Dorsiflexion shoe
A high performance dorsiflexion shoe has a sole and a constraining device above the metatarsal-phalangeal joint. The sole has a ground-contacting surface, a forefoot region, a midfoot region and a heel portion. The forefoot region is made of a high density material, and has a thickness, measured in a direction perpendicular to the ground-contacting surface of the sole, greater than the thickness of the heel portion, thereby defining a characteristic angle of declination from the forefoot region to the heel portion. The constraining device substantially constrains a wearer's metatarsal-phalangeal joints from movement when exercising. The forefoot region has a curved form defined so as to further minimize flexion of the metatarsal-phalangeal joint.
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This invention relates to shoes, and, more particularly, to leisure and athletic shoes that promote dorsiflexion.
In standard shoes, the metatarsal phalangeal joints remain in a bend position at take-off and is unable to generate any energy during jumping and only a very small amount of energy during running due to the fact that the shoe does not straighten until after take-off when any return of energy is too little, too late, having no influence on performance. The used energy is therefore lost and useless for aiding propulsion in jumping or running. Over the past years, specialized track and field shoes have progressed in that they have begun to have relatively stiff midsoles.
In contrast, general athletic shoe manufacturers seem to be moving toward running shoes that are more flexible at the metatarsal phalangeal joint by either increasing the flexibility of materials used in their manufacture or by modifying the structure of the midsole (e.g., incorporating flexion grooves). This, unfortunately, has no benefit with respect to propulsive performance and is driven by pre-conceived notions.
During athletic activities, analysis of resultant joint moments and joint power indicate that for each joint, there are phases when energy is absorbed and phases when energy is generated. If the absorbed energy is dissipated and not stored for later re-use, it is wasted (i.e., it merely generates heat). If the stored energy can be reused, then performance can be increased.
The metatarsal phalangeal joint is one joint which, heretofore, has been a sink for energy dissipation and very little energy generation at or before take-off. This is because an athlete's foot rolls onto the forefoot and does not plantarflex until after take-off.
U.S. patent application Ser. No. 09/833,485 to Whatley, the content of which is herein incorporated by reference thereto, describes a shoe that utilizes dorsiflexion in an effort to increase the working of the certain muscles during exercise, with particular emphasis on enabling a larger range of motion of the foot so as to better work the calf. Dorsiflexion is brought about by a shoe which is inclined backwards (i.e., declined) to that of a normal plantar shoe. Essentially, instead of the heel being supported at a point higher than the toe, the inverse is true, with the angle of reverse incline being approximately 10 degrees. The shoe has proven to be extraordinarily stable. However, the incline of 10 degrees and the particular clumsy appearance of the shoe have limited its marketability and usefulness to all but those who are professional athletes.
Because of the dorsiflexion, one must ensure a rolling effort of the foot in order to avoid harm to the user's musculature and joints. The form of the sole, in which, in a forward end of the sole, the sole is thicker and of a cylindrical form, is such that it approximates the natural rolling effect of the foot.
What is needed is an athletic shoe that takes advantage of the energy generation capacity of the metatarsal phalangeal joint. Further, what is needed is an improved dorsiflexion shoe that takes better advantage of the mechanism of dorsiflex action in order to gain improved power output, comfort and performance. Still further, what is needed is a dorsiflex shoe that has a more conventional form, in order to improve the marketability and comfort of the shoe.
SUMMARY OF THE INVENTIONA high performance dorsiflexion shoe has a shell, an upper, and a constraining device above the metatarsal-phalangeal joint. The shell has a sidewall portion connected to a sole portion. The sole portion has a ground-contacting surface, a forefoot region, a midfoot region and a heel portion. The forefoot region is made of a high density material, and has a thickness, measured in a direction perpendicular to the ground-contacting surface of the sole, greater than the thickness of the heel portion, thereby defining a characteristic angle of declination from the forefoot region to the heel portion, when the wearer is in a standing position. The constraining device substantially constrains a wearer's metatarsal-phalangeal joints from movement when exercising. The forefoot region has a curved form defined so as to further minimize flexion of the metatarsal-phalangeal joint.
In another feature, the angle of declination is between 1 degree to 15 degrees, preferably 5 degrees.
In another feature, the shoe includes a reinforced, padded toe portion.
In another feature, the heel portion is substantially comprised of a low density, viscous-like material, adapted for fitness and training shoes.
In another feature, the sidewall of the shell is formed so as to give the impression that the shoe is a conventional plantarflex shoe.
In a further advantage of the invention, the 5 degree dorsiflex angle produces a shoe that appears more conventional (plantar flex) and thus to be significantly less clumsy, more natural and comfortable, and therefore, much more likely to be purchased and used by amateur athletes as well as professional athletes.
In another advantage, the fact that the angle of reverse incline is lesser with the invention as compared to dorsiflex shoes of the prior art, less material is required in the manufacture. Less material equates to less cost in manufacture as well as a lower minimum weight to the shoe.
In another advantage, the shoe of the invention is capable of interfacing with interchangeable insoles of various weight, energy absorption capacity, and rigidity, thus enabling the wearer a greater flexibility in configuring the invention for a particular type of sports activity. Further, the fact that the minimum weight has been reduced, due to the reduced bulk in the sole, means that an even greater range of weight of the shoe is possible.
In a further advantage, the shoe is configured to receive insoles which adjust the thickness of the rear of the shoe from extreme dorsiflex to plantarflex, thus avoiding morphological problems which occur where an insole is designed so as to increase the thickness of the forward portion of the sole from plantarfex to dorsiflex.
In another advantage, the invention eliminates the need for the metatarsal-phalangeal joint to flex because the shoe itself reproduces the movement of this joint and the toes.
In another advantage, the invention improves the capacity of the foot by improving its efficiency while minimizing the risk to harm to the foot by making the shoe out of materials that absorb stress and by reproducing the rolling motion of the foot.
BRIEF DESCRIPTION OF THE DRAWINGS
In the preferred embodiment, as shown in
The angle α of declination may vary significantly, from between 1 degree and 15 degrees. The preferred angle is 5 degrees.
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The measured stiffness of the shoe 10 in the region of the power plate 66 is selected so as to be in the range of 0.1N.M.Deg-1 and 0.5N.M.Deg-1. The shape, length, positioning and density of the power plate 66 vary depending on the intended sport or competitive application. In order to minimize impact on the metabolic cost of propulsion, the weight of the power plate 66 is in the range from 30 to 250 grams. Essentially, the power plate 66 is positioned so as to minimize flexing of the metatarsal phalangeal joint 20, in an effort to reduce energy loss at this joint, particularly during running and jumping.
The invention substantially reduces energy loss due to metatarsal-phalangeal flexing during running (including slow jogging from speeds of 2 meters/sec through fast sprinting at speeds of 10 meters/sec) and jumping (including any propulsive activity from submaximal hopping to maximal jumping in vertical, horizontal and lateral directions). The inventors have shown that, using the invention as compared to a conventional plantarflex shoe, jumping performance can be increased from 5% to 10%, and in running, by about 5%. Testing has shown that, in jumping, the power plate 66 absorbed an average of 24 J during one-legged jumping, assuming a body mass of 70 Kg, which corresponds to a difference in jump height of approximately 3.5 cm.
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The selection of a suitable relative thickness and rigidity for the materials used in the construction of this hybrid sole 130 is important in order to balance the interests of providing dorsiflexion working and protection to the heel.
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In the configuration shown in
The embodiment of
In another embodiment, the insoles 104′ are designed so as to be stackable, lifting the heel in 2.5 mm to 15 mm increments which represent from 1 to 6 degree changes in dorsiflexion. The dashed line 108 indicates a possible location of the interface between two layering insoles 104″. The insoles 104″ are formed so that The first-installed insole 104″ has a lower surface which conforms to the form of the shell 12, and an upper surface formed to adapt to a wear's foot 40, and the second-installed insole 104″ formed to conform to the top surface of the first-installed insole, itself having a top surface that conforms to a wearer's foot. This provides the wearer with the ability to select the angle of declination, and thus the degree of dorsiflexion. It should be noted that the insoles 104′ must also be constructed of a material having a comparable compression factor with the shell 12, in order to ensure the selected dorsiflexion performance in operation.
Still further, in order to create a shoe that does not appear, from the exterior to be a dorsiflex shoe, the side wall portion 22 rises up and surrounds the heel area of the wearer and continues in a direction toward the toe region 62 at an angle ⊖ which is less than dorsiflex than the maximum dorsiflex attainable in the shoe. In this embodiment, the angle ⊖ is in fact plantarflex, so that the dorsiflex configuration is only apparent to the wearer.
The insoles 104′ are constructed anatomically and is constructed of materials typically used for orthopedic applications in shoes, such materials selected so that the tolerance of deviation due to material expansion is low, shape memory characteristics high, which high cycling endurance in compression.
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In operation, a traditional shoe provides for flexing of the metatarsal phalangeal 20, in order, anatomically, to maintain a reasonable footprint on the ground, to both improve traction and to reduce the stress on the wearer's toes 94. In fact, the metatarsal phalange 20 is the only part of the foot 40 (ankle excluded) that is actually bending during walking. The inventors have found that by increasing the stiffness of the sole portion 24 in the forefoot region 30, and further by restraining the top of the foot 40 above the metatarsal phalangeal region 20 (restraining the foot against bending of the metatarsals), the lever of the foot is increased. When the length of the lever can be increased, the moment is increased and thus the power output of the foot is increased, which results in a lengthening of the stride while running. The result is improved “toe off” and an extended range of motion, less energy depredation in the toe area and a more efficient stride.
Increased efficiency of the stride leads to a corresponding reduction in strenuous training protocol and improved technique, which, consequently results in reduced injury risk often associated with overtraining.
In an advantage of the invention, the 5 degree dorsiflex angle 30 produces a shoe 10, 10′ that appears to be significantly less clumsy, more natural and comfortable, and therefore, much more likely to be purchased and used by amateur athletes as well as professional athletes. The invention provides a reverse, dorsiflex to the orientation of the foot, to a level which experimentation has shown produces the maximum power output, namely 5 degrees. In fact, the inventors have learned that there is no remarkable benefit to be gained by providing a shoe which a greater reverse dorsiflex incline of 5 degrees.
In another advantage, the fact that the angle of reverse incline is lesser with the invention as compared to dorsiflex shoes of the prior art, means that less material is required in manufacture less material equates to less cost in manufacture as well as a lower minimum weight to the shoe.
In another feature, the sidewall of the shell 12 is formed so as to give the impression that the shoe is a conventional plantarflex shoe.
In another advantage, the invention eliminates the need for the metatarsal-phalange joint to flex because the shoe itself reproduces the movement of this joint and the toes.
In an advantage, the invention substantially reduces energy loss due to metatarsal-phalangeal flexing during running and jumping.
In another advantage, the invention improves the capacity of the foot by improving its efficiency while mininimizing the risk to harm to the foot by selecting the materials of the shoe to absorb stress and by reproducing the rolling motion of the foot.
In a further advantage, the shoe is configured to receive insoles which adjust the thickness of the rear of the shoe from extreme dorsiflex to plantarflex, thus avoiding morphological problems which occur where an insole is designed so as to increase the thickness of the forward portion of the sole from plantarflex to dorsiflex.
In another advantage, insoles may be stackably inserted into the shoe, thereby reducing the total bulk and weight of the assembly including all insoles which interface therewith.
In an advantage, the shoe improves the capacity of the foot by improving its efficiency. Thus, the risk of harm to the foot is minimized by selecting the materials of the shoe to absorb stress and by reproducing the rolling motion of the foot.
In another advantage, the shoe configuration allows for improved performance of the plantar flexor muscles.
In another advantage, the invention increases the power output of a runner and of forces applied to the ground. The athlete is able to run faster because stride length is increased and contact time of the foot on the ground is decreased.
Multiple variations and modifications are possible in the embodiments of the invention described here. Although certain illustrative embodiments of the invention have been shown and described here, a wide range of modifications, changes, and substitutions is contemplated in the foregoing disclosure. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the foregoing description be construed broadly and understood as being given by way of illustration and example only, the spirit and scope of the invention being limited only by the appended claims.
Claims
1. A high performance dorsiflexion shoe for enveloping a foot (40) of a wearer, including the wearer's metatarsal-phalangeal joint (20), the shoe comprising
- (a) a sole portion (24) having a ground-contacting surface (26), a forefoot region (30), a midfoot region (32) and a heel portion (34), and
- (b) a constraining device (16) above the metatarsal-phalangeal joint;
- wherein the forefoot region is made of a high density material, and has a thickness, measured in a direction perpendicular to the ground-contacting surface of the sole portion, greater than the thickness of the heel portion, thereby defining a dorsiflexion shoe having a characteristic angle (a) of declination from the forefoot region to the heel portion;
- wherein the constraining device substantially constrains a wearer's metatarsal-phalangeal joints from movement when exercising, and
- wherein the forefoot region has a curved form defined so as to further minimize flexion of the metatarsal-phalangeal joint during walking or running.
2. The shoe of claim 1, wherein the sole portion (24) is a component of a shell (12) which includes sidewall portions (22) extending upwardly from the sole portion to a circumferential edge (13) which surrounds the wearer's foot (40).
3. The shoe of claim 2, wherein the circumferential edge (13) is higher in the heel region (34) than in the forefoot region (30), thus giving the outward appearance of a plantarflex shoe.
4. The shoe of claim 1, wherein the forefoot region (30) includes at least one hard, high density insert (66, 162, 180, 182, 184, 186, 190) formed to follow the curvature of the sole portion (24).
5. The shoe of claim 4, wherein the at least one insert (66, 162, 180, 182, 184, 186, 190) includes reinforcing ribs (90).
6. The shoe of claim 4, wherein the at least one insert (66, 162, 180, 182, 184, 186, 190) includes slits (200) for defining the bending moment of inertia of the insert.
7. The shoe of claim 4, wherein the at least one insert (66, 162) extends from the forefoot region (30) to the midfoot region (32).
8. The shoe of claim 4, wherein the at least one insert (66, 162, 180) extends from the forefoot region (30) to an area adjacent the cuniform bones of the wearer.
9. The shoe of claim 4, wherein the at least one insert (184, 186, 190) extends from the forefoot region (30) to the heel portion (34).
10. The shoe of claim 5, wherein the ribs (90) pass through a softer endo layer (92) and thus, present an exposed surface (91).
11. The shoe of claim 10, wherein the at least one insert (66, 162, 180, 182, 184, 186, 190) is molded of a color different from the sole, so as to prominently expose the form of the ribs (90) on an outside surface (91) of the shoe (10).
12. The shoe of claim 1, wherein the angle (a) of declination is within the range of 1 degree to 15 degrees, preferably 5 degrees.
13. The shoe of claim 1 wherein the forefoot region (30) includes a reinforced, padded toe portion (64).
14. The shoe of claim 1, wherein the heel portion (34) is substantially comprised of a low density, viscous-like material.
15. The shoe of claim 1 wherein the forefoot region (30) has a varying thickness defining a ground contact surface (26) of a curved form which mimics the function of natural metatarsal-phalangeal flexion.
16. The shoe of claim 11, wherein the curved form includes a straight portion, extending approximately from the heel portion (34) to the forefoot region (30), and a curved portion (28), substantially tangentially extending from the straight portion, and then curving upward about the toe.
17. An adaptable shoe assembly wherein the assembly includes:
- a shoe having a sole portion (24) of a pre-determined angle of inclination, adapted to receive an interchangeable insole (104, 104′); and
- at least one insole which inserts into the shoe, the assembly changing the posture of a wearer's foot (40) from one angle in a range between dorsiflexion and plantarflexion to another angle in the range resulting in a shoe defined by an angle of declination different from the pre-determined angle.
18. The shoe of claim 17, wherein the sole portion (24) is a component of a shell (12) which includes sidewall portions (22) extending upwardly from the sole portion to a circumferential edge (13) which surrounds the wearer's foot.
19. The shoe of claim 18, wherein the circumferential edge (13) is higher in the heel region (34) than in the forefoot region (30), thus giving the outward appearance of a plantarflex shoe.
20. The shoe of claim 19, wherein the insole (104, 104′) includes three dimensional structures (120) which interface with a mating surface on the sole so as to lock the insole and the sole together, thus minimizing relative motion therebetween.
21. The assembly of claim 17, wherein the shoe is of a substantially normal plantarflexion form in which the metatarsal-phalangeal restraining device (16) is adjustable over the metatarsal-phalangeal joints (20) of the wearer with or without an insole (104, 104′) installed, and the foot-contacting portion (26) of the sole portion (24) of the shoe is of a form which suitably interfaces with the foot (40) so that, when the insole is not installed, the shoe functions as a conventional plantarflexion shoe.
22. The assembly of claim 17, wherein the at least one insole (104) has a weight (106) selected to provide a particular level of energy consumption during use.
23. The assembly of claim 17, wherein the assembly is adapted to receive one of at least two insoles (104, 104′) which alternatively insert into the shoe, providing the wearer with the ability to select the angle (α) of declination, and thus the degree of dorsiflexion.
24. The assembly of claim 23, wherein the insoles (104, 104′) are of a thickness selected in the range of between 2.5 mm and 15 mm, representing approximately 0 to 6 degree changes in dorsiflexion.
25. The assembly of claim 17, wherein the assembly is adapted to receive at least two insoles (104″), stacked one on the other, a first-installed insole having a lower surface which conforms to the form of the shell, and an upper surface formed to adapt to a wear's foot, and the second-installed insole formed to conform to the top surface of the first-installed insole, itself having a top surface that conforms to a wearer's foot, thus providing the wearer with the ability to select the angle (β) of declination, and thus the degree of dorsiflexion.
26. The assembly of claim 25, wherein the insoles (104, 104′) are of a thickness selected in the range of between 2.5 mm and 15 mm, representing approximately 0 to 6 degree changes in dorsiflexion.
27. The assembly of claim 17, wherein the assembly includes at least two insoles (104) of substantially differing weights, which alternatively insert into the shoe, providing the wearer with the ability to select a weight (106) to provide a particular level of energy consumption during use.
28. The shoe of claim 17, wherein the forefoot region (30) includes at least one hard, high density insert (66, 162, 180, 182, 184, 186, 190) formed to follow the curvature of the sole portion (24).
29. The shoe of claim 29, wherein the at least one insert (66, 162, 180, 182, 184, 186, 190) includes reinforcing ribs (90).
30. The shoe of claim 29, wherein the ribs (90) pass through a softer endo layer (92) and thus, present an exposed surface (91).
31. The shoe of claim 30, wherein the at least one insert (66, 162, 180, 182, 184, 186, 190) is molded of a color different from the sole portion (24), so as to prominently expose the form of the ribs (90) on an outside surface of the shoe.
32. The shoe of claim 28, wherein the at least one insert (66, 162, 180, 182, 184, 186, 190) includes slits (200) for defining the bending moment of inertia of the insert.
33. The shoe of claim 28, wherein the at least one insert (66, 162) extends from the forefoot region to the midfoot region.
34. The shoe of claim 28, wherein the at least one insert (180) extends from the forefoot region to an area adjacent the cuniform bones of the wearer.
35. The shoe of claim 28, wherein the at least one insert (182, 184, 186, 190)extends from the forefoot region to the heel portion.
36. A high performance dorsiflexion shoe for enveloping a wearer's foot, the shoe comprising a sole portion (24) having a ground-contacting surface (26), a forefoot region (30), a midfoot region (32) and a heel portion (34), wherein the forefoot region includes a hard, high density insert (66, 162, 180, 182, 184, 186, 190) formed to follow the curvature of the sole portion, wherein the heel portion is made substantially of a soft, viscous-like material, the overall thickness of the sole portion being such that the angle (α) on declination is at most 0 degrees, and wherein the differences in deformation of the hard and the soft materials are defined so as to enable the sole portion to deform during exercise in a manner that creates the effect of a dorsiflexion shoe.
Type: Application
Filed: Feb 6, 2004
Publication Date: Nov 16, 2006
Applicant: SPRINGBOOST S.A. (Commugny)
Inventors: Joerg Fuchslocher (Lonay), Behrouz Bayat (Lausanne)
Application Number: 10/558,884
International Classification: A43B 13/00 (20060101);