Cuboid Inserts for Improving Balance and Preventing Falls

Abstract

Unique pads, called cuboid lifts, cuboid inserts, or balance-enhancing textured insoles, prevent falls and improve balance by producing site-specific stimulation of different types of cutaneous receptors located along the outer sides of the foot. These cutaneous receptors play a key role in maintaining balance. The outer placement also makes them important in preventing lateral falls, which are far and away the most likely to result in injury. Domes on the upper side of the cuboid inserts increase feedback from the cutaneous receptors as the center of pressure of the person wearing the cuboid inserts moves too far to the outer side of the midfoot. These cuboid inserts are also helpful when managing ankle sprains, as this common injury frequently results in impaired balance.

Claims

1. A cuboid lift comprising: an elastomeric pad having a first side and a second side opposite the first side and sized and shaped to fit on an insole of a shoe or footbed of a sandal with a portion of the elastomeric pad overhanging the insole of the shoe or footbed of the sandal; first domes disposed along a lateral edge of the first side of the elastomeric pad, each of the first domes having a first height and being positioned at least partially on the portion of the elastomeric pad overhanging the insole or footbed; and second domes disposed on the first side of the elastomeric pad medial to the first domes, each of the second domes having a second height smaller than the first height.

2. The cuboid lift of claim 1, wherein the elastomeric pad is sized and shaped to fold at a lateral edge of the insole such that respective portions of the first domes are positioned to apply pressure to a lateral side of a foot of a person wearing the shoe or sandal in response to excessive lateral displacement of a center of pressure of the person wearing the shoe or sandal.

3. The cuboid lift of claim 1, wherein the elastomeric pad has a thickness of about 2 mm to about 4 mm.

4. The cuboid lift of claim 1, wherein the elastomeric pad, first domes, and second domes are formed from a single piece of elastomeric material.

5. The cuboid lift of claim 4, wherein the elastomeric material comprises at least one of polyurethane or ethylene vinyl acetate.

6. The cuboid lift of claim 4, wherein the elastomeric material has a Shore A hardness of about 40 to about 60.

7. The cuboid lift of claim 4, wherein the elastomeric material has a Shore A hardness of about 45.

8. The cuboid lift of claim 1, wherein adjacent ones of the second domes are spaced apart from each other by about 12 mm to about 16 mm.

9. The cuboid lift of claim 1, further comprising: third domes disposed on the first side of the elastomeric pad between the first domes and the second domes, each of the third domes having a third height greater than the second height and smaller than the first height.

10. The cuboid lift of claim 9, wherein the first height is about 4 mm to about 5 mm, the second height is about 2 mm to about 3 mm, and the third height is about 3 mm to about 4 mm.

11. The cuboid lift of claim 9, wherein the first domes have diameters of about 9 mm to about 12 mm, the second domes have diameters of about 5 mm to about 7 mm, and the third domes have diameters of about 7 mm to about 9 mm.

12. The cuboid lift of claim 1, further comprising: a pressure-sensitive adhesive, disposed on the second side of the elastomeric pad, to adhere the cuboid lift to the insole of the shoe or footbed of the sandal.

13. A cuboid lift comprising: an elastomeric pad, having a first side and a second side opposite the first side, to fit on an insole of a shoe or footbed of a sandal and shaped such that a lateral edge of the elastomeric pad extends beyond a lateral edge of the insole or footbed when fit on the insole or footbed; first domes, disposed along the lateral edge of the first side of the elastomeric pad, to stimulate a lateral side of a midfoot of a person wearing the shoe or sandal; and second domes, disposed on the first side of the elastomeric pad medial to the first domes, to stimulate a lateral aspect of a plantar portion of the midfoot of the person wearing the shoe or sandal.

14. The cuboid lift of claim 13, further comprising: a pressure-sensitive adhesive, disposed on the second side of the elastomeric pad, to adhere the elastomeric pad to the insole of the shoe or footbed of the sandal.

15. A balance-enhancing textured insert for an insole of a shoe or footbed of a sandal, the balance-enhancing textured insert comprising: a base having two curved outer edges joined at each of two apex corners, the two curved outer edges and the two apex corners defining a perimeter of the base, a lateral portion of the base extending beyond a lateral edge of the insole or footbed when the balance-enhancing textured insert is disposed on the insole or footbed; and curved nodules extending from an upper surface of the base and configured to stimulate cutaneous receptors on a sole and a lateral side of a foot of a person wearing the shoe or sandal so as to prompt a reflexive muscle response to a lateral shift in a center of pressure of the person, the reflexive muscle response preventing the person from falling.

16. The balance-enhancing textured insert of claim 15, wherein the base and curved nodules are formed from a single piece of elastomeric material having a Shore A hardness of about 40 to about 60.

17. The balance-enhancing textured insert of claim 15, wherein the curved nodules are arranged in arcuate rows on the upper surface of the base.

18. The balance-enhancing textured insert of claim 15, wherein the curved nodules progressively increase in height from a medial side of the base to a lateral side of the base.

19. The balance-enhancing textured insert of claim 15, wherein the curved nodules progressively increase in diameter from a medial side of the base to a lateral side of the base.

20. The balance-enhancing textured insert of claim 15, wherein respective portions of at least some of the curved nodules are disposed on the lateral portion of the base.

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0019] The skilled artisan will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and/or structurally similar elements).

[0020] FIG. 1A shows the center of pressure (COP) of a person standing still.

[0021] FIG. 1B illustrates how a person's COP moves as the person leans forward.

[0022] FIG. 1C illustrates movement of a person's COP moves as the person walk.

[0023] FIG. 2 illustrates cutaneous receptors in a section of the sole of a person's foot.

[0024] FIG. 3 shows locations of different types of cutaneous receptor along the sole of a person's foot.

[0025] FIG. 4A shows that stimulating cutaneous receptors in the heel increases activity in the gastroc/soleus muscles (G/S).

[0026] FIG. 4B shows that stimulating the lateral midfoot increases activity in peroneus brevis (PB).

[0027] FIG. 4C shows that stimulating the forefoot increases activity in tibialis anterior (TA).

[0028] FIG. 5A shows a perspective view of a top side of a cuboid insert, also called a balance-enhancing textured insole or balance-enhancing insert.

[0029] FIG. 5B shows a plan view of the top side of the cuboid insert.

[0030] FIG. 5C shows a perspective view of a bottom side of the cuboid insert.

[0031] FIG. 5D shows a plan view of the bottom side of the cuboid insert.

[0032] FIG. 5E shows a profile view of a medial (inner) edge of the cuboid insert.

[0033] FIG. 5F shows a profile view of a lateral (outer) edge of the cuboid insert.

[0034] FIG. 5G shows a profile view of the cuboid insert from one apex corner (intersection of the medial and lateral edges) of the cuboid insert.

[0035] FIG. 5H shows a profile view of the cuboid insert from the other apex corner of the cuboid insert.

[0036] FIG. 6 shows a cuboid insert positioned on top of an insole with the outer (lateral) edge handing (extending) slightly off the outer (lateral) edge of the insole.

DETAILED DESCRIPTION

[0037] FIGS. 4A-4C illustrate site-specific muscular response to cutaneous stimulation of the sole of the foot of a person walking forward-behavior that can be exploited for fall prevention. A study using advanced EMG technologies to stimulate specific cutaneous receptors in different locations along the bottom of the foot shows that when cutaneous receptors beneath the heel are stimulated, there is an immediate increase in activity of the gastroc and soleus (G/S) muscles (FIG. 4A), with inhibition of tibialis anterior. Stimulating the lateral midfoot increases activity in peroneus brevis (PB; FIG. 4B), while stimulating the lateral forefoot (FIG. 4C) increases activity in tibialis anterior (TA). Stimulating the peroneal muscles is extremely useful for fall prevention because it can prevent lateral displacement of the center of mass while balancing over one foot.

[0038] More generally, FIGS. 4A-4C show bones and muscles of a foot and a lower leg in different stages of movement. The foot includes a heel part, a midfoot part, a ball part, a toe part, and a sole. The sole of the foot has many cutaneous receptors as described above with respect to FIGS. 2 and 3. The foot also includes a lateral (outer) portion and a medial (inner) portion. The midfoot part includes an arch with the arch more pronounced on the medial portion of the midfoot part. The lateral portion of the sole of the foot includes a large number of the cutaneous receptors. While walking and running, the lateral portion of the heel part of the sole of the foot is generally the first part of the foot to strike a surface. The foot then pivots on the heel bringing forward and down the other parts of the foot.

[0039] As shown in FIGS. 4A-4C, the center of pressure on the sole of the foot changes with different stages of movement. The center of pressure with the greatest amount of pressure is position B (FIG. 4B) when the person's body mass is centered over the foot while walking or running. FIGS. 4A and 4B show centers of pressure A and C representing, respectively, when the foot is first placed down on the surface and when the foot is about to be raised off the surface when walking or running. The changing of the center of pressures as someone moves changes the stimuli that is sent. When a foot is in position A, the cutaneous receptors send stimuli and there is an immediate increase in activity of soleus and gastric muscles G/S in FIG. 4A. When a foot is in position B, the cutaneous receptors send stimuli and there is an immediate increase in activity of peroneal muscles PB in FIG. 4B. When a foot is in position C, the cutaneous receptors send stimuli and there is an immediate increase in activity of tibialis anterior muscles TA in FIG. 4C. Given the large number of cutaneous receptors of the lateral portion of the sole of the foot and the understanding that a person spends most of their time with the person's weight on the lateral portion of the midfoot part of the sole of the foot while in position C, the midfoot lateral portion generally gives the highest amount of stimuli output.

[0040] FIGS. 5A-5H show different views of a cuboid insert 100, also called a balance-enhancing textured insole or balance-enhancing insert, designed to stimulate cutaneous receptors along the lateral portion of the midfoot part of the sole for preventing falls. This cuboid insert 100 is intended to be placed on the insole of a shoe or footbed of a sandal. When a person is wearing the shoe or sandal, the cuboid insert extends underneath the cuboid, which is a squat tarsal bone on the outer side of the foot, articulating with the heel bone and the fourth and fifth metatarsals, and around the lateral edge of the foot as described below.

[0041] The cuboid insert 100 has a series of rounded elevations 120-122, also called domes, nodules, protrusions, or balance buttons, which get progressively larger when moving laterally across the cuboid insert 100. The domes 122 on the inner (medial) side of the cuboid insert 100 have smaller elevations (heights) to stimulate slow-adapting cutaneous receptors on the lateral aspect of a plantar portion of the midfoot of the person wearing the shoe or sandal. These cutaneous receptors provide constant information regarding the location of the center of mass. The domes 120 on the outer (lateral) side of the cuboid insert 100 have larger elevations stimulate a lateral side of a midfoot of a person wearing the shoe or sandal if that person leans too far laterally. The domes 120 on the outer side are placed far enough laterally that a person wearing a shoe or sandal with the cuboid insert 100 could avoid pressing them by walking with a slightly wider base of gait. Walking with your feet farther apart greatly diminishes the risk of lateral falls as your center of pressure is maintained in a more central position. Should the person wearing the cuboid inserts 100 accidentally shift his or her weight so far to the side that they press on the larger nodules (domes 120), it is likely to initiate an immediate response from the fast-adapting Meissner's corpuscles, which have extensive branches to specific muscles in the lower extremity responsible for fall prevention. Last but not least, the entire cuboid insert 100 acts as a wedge lifting the outer side of the foot, which shifts the center of pressure to a safer midline position.

[0042] The cuboid insert 100 comprises an elastomeric base or pad with a top (foot-facing) side 101, a bottom (ground-facing) side 102, and a generally constant thickness (e.g., about 2 mm, 3 mm, 4 mm, or any value from about 2 mm to about 4 mm). The pad pushes the balance buttons (domes 120-122) up with a little more force, improving their efficacy. The domes 120-122 extend from the top side 101 of the cuboid insert 100. The bottom 102 of the cuboid insert 100 is generally flat and may be at least partially coated with a pressure-sensitive adhesive layer 130 that adheres the bottom 102 of the cuboid insert 100 to the insole of a shoe or footbed of a sandal. If desired, the pressure-sensitive adhesive layer 130 can be protected by a removable adhesive backing (not shown) until the cuboid insert 100 is placed on an insole or footbed.

[0043] The base has a lateral edge 111 and a medial edge 112. The medial edge 112 has a greater arc than the lateral edge 111. The arc of the medial edge 112 is to allow the cuboid insert 100 to best fit the arch of the foot. The lateral and medial edges 111, 112 intersect at first and second apex corners 113. The lateral and/or medial edges 111, 112 may have chamfers 114 (sloped surfaces, e.g., sloped between 15 to 45 degrees) as shown in FIGS. 5E-5H but could be straight or curved instead.

[0044] As shown in FIGS. 5A, 5B, and 5E-5H, the domes 120-122 have different sizes and are arrayed in arcuate rows with a fixed or pre-determined space between each dome. The largest domes 120 are in a lateral curved or arcuate row that runs along the lateral edge 111 of the cuboid insert 100, the smallest domes 122 are in a medial arcuate row that runs along the medial edge 112, and the medium domes 121 are in a middle arcuate row that runs between the other two arcuate rows of domes 120, 122. Each row can have the same number of domes or a different number of domes. In FIGS. 5A, 5B, and 5E-5H, there are six large domes 120 in the lateral arcuate row, four medium domes 121 in the middle arcuate row, and three small domes 122 in the medial arcuate row. Other cuboid inserts may have more or fewer arcuate rows, with more or fewer domes per row and/or total.

[0045] The domes 120-122 have sizes and positions selected to increase or maximize the stimulation that the domes 120-122 apply to the cutaneous receptors on the bottom of the foot when the cuboid insert 100 is worn in a shoe or sandal. The domes 120-122 may be roughly hemispherical, as shown in FIGS. 5A and 5C-5H, but other shapes are also possible, including, for example, oblate hemispheroids, prolate hemispheroids, paraboloids, hemi-ellipsoids, and portions (e.g., halves) of convex polyhedrons. The smallest domes 122 may have radii of about 2.94 mm to about 3.78 mm (e.g., 3.36 mm), the medium domes 121 may have radii of about 3.78 mm to about 4.725 mm (e.g., 4.20 mm), and the largest domes 122 may have radii of greater than about 4.725 mm (e.g., 5 mm or 5.25 mm). The domes 120-121 in each arcuate row may be spaced apart evenly, as shown in FIGS. 5A and 5B, or unevenly. The spaces between adjacent domes are generally selected to increase or maximize the stimulation that the domes 120-122 apply to the cutaneous receptors on the bottom of the foot.

[0046] The cuboid insert 100 can be made of injection-molded or stamped elastomeric material, such as polyurethane (PU) or ethylene vinyl acetate (EVA). The elastomeric material should be firm, flexible, and resilient, e.g., with a Shore A hardness of about 40 to about 60 (e.g., 45, 50, or 55). In other words, the elastomeric material should be hard enough to stimulate the cutaneous receptors but not so hard as to be uncomfortable. If desired, the hardness can be tailored to the person wearing the cuboid insert 100. The domes 120-122 can be integral with the elastomeric base or padthat is, the domes 120-122 and pad can be formed of a single piece of materialor can be formed of separate pieces of material or a separate layer adhered or otherwise affixed to the pad.

[0047] FIG. 6 shows the cuboid insert 100 applied to an insole 60, e.g., by sticking the adhesive layer 130 on the bottom 102 of the cuboid insert 100 to the top surface of the insole. In this example, the cuboid insert 100 is about 90 mm long (from apex corner 113 to apex corner 113) and about 43 mm wide at its widest point (from lateral edge 111 to medial edge 112). The largest domes 120 are about 4 mm high (measure from the bottom of the cuboid insert 100) and 10 mm in diameter, the medium domes 121 are about 3 mm high and 8 mm in diameter, and the smallest domes 122 are about 2 mm high and 6 mm in diameter. The apex corners 113 are positioned so they align with the outer edge of the insole 60 (points A and B in FIG. 6) and a portion 115 of the cuboid insert 100, including portions of the larger domes 120, extends slightly off the side of the insole 60 as shown in FIG. 6. In other words, the apex corners 113 are generally in line with the lateral edge of the foot, the lateral row of domes 120 is on the periphery of the lateral portion of the foot, and the middle and medial rows of domes 121, 122 are positioned under the midfoot.

[0048] When the cuboid insert 100 is positioned correctly on the insole 60, the cuboid insert 100 shown in FIG. 6 acts as a wedge that lifts up the cuboid, lifting the lateral portion higher relative to the medial portion, shifting the center of pressure to a safer midline position and creating a locking mechanism that stabilizes the foot. The lateral row of domes 120 does not stimulate the cutaneous receptors while a person wearing the cuboid insert 100 is walking with a slightly wider base of gait, whereas the middle and medial rows of domes 121, 122 provide constant stimuli to the cutaneous receptors regarding the location of the center of pressure. As the person is walking or running and starts to (accidentally) shift his or her weight too far to the side, the lateral portion of the sole of the foot will press on the lateral row of domes 120, thereby increasing pressure on the appropriate cutaneous receptors. These stimuli may induce a favorable muscle response that prevents the person from leaning too far to the side and falling. Put differently, when positioned at least partially off the side of the insole 60 as in FIG. 6, the larger domes 120 should stimulate pressure receptors in the skin only when the person wearing the cuboid insert 100 and insoles 60 shifts his or her weight too far to the outside (laterally). Most falls occur as the result of lateral weight shifts, and this stimulation triggers a muscular response that prevents the person from falling due to a lateral weight shift.

[0049] An easy way to determine if you might benefit from using cuboid inserts is to get into a safe location and stand on one foot with your eyes open and try to balance for a full 10 seconds. If you cannot balance on one foot with your eyes open for at least 10 seconds, then you should benefit from using cuboid inserts. Using cuboid inserts improves balance, which leads to better health and longer life. In a 12-year study of more than 1,700 older adults, the ability to successfully balance on one foot with eyes open was strongly correlated with longevity. In fact, individuals who were unable to balance for 10 seconds after 3 tries had an 84% higher risk of all-cause mortality, even when adjusting for other risk factors, such as heart disease, hypertension, and obesity. This study emphasizes the disastrous consequences associated with impaired balance. It also shows that it is imperative that people have their balance evaluated regularly, just like they have their cholesterol, blood pressure, and eyes examined annually. If impairment is found, preventive measures should be initiated as soon as possible, and inexpensive cuboid inserts coupled with a few simple home exercises can make a tremendous difference.

[0050] While some people find cuboid inserts 100 uncomfortable for the first few days, most people are able to tolerate them right away, often noticing a slight improvement in balance almost immediately. Cuboid inserts 100 work well when used in conjunction with a program of strengthening toes, feet, legs, and ankles for maintaining/improving balance. The cuboid inserts 100, like all textured insoles, only work while they are being worn there is an almost immediate return to baseline poor balance when discontinued. As a result, it is extremely important to strengthen feet and legs, especially toes, as foot strength plays a huge role in fall prevention. Every 1% increase in toe strength decreases a senior citizen's risk of falling by 7%.

CONCLUSION

[0051] While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0052] Also, various inventive concepts may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0053] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

[0054] The indefinite articles a and an, as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean at least one.

[0055] The phrase and/or, as used herein in the specification and in the claims, should be understood to mean either or both of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with and/or should be construed in the same fashion, i.e., one or more of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the and/or clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to A and/or B, when used in conjunction with open-ended language such as comprising can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0056] As used herein in the specification and in the claims, or should be understood to have the same meaning as and/or as defined above. For example, when separating items in a list, or or and/or shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as only one of or exactly one of, or, when used in the claims, consisting of, will refer to the inclusion of exactly one element of a number or list of elements. In general, the term or as used herein shall only be interpreted as indicating exclusive alternatives (i.e. one or the other but not both) when preceded by terms of exclusivity, such as either, one of, only one of, or exactly one of. Consisting essentially of, when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0057] As used herein in the specification and in the claims, the phrase at least one, in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase at least one refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, at least one of A and B (or, equivalently, at least one of A or B, or, equivalently at least one of A and/or B) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0058] In the claims, as well as in the specification above, all transitional phrases such as comprising, including, carrying, having, containing, involving, holding, composed of, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases consisting of and consisting essentially of shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.