Abstract:
An ankle brace provides a variety of features that contribute to comfort, stability, and support. One embodiment provides thin, elongated gripping surfaces on the bottom of the brace, to reduce the opportunity for the brace to slip relative to the wearer&#39;s shoe. One embodiment provides substantially horizontal strap-receiving slots in the forefoot area, which; pull the foot down, toward the bottom of the brace, not relying on the shoe to hold the foot down against the brace.

Description:
BACKGROUND 
   This application is a continuation-in-part of U.S. patent application Ser. No. 11/535,829, filed Sep. 27, 2006. 

   BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1  is a front perspective view of one embodiment of an ankle brace; 
     FIG. 2  is a left side view of the ankle brace of  FIG. 1 ; 
     FIG. 3  is a front view of the ankle brace of  FIG. 1 ; 
     FIG. 4  is a rear view of the ankle brace of  FIG. 1 ; 
     FIG. 5  is a right side view of the brace of  FIG. 1  being worn on a human foot; 
     FIG. 6  is a front view of the lower adjustment strap of  FIG. 1  in the open position, removed from the ankle brace; 
     FIG. 6A  is a view of another strap that may be used to tighten the ankle brace of  FIG. 1 ; 
     FIG. 6B  is a view of the strap of  FIG. 6A , showing one manner of tightening the strap; 
     FIG. 6C  is a view of the strap of  FIG. 6A , showing a second manner of tightening the strap; 
     FIG. 7  is a view taken along line  7 - 7  of  FIG. 2 ; 
     FIG. 8  is a view taken along line  8 - 8  of  FIG. 2 ; 
     FIG. 9  is a bottom view of the brace of  FIG. 1 ; 
     FIG. 10  is a front perspective view of a second embodiment of an ankle brace; 
     FIG. 11  is a left side view of the ankle brace of  FIG. 10 ; 
     FIG. 12  is a front view of the ankle brace of  FIG. 10 ; 
     FIG. 13  is a rear view of the ankle brace of  FIG. 10   
     FIG. 14  is a right side view of the ankle brace of  FIG. 10 ; and 
     FIG. 15  is a bottom view of the ankle brace of  FIG. 10 . 

   DETAILED DESCRIPTION 
     FIGS. 1-8  show one embodiment of an ankle brace  10 . The basic components of the ankle brace are a substantially U-shaped stirrup  20 , a left pivot leg  30 , and a right pivot leg  40 . The stirrup  20  includes a bottom portion  22 , a left upright portion  24 , and a right upright portion  26 . When worn, the bottom portion  22  extends under the wearer&#39;s foot, and the left and right upright portions  24 ,  26  extend upwardly along the sides of the wearer&#39;s foot. A forward projection  22 A on the bottom portion  22  is substantially thinner and more flexible than the rest of the stirrup  20 , providing for the wearer&#39;s comfort. The left and right pivot legs  30 ,  40  are pivotally attached to the left and right upright portions  24 ,  26  at left and right pivot points  32 ,  42 , respectively, and are connected together by a rear cuff  50 , which extends around the rear of the wearer&#39;s leg. The left and right sides of the brace  10  are mirror images of each other, except that the right pivot leg  40  has two vertical slots  37  for receiving an upper adjustment strap  60 , while the left pivot leg  30  has only one vertical slot  36  for receiving the upper adjustment strap  60 . 
   This particular ankle brace  10  is made of a polyester-based thermoplastic polyurethane (TPU) resin made by Bayer MaterialScience LLC and sold under the name Texin® 255. This material has a flexural modulus of 20,000 psi at 73 degrees Fahrenheit (a.k.a. room temperature) and a tensile strength of 7,000 psi. A known standard test that is used to determine the flexural modulus of a given material is ASTM D 790, and a standard test for determining the tensile strength is ASTM D412. The flexural modulus for the materials such as polypropylene and nylon that are typically used for prior art rigid braces is well over 100,000 psi. For example, a flexural modulus for polypropylene is typically over 110,000 psi, and may be as high as 600,000 psi. A flexural modulus for nylon is typically over 130,000 psi, and may be as high as 1,200,000 psi. Because this brace  10  is more flexible than prior art rigid braces, it is able to conform more closely to the shape of the wearer&#39;s foot. This means that, in many cases, in addition to being more comfortable, it actually can provide better support than a more rigid brace. Prior art wraps such as “Ace” bandages, also are able to conform to the shape of the wearer&#39;s foot, but they are too flexible to provide good support. For comfort and support, it is preferable to use a material having a flexural modulus at room temperature (73° F.) between 10,000 psi and 80,000 psi, and more preferable between 10,000 psi and 50,000 psi. It is also desirable for the material to have a tensile strength greater than 4,000 psi in order to maintain structural integrity. 
   It would be possible to make portions of the brace  10  from different materials, if desired. For example, it would be possible to make the right and left pivot legs  30 ,  40  from polyurethane and to make the stirrup portion  20  of the brace from traditional, more rigid materials, or the reverse. Of course, other materials besides polyurethane could be used to provide the desired flexural modulus and tensile strength. 
   As best shown in  FIGS. 2 and 7 , the major portion of the left pivot leg  30  is relatively thin, and there is a raised, U-shaped rib  34  near the front of the leg  30 . The right pivot leg  40  is almost a mirror image of the left pivot leg  30 , with the only difference being that it has two vertical slots  37 , with the front slot being cut through the rib  34 A. The U-shaped rib  34  includes a first portion  34 A, that extends generally in a top to bottom direction along the front of the pivot leg  30 , and second and third portions  34 B,  34 C that extend generally rearwardly from the top and bottom of the first portion  34 A. The major portion of the pivot leg  30  preferably is between 0.050 and 0.150 inches thick, and the U-shaped rib  34  is tapered, being thinner where it blends into the rest of the leg  30  and thicker in the middle. The thickest portion of the rib  34  preferably is, between 0.150 inches and 0.250 inches thick.  FIG. 7  best shows that the first portion  34 A of the rib  34  is thicker than the major portion of the pivot leg  30 . 
   Referring again to  FIGS. 2 and 7 , the left pivot leg  30  defines a vertical slot  36  rearwardly and general parallel to the first portion  34 A of the rib  34 . The slot  36  extends between the second portion  34 B and third portion  34 C of the rib. The slot  36  receives the upper adjustment strap  60 , which includes hook and loop fastener material, such as Velcro®, which is used to tighten the pivot legs  30 ,  40  against a wearer&#39;s leg when in use. As best shown in  FIG. 7 , the right end  60 A of the strap  60  is fed through the two slots  37  in the right pivot leg  40 , and then the strap  60  extends across the front of the brace between the two pivot legs  40 ,  30 , through the vertical slot  36 , and then wraps back around the front of the brace onto itself. Friction prevents the right end  60 A of the strap from coming loose from the right pivot leg  40 , and the hook and loop fastener secures the other end  60 B of the strap  60  in place. The main function of the rib  34  is to beef up the slot portion of the brace in order to withstand the forces from the strap  60 . 
   The right and left pivot legs  30 ,  40  are connected together in a unitary piece by a cuff  50 , which extends around the rear side of the ankle brace  10 . (Alternatively, it would be possible to provide a cuff that extends around the front side of the brace or to eliminate the cuff completely.) As best shown in  FIG. 4 , the cuff  50  includes upper and lower bands  52 ,  54  having different thicknesses. The lower band  54  is thinner than the upper band  52 , with the upper band having a thickness in the same range as the right and left pivot legs  30 ,  40 , and the lower band  54  preferably being between 0.030 inches and 0.050 inches thick. The lower band  54  forms the bottom edge of the cuff  50 . This allows the lower portion of the cuff  50  and the bottom edge which impinges on the wearer&#39;s leg when he is walking, to be more flexible and the upper portion to provide more support, which helps make the brace  10  more comfortable for the wearer. Of course, the entire cuff  50  could be made of a single thickness, or the thickness of the cuff could vary throughout the cuff, if desired. 
   The lower band  54  also defines a plurality of openings  56 , which are slightly elongated in the left to right direction. The cuff  50  also has vertical indentations  58  at the center top and bottom edges, which reduce the height of the cuff at its center, making it easier for the cuff  50  to flex about a vertical axis at its center. 
   As best shown in  FIG. 2 , the right pivot leg  30  defines larger elongated openings  39 , which extend in a generally front to back direction, with the front of each opening  39  being a bit lower than the rear. The number, size, and arrangement of the openings  39  may be selected by the designer as desired. 
   As best shown in  FIG. 2 , the right upright portion  24  of the stirrup  20  also includes elongated openings  28  which are generally elongated in the front to back direction. 
   As best shown in  FIGS. 3 and 4 , the left and right upright portions  24 ,  26  are connected at the rear by a heel strip  25 . The heel strip  25  and left and right upright portions  24 ,  26  define a rounded heel opening  27 , which receives the wearer&#39;s heel, as shown in  FIG. 5 . 
   The left and right upright portions  26 ,  24  also define arcuate strap-receiving slots  29  near their front edge. Each strap-receiving slot  29  is elongated, having first and second ends and first and second sides. The first and second sides extend substantially parallel to the front edge of the respective upright portion, with the first side of each slot  29  lying closer to the front edge of the upright portion than the second side of that slot. In this case, two parallel slots  29  are defined by the left upright portion  26 , and two parallel slots are formed by the right upright portion  24 . The two parallel slots  29  on each upright portion  24 ,  26  are aligned side-to-side with each other, with the first side of the second slot  29  adjacent to the second side of the first slot  29 . The slots are essentially the same length, and the respective first and second ends of each pair of parallel slots also lie adjacent to each other, so the slots  29  are coextensive with each other for essentially their entire length. These slots  29  receive a lower adjustment strap  70 , which is used to tighten the left and right upright portions  24 ,  26  of the stirrup  20  to the wearer&#39;s foot. 
   The lower adjustment strap  70  is shown in more detail in  FIG. 6  and includes a middle portion  72 , a left end  74 , and a right end  76 . On the top surface of the lower adjustment strap  70  is hook and loop fastener material. In this embodiment, there are hook portions  74 A,  76 A near each end  74 ,  76 , and a loop portion  75  extending between the hook portions- 74 A,  76 A through the middle portion  72 . There is also a cushion  78  secured to the rear surface of the middle portion  72  of the adjustment strap  70 , and the middle portion of the cushion  78  defines an upwardly-extending tongue  79 . 
   In use, the adjustment strap  70  functions in a very similar manner to a lace-up shoe. The left end  74  of the adjustment strap  70  is inserted through a slot  29  in the left upright portion  24  of the stirrup  20 , and the right end  76  of the adjustment strap  70  is inserted through a slot  29  in the right upright portion  26  of the stirrup  20 . The wearer puts on the ankle brace, pulls up on the tongue  79  and pulls both ends  74 ,  76  of the strap  70  toward the middle, where each of the hook portions  74 A,  76 A engages with the loop portion  75 . This differs from a typical strap arrangement, in which one side of the strap is fixed to the brace, and there is only one free end of the strap, which is pulled in order to tighten the strap. Since this arrangement allows the wearer to pull on both ends of the strap  70  simultaneously in order to tighten the strap  70 , the forces are applied more evenly and more like tightening the laces on a shoe. In fact, this arrangement could be used on other types of footwear that include a U-shaped stirrup, such as a shoe, in the same manner that it is used on this brace  10 . The reason for the second set of slots  29  is to provide for additional adjustment, allowing the wearer to decide which set of slots is to be used. 
     FIGS. 6A-6C  show an alternate embodiment of an adjustment strap  170  that may be used with the ankle brace  10  (or with other articles of footwear). The article of footwear includes left and right upright side portions  124 ,  126 , each defining at least one slot  129 , as shown in  FIGS. 6A-6C . Like the previous embodiment, the adjustment strap  170  includes a middle portion  172 , a left end  174  and a right end  176 , and on the top surface of the strap  170  there are hook portions  174 A,  176 A near each end  174 ,  176 , and a first loop portion  175  extending through the middle portion  172  between the hook portions  174 A,  176 A. However, unlike the previous embodiment, there is no separate cushion in the central portion of the adjustment strap  170  and no tongue  79 . In this embodiment, the entire back surface of the strap is covered by a second loop portion  177 , which acts as a cushion and provides an additional surface to which one of the ends of the strap may be fastened, as will be explained in more detail later. 
     FIG. 6A  is a view of the strap in its open position. The left end  174  of the strap  170  has been inserted through the slot  129  in the left portion  124 , and the right end  176  of the strap  170  has been inserted through the slot  129  in the right portion  126 . To tighten the brace around his foot, the wearer pulls the left and right ends  174 ,  176  of the strap simultaneously until there is a snug fit. Then, the wearer folds the left and right ends  174 ,  176  back over the middle portion  172  and fastens the left and right portions onto the strap  170  by means of the hook and loop fastener. 
   In  FIG. 6B , the left and right ends  174 ,  176  are secured to the middle portion  172  by engaging each of the hook portions  174 A,  176 A (not visible in  FIG. 6B ) with the first loop portion  175  on the top surface of the strap  170 . In  FIG. 6C , the left and right ends  174 ,  176  overlap, with the right end  176  being secured to the middle portion  172  and the left end  174  being secured on top of the right end  176 . Of course, the user could arrange the same strap  170  in reverse, with the left end being secured to the middle and then the right end being secured on top of the left end. In the arrangement shown in  FIG. 6C , the hook portion  176 A (not visible in  FIG. 6C ) near the right end  176  is engaged with the loop portion  175  on the top surface of the middle portion  172  of the strap  170 , and the hook portion  174 A (also not visible in  FIG. 6C ) near the left end  174  is engaged with the second loop portion  177  on the back of the right end  176  of the strap  170 . 
   It should be noted that various forms of additional cushioning could be added between the ankle brace  10  and the wearer&#39;s ankle, such as one or more air cushions, a neoprene sleeve, or various other types of cushions, if desired. As shown in  FIGS. 1 ,  3 , and  8 , some Velcro® dots  80  are adhered to the inner surface of this brace  10  in order to help secure such cushioning. Otherwise, the inner surface of the upper portion of the brace  10  preferably is smooth. 
     FIG. 9  is a view of the bottom of the ankle brace  10 . The outside of the bottom portion  22  of the stirrup  20  has added texturing in order to provide some friction between the bottom portion  22  of the stirrup  20  and a shoe (or the ground, if a shoe is not being worn). The bottom portion  22  includes generally triangular shaped ridges  82  that protrude slightly downwardly from the bottom portion  22 . These triangular shaped ridges  82  have thin, elongated sides, some of which extend mainly in the front-to-rear direction, and others of which extend mainly in the left-to-right direction. The ridges  82  extending in different directions form continuous shapes, which, in this case, are triangles. The elongated ridges help prevent the brace from sliding in a direction perpendicular to the direction of the ridge. Thus, the left-to-right-directed ridges help prevent the brace from sliding in a front-to-back direction, and the ridges that are directed in a more front-to-back direction help prevent the brace from sliding in a left-to-right direction. This makes the brace more stable so it functions better for the wearer. 
   Inside the ridges  82 , there are circular recesses  84 . The ridges  82  and recesses  84  provide an uneven bottom-surface for increased friction. As shown in  FIG. 8 , on the inside of the bottom portion  20 , there are slight indentations  85  corresponding to the ridges  82  protruding on the outside of the bottom portion  20 .  FIGS. 8 and 9  also show that the forward projection  22 A on the bottom portion  22  defines triangular openings  86 . The forward projection  22 A is substantially thinner than the rest of the bottom  20 . It should be noted that other texture arrangements, besides the ridges  82  and recesses  84  shown in  FIG. 9 , may be used on the outside of the bottom portion  22  to provide friction, or the outside of the bottom portion  22  could be smooth. 
     FIG. 10  is a second embodiment of a brace  110 , which is very similar to the first embodiment  10 . As with the previous embodiment, this embodiment is intended primarily to be worn inside a shoe, although it could be worn without a shoe, if desired. It includes a stirrup portion  120 , left and right pivot legs  130 ,  140 , and a rear cuff  150 . The pivot legs  130 ,  140  pivot relative to the stirrup portion  120  about left and light pivot points  132 ,  142 , respectively, each of which defines a pivot axis. As with the previous embodiment, the stirrup  120  includes a bottom portion  122  and left and right upright portions  124 ,  126 . The bottom portion  122  extends beneath the wearer&#39;s foot, and the upright portions  124 ,  126  cradle the sides of the foot. As can be seen clearly in  FIG. 11 , in this embodiment, the upright portions  124 ,  126  extend a substantial distance forward of an imaginary vertical plane  132 A extending through the pivot axis  132 , and the parallel, arcuate, strap-receiving slots  129  extend in a generally horizontal direction, as compared with the strap-receiving slots  29  of the previous embodiment, which extend in a generally vertical direction. 
   As shown in  FIG. 11 , the upper slot  129  is elongated and has a forward-most point or end  129 F and a rearwardmost point or end  129 R as well as a top side and a bottom side. The lower slot  129  is aligned side-to-side with the upper slot  129 , so the upper side of the lower slot is adjacent to the lower side of the upper slot. The slots are essentially the same length, and the respective forward and rear ends of each pair of parallel slots also lie adjacent to each other, so the slots  29  are coextensive with each other for essentially their entire length. In this embodiment, the forward-most point  129 F is 2.5 inches forward of the imaginary vertical plane  132 A, and the rearwardmost point  129 R is approximately 1⅛ inches rearward of the forward-most point  129 F. It is preferable that the forward-most point  129 F be at least 1.5 inches forward of the imaginary vertical plane  132 A and more preferable that it be at least 2 inches forward of the imaginary vertical plane  132 A. A strap  170 A is received in the opposed upper strap-receiving slots  129  for tightening the stirrup  120  onto the wearer&#39;s foot. This embodiment differs from the previous embodiment, in that the strap  170 A and slots  129  are located and oriented to pull the foot downwardly, against the bottom  122 , whereas the lower strap  70  of the first embodiment pulled the foot rearwardly against the heel strip  25 . It also means that this brace extends forward on the sides and bottom of the foot a substantial distance to provide good support. Since the brace  110  is essentially symmetrical about an imaginary vertical plane extending from front to back along the center of the brace, its left and right sides are almost identical, and the slots  129  on the left are directly opposite the slots  129  on the right. 
   The strap  170 A can secure in any number of ways. As shown here, it uses a hook and loop type of fastener to secure both ends. Since the brace is symmetrical, the wearer is free to arrange the strap  170 A to be pulled tight from either side, whichever is preferred, or to pull from both sides as described with respect to the previous embodiment. The arcuate shape of the slots  129  provides good surface area of contact between the strap  170 A and the brace. 
   The uppermost point of the upper slot  129  is approximately ¾ inch below an imaginary horizontal plane  132 B extending through the pivot axis  132 . Since the pivot axis  132  aligns closely with the pivot point of the ankle joint, this means that the sides  124 ,  126  of the stirrup  120  wrap up a substantial distance around the sides of the foot for a substantial forward distance in order to give good support. 
   The upper strap  160  is secured in the same manner as in the first embodiment. 
     FIG. 12  shows that there is texturing on the top surface of the bottom portion  122 , which, in this embodiment, includes narrow, elongated ridges extending from front to back as well as recessed tiny dots. This helps prevent the wearer&#39;s foot from slipping relative to the brace  110  while not creating any discomfort for the wearer. 
   On the bottom surface of the bottom portion  122 , as shown in  FIG. 15 , are more aggressive thin, elongated ridges  182 , which help prevent the brace  110  from slipping relative to the wearer&#39;s shoe. Since they concentrate the weight of the wearer over a very small surface area, they provide a large number of pounds per square inch of pressure with which to grip the shoe. These ridges project downwardly about 1/32 inches and have a width of about 1/32 inches. The width of the spaces between adjacent ridges  182  is much greater than the width of the ridges themselves, so the total surface area of the ridges is very small, which helps concentrate the weight of the wearer over a very small surface area. The ridges include portions that extend primarily in a front-to-rear direction and portions that extend primarily in a left-to-right direction. In this embodiment, pairs of front-to-rear ridge portions  182  are continuous with left-to-right portions, and the ridges  182  form a plurality of nested ellipsoids. 
   As shown best in  FIG. 14 , there are some portions of the brace  110  that are substantially thinner than others, making those portions more flexible, while the thicker portions are more rigid. For example, the rear cuff  150  has a plurality of bands extending from side to side. The upper and lower bands  152 ,  155 , which form the top and bottom edges of the cuff  150 , are thinner than some intermediate bands  153 ,  154 , which allows the top and bottom edges of the cuff  150  to flex more, making the brace more comfortable for the wearer. Also, as in the previous embodiment, there are central indentations  158  in the top and bottom edges of the cuff  150 , making the cuff  150  shorter at its center, so it can flex more easily in that shorter portion. 
   It will be obvious to those skilled in the foregoing description describes just one example of a product made in accordance with the present invention. It is understood that various modifications may be made without departing from the scope of the invention as claimed.