other words, the line connecting the ball of the big toe and the ball of the little toe is closer to the heel. Furthermore, when standing barefoot, the weight is supported by three points, as shown in Figure 13: the ball of the big toe (below the base of the big toe), the ball of the little toe (below the base of the little toe), and the heel (connecting these points forms an inverted triangle). The weight of the foot is distributed in a ratio of 3 (heel): 2 (ball of the big toe): 1 (ball of the little toe). The point where the shoe comes into contact with the ground should be in the diagonally shaded area shown in Figure 15, but because the shoe is tilted outward, it is thought that this ratio is disrupted and the proportion of the heel and ball of the little toe increases due to a misalignment with the structure that supports the weight of the foot. Heel-flat insoles can also correct this balance.

[0035] The inclination of the inner sole of a pair of sneakers was measured using a round level. The results are as follows: The outward tilt was 1-4°. In order to correct this outward tilt, the thickness and tilt of the sneaker insole of the present invention are configured as follows. Insole thickness and inclination Thickness: 5mm, Inclination: Inward 2-3°← Thick and soft outsole Thickness: 3mm, Inclination: Inward 1-2°←Outsole is thin and hard When the outsole of a sneaker wears down, it is common for the outside of the heel to wear down, but the actual area that wears down is the center of the heel. This has been said for a long time, and recent research has also shown the same thing. However, it is rare to see the center of the heel wear down in shoes sold in Japan. This is because, like pumps, the outside of the inner sole of sneakers is also lower. The shape of the insole is almost the same as that of pumps, but the heel height and outer slope are different, so the design takes this into consideration.

[0036] As shown in Figure 16, the topmost part has the same shape as pumps, and is shaped to support the heel and midfoot. This is because, like pumps, sneakers also have a lower outer edge, and this shape is designed to support this. The middle part in the second image is slightly smaller than the top part, to facilitate eversion (the heel tilting inward) of the subtalar joint (the joint formed by the calcaneus and heel), just like pumps. The reason for this size and shape was to adjust the overall inclination angle and to address pain that occurred in the plantar area (sole). The width behind the heel is wider by 1 cm than the middle part of pumps, and the inclination is gentler by 1°, making the inclination of the shoe closer to flat. A flatter inside the shoe makes it easier for the toes to move, allowing each person to perform their natural foot movements. The front part of the midfoot plate is half the length of the upper midfoot plate. This is to avoid interfering with the role of the lateral longitudinal arch (the arch at the base of the heel and little toe) in stabilizing the foot; in other words, it is set short by being at a height that does not come into contact with the lateral longitudinal arch (the arch at the base of the heel and little toe). Unlike pumps, sneakers do not have a front slope, so if the midfoot plate is too thick, the fifth metatarsal bone will be lifted too much when weight is applied, causing discomfort or pain. Therefore, the length was designed taking into account the lateral slope and the lateral longitudinal arch (the arch at the base of the heel and little toe).

[0037] The biggest difference is the heel tilt at the rear, where the heel rests (Figure 17). This part is slightly smaller than the upper part to induce eversion (the heel tilts inward) of the subtalar joint (the joint formed by the calcaneus and heel). The reason for this size is to adjust the overall tilt angle and to address pain that occurred in the plantar area (sole). This width is appropriate for creating the angle required for sneakers. Increasing the width by 1 cm makes the tilt 1° gentler. Therefore, in the case of sneaker-specific shoes, widening the width by 1 cm and easing the inclination by 1° reduces discomfort. Furthermore, when the rear section was cut diagonally from the front medial to the rear lateral, pain occurred in the plantar region (sole of the foot). This was caused by the numerous sensory receptors (receptors for touch, pressure, etc.) present in the sole of the foot, which were irritated by the diagonally cut section. Therefore, to prevent this sensation on the sole, a stepped shape (shown by the lines on the right in Figure 17, a straight vertical line, a diagonal left line, and then a straight downward line) was used. The reason for the 1 cm shorter medial width is that the medial longitudinal arch (the arch from the heel to the base of the big toe) is located in this area, so bone support is not required (the bones between the heel and the base of the big toe are floating), so it was shortened. Furthermore, supporting the arch from below would inhibit the truss mechanism, which is the foot's shock-absorbing mechanism (when weight is applied to the sole, the arch lowers, increasing the contact area and dispersing impact), which could potentially put strain on the foot, so the design does not support the arch.

[0038] The third and lowest midfoot plate was also made short for the same reason as the second midfoot plate. It was set to about 1 / 4 the length of the top midfoot plate, taking into account the length required for lateral support. Just like the insoles for pumps, the insoles for sneakers are designed not to support the medial longitudinal arch (the arch from the heel to the base of the big toe) from below. This is to avoid interfering with the medial longitudinal arch's role in dispersing shock. Excessive support from below prevents the foot from moving naturally and inhibits the arch's role. In order to efficiently use the two arches - the lateral longitudinal arch (the arch from the heel and base of the little toe), which is involved in foot stability, and the medial longitudinal arch, which is involved in dispersing shock - a stable environment inside the shoe is necessary. The design efficiently uses the foot's functions and reduces strain on the body. When walking with sneaker insoles, the wear on the shoes was corrected to the center. This was the result of eliminating the tilt inside the sneakers. It is thought that eliminating the external load in shoes that are worn frequently will also change the strain on the body. The survey results are shown below. Many people commented that the way they use their toes changed before and after putting the flat heel soles into their sneakers, making it easier to push off, that swelling in their feet was reduced, and that pain in their knees and hip joints was reduced even after walking for long periods of time. This shows that the present invention has been effective. [Example]

[0039] An example of sports shoes (inclination: outward inclination 1-4°) will be described. Sports shoes not only have an insole but also a shoe structure that raises the medial longitudinal arch (the arch from the heel to the base of the big toe). This creates a slope inside the shoe that is steeper than sneakers. It is thought that the internal structure is designed with the idea that a higher arch is better, but this leads to negative effects. Furthermore, the more strain a sport places on the body, the more effort is put into the construction and materials of shoes, but this does not take into account the actual condition of the feet when worn. As a result, there are shoes that work well when worn during exercise, and shoes that, despite their design, hinder foot movement and make it difficult to exercise. For example, when standing on one leg, such as in a volleyball or golf stance or when pitching, weight tends to be placed on the outside of the foot, causing the body to lean, which is thought to be due to the tilt inside the shoe.

[0040] The specific size and shape of the heel flat sole for sports shoes of the present invention is similar to that of sneakers, with a lesser inclination than pumps. Since sports involve movement in various directions, not just forward and backward, if the inclination is too strong, it may lead to strong movement guidance or restrict movement, so the inclination has been designed with this in mind. The shape will be as follows: Thickness: 5mm, Inclination: Inward 2-3°←For marathons and other races with thick outsoles and insoles Thickness: 3mm, Inclination: Inner 1-2° ← For indoor sports with thin outsoles and insoles The structure of the parts is the same as that of sneakers, and is designed to take the arch of the foot into consideration. This embodiment does not use a three-layer structure, but is instead molded as a single piece. Even if it is not three layers, as long as the thickness at the position where the foot rests is changed according to the purpose, it is not necessary to form it in two or three layers, and the same effect can be obtained with a single piece. Rather than supporting the foot with something, the focus is on efficiently using the foot's natural functions, and by setting the thickness and slope so that the foot movement is not restricted so that the athlete can move naturally, the insole can be used to move the foot naturally, allowing for more comfortable sports.

[0041] Additionally, because the lateral longitudinal arch (the arch between the heel and the base of the little toe) is lower than the medial longitudinal arch (the arch from the heel to the base of the big toe: arch of the foot), the thickness of the midfoot plate causes it to hit the fifth metatarsal, causing pain and discomfort. Therefore, by halving the length of the second midfoot plate and shortening the bottom third plate to 1cm, we were able to avoid obstructing the lateral longitudinal arch (the arch between the heel and the base of the little toe). By using the developed insole, the center of gravity is stabilized in the center when the player is ready to throw, making it easier to plant one's feet and providing a smoother and more stable pitching motion. The survey results are shown below. Many golfers commented that it was easier to plant their feet firmly when addressing the ball, and that their body swayed less. Additionally, many baseball players commented that it became easier to stand on one leg when pitching, and that their feet no longer moved around inside their shoes. Sprinters commented that they were now able to kick with the ball of their foot without thinking about it. Overall, using the insole of the present invention in sports shoes eliminated the need to consciously brace the foot or kick with the toes, making sports movements easier and more stable. [Industrial Applicability]

[0042] The present invention corrects the lateral height of the shoe sole, which is tilted so that the heel of the foot placed inside the shoe is horizontal to the ground, allowing the heel to maintain stability and balance. Furthermore, by adopting a shape that does not support the natural arch of the foot from below, the shoe creates an environment inside the shoe that allows for smooth movement of the natural human foot, including backward, sideways, and diagonal movements, as well as standing, sitting, and stopping. This solves many walking problems for all mankind and contributes to solving shoe troubles for people throughout society, and has industrial applicability.

Claims

1. The heel flat sole is an insole inserted into the inside of a shoe, and corrects the height of each outer side of the inclined sole of the inclined sole of the shoe so that the heel of the foot inserted in the shoe, which is inclined to the left and right outer sides relative to the ground, becomes horizontal to the ground, thereby correcting the inclination of the inclination of the inclined sole of the shoe.

2. 2. The heel flat sole according to claim 1, characterized in that it is shaped so as not to support the arch that the foot naturally has from below.

3. The heel flat sole according to claim 1 or 2, characterized in that it is not designed to be used only for moving forward, but does not have a forward tilt angle in order to accommodate the various movements that are necessary for natural human foot movements, such as moving backward, sideways, and diagonally, as well as standing, sitting, and stopping.

4. 4. The heat flat sole according to claim 1, wherein the heel flat sole has a layered structure or is integrally molded, and is composed of at least one of an upper part, a middle part, and a lower part.

5. The heel flat sole according to any one of claims 1 to 4, characterized in that the heel flat sole has a shape without a forefoot portion.

6. The upper, middle and lower parts have a length that is 50% to 70% of the user's foot size for lateral correction, the upper part has a heel width that is 70% to 90%, the middle part is smaller than the upper part from the center to the heel and the width decreases toward the heel, and the lower part has a width of 1 cm to 2 cm except for the center.

7. The heel flat insole for sneakers of the present invention is characterized in that it is composed of at least two parts, at least an upper part and a middle part, and in the case of a three-part composition, the length of the midfoot plate, which is the outer midfoot correction part of the middle part, is half the length of the midfoot plate of the upper part, and the length of the lower part is 1 cm.

8. The heel flat insole for sports shoes of the present invention is characterized in that it has a shape that corrects the outward tilt to a greater height than that of sneakers, since general sports shoes have a raised medial longitudinal arch, and the more it is raised, the more severe the outward tilt of the shoe's insole becomes.

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