Abstract:
The present invention relates to a device for limiting plantarflexion of an ankle and thereby maintaining the plantar fascia in a neutral to slight dorsiflection. The device includes a foot assembly, tension members, and a leg strap. The leg strap, is adapted so that a portion of the leg strap is removable and can be engaged above the knee. In some embodiments of the present invention, the leg strap, includes at least one connection member for receiving the tension member wherein the connection member is affixed to the leg strap at or about the knee when the leg strap is engaged to the leg.

Description:
RELATED FILING(S) 
     Priority based on Provisional Application No. 61/508,045; Filing Date Jul. 14, 2011. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a foot support device. More specifically, the present invention relates to a foot support device for limiting plantar flexion of an ankle thereby maintaining the plantar fascia in a neutral to slight dorsiflexion. More specifically, the present invention relates to a foot support device wherein a tension is applied to the ball of the foot via a tension member removably engaged to at least a portion of the leg at or about the knee. 
     BACKGROUND OF THE INVENTION 
     The human foot and ankle contain 26 bones and more than 100 muscles, tendons, and ligaments. This complex structure receives the impact of each step experienced by an individual. 
     One source of heel pain commonly observed is due to a condition known as recalcitrant plantar fasciitis. Plantar fasciitis occurs in the plantar fascia, a fibrous membrane disposed longitudinally across the bottom of the foot. The plantar fascia is attached at the heel bone. The plantar fascia becomes broader and thinner as it extends longitudinally across the bottom of the foot, eventually dividing near the heads of the metatarsal bones into five processes, one for each of the five toes. The strongest ligament in the body, the plantar fascia&#39;s purpose is to protect the softer muscles and tissues of the bottom of the foot from injury, as well as to help maintain the integrity of the foot structure itself. 
     If the fascia becomes stretched or strained, the arch area becomes tender and swollen as well as the area about the heel bone. This inflammation is called plantar fasciitis and is typically painful from the heel throughout the arch up into the Achilles tendon. Patients suffering from this condition usually have relatively tight and inflexible heel cords, sometimes referred to as Achilles tendon tightness. When the heel cord is tight, it causes compensation in the foot with over pronation of the foot during weight bearing. The pain is consistently worse when you first get up in the morning and at the end of the day. The pain usually lurks in the heel pad and may include the arch ligament. 
     Plantar fasciitis is often caused by contracture of the Achilles tendon and the plantar fascia, which can occur at night during sleep, or during daytime inactivity. The Achilles tendon, the strongest and thickest tendon in the human body, begins at or about the middle of the posterior side of the leg extending downward towards the heel, narrowing as it progresses towards its point of insertion at the posterior surface of the os calcis. When an individual is standing, walking, running, or even sitting in a position in which the feet are in contact with the floor or other surface, both the plantar fascia and the Achilles tendon are extended to varying degrees depending of course on the nature and intensity of the activity. During sleep, an individual has a natural tendency to plantar flex the ankle joint beyond the position, which is normal during walking, standing, or sitting with one&#39;s feet on the floor. Plantar flexion is when the bottom of the foot is extended so as to form an angle with the lower leg of greater than 90 degrees, i.e., extend such that the forefoot moves away from the body. Dorsiflexion is the opposite motion, when the foot is moved to a position in which the bottom of the foot forms an angle with the lower leg of less than 90 degrees, i.e., such that the top of the foot moves toward the body. 
     Another condition, Achilles tendonitis can result from overuse of the tendon in sports activities, and can also result from a number of inflammatory diseases, of which rheumatoid arthritis is one. 
     For some time, a common method of treatment of plantar fasciitis and Achilles tendonitis has been the use of a night splint. The night splint typically consists, essentially, of a boot-like structure, which is strapped to a patient&#39;s lower leg and foot, holding the foot relative to the lower leg in a position such that the ankle joint is held in slight dorsiflexion. In so doing, both the plantar fascia and the Achilles tendon are slightly extended and are not allowed to contract during the night. The use of night splints together with the variety of other elements of treatment including anti-inflammatory medications, physical therapy, and foot cushions for use during the daytime, has proved beneficial in the treatment of plantar fasciitis. 
     Various braces and splints, sometimes referred to as night splints, are advertised for treatment of plantar fasciitis and/or Achilles tendonitis. These devices typically consist of a molded splint or a combination of molded plastic and metal framework, with the dorsiflexion set at, for example, about 5 degrees. Illustrative examples are disclosed in U.S. Pat. No. 5,399,155 (Strassburg et al.), U.S. Pat. No. 5,718,673 (Shipstead), U.S. Pat. No. 5,799,659 (Stano), U.S. Pat. No. 5,897,520 (Gerig), U.S. Pat. No. 6,019,741 (Prieskom), U.S. Pat. No. 6,267,742 (Krivosha et al.), U.S. Pat. No. 6,602,216 (Nordt, III), U.S. Pat. No. 6,695,797 (Trieloff), and U.S. Pat. No. 6,755,798 (McCarthy et al.), and U.S. Patent Application Publication Nos. 2004/0215123 (Slautterback et al.) and 2006/0064048 (Stano). 
     U.S. Pat. No. 7,753,864 (Beckwith et al.) discloses a foot support device that when worn maintains the plantar fascia and other structures on the plantar surface of the foot in a neutral to slight dorsiflexion under application of static tension. The Beckwith device includes (a) a calf strap removably engagable to the calf of a leg; (b) a foot assembly removably engagable to the foot of the leg such that when the device is worn the assembly can be positioned proximate to the ball of the foot intermediate to the midfoot and forefoot areas of the foot to secure it to the foot; and (c) a substantially inelastic tension member connectable between the calf strap and the foot assembly in a tensioned manner such that when the device is worn the plantar flexion of the ankle is limited such that the plantar surface of the foot is held in a neutral to slight dorsiflexion. 
     Although such known devices may hold the plantar fascia in neutral to slight dorsiflexion, there are a number of disadvantages to such devices. 
     One disadvantage of such known devices is that the calf strap is connected to the leg below the knee, thus generating a downward force on the calf. In this known device, a calf strap is connected to the foot assembly via a tension member. After the tension member is tightened, the foot is maintained in neutral to slight dorsiflexion. In known devices, the calf strap comprises a belt or strap. The belt is arranged such that it is secured around the upper calf of a leg. The user may adjust the size of the loop formed by the strap around the calf to maintain the calf strap in position while the device is in use. 
     One disadvantage of the calf strap configuration is that the calf muscle receives the tension force. This leads to discomfort for the user, especially during prolonged use of the foot support device. 
     Another disadvantage of the calf strap configuration is that it is difficult to maintain a secure engagement with the leg at the upper calf. This disadvantage leads to discomfort for the user. In addition, this disadvantage reduces the effectiveness of the known device because the calf strap tends to loosen during prolonged use. In such cases, the calf strap slides down the leg toward the foot, thus eliminating the tension force between the foot and the calf, and rendering the foot support device completely useless. 
     Another disadvantage of known foot support devices is that they use a single linear tension member to connect the calf strap and the foot assembly. This design prevents the user from making lateral adjustments to the tension in the foot support device. 
     What is desired, therefore, is a device for limiting plantar flexion of an ankle thereby maintaining the plantar fascia in a neutral to slight dorsiflexion. The desired device should include a removable foot assembly [ FIG. 1 , member  1 ] and can be engaged to the foot, a removable leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ] and can be engaged to at least a portion of the leg at or about the knee, and a tension member [ FIG. 1 , member  3 ] and connectable between the foot assembly [ FIG. 1 , member  1 ] and the tension member [ FIG. 1 , member  3 ] in a tensioned manner such that when the device is worn the plantar flexion of the ankle is limited. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a foot support for maintaining the foot in a neutral to slight dorsiflexion under application of static tension, wherein the foot assembly is connected to the leg at or about the knee. 
     It is another object of the present invention to provide a more comfortable foot support device. 
     It is another object of the present invention to provide a leg strap, which is part of the knee assembly, wherein a least a portion of the leg strap is removable and can be engaged at or about at least a portion of a knee. 
     It is yet a further object of the present invention to provide a leg support device having two or more linear tension members [illustrated in  FIG. 2 , members  3  and  4 ], which are portions of a continuous strap, thereby providing an additional degree of customization of the static positioning of the device when worn. 
     In order to overcome the deficiencies of the prior art and to achieve at least some of the objects and advantages listed, the invention comprises a device for limiting plantar flexion of an ankle thereby maintaining the plantar fascia in a neutral to slight dorsiflexion. The device comprises a removable foot assembly and can be engaged to a foot of a leg, a knee assembly having a removable leg strap and can be engaged to the leg at or about a knee of said leg, and a tension member which are portions of a single continuous strap, connectable between the foot assembly and the leg strap, which is part of the knee assembly, in a tensioned manner such that when the device is worn the plantar flexion of the ankle is limited. [See for example  FIG. 1 , members  1 - 4 ]. 
     In some embodiments of the present invention a portion of the leg strap, which is part of the knee assembly [e.g.  FIG. 1  member  2 ] is removable and can be engaged above the knee, while the remaining portion of the knee assembly [member  2 ] can be engaged below the knee. In some embodiments of the present invention, the knee assembly [member  2 ], is configured such that it is similar to a knee brace in that it comprises at least two leg straps that wrap around the leg, one above the knee [leg strap  12 ] and one below the knee [leg strap  11 ], and a material section  14  interconnecting leg strap  12  to leg strap  11  as is shown in  FIGS. 1 and 2 . In this manner the knee assembly [ FIG. 1 , member  2 ] is removable and engages the leg at or about the knee. 
     In yet other embodiments of the present invention the foot support device comprises a foot assembly [ FIG. 2 , member  9 ] arranged such that the tension force is directed to the ball of the foot, thereby limiting the plantar flexion of the ankle. 
     In yet further embodiments of the present invention, the tension members are comprised of at least two linear members extending between the foot assembly [ FIG. 1 , member  1 ] and the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ], said two linear members which are portions of a single continuous strap, extending below the foot through a guide member [ FIG. 2 , member  9 ]. In some embodiments, the at least two linear members are parallel between the foot assembly [ FIG. 1 , member  1 ] and the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ]. In yet other embodiments, the present invention comprises at least two linear tension members that are portions of a single continuous tension member [ FIG. 2 , members  3  and  4 ] which may be parallel between the foot assembly [ FIG. 2 , member  1 ] and the knee assembly, [ FIG. 2 , member  2 ]. As is apparent to one of ordinary skill in the art, the two linear tension members which are portions of a single continuous tension member [ FIG. 2 , members  3  and  4 ] may cross each other at any point between the knee assembly and the foot assembly while maintaining tension force directed to the ball of the foot, limiting plantar flexion of the ankle. 
     The embodiments of this invention achieve the objective of maintaining a stable foot position without the tension caused by the “tourniquet” or tightness required by other devices to maintain the foot in a stable desired position. Tightness around the leg constricts blood circulation causing discomfort and discouraging the use of a foot stabilizing device for any extended period of time. In sharp contrast, the embodiments of this invention do not employ such blood constricting tightness and thereby enable the continuous use of this device for much longer periods of time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a perspective view of one embodiment of the present invention. 
         FIG. 2  illustrates a front view of the foot assembly [ FIG. 2 , member  1 ] of one embodiment of the present. 
         FIG. 3  illustrates a perspective view of one embodiment of the present invention wherein the first tension member [ FIG. 3 , member  3 ] and second tension member [ FIG. 3  member  4 ] are parallel. 
         FIG. 4  illustrates a cross section of the one embodiment of the present invention shown in  FIG. 2  wherein the first tension member [ FIG. 2 , member  3 ] and second tension member [ FIG. 2 , member  4 ] are parallel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In reference to  FIG. 1 , one embodiment of the present invention is shown. The device comprises at least three elements: (a) a foot assembly [ FIG. 1 , member  1 ], (b) a tension assembly comprising two tension members [ FIG. 1  member  3  and member  4 ], and (c) a knee assembly [ FIG. 1 , member  2 ]. The knee assembly, [ FIG. 1 , member  2 ] comprises a brace for the knee formed by the upper leg strap  12 , the lower leg strap  11  and the interconnecting material section  14 . The brace has an upper portion, represented by the leg strap [ FIG. 1 , member  12 ], that is removably engaged to the leg above the knee, and a lower portion, represented by the leg strap [ FIG. 1 , member  11 ], that is removably engaged to the leg below the knee. The upper portion and the lower portion of the brace both comprise a strap that is engaged around the leg and held in place by a hook and loop fastener. 
     It will be understood by a person having ordinary skill in the art that the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ] may take many different forms as long as it is designed to engage with at least a portion of the leg above the knee and below the knee. In the embodiment shown in  FIG. 1 , the brace is made from synthetic fabric. It will be understood by a person having ordinary skill in the art that any known material may be used to construct the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ]. 
     In further reference to the embodiment of the present invention shown in  FIG. 1 , the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ] includes at least one connection point. In the embodiment shown in  FIG. 2  the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ] includes two connection points [ FIG. 2 , members  5  and  6 ) wherein the securing material connects to opposite sides of the leg strap. The opposite points at which the securing material connects to the leg strap, which is part of the knee assembly, provide stability in the ankle and uniform tension on both sides of the foot. 
     The connection point comprises a rigid loop [ FIG. 1 , member  7 ] that is fastened to the brace by a piece of material [ FIG. 1 , member  5 ] secured thereto. The connection point is fastened to the leg strap, which is part of the knee assembly, [ FIG. 1 , member  2 ] such that tension force is transferred to a portion of the leg above the knee. The embodiment shown in  FIG. 2  includes a symmetrically arranged fastener on the opposite side of the leg strap, which is part of the knee assembly, [ FIG. 2 , member  6 ]. Thus, when the foot support device is in use, the tension force is applied to a portion of the leg above the knee, thereby providing a more stable and comfortable configuration. 
       FIG. 2  illustrates a front view of the foot assembly [ FIG. 2 , member  1 ] of one embodiment of the present invention. In the embodiment shown, the foot assembly [ FIG. 2 , member  1 ] comprises a sock [ FIG. 2 , member  10 ] in combination with a guide member [ FIG. 2 , member  9 ] for receiving the tension member [ FIG. 2 , members  3  and  4 ]. The guide member [ FIG. 2 , member  9 ] is fixed to the bottom of the sock [ FIG. 2 , member  10 ] proximate to the ball of the foot. The guide member [ FIG. 2 , member  9 ] may be fixed to the sock [ FIG. 2 , member  10 ] with adhesive, stitching, or any other known method. 
     The guide member [ FIG. 2 , member  9 ] is arranged such that it can receive the tension members [ FIG. 2  members  3  and  4 ]. In the embodiment shown, the tension members [ FIG. 2  members  3  and  4 ] are interconnected to one another to form a single strap which is fed through the passageway  13  in the guide member [ FIG. 2 , member  9 ] such that the tension members [ FIG. 2  members  3  and  4 ] pass under the ball of the foot. While in use, the force on the tension members [ FIG. 2  members  3  and  4 ] is increased and the plantar fascia is maintained in a neutral to slight dorsiflexion. 
     It will be understood by a person of ordinary skill in the art that many different foot assemblies are possible. For example, the guide member [ FIG. 2 , member  9 ] may be fastened to different areas of the sock [ FIG. 2 , member  10 ]. In some embodiments a sock [ FIG. 2 , member  10 ] is not necessary. In some embodiments the tension member [ FIG. 2 , members  3  and  4 ] is connected to the foot assembly [ FIG. 2 , member  1 ] by some other known means. In some embodiments the tension members [ FIG. 2 , members  3  and  4 ] are connected to the toe of the foot. In yet other embodiments of the present invention, the tension members [ FIG. 2 , member  3  and  4 ] are connected to the top of the sock [ FIG. 2 , member  10 ]. 
     The arrangement of the foot assembly [ FIG. 2 , member  1 ] disclosed in the figure is preferred for a number of reasons. First, the sock [ FIG. 2 , member  10 ] increases the comfort of the user. Second, the fact that the guide member [ FIG. 2 , member  9 ] is secured to the bottom of the sock [ FIG. 2 , member  10 ] proximate to the ball of the foot is preferred because it concentrates the tension force at the ball of the foot. Third, the foot assembly [ FIG. 2 , member  1 ] is made from materials that can be easily cleaned. 
     In reference to  FIG. 2 , a front view of an embodiment of the present invention is shown. In this embodiment the tension member [ FIG. 2 , members  3  and  4 ] comprises two linear members that are portions of one continuous strap that extends from the foot assembly [ FIG. 2 , member  1 ] to the leg strap, which is part of the knee assembly, [ FIG. 2 , member  2 ]. Each linear strap is secured to the leg strap, which is part of the knee assembly, [ FIG. 2 , member  2 ] via a connection point. In the embodiment shown, the linear members are each looped through a buckle and secured using a hook and loop fastener. The user can tighten the tension members [ FIG. 2 , members  3  and  4 ] by pulling the tension member [ FIG. 2 , members  3  and  4 ] further through the buckle and securing its end via a hook and loop fastener. In the embodiment shown in  FIG. 2 , the tension members [ FIG. 2 , members  3  and  4 ] are parallel. In some embodiments, it is preferred that the tension members [ FIG. 2 , members  3  and  4 ] are crossed. In most embodiments it is preferred that the tension members comprise a single continuous member fed through a guide member below the ball of the foot as illustrated in  FIG. 2 . In reference to the embodiment shown in  FIG. 2 , the tension members [ FIG. 2 , members  3  and  4 ] are secured to the leg strap, which is part of the knee assembly, [ FIG. 2 , member  2 ] such that the great majority of the tension force applied to the leg via the brace is applied above the knee. 
     It should be understood that the foregoing is illustrative and not limiting, and that obvious modifications may be made by those skilled in the art without departing from the essence of the invention.