Patent Application
20190069514
This invention relates to an equine accommodative orthotic hoof support system that has a tapered bottom to facilitate breakover when walking and which includes, optionally, a series of shock absorbing orthotic pads of varying thickness to allow customization.
It has been reported that the estimated economic loss due to lameness in horses is between $678 million and $1 billion annually (USDA-APHIS, 2001). Although there are many reasons, sole bruising and disease such as laminitis are a common cause of lameness in horses. As explained in the website www.therapeutichorseshoeing.com, “Laminitis or ‘founder’ is an equine hoof disease where the coffin bone (third phalanx, P3) begins to lose its attachment to the inner hoof wall and begins to rotate toward the front of the hoof or sink within the hoof capsule. Laminitis is generally thought to result from an imbalance in the horse's internal system. For example, an injury or upset to some part of the body is combated by the circulatory system as blood rushes to the injured area. The momentary reduction in blood flow deprives the capillaries which feed the lamina. The lamina is the ‘Velcro’ that attaches the bone to the hoof wall. In the brief time the lamina lacks sufficient blood flow, the capillaries begin to die and the ‘Velcro’ attachment is weakened. The deep flexor tendon is attached to the bottom (palmar surface) of the coffin bone. This tendon is an extension of a muscle which reacts to the pain of the tearing lamina. As the muscle contracts, the tendon is in tension and pulls on the coffin bone. Once this pain cycle is established, it must be broken before healing can begin.”
While lameness, especially that caused by laminitis is difficult to cure, it is possible to relieve some of the pressure and pain through proper trimming, or by using shoes or boots that allow the horse to find a comfortable position and relieves unnecessary pressure on a lame hoof. Such relief is often essential to an eventual cure.
One commercial shoe that has found acceptance is sometimes referred to as a “banana” or “rocker” shoe or clog. This shoe is shaped to allow breakover adjustment by a “rocker” action of the sole of the hoof so that the horse can more easily find a comfortable position—by adjusting the palmar/planar angle to take pressure and stress off affected areas of the hoof. The “Clog,” developed by Dr. Micheal L. Steward, DVM of Oklahoma, utilizes the “self-adjusting” concept in a wooden shoe that is screwed and/or glued directly to the hoof. Adaptations of the Stewart Clog have been made of other materials as well. These shoes, while somewhat effective, are attached directly to the hoof and are not, therefore, easily changed without damage to the hoof. The present invention is an equine shoe system that overcomes the deficiencies of other shoes or boots.
This invention is an equine accomodative hoof support system consisting of a tapered base that allows, in some embodiments, the equine hoof to roll forward or to the side, without unnecessary bending, thus allowing it to find a comfortable natural position to relieve stress on a sore, injured, or diseased hoof. The ability of the base to rock allows the equine to adjust its stance to find the most comfortable position, not unlike standing in a bed of sand. This ability to find a naturally comfortable standing position is especially important for equine with lameness such as laminitis.
One benefit of the present invention is that it can replace expensive hoof treatment by a farrier and can easily be utilized directly by an equine practitioner or equine owner. The hoof support system of this invention provides an efficient, user friendly self-adjusting approach to sole supportive realignment of the P3 (third phalanx) as the hoof grows out. Another advantage of the sloped base of the shoe is that it greatly reduces the surface area in contact with the ground or other surface onto which the equine stands.
A more complete understanding of the method and apparatus of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein:
All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific implementations (embodiments) which may be practiced. These implementations are described in sufficient detail to enable those skilled in the art to practice the implementations, and it is to be understood that other implementations may be utilized. Further, logical, mechanical, and other changes may be made without departing from the scope of the implementations. The following detailed description is, therefore, not to be taken in a limiting sense.
In broad aspect, the present invention is an equine accomodative hoof support or rocker shoe system that has a tapered base of flexible polymer and a harder shoe rim disposed on the topside of the base. The shoe rim forms a complete enclosed receptacle that acts to constrain the lateral expansion of an elastomer gel orthotic pad that may be placed in the space inside the open section of the shoe rim enclosure. The system also, optionally, includes a shock-absorbing elastomer pad removably disposed in the space inside the shoe rim and on the top surface of the base. The base may be patterned. The base, in some embodiments, has a critical range of hardness that allows it to remain sufficiently flexible to be able to push the top surface of the base upward when pressure of an equine body weight is placed on it, as further explained below. Accommodative orthotic systems are used to distribute the body weight away from a painful area and/or provide needed support to decrease pain.
Referring to the figures that are exemplary of embodiments of the invention,
An important feature of the shoe system of this invention is the ability of the rocker base (106 in the Figures) to flex when pressure is applied (as when attached to an equine and the equine is standing on the shoe). When pressure is applied to the base the inside surface 108 of the base is pushed upward. This causes a pad in the recess to be pushed upward and fill the space in the underside of the hoof to provide support. When the equine lifts its hoof, pressure is released and the pad returns to the original position without pressure on the hoof bottom. This relief from constant pad pressure on the underside of the hoof distinguishes this system from other similar shoeing means. For example, farriers sometimes fill the underside off the hoof cavity with a filler. This keeps constant pressure on the hoof underside and can be the cause of irritation, soreness, and infections. Other solid-surface shoes with or without pads similarly apply constant pressure to the hoof underside. The flexible shoe base of the present system is thus very different. The flexibility (evidenced by Shore A hardness of the base composition) as well as the shape of the base is critical. The base must be of a polymer having a Shore A hardness of from about 50-80 and preferably 60 to 70. The harder shoe rim (102 in the Figures) is harder, having a critical hardness of about 75-95 Shore A, or 75 Shore A to 65 Shore D, with a hardness of Shore A of about 90 to 95 being preferred. It is also preferred that the shoe be made of a polymer that has a composition structure that is like that of a natural hoof. A two-component, low-viscosity, rapid-setting urethane compound polymer with high strength and durometer is very suitable. It is easily nailed, holds the nails tightly, and otherwise simulates the characteristics of a natural hoof composition. It is important that the shoe structure form a complete surround to constrain the orthotic pad from lateral expansion. As explained above, by constraining lateral expansion, the elastomeric orthotic pad will be forced upward (into the underside of the hoof when pressure is applied on the shoe base) and cause it to conform to the shape of the hoof's underside cavity. This is an important aspect to the function of an embodiment of the shoe system of this invention.
In the above described embodiments, the shoe rim, 102, will be relatively hard as detailed above but in other embodiments the rim may be relatively soft (Shore A of about 50-80 and preferably 60 to 70) and the orthotic relatively hard (Shore A of about 60 to 90). This configuration will provide relief to the hoof wall (relieve the wall from undue pressure, which is important in relief for laminitic equine) and provide more support on the underside of the hoof. The orthotic pad may also have a frog support (as illustrated) for similar orthotic pad disclosed in U.S. Pat. No. 8,220,231, issued Jul. 17, 2012, U.S. D709,656 issued Jul. 2, 2014, and U.S. application Ser. No. 29/581,806 filed June 2008 581,806. The disclosures of these patents and application are incorporated herein by reference.
The shoe system can be attached to an equine hoof by conventional nailing, screwing, or gluing. Suitable techniques for such attachment are well known in the art. Suitable glues are readily available and include both acrylic-based glues and urethane-based glues. Both are two-part glues in which curing is achieved through a chemical reaction between the two parts. Equilox™ and Equibond™ are examples of suitable commercial shoe glues. The shoe system may also be attached to an equine hoof through the wrapping of casting material or by duct taping it to the cast. Attachment by wrapping will be very convenient for many users as the shoes usually need to be changed and the hoof worked on about every 3 to 6 weeks as the hoof grows. A new casting tape, Braeon™, that hardens into a very strong and durable material upon heating, may be very useful in attaching the shoes. Braeön™ is a high strength, lightweight plastic ribbon that molecularly fuses to itself in a matter of seconds. Users only need to simply heat, press, and repeat to form the plastic into any desired shape. Once cooled, the self-bonding plastic hardens, creating a bond as strong as steel. It is available through the company, see http://braeon.com/about-braeon.
One farrier attaches a prototype of the rocker shoe to horse's hooves with screws in the front of the hoof to stabilize the hoof temporarily and then wraps the hoof and sides of the shoe with traditional casting tape. The shoe shape is an advantage as well as the ease with which it may be shaped and custom-fitted to an individual hoof by a common farriers' rasp—no special tools needed. Attaching with casting tape minimizes damage to the hoof (as could result from nailing the shoe to the hoof) and provides an attachment that can be easily replaced (generally shoes need to be replaced or reset about every 3-6 weeks because of hoof growth).
The shoe base, 106, and shoe rim, 102, may suitable be made of molded elastomeric polymer. Molded polyurethane is very suitable and convenient to work with. Shore A of about 90 is especially suitable. Polyurethanes are easily moldable in open molds or by injection molding. Other polymer materials with similar characteristics as polyurethane, such as polyvinyl chlorides, styrene butadiene styrene polymer, epoxies, and the like, are also usable. It is also suitable to incorporate filaments or fibers (such as Dyeema or Teflon™ fiber) or Teflon™ powder, to strengthen and improve abrasion resistance of the base. Choice of these materials will be well within the ability of those skilled in the polymer art to select.
As shown in the Figures (
Alternatively, the base can be tapered (sloped) toward the front of the hoof and tapered towards the rear and/or from side-to-side. While not shown in the Figures, the shoe system base, can slope from the centerline-side to side-side—to allow the hoof to rotate or tilt from side-to-side as well as forward. Tapering to the side can also be beneficial in relieving pressure when the hoof is turning since during turning there is generally the most pressure upon and therefore the most damage to the coffin bone and lamina. This allows maximum flexibility of movement and enables the horse to find the optimum position of comfort; however, it is the least stable of the configurations. This sole shape is useful to enhance self-stretching of ligaments as when preparing for exercise, much like a person stretching their Achilles tendons by leaning on a wall before a run.
Both taper configurations are useful in appropriate situations, and both are within the scope of this invention. Several possible rocker shapes are described in co-pending U.S. published applications. 2011/0067366, Mar. 24, 2011 (Ser. No. 12/882,352), and U.S. D728,867 issued May 5, 2015, the disclosure of which are incorporated herein by reference for all purposes.
Another advantage of the sloped base of the shoe is that it greatly reduces the surface area in contact with the ground or other surface onto which the equine stands. For example, a typical hoof bottom would be about 8 inches×8 inches or 64 square inches. A suitable shoe sole should be about 4 inches×5 inches or 20 square inches, which is only about 30% of the surface of the hoof bottom. Smaller shoe bases would reduce the ground contact even further.
An orthotic pad, 202, 204 and 206, is illustrated in
In other embodiments, the shoe rim (110) may be tapered as shown in
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Therefore, the scope of the invention should be limited only by the appended claims.
