Shoe insert

Abstract

A shoe insert including a bladder positioned within a main body. The bladder includes a fluid tight membrane defining an interior chamber containing a liquid. The bladder further includes a heel portion in fluid communication with lateral and medial passages, which are in turn in fluid communication with a metatarsal portion. A central island of solid material is bounded by the heel portion, the lateral and medial passages, and the metatarsal portion, such that the bladder is configured to move liquid contained within the interior chamber in a cycle that conforms to a natural gait cycle.

Description

RELATED APPLICATIONS

The present application claims priority benefits of U.S. patent application Ser. No. 60/565,918, entitled “Improved Shoe Insert,” which was filed Apr. 28, 2004, and is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Embodiments of the present invention generally relate to shoe inserts, and more particularly, to shoe inserts having a fluid filled bladder.

Typical shoe inserts are designed to cushion a foot during a gait cycle in order to reduce pressure on the foot. A normal gait cycle exerts pressure on the heel first, then the lateral portion of the foot, and then onto the metatarsal area of the foot. That is, when a person walks, the heel of the foot usually strikes the ground first. The natural progression of the gait then shifts the weight of the person from the heel area, to the lateral portion of the foot, and onto the metatarsal area of the foot.

FIG. 1 illustrates a plan view of bones of a human foot 10 and exertion of force by the foot during a gait cycle. The foot 10 includes a medial heel area 12, a lateral heel area 14, a lateral midfoot area 16, a lateral metatarsal area 18, a medial metatarsal area 20, a toe area 22, and a medial midfoot area 24. When a person walks, the weight of the person is distributed over the plantar surface of the foot as shown by arrows A. That is, as a person walks, a supporting surface (such as a floor) is first contacted by the medial heel area 12. As the walk progresses, contact is transferred from the medial heel area 12 to the lateral heel area 14, to the lateral midfoot area 16, onto the lateral metatarsal area 18, to the medial metatarsal area 20, and up through the toe area 22.

A need exists for an improved shoe insert that cushions and massages the plantar surface of the foot during the natural gait cycle.

SUMMARY OF THE INVENTION

Certain embodiments of the present invention provide a shoe insert including a fluid-filled central chamber, core, or bladder. The bladder includes a robust, fluid-tight membrane that defines an interior cavity, chamber, or the like that acts as a fluid circuit or track. The interior chamber is configured so that fluid contained therein is allowed to flow through the chamber. The shoe insert may be formed of solid, malleable silicone, rubber, elastomeric, foam, or other such cushioning materials. The fluid within the bladder may be liquid silicone, such as used with breast implants, water, saline, or various gelatinous materials mixed with a gas, such as air.

The fluid is configured to flow within the bladder when pressure is exerted on the bladder. In general, the fluid within the bladder flows in the exact manner in which the human foot distributes the body's weight across the plantar (bottom) surface of the foot during a natural gait cycle. For example, the fluid may flow in a direction from the heel to the lateral portion of the foot, through the metatarsal area of the foot, and finally through the toes in a medial portion of the foot. The displacement of fluid within the bladder of the shoe insert reduces shearing and stress forces on the foot as a person walks, and provides a shock absorbing cushion across the bottom of the foot.

Certain embodiments of the present invention provide a shoe insert configured to reduce the shear, stress and shock forces exerted on a human foot during a gait cycle. The insert includes a sealed bladder forming a chamber containing a mixture of liquid silicone and air. Optionally, the fluid may be any liquid, or semi-liquid material that is capable of flowing within the bladder. The bladder is shaped to directly correspond to the weight distribution pattern of the human foot. A central area or island of solid material may be positioned within the bladder that separates the medial portion of the foot from the lateral portion of the foot, and the heel portion from the metatarsal head area of the foot. The central area or island may be disposed within the bladder, or the bladder may be formed around the central area or island. Fluid flows from the heel portion, to the lateral portion, to the metatarsal head portion, to the medial portion, and back to the heel portion. The medial portion of the bladder may be expanded or widened to provide additional arch support to the foot.

Certain embodiments of the present invention provide a shoe insert in which the heel portion of the bladder is circular in shape. Further, the metatarsal head area may be shaped as a semi-circle or rectangle. The lateral and medial portions of the bladder may be elongated tubes spanning from the heel portion to the metatarsal head portion.

The shoe insert may be formed as a singular piece of material, such as solid, malleable silicone, foam, rubber, or the like, having the bladder formed therein. Optionally, the shoe insert may include a base member integrally formed with an upper cushioning member. The base member may be harder than the cushioning member. For example, the base member may be formed of solid silicone having a hardness of 50-75 durometer, while the cushioning member may have a hardness on the order of 10-25 durometer.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a plan view of bones of a human foot and exertion of force by the foot during a gait cycle.

FIG. 2 illustrates an isometric view of a shoe insert, according to an embodiment of the present invention.

FIG. 3 illustrates a cross-sectional view of a shoe insert along line 3-3 of FIG. 2, according to an embodiment of the present invention.

FIG. 4 illustrates a plan view of a shoe insert, according to an embodiment of the present invention.

FIG. 5 illustrates a plan view of a shoe insert, according to an alternative embodiment of the present invention.

FIG. 6 illustrates a plan view of a shoe insert, according to another alternative embodiment of the present invention.

FIG. 7 illustrates an isometric view of a heel wedge having an interior fluid bladder, according to an embodiment of the present invention.

FIG. 8 illustrates a transverse cross-sectional view of a heel wedge along line 8-8 shown in FIG. 7.

The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 illustrates an isometric view of a shoe insert 26, according to an embodiment of the present invention. As shown in FIG. 2, the insert 26 is foot-shaped and is configured to be inserted into a shoe. The shoe insert 26 may be sized to fit into various size shoes. The insert 26 may include a base member integrally formed with a top cushion member. The base member may be harder than the cushion member. For example, the hardness of the base member may be on the order of 50-75 durometer, while the hardness of the top cushion member may be on the order of 10-25 durometer.

The insert 26 includes a main body 28 having a base 30 (such as the base member discussed above), a top surface 32 (such as the top cushion member discussed above), and outer walls 34 that are integrally formed with the base 30 and top surface 32. A cushioning system 36 is positioned within the main body 28. The cushioning system 36 includes a bladder 38 that surrounds a solid interior area or island 40. The bladder 38 includes a robust, fluid-tight membrane 42 that defines an interior cavity 43, chamber, or the like that acts as a fluid circuit or track. The bladder 38 includes a heel portion 39 in fluid communication with lateral and medial passages 41 and 45, respectively. The lateral and medial passages 41 and 45 are in turn in fluid communication with a metatarsal portion 47. Thus, fluid contained within the bladder 38 may pass from the heel portion 39 to the lateral passage 41, onto the metatarsal portion 45, and returned to the heel portion 39 by way of the medial passage 45.

The interior island 40, which is bounded by the heel portion 39, the lateral and medial passages 41 and 45, and the metatarsal portion 47, is a solid piece of material that is integrally connected to the base 30 and the top surface 32. The main body 28 also includes solid areas that surround the perimeter of the bladder 38. Namely, the main body 28 includes an area defined by a medial area 44, a lateral area 46, a heel area 48 and a toe area 50 that surrounds the outer perimeter 52 of the bladder 38.

As shown in FIG. 2, the bladder 38 does not extend to the edges of the shoe insert 26. Instead, the lateral and medial passages 41 and 45 are recessed inwardly toward the interior island 40. For example, the medial passage 45 may be configured to conform to the medial shape of the foot. Because a normal arch of a foot raises above the bottom surface of the foot, the medial passage 45 may be recessed inwardly toward the island 40 to accommodate the anatomical shape of the normal arch. Additionally, the metatarsal portion 47 does not extend to the tip of the insert 26. Instead, the metatarsal portion 47 may be configured to not underlie or support a substantial portion of the toes. Optionally, the bladder 38 may extend to various areas of the shoe insert 26, including to portions that would substantially support the toes.

The fluid-tight membrane 42 of the bladder 38 may be formed of silicone, elastomeric materials, rubber, or any other materials that are capable of providing a fluid-tight barrier and robust enough to support the weight of a person without puncturing, tearing, or otherwise breaking. The cavity 43 defined by the fluid-tight membrane 42 contains a liquid such as liquid silicone, water, saline solution, or various other liquids. The cavity 43 may not be completely filled with liquid. Instead, a portion of the cavity 43 is filled with liquid, while the remaining portion is filled with a gas, such as air, thereby allowing the liquid contained within the cavity 43 to be displaced when a force is exerted on the bladder 38. During a gait cycle, as described with respect to FIG. 1, fluid is displaced within the bladder 38 as denoted by arrows C.

Alternatively, instead of a separate base member and top cushion member, the insert 26 may be formed of a single, unitary piece of material having the bladders 38 formed therein. For example, the insert 26 may include a single unitary main body having a uniform durometer and a bladder, which may have a different durometer, formed within the main body.

FIG. 3 illustrates a cross-sectional view of the shoe insert 26 along line 3-3 of FIG. 2, according to an embodiment of the present invention. As shown in FIG. 3, the metatarsal portion 47 is thinner than the heel portion 39. In particular, the shape of the shoe insert 26, and the bladder 38, tapers down from the heel portion 39 to the metatarsal portion 47.

FIG. 4 illustrates a plan view of the shoe insert 26. During a gait cycle, when the heel hits the ground, fluid is displaced from the heel portion 39 into the lateral passage 41, thereby supporting the heel and lateral portion of the foot as those portions of the foot support the weight of the person (i.e., as those portions of the foot are proximate the ground). As the gait progresses such that the metatarsals support the weight of the body, fluid is displaced from the lateral passage 41 to the metatarsal portion 47 of the bladder 38. As the shoe leaves contact with the ground, the fluid is passed from the metatarsal portion 47 back to the heel portion 39 by way of the medial passage 45. In general, as force, such as the weight of person, is exerted on the bladder 38 through a person's foot, a fluid cycle is produced in the direction of arrows C, which corresponds to, and follows, the gait cycle (as shown in FIG. 1) of a human foot during a natural gait or walk.

FIG. 5 illustrates a plan view of a shoe insert 54, according to an alternative embodiment of the present invention. As shown in FIG. 5, the bladder 55 occupies more space within the insert 54.

FIG. 6 illustrates a plan view of a shoe insert 56, according to another alternative embodiment of the present invention. As shown in FIG. 6, the insert 56 includes a bladder 57 having an expanded medial portion 59 configured to provide additional arch support.

FIG. 7 illustrates an isometric view of a heel wedge 60 having an interior fluid bladder 62, according to an embodiment of the present invention.

FIG. 8 illustrates a transverse cross-sectional view of the heel wedge 60 along line 8-8 shown in FIG. 7.

As discussed above and shown in the drawings, embodiments of the present invention provide an improved shoe insert that cushions and massages the plantar surface of the foot during the natural gait cycle. The embodiments of the present invention also provide a simple shoe insert having a fluid bladder that is devoid of valves, throttles, distinct fluid regulators, and the like.

While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A shoe insert configured to cushion a foot through a normal gait cycle comprising:

a main body formed of a solid material configured to support and cushion a foot, said main body being defined by an outer perimeter that bounds a heel area, a lateral area, a medial area, and a toe area; and

a bladder positioned within said main body, said bladder including a fluid tight membrane defining an interior chamber containing a fluid, said interior chamber being defined by a heel portion in fluid communication with lateral and medial passages, which are in turn in fluid communication with a metatarsal portion, wherein a central island of solid material is bounded by said heel portion, said lateral and medial passages, and said metatarsal portion, wherein said bladder is configured to move said fluid contained within said interior chamber in a cycle that conforms to the natural gait cycle.

2. The shoe insert of claim 1, wherein said fluid moves from said heel portion to said lateral passage during the natural gait cycle, wherein said fluid passes from said lateral passage onto said metatarsal portion during the natural gait cycle, and wherein said fluid is returned to said heel portion by way of said medial passage during the natural gait cycle.

3. The shoe insert of claim 1, wherein said fluid moves within said interior chamber in an exact manner in which a human foot distributes weight across a plantar surface of the foot during the natural gait cycle.

4. The shoe insert of claim 1, wherein said fluid is a mixture of liquid silicone and air.

5. The shoe insert of claim 1, wherein said main body includes a base secured to an upper cushion.

6. The shoe insert of claim 5, wherein said base is formed of solid silicone having a hardness on the order of 50-75 durometer.

7. The shoe insert of claim 5, wherein said upper cushion is formed of solid silicone having a hardness on the order of 10-25 durometer.

8. The shoe insert of claim 1, wherein at least one of said heel portion, said lateral and medial passages, and said metatarsal portion are recessed away from said outer perimeter toward said central island.

9. A shoe insert configured to cushion a foot through a normal gait cycle comprising:

a main body formed of a solid material configured to support and cushion a foot, said main body being defined by an outer perimeter that bounds a heel area, a lateral area, a medial area, and a toe area; and

a fluid-tight bladder containing a fluid supported by said main body, wherein said fluid is a mixture of liquid silicone and air, said bladder comprising a heel portion in fluid communication with lateral and medial passages, said lateral and medial portions also being in fluid communication with a metatarsal portion, wherein a central island of solid material is bounded by said heel portion, said lateral and medial passages, and said metatarsal portion, wherein said bladder is configured to move said fluid in a cycle that conforms to the exact manner in which a human foot distributes weight across a plantar surface of the foot during the natural gait cycle.

10. The shoe insert of claim 9, wherein said fluid moves from said heel portion to said lateral passage during the natural gait cycle, wherein said fluid passes from said lateral passage onto said metatarsal portion during the natural gait cycle, and wherein said fluid is returned to said heel portion by way of said medial passage during the natural gait cycle.

11. The shoe insert of claim 9, wherein said main body includes a base secured to an upper cushion.

12. The shoe insert of claim 11, wherein said base is formed of solid silicone having a hardness on the order of 50-75 durometer.

13. The shoe insert of claim 11, wherein said upper cushion is formed of solid silicone having a hardness on the order of 10-25 durometer.

14. The shoe insert of claim 9, wherein at least one of said heel portion, said lateral and medial passages, and said metatarsal portion are recessed toward said central island.

15. A shoe insert configured to cushion a foot through a normal gait cycle comprising:

a main body formed of a solid material configured to support and cushion a foot, said main body being defined by an outer perimeter that bounds a heel area, a lateral area, a medial area, and a toe area; and

a fluid-tight bladder containing a fluid supported by said main body, said bladder comprising a heel portion in fluid communication with lateral and medial passages, said lateral and medial portions also being in fluid communication with a metatarsal portion, wherein a central island of solid material is bounded by said heel portion, said lateral and medial passages, and said metatarsal portion, at least one of said heel portion, said lateral and medial passages, and said metatarsal portion being recessed away from said outer perimeter and toward said central island,

wherein said bladder is configured to move said fluid in a cycle that conforms to the exact manner in which a human foot distributes weight across a plantar surface of the foot during the natural gait cycle, wherein said fluid moves from said heel portion to said lateral passage during the natural gait cycle, wherein said fluid passes from said lateral passage onto said metatarsal portion during the natural gait cycle, and wherein said fluid is returned to said heel portion by way of said medial passage during the natural gait cycle.

16. The shoe insert of claim 15, wherein said main body includes a base secured to an upper cushion.

17. The shoe insert of claim 16, wherein said base is formed of solid silicone having a hardness on the order of 50-75 durometer.

18. The shoe insert of claim 17, wherein said upper cushion is formed of solid silicone having a hardness on the order of 10-25 durometer.

19. The shoe insert of claim 15, wherein the shoe insert is devoid of any valves.