IE47185B1 - Improvements in or relating to footwear - Google Patents

Description

The invention relates to footwear.

Footwear is known which is adapted to various demands to the function of the foot. This may be a suitable elaboration of the inner contact surface of the 5 sole and possibly combined with a special elaboration of the sole parts on the outer sole of the shoe. The designation of footwear adapted to the undeformed foot is natural-shaped footwear. However, the previously known footwear is not ideal for the foot in all respects.

According to the invention, there is provided a sole for footwear, having an upper surface with an indentation for receiving the ball of the heel of a foot of a wearer, the indentation forming a cup-shaped hollow which is arranged to be in contact with the lower surface of the heel of the wearer, there being provided an elevation arranged to be under the rearmost internal part of the arch of the foot in order to form a heel stop for preventing the foot from sliding forwards, the upper surface being provided under the ball of the foot and toes with a support that is sufficiently plastic to be substantially permanently formed by the foot and toes when the footwear is used, the upper side of the support - 3 being on a level with the rest of the upper surface prior to wearing of the footwear, the upper surface having no further elevations between the cup-shaped hollow for the heel and the plastic support.

A preferred sole gives the toes an increased freedom of movement, as the foot is prevented from sliding forwards in the shoe, when the foot touches the ground and rolls inwards during a step. In this way, complete heel contact with the upper surface may be achieved together with good weight distribution over the whole sole of the foot which is particularly useful for those who have to stand for long periods of time. Further, the risk for the foot to fall into a valgus-position in the ankle joint during standstill is reduced. The preferred sole does not provide a usual arch support because the arch of the foot can move freely, only the rearback third of the arch of the foot being supported. Bending of the big toe more or less inwards is thus avoided, causing a reduced possibility of function for the outwards guiding muscle and the long flexor muscle of the big toe.

In making the upper surface even in the part between the cup-shaped hollow and the ball of the little toe, a complete contact surface between the foot and the upper surface may be obtained, which means an even pressure on the foot, whereby callous skin, corns and 4718S - 4 blisters can be substantially completely avoided.

In using a support which is sufficiently plastic to be formed by the foot and toes when the footwear is worn, under the ball of the foot and toes, the forefoot may achieve a greater contact surface, as it may sink down into the sole to a suitable depth. This means that the ball of the foot is not overloaded especially at the end of the step, where the toes are bent very much upwards, as the toes can always take part in the step by the strong stretching out of the toe bending muscles, and thereby take up part of the weight load. This also means that the spreading- and gripping reflex can freely activate the muscles of the foot, as the toes to some extent can seize the support and keep together the forefoot when necessary. Because the support is workable, this also means that the support can take form according to the shape of the foot of the user, i.e. can be adapted to the user.

Further a small elevation will occur crosswise just behind the balls of the toe. Together with the heel stop, this will contribute to prevent the foot from sliding forwards in the shoe.

In elaborating the underside of the shoe as mentioned in claim 2, i.e. because the support for the ball is neither above nor below the support for the toe - 5 balls, favourable function conditions may be achieved under all conditions, i.e. when walking upwards as well as downwards. Hereby is achieved that the leg can be swung forwards in a relaxed way in general in the phase of stepping forwards without any unnecessary bending of the knee - and especially the hip joint. Further the heel is rounded in the front and in the back, whereby the shoe is worn into shape from the start. Thus unnecessary wear on the outside of the heel is avoided, and a wear distributed evenly over the whole underside is achieved.

In elaborating the sole with a straight axis as mentioned in claim 3, the heel part of the shoe will guide the foot straight forwards in the front part of the shoe, so that neither the big toe nor the little toe is squeezed.

As mentioned in claim 4, the sole may be made in one piece of plastics. This gives a light and flexible as well as wear-proof sole which to the least possible extent prevents the strong upwards bending in the metatarsophalangeal joint of the toes. Thus a functional wringing of the foot is possible and also of the whole sole lengthwise at the end of the step.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: - 6 Figure 1 shows the upper surface of a sole, Figure 2 shows the lower surface of the sole; Figure 3 is a sectional view of the sole taken on the line III-III in Figures 1 and 2; Figure 4 shows the sole as seen from the outer side; Figure 5 is a sectional view of the sole on the line V-V in Figures 1 and 2; and Figure 6 is a sectional view of the sole on the 10 line VI-VI in Figures 1 and 2.

The accompanying drawings illustrate an embodiment of a sole 1 of a right shoe, which sole has an outline as shown in Figure 1 and 2.

As shown in Figures 1 and 6 an indentation is 15 provided in the area of the balls of the foot and toes, in which indentation a piece of material 6 sufficiently plastic to be formed by the foot and toes when the footwear is worn is placed, for example a settled sheet of felt, the surface of which is on a level with the rest of the upper surface of the sole.

This yielding contact surface provides protection against overloading of the ball of the foot so that the spreading- gripping reflex can freely activate the muscles of the foot. Thus the risk of getting callous skin under the forefoot is reduced, and the contact - 7 surface is adapted individually to the foot after a short time so that an optimum even weight distribution and free function may be achieved in each case.

The condition that the toes can work as 5 described is that the front part of the shoe has room enough for the toes to bend, and further that the bones of the toes can lie in a straight extension of their metatarsal bones. This is achieved in that the sole is fan-shaped at the front, as shown in Figures 1 and 2.

Thus a slight spreading out of the toes is possible without the toes bumping against the vertical front wall of the shoe at full load. Further the front outline of the sole is softly rounded so that the shoe suits most foot types and not only the usual chamfered forefoot. Finally, there is provided enough room upwardly for the toes with the largest height at the big toe, and there is provided room for a slight upward bending of the toes during the phase of stepping forwards, as well as a slight curling when the foot is placed on the ground.

At the ball of the heel, the upper surface of the sole is slightly cup-shaped as shown in Figure 3 and 5. A cup-shaped hollow 7 is formed directly in the upper surface of the sole, so that the heel contact of the foot with the upper surface is optimum. The outline of the cup-shaped hollow 7 is indicated in - 8 Figure 1 by a circle. Thus the body weight is distributed over the whole heel and the surface pressure will be the lowest possible. Further, the sole is provided with a small elevation 8 under the rearmost third of the arch of the foot, the outline of this being indicated by a triangle in Figure 1. This elevation 8 is not the nature of an arch support, but a heel stop which prevents the foot from sliding forwards in the shoe. When the shoe is further provided with a suitable lacing, an unknown large freedom of movement for the toes is achieved, as the rearmost part of the shoe fits so tightly to the foot that the metatarsus and the toes are given complete freedom of movement.

The welt section of the sole slopes downwards from the outermost edge 9 at the bead towards the interior of the sole as shown in Figures 3 and 6.

This contributes to the keeping, of the foot over the upper surface of the sole and thus maintains the foot in a correct position on the support surface.

The lower surface 2 of the sole is in all essentials even with the exception of a minor upward bending at the front and back of the shoe, namely where the direction of motion of the foot runs through the ball of the big toe and heel. Further, the sole is without heel, i.e. without artificial heel indentation . - 9 Hereby an effective tightening of the strong peronei is secured before the actual step, and thus a stretching of the ankle, as a beginning of the step of the foot.

As a whole the sole is formed with a straight 5 axis, i.e. the sole does not curve. With a mounted upper part, this means that the heel section of the shoe and the sole guides the forefoot straight forwards in the front part of the shoe, so that neither the big toe nor the little toe is squeezed.

This elaboration with straight axis is in practice achieved in that the axis line of the foot, shown in Figures 1 and 2 as d-d, runs through the middle of the metatarsal bone of the second toe and through the centre of the cup-shaped hollow 7. The axis line d-d divides the front part of the sole in the proportion 3:4 over the ball of the foot, in Figure 1 in the section line VI-VI.

Thus the sole is as anatomically correctly formed as in practically possible in order to give the foot as much freedom in its function as possible. The freedom of movement achieved is comparable to the freedom of movement which is felt when walking without shoes. 4718S - 10 In the heel part and the instep part of the upper surface of the sole, some evenly distributed round recesses are arranged in order to reduce the weight of the sole. The sole may be manufactured of any suitable material. A preferred material is polyurethane which gives a light and wearproof as well as suitably yielding sole.

Claims (6)

1. WHAT WE CLAIM IS:1. A sole for footwear, having an upper surface with an indentation for receiving the ball of the heel of a foot of a wearer, the indentation forming a cup5 shaped hollow which is arranged to be in contact with the lower surface of the heel of the wearer, there being provided an elevation arranged to be under the rearmost internal part of the arch of the foot in order to form a heel stop for preventing the foot from sliding 10 forwards, the upper surface being provided under the ball of the foot and toes with a support that is sufficiently plastic to be substantially permanently formed by the foot and toes when the footwear is used, the upper side of the support being on a level with the 15 rest of the upper surface prior to wearing of the footwear, the upper surface having no further elevations between the cupshaped hollow for the heel and the plastic support.

2. A sole as claimed in Claim 1, in which the 20 underside of the sole is substantially even with the exception of a curved surface below the ball of the big toe and a curved surface below the ball of the heel, which curved surfaces bend upwards from a generatrix perpendicular to the direction of motion of the foot 25 towards the outer edge of the sole. 47188 - 12

3. A sole as claimed in claim 1 or 2, in which the sole is formed with a straight axis in order to guide the foot from the cupshaped hollow straight forwards in a line through the metatarsal bone of the 5 second toe.

4. A sole as claimed in any one of claims 1 to 3, in which the sole without the support is manufactured in one piece of a flexible plastics.

5. A sole substantially as hereinbefore 10 described with reference to and as illustrating in the accompanying drawings.

6. Footwear including a sole as claimed in any one of the preceding claims.