MXPA98000432A - Planti - Google Patents

Abstract

The invention relates to a suitable insole for relieving the foot, knee, hip and back in an upright position of rest and movement during walking or jogging, while obtaining a massage effect and equalizing pressure in an upright position of rest. The sole comprises a first chamber (5) filled with fluid and at least a second chamber (7,8) filled with fluid. The first fluid chamber (5) is preferably provided between a back sheet (3) and an intermediate sheet two, while at least a second fluid chamber (7,8) is provided between the intermediate sheet (2) and the top sheet (1). In a preferred embodiment the sole according to the invention comprises the additional chambers (25, 26) disposed in a central part (20) respectively along the inner side (21) of the sole, and having a convex surface (29, 30). The sole according to the invention makes it possible with only one sole to provide the foot with relief from both impact and pressure equalization during walking or jogging, while providing a massage effect and pressure equalization in an upright position. of rest

Description

TEMPLATE - DESCRIPTION OF THE INVENTION The present invention relates to a shoe insole, such insole comprising a top sheet and a back sheet, which are joined along their respective flange areas to form a first closed chamber between the top sheet and the back sheet, and said first chamber being filled with a fluid, and the template also comprising at least one intermediate sheet disposed between the top sheet and the back sheet and joined with the top sheet and the back sheet along the flange areas. US 4,115,934 describes a template produced from a plastic material comprising a first chamber filled with fluid. The sole further comprises second chambers filled with fluid and having a sealed periphery and placed completely within the periphery of the first chamber, but separated from the first chamber. The second chambers can be provided in a central or back front part of the sole. This template has the disadvantage that the individual cameras are completely separate. This is a disadvantage if the foot is going to be relieved in the form of impact absorption or foot massage. A fluid contained in a limited chamber is only capable of relieving impacts in the form of static pressure. US 4,567,677 also describes a template.

The sole also comprises a first chamber filled with fluid. The sole also comprises two flow barriers provided in the central part of the sole. The flow barriers extend in C shapes to form four additional flow channels and a large internal flow channel in the central part of the sole. This template has the disadvantage that there are no independent chambers that have fluid completely separated from the rest of the fluid. This is a disadvantage if the foot is going to be relieved from the pressure when the person is moving. A fluid that is capable, freely or subject to some restrictions in the form of barriers, of fluid freely in the entire extension of the sole, will be subjected to pressure from the loading area by the movement of the person which means that such sole it is only capable of relieving impacts that require absorption of impact when walking or running or a massage effect is required. US 4,864,737 discloses a sole for a shoe, such a sole having a plurality of first and second chambers separated by a sheet between the chambers. The first chamber contains a liquid and the second fluid contains gas. During the walk, the liquid that is not understandable will level out the pressure differences in the foot and the flow of liquid in the first chamber can vary by equalizing pressure with the gas in the second chamber. That sole has the disadvantage that the pressure relief that is effected is not controlled, that is, the pressure equalization can not be directed to specific parts of the foot that may require equalization or specific pressure relief. The gas has to be contained in the chamber without the purpose of establishing a pressure equalization at all in those known soles but it leads to a pressure equalization that is out of control. US 2,677,906 also describes a sole for a shoe. The sole comprises a topsheet, a backsheet and an intermediate sheet extending between the topsheet and the backsheet. Between the backsheet and the intermediate sheet, first chambers are formed and second chambers are formed between the intermediate sheet and the upper sheet. The first and second chambers are identical and all extend over a distance that is the entire width of the sole.

This sole also has the disadvantage that the pressure relief of the foot is symmetrically at least along the width of the foot. Along the length of the foot the pressure relief may be different. Nevertheless, there is no possibility of relieving pressure at different points of the foot, for example bones or specific areas within the ball of the foot. In addition, pressure relief will not occur and a massage effect will not occur due to lack of communication between the first and second different chambers. Therefore, there is a direct incompatibility of soles that are capable of equalizing pressure differences in portions of the sole and soles that are capable of absorbing impact or massaging the foot. In order to obtain the desired pressure equalization, the first comprises delimited chambers filled with fluid wherein in order to obtain the desired impact absorption and massage effect, the latter precisely does not comprise delimited fluid chambers, but rather a large chamber in which fluid can flow over the flow barriers from one end of the sole to the other. Accordingly, it is not possible, with the soles known so far, to provide a sole which is capable of providing the foot with equalization of pressure in an upright position of rest and movement while at the same time the sole is capable of providing foot absorption of the foot. impact and effect of massage. US 4,567,677 attempts to solve this problem by providing barriers around the middle part of the sole in such a manner that the front and back sides of the sole similarly show delimited fluid chambers. However, this means that the various types of foot relief are not optimal since US 4,567,677 describes an accommodation solution. The object of the present invention is to provide a sole which does not possess the aforementioned disadvantages and, therefore, provides the foot with optimum relief of all types of impacts on the foot and not only certain types of foot impacts. This object is achieved by the present invention, characterized in that the first chamber extends along a distance from a more frontal boundary line to a more posterior boundary line, such distance being at least substantially the length of a foot from the heel at the most posterior end of the fingers, and the width of the sole being substantially, and because at least two second chambers extend along distances that are less than the distances in length and width along which the first chamber is extended, and because the first chamber has joints between the back sheet and the intermediate sheet, such joints extend into the first chamber. A sole that possesses these characteristics is capable in any optimal signature of providing the foot with relief from both pressure loads in the upright position of rest and movement in the form of walking or jogging as well as impacts during walking or jogging along with the establishment of a massage effect. The objective is furthermore obtained by means of a jig characterized in that the first chamber extends along a distance from a more frontal delimiting line to a more posterior delimiting line, such distance being at least substantially the length of a foot from the heel at the rearmost end of the fingers, and the width of the sole being substantially, and in that at least two second chambers extend along distances that are less than the distances in length and width along which the distance extends. First chamber, and because the first chamber has joints between the back sheet and the intermediate sheet, such joints extend into the first chamber. The topsheet, the intermediate sheet and the backsheet are preferably made of plastic. The first chamber is preferably disposed between the intermediate sheet and the backsheet and at least the second chamber between the intermediate sheet and the topsheet. It will also be possible, however, to arrange the first chamber between the intermediate sheet and the upper sheet and at least one second chamber between the intermediate sheet and the back sheet. In a preferred embodiment at least the first chamber is provided with assemblies of the backsheet and the intermediate sheet, alternatively the upper sheet and the intermediate sheet. The gaskets are provided on part of the sole extension to create restrictions on the liquid flow of the first chamber such that the flow velocity in the first chamber is reduced. In a second preferred embodiment a delimiting line is formed between an area of the sole intended to come into contact with the barefoot and the area of the sole intended to be in contact with the fingers. A second boundary line is formed between an area intended to contact the metatarsal and an area intended to contact the heel.

DESCRIPTION OF THE DRAWINGS The invention will now be described in detail with reference to the accompanying drawings in which: Figure 1 is a sectional view of a first embodiment of a sole according to the invention, and Figure 2 is a plan view of the first embodiment of the sole according to the invention, Figure 3 is a view in plant of a second embodiment of a sole according to the invention, Figure 4 is a plan view of the second embodiment according to the invention illustrating the flow lines for the fluid flow, Figure 5 is a view in plant of a third embodiment of a sole according to the invention, Figure 6 is a plan view of a fourth embodiment of a sole according to the invention, Figure 7 is a plan view of a fifth embodiment of a sole according to the invention, and Figures 8-11 are sectional views of the fifth embodiment according to the invention. Figure 1 illustrates a modality of a sole according to the invention. The sole consists of three capable of sheet, a top sheet 1, an intermediate sheet 2 and a back sheet 3, respectively. The topsheet 1 is intended to be placed in contact with the foot of a person wearing shoes with the insole disposed therein, while the backsheet is directed to contact the inner sole of the shoe. The upper sheet 1, the intermediate sheet 2 and the back sheet 3 of the embodiment shown extend over the entire extension of the sole in a length L and in a width B. The upper sheet 1, the intermediate sheet 2 respectively the back sheet 3, are joined along a flange area 4. The sheets 1, 2, 3 of the embodiment shown are produced from plastic and the joints have been established by welding the sheets. Between the back sheet 3 and the intermediate sheet 2, a first fluid chamber 5 is formed in the lower part of the sole. The first fluid chamber 5 extends substantially all along the length L of the sole except for the area 6 which is directed to contact the toes of the person wearing shoes with the insole disposed therein. Between the upper sheet 1 and the intermediate sheet 2 at least a second fluid chamber 7 is formed in the upper part of the sole, in the embodiment shown two second chambers 7,8 of fluid. The second fluid chambers 7, 8 are formed by joining the intermediate sheet 1, the intermediate sheet 2 and the top sheet 1 along the boundary lines 9.9a and along the flange area 4 (see FIG. 2) of FIG. such that they are designed to be in contact with the foot ball, respectively a heel, of the person wearing shoes with the insole arranged inside. Other additional positions or positions of the second fluid chambers 7,8 may be provided, however, for example one or more fluid chambers may be formed under the metatarsal of the person in question. The second fluid chambers are filled with fluid at a given pressure, which in the embodiment shown means that an upper side 10 of the top sheet 1 is flat and the second chambers 7,8 of fluid in a discharged condition. However, it will also be possible to fill a liquid at a higher pressure in such a way that the upper side of the upper sheet is convex in the second chambers 7, 8 of fluid in a discharged condition. In the first chamber 5, the joints 11 of at least the intermediate sheet 2 and the back sheet 3, alternatively also the upper sheet 1, are provided in the area 12 in the metatarsal (see Figure 2). The joints 11 are formed as enhancements, but other modalities of the joints can be established. The joints 11 are established to prevent the liquid in the first chamber 5 from accumulating under the metatarsal. In the first chamber, the joints 15 of at least the intermediate sheet 2 and the back sheet 3 are provided as alternately illustrated also the upper sheet 1, immediately after the position of the heel on the sole and immediately before a pressure area of the foot bones (see Figure 2) as seen in the direction from the heel act the fingers. The gaskets 15 are formed as enhancements, but other embodiments of the gaskets 15 can be established. The gaskets 15 are provided to give the sole two impact absorbing functions by reducing the flow velocity of the fluid as the flow flows back and forth. forwardly between the front part 13 and the rear part 14 of the sole respectively forward on the sole during loading on the heel and backward on the sole during loading on the front of the foot. In the second chambers 7,8 the corresponding joints 15 can also be provided between the upper sheet 1 and the intermediate sheet 2, possibly through the back sheet 3. Figure 2 illustrates the embodiment of the sole according to the invention shown in FIG. Figure 1. The topsheet 1, the intermediate sheet 2 and the backsheet 3, (see Figure 1) are joined, as mentioned along the respective flange areas 4 of the sheets. The intermediate sheet two (see Figure 1) is attached along the lines 9.9a delimiters preferably with the topsheet 1 as illustrated in Figure 1, alternatively the backsheet 2 if the second cameras 7,8 are set in the lower part of the sole instead of the upper part of the sole. In the embodiment shown, as mentioned, the seals 11 in the form of enhancements are provided in the first chamber 5 between the intermediate sheet 2 and the back sheet 3, but the enhancements 11 can be made through the 3 capable of the sheets 1, 2, 3. Similarly in the embodiment shown the joints 5 in the form of enhancement are provided in the first chamber between the intermediate sheet 2 and the back sheet 3, but the enhancements 15 can also be made through the 3 capable of sheets and therefore also through the second cameras 7,8. The area 6, which is intended to be brought into contact with the fingers, is not provided with the fluid chambers, since the fingers are not subjected to very heavy loads in an upright rest or moving position. Figures 3-5 illustrate other embodiments of a sole according to the invention. The topsheet 1, the bottom sheet 2 and the backsheet 3 (see Figure 1) are, like the sole shown in Figure 1 and Figure 2, joined through the respective flange areas 4. The intermediate sheet 2 is also, like the sole illustrated in Figure 1 and Figure 2, attached along the delimiting lines 9, 29a preferably with the upper sheet 1 as illustrated in Figure 1, alternatively the sheet posterior 3 if the second chambers 7,8 are set in the lower part of the sole instead of the upper part of the sole. Figure 3 illustrates the seals 11, 15 in the form of enhancements which in the embodiment shown are provided in the first chamber 5 and the second chamber 7 between the upper sheet 1 and the back sheet through the intermediate sheet 3. The highlights 11, 15 can also be provided in the second chamber 7 between the upper sheet 1 and the intermediate sheet 2. Correspondingly, the joints in the shapes of the connecting lines 16, 17, 18 are provided in the first embodiment shown in the first chamber 5 and the second chamber 7 between the upper sheet 1 and the rear sheet 3 through the intermediate sheet 2. The connecting lines 16, 17, 18 can also be provided in the second chamber 7 carried through the three capable of lamellae and also also of the second chambers 7, 8. The area 6 which is intended to be put in contact with the fingers, is not provided with the fluid chambers. The lugs 11, 15 are circular and are provided between the heel and the metatarsal as well as on the outer side 19 of the sole between the heel and the forefoot. The connecting lines 16, 17, 18 has the same thickness. and they also extend between the heel and forefoot both in a central part 20 of the sole and along an inner side 21 of the sole. The connecting lines 16, 17, 18 are divided into a first line 16, a second line 17, and a third line 18. The first line 16 extends in a forward arc of the foot and inwards towards a central line A of the sole. The second line 18 extends downward toward the heel from the central line A, along the central line A and further inward toward the inner side 21 of the sole. A third line extends in the central portion 20 of the soles substantially parallel to the second line 1 7 between the foot and the heel. Between the foot and the area 6 intended to be brought into contact with the fingers, a delimiting line 9a is provided with the delimiting tabs 9b extending from the line 9a delimiters back towards the foot. The delimiting tabs 9b are directed to prevent the flow from being subjected to pressure between the transition of the foot and fingers. Figure 4 illustrates that on the walk the extensions of the lugs 11, 15 and the connecting lines 16, 17, 18 lead to a flow of fluid between the heel and the foot and back of the heel as illustrated with the arrows The fluid flow extends from the boundary line 9 between the heel and the metatarsal passes the lugs 11, 15 along the outer side 19 of the sole and around the first line of junction 16 as illustrated by the black arrows . The fluid then extends backwards towards the heel between the connecting lines 16, 17, 18 and between the outer side 19 and the inner side 21 of the sole. Figure 5 also illustrates the embossments 11, 15, the connecting lines 16, 17 and the delimiting tabs 9b. The lugs 11, 15 are oval and are provided both along the outer side 19 of the sole and along the inner side 21 of the sole between the heel and the foot. The gasket 15 is drop-shaped with the tip of the drop extending away from the bead. The connecting lines 16, 17 also extend between the heel and the foot in the central part of the sole. The joining lines 16, 17 are divided into a first line 16 and a second line 17. The first line 16 is of uniform thickness and extends in an arc forward towards the foot, inwards and crosses the central line A of the sole. The second line 17 is provided with the drop shapes 22 and extends downward toward the heel from the inner side 21 of the sole towards the central line A of the sole, further along the central line A and further inward towards the inner side 21 of the sole to converge with the enhancement 15. Between the foot and the area 6, which is intended to come into contact with the fingers, the delimiting line 9a is provided with the delimiting tabs 9b extending from the line 9a delimiter back towards the foot. The embossments 11, 15 of the embodiment shown are in the form of a drop, and the attachment line 1 7 of the relief shown is provided with the drop shapes 22 at the ends of the line 17 and in a first fold 23 of the line. By designing the lugs 11, 15 and the joining line 17 in this way, a quieter fluid flow is obtained since a fluid diffusion that flows past the lugs 11, 15 the liner lines 16, 1 7 is reduced with which reduces the formation of turbulence in the fluid to a minimum. Figure 6 illustrates a sole substantially similar to the sole illustrated in Figure 3. In the embodiment shown, the joints 11, 15 in the form of enhancement are also provided in the first chamber 5 between the top sheet 1 and the back sheet 3 through the intermediate sheet 2, but the lugs 11, 15 can also be provided between the upper sheet 1 and the intermediate sheet 2 and the back sheet 3. Correspondingly, the joints in the shape of the joining lines 16, 17, 18 they are also provided in the first chamber 5 and the second chamber 7 between the top sheet 1 and the back sheet 3, but the joining lines 16, 17, 18 can also The upper sheet 1 is provided with the intermediate sheet 2 or between the intermediate sheet 2 and the back sheet 3. In contrast to the embodiment shown in Figure 3, however, the area 6 (see Figure 3), which is intended for get in touch with your fingers, has been discarded. In addition, the delimiting tabs 9b (see Figure 3) have been discarded at the same time that a bevelling 24 of the sole has been established. Omitting the area 6, it is achieved that fingers that bend strongly as hammer toes have the largest possible space in the shoe without the sole according to the invention taking up space under the fingers. The bevelling 24 does not feel the transition between the insole and the inner sole of the shoe. Figure 7 illustrates a sole substantially similar to Figure 3, but provided with more delimiting lines 9. By providing the sole with several delimiting lines 9, it achieves that the individual divisions of the second chambers 7, 8 can be established. The divisions are illustrated by the second chambers 25, 26, 27. The divisions in the shape of the second chambers 25, 26, 27 may have different characteristics and qualities of pressure equalization and relief (see Figures 8-11). In the embodiment shown, the seals 11, 15 in the form of enhancements are also provided in the first chamber 5 and the second chambers 27 between the topsheet 1 and the backsheet 3 through the intermediate sheet 2, but the enhancements 11 they can also be provided between the upper sheet 1 and the intermediate sheet 2 or between the intermediate sheet 2 and the back sheet 3. Correspondingly, in the embodiment shown, the joints in the shape of the lines 16, 17, 18 together are also provided to the first chamber 5 and in the second chambers 7, 8 between the upper sheet 1 and the back sheet 3 through the intermediate sheet 2, but the joining lines 16, 17, 18 can also be provided between the upper sheets 1 and the intermediate sheet 2 or between intermediate sheet 2 and back sheet 3. Area 6, which is intended to be in contact with the fingers, is also illustrated. Figures 8 to Figures 11 illustrate sectional views through the sole illustrated in Figure 7. The sections are illustrated through different planes, which are all perpendicular to the central axis A of the sole. Figure 8 is a first sectional view through a part of the sole intended to be placed in contact with the foot. The sectional view illustrates the first chamber 5 formed between the backsheet 3 and the intermediate sheet 2 and the second chamber 7 formed between the intermediate sheet 2 and the upper sheet 1. The second chamber 7 extends substantially over the entire width B of the sole and has a substantially planar surface 28. One of the delimiting tabs 9b is illustrated.

Figure 9 is a second sectional view through a part of the sole intended to be in contact with the metatarsal. The sectional view illustrates the first chamber 5 formed between the back sheet 3 and the intermediate sheet 2 and the second chambers 25, 26, 27 formed between the intermediate sheet 2 and the upper sheet 1. The second chamber 25 extends in the central part 20 of the sole a relatively pronounced convex surface 29. The second chamber 26 extending along the inner side 21 of the sole has a relatively lightly convex shaped surface 30. The second chamber 27 that extends along the outer side 19 of the sole has a flat surface 31 since the second chamber 27 of the embodiment shown does not contain fluid. Lines 16, 17 are illustrated. Figure 10 is a third sectional view through a part of the sole intended to be in contact with the arch of the foot. The sectional view illustrates the first chamber 5 formed between the back sheet 3 and the intermediate sheet 2 and the second chambers 26, 27 formed between the intermediate sheet 2 and the upper sheet 1. The second chamber 26 extending along the inner side 21 of the sole has a relatively hard convex surface 32 in the view shown. In the second chamber 27 that extends along the outer side 19 of the sole has a flat surface 31 since the second chamber 27 of the embodiment shown does not contain fluid. The joining line 7 is illustrated. Figure 11 is a fourth sectional view of the sole intended to come into contact with the heel of the foot. The sectional view illustrates the first chamber 5 formed between the backsheet 3 and the intermediate sheet 2 and the second chamber 8 formed between the intermediate sheet 2 and the upper sheet 1. The second chamber 8 extends substantially over the entire width B of the sole and has a substantially planar surface 33. The convex surface 29, 30 of the second chambers 25, 26 is provided by applying some pressure to the fluid in the second chambers 25, 26. Orthopedic favorable qualities are obtained in the sole by giving the second chamber 25 a relatively hard, convex surface 29 along the length of the sole which is intended to be brought into contact with the center of the metatarsal and, likewise, giving the second chamber 26 a convex surface 30 along the part of the sole which is intended to be brought into contact, with the arch of the sole. foot. In the embodiments of a sole according to the invention shown in the Figures, a sole is shown having an outline corresponding to the majority of the footwear. However, it will be possible to provide a sole having a different contour for special footwear, for example orthopedic shoes. Therefore, in the embodiment shown the sole is illustrated with the first chamber formed between the intermediate sheet and the backsheet and the second chambers between the intermediate sheet and the upper sheet. Alternatively, the second chambers may be formed against the backsheet and the first chamber against the topsheet. The intermediate sheet of the embodiment shown extends over the entire length L of the sole but it will be possible to allow the intermediate sheet to extend to the same extent that it is desired to extend the second fluid chambers. The number of second fluid chambers and the extensions and shapes of the fluid chambers can also be varied. Finally, the shape, number and positions of the seals constituting the flow restrictions on the fluid in the first chamber and the second chambers, respectively, can vary.

Claims (10)

1. A shoe insole, such a sole having a width B and a length L and comprising a top sheet, a back sheet, which are joined along their respective flange areas and at least one intermediate sheet disposed between the top sheet and the back sheet and joined with the top sheet and the back sheet along the flange areas, a first closed chamber is formed between the back sheet and the intermediate sheet and is filled with a fluid, the second closed chambers are formed between the intermediate sheet and the upper sheet and are also filled with a fluid, and the intermediate sheet joins the upper sheet along the boundary lines characterized in that the first chamber extends over a distance from a further boundary line frontal to a further posterior boundary line, such distance being at least substantially the length of a foot from the heel to the posterior end r of the fingers and substantially being the width B of the sole, and at least two second chambers extend in at least one area corresponding to the areas for support of a foot, the metatarsal or the arch or the heel of a foot and along distances that are less than the distances in wide length along which the first chamber extends, and the first chamber has the joints between the back sheet and the intermediate sheet, such joints extending within the first camera.

2. A sole footwear insole having a width B and a length L and comprising a topsheet and a backsheet that are joined along their respective flange areas and at least one intermediate sheet disposed between the topsheet and the top sheet. back sheet and joined with the top sheet and the back sheet along the flange areas, a closed first chamber is formed between the top sheet and the intermediate sheet and is filled with a fluid, the second closed chambers are formed between the intermediate sheet and the backsheet and also are filled with a fluid, and the intermediate sheet is joined to the backsheet along the boundary lines characterized in that the first chamber extends over a distance from a more frontal boundary line to a more posterior boundary line, such distance being at least substantially foot length from the heel to the most posterior end of the heel fingers and substantially the width B of the sole, and at least two second chambers extend in at least one area corresponding to the areas for support of a foot ball, the metatarsal or the arch or the heel of a foot and over the distances being less than the distances in length and width along which the first chamber extends, and the first chamber has the joints between the backsheet and the intermediate sheet, such joints extend within the first camera.

3. A template according to claim 1 or claim 2 characterized in that the joints extend along distances that are less than one length and less than a width of the first chamber within which the joints extend.

4. A template according to any of the preceding claims, characterized in that the sole comprises a second chamber disposed in a central part of the sole in an area preferably in the arch of the foot, more preferably in the back part of the sole in the heel of the foot. foot, and more preferably on the front of the sole in the foot bones.

5. A template according to any of claims 1-3, characterized in that the sole comprises a second anterior chamber disposed in a front part of the sole in the foot bones and a second posterior chamber disposed in a posterior part of the sole in the foot. heel of the foot .

6. A template according to claim 5, characterized in that the sole also comprises at least a second central chamber disposed in a central part of the sole preferably in the metatarsal bones of the foot, more preferably in the arch of the foot, more preferably both in the metatarsal bones and in the bones of the foot.

7. A template according to any of the previous claims, characterized in that the sole is provided with barriers formed by means of joints of the intermediate sheet and the posterior sheet and optionally joining the upper sheet, the intermediate sheet and the posterior sheet in the areas between respective flange areas.

8. A template according to any of the previous claims, characterized in that the upper sheet, the back sheet and the intermediate sheet are produced from plastic, and the respective flange areas, the delimiting lines and the joints consist of plastic welds.

9. A template according to any of the preceding claims, characterized in that the sole comprises at least a second chamber extending in a central part of the sole, preferably two second chambers extending in the central part of the sole, respectively along an inner side of the sole, and at least one second chamber, preferably at least two second chambers, has or have a convex surface.

10. A template according to any one of the preceding claims, characterized in that the sole comprises delimiting tabs extending from the delimiting line between an area intended to be in contact with the fingers and an area intended to be in contact with the foot and the delimiting tabs they extend from the delimiting line and inwards in the area destined to get in contact with the foot.