Abstract:
A versatile orthopedic walker includes a high strength engineered plastic base with spaced upper and lower surfaces and upwardly extending slotted strut supports. The base may be laterally and vertically cored, and an outer sole is provided which extends upward over the core openings, with the upper edges of the outsole being ridged to fit into a peripheral groove in the base to provide a smooth exterior surface. Struts of different lengths are provided, and all of the struts have identical arrangements for interlocking with the base. All of the struts may be provided with a three pronged construction to triply lock the struts into the base. The struts may have areas of reduced cross-section providing pivot points or areas of flexibility to accommodate different size patients, and limiting stops may be provided to assure adequate orthopedic support. Fully integrally molded pivoting D-rings may hold walker straps in place.

Description:
FIELD OF THE INVENTION 
   This invention relates to orthopedic walkers, which are orthopedic support boots which encompass the foot, ankle and lower legs, for use by persons recovering from injuries such as broken bones or other trauma of the lower leg, ankle or foot. This type of orthopaedic product is often referred to as a “short leg walker”. 
   BACKGROUND OF THE INVENTION 
   Leg mounted orthopaedic walkers are well known, and typical patents disclosing such walkers include the following 
   
     
       
             
             
           
         
             
                 
             
           
           
             
               U.S. Pat. No. 5,368,5581 
               Granted: Nov. 29, 1994 
             
             
               Inventor: Zuckerman 
             
             
               Title: Ankle Brace Walker 
             
             
               U.S. Pat. No. 4,771,768 
               Granted: Sep. 20, 1988 
             
             
               Inventor: Crispin 
             
             
               Title: Controlled Motion Ankle Fracture 
             
             
               Walker 
             
             
               U.S. Pat. No. 5,078,128 
               Granted: Jan. 7, 1992 
             
             
               Inventor: Grim et al. 
             
             
               Title: Removable Leg Walker 
             
             
               U.S. Pat. No. 5,329,705 
               Granted: Jul. 19, 1994 
             
             
               Inventor: Grim et al. 
             
             
               Title: Footgear with Pressure Relief Zones 
             
             
               U.S. Pat. No. 5,464,385 
               Granted: Nov. 7, 1995 
             
             
               Inventor: Grim 
             
             
               Title: Walker with Open Heel 
             
             
                 
             
           
        
       
     
   
   SUMMARY OF THE INVENTION 
   However, the known prior art walkers suffer from various shortcomings or disadvantages. 
   In this regard, the exteriors of some walkers are irregular so that they may catch on adjacent objects or fabric, and do not have an aesthetically pleasing configuration. 
   Concerning the struts which normally extend upwardly from the base of the walker, (1) they may not include readily interchangeable long and short struts; (2); they may not readily accommodate different size lower legs; (3) the mechanisms for securing the struts to the base may be either permanent, or subject to failure; (4) the flexibility of the struts may be substantially linear, and therefore may be too flexible throughout bending cycles to provide adequate orthopaedic support, or may be unduly stiff so as to irritate the user. 
   Regarding the walker bases, some available walkers do not have adequate resiliency to prevent undue shock during walking motion such as heel strike or other shock. 
   The walker base may have a substantially flat outer sole, or outsole, adhered to the lower surface of the base; and these substantially flat outsoles may be subject to delamination from the base. 
   In respect to the strap retaining loops or D-rings, the multipart units which are frequently employed for pivot applications are often unduly complex and expensive. 
   In accordance with one specific illustrative embodiment of the invention, a versatile walker which overcomes the shortcomings outlined hereinabove includes the following integral features: 
   1. The struts are secured to the base on a snap-in basis using a three pronged extension on the laser end of the struts, with the two outer prongs constituting locking members which fit into grooves and recesses in the base, with the third, central prong being resiliently biased toward the outer prongs so that when the two outer prongs lock into place, the central prong blocks their release. 
   2. Both long struts and short struts are provided, with identical locking arrangements on their lower ends, which may be of the type as outlined hereinabove. 
   3. The struts may be provided with reduced thickness zones to increase flexibility and to accommodate different anatomical configurations without sacrificing stability. Reduced thickness zones located below the upper end of the struts but at least an inch or two above the ankle joint can provide medial/lateral flexibility or hinge points to accommodate patients with relatively large lower legs. It is also noted that the medial/lateral hinge action may be provided by physical hinges or pivot points along the length of the strut, rather than by reduced strut thickness. 
   4. The struts may be provided either at the juncture with the base or along their length, with variable resiliency mechanisms, to permit initial easy deflection to accommodate minor deflections of the struts, and with arrangements for increasing resistance to deflections greater than a predetermined distance or angle. These arrangements may include reduced thickness in the struts, and a stop which is engaged when the deflection exceeds a predetermined amount. 
   5. The struts may have outwardly extending flaps or wings which may be hingedly secured to the central part of the strut, to accommodate various sizes of the patients&#39; anatomies. So called “living hinges”, or lines of reduced thickness, or grooves, extending partially through the plastic strut, may be employed to provide the hinging function. 
   6. The outer sole or outsole of the walker may include protrusions which may be hollow or doughnut shaped, in its upper surface to provide resiliency and cushioning during walking. And the outsole may extend upward around the outer periphery of the base, and have a peripheral bead interfitting with a mating recess in the base and providing a continuous smooth exterior surface at the junction between the outsole and the base. The base may be cored from the sides at the central area of the walker, and may be cored with relative small recesses from the top, toward the front and rear of the base, to reduce the weight of the walker. The outsole extends over the side core openings, thereby preventing the entry of foreign material, and provides a pleasing aesthetic appearance. 
   7. The strap retention loops or D-rings which are employed for pivoting functions are formed of one piece moldings, with the integral pivot pin pivotally locking the D-ring onto the plastic walker base. 
   It is to be understood that all of the foregoing features contribute to the realization of versatile walkers in which either long or short struts may be employed and which accommodate patients with different types of injuries, and patients with different anatomical configurations. 
   It is further noted that in some cases, instead of having separate struts secured to a base, the struts may be integrally molded with the base. 
   Advantages of the new design include the elimination of decorative side caps, increased outsole adhesion to the plastic base, resistance to water, mud and dirt, increased surface contact and gripping action, increased resiliency between outsole and plastic base and improved aesthetic appearance resulting from the smooth outer surface mating of the outsole and the plastic base. The upward extent of the oustsole of the base, and the interfitting recess and groove also prevents delamination of the outsole from the base. Variations in the size of the ankles and lower leg are accommodated by living hinges and by increased flexibility within preset angular limits. Safety is assured by the triple locking mating arrangements between the struts and plastic base. Finally, costs are reduced by the use of integrally molded d-rings which may provide pivoting action, by the simplification of the walker structure, and by avoiding the need for different walker configurations for different anatomical configurations. 
   Other objects, features and advantage will become apparent from a consideration of the following detailed description, and from the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an orthopaedic walker illustrating the principles of the invention; 
       FIG. 2  is a left side elevational view of the walker of  FIG. 1 ; 
       FIG. 3  is a front elevational view of the walker of  FIG. 1 ; 
       FIG. 4  is a right side elevational view of the walker of  FIG. 1 ; 
       FIG. 5  is a rear elevational view of the walker of  FIG. 1 ; 
       FIGS. 6 and 7  are top and bottom plan views of the walker; 
       FIG. 8  is a partial exploded side view of the walker with the outer sole, or outsole spaced from the walker base; 
       FIG. 9  is a partial cross sectional view showing the smooth interfit between the walker base and the outsole; 
       FIG. 10  is a top plan view of the outsole; 
       FIG. 11  is a side elevational view of the walker with the straps and padding removed; 
       FIG. 12  is a side view of a long strut shown separate from the complete walker; 
       FIG. 13  is a view from the inside of a short strut which may be employed when the injury is confined to the ankle or lower ends of the lower leg bones; 
       FIG. 14  is a perspective view of the three prong locking mechanism for the struts; 
       FIG. 15  is a fragmentary assembly drawing showing the strut partially assembled to the base; 
       FIG. 16  is similar to  FIG. 15  but shows the strut locking mechanism fully assembled and locked; 
       FIG. 17  is a partial cross-sectional view of one of the long struts showing the reduced cross-section, for increased flexibility and the limiting stop arrangements; 
       FIG. 18  is a transverse cross-section of one of the shorter struts showing the hinge lines of flexibility; 
       FIG. 19  is a perspective view of an integral pivotal “D-ring”; and 
       FIG. 20  is a partial elevational view of the D-ring of  FIG. 19 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring more particularly to the drawings,  FIG. 1  is a perspective view of a walker  32  illustrating the principles of the invention. The walker of  FIG. 1  includes an engineered plastic base member  34 , two struts, one of which is visible at reference  36 , and an outersole, or outsole  38 . The plastic base  34  may, for example be formed of fiber glass filled nylon, but other high strength plastics or other materials may be employed such as aluminum which may for example be powder coated. A resilient layer  40 , which may be formed of one-quarter inch thick resilient foam, provides a cushion between the foot and the upper surface of the plastic base  34 . Additional padding  42  extends around the foot, ankle and lower leg of the patient. The padding  42  is held in place between the struts including strut  36  by hook and loop material of the Velcro® type, with hook type material extending along the inner surface of the struts, and with the padding  42  either having mating loop material on its outer surface, or being of a type of fabric which will inherently mate with hook type material. 
   It may be noted in passing that  FIGS. 1 through 6  of the drawings are substantially the same as the first six figures of a design patent application filed on Jul. 23, 2002, and entitled “Top and Sides of Resilient Orthopaedic Walker”. 
   Continuing with the description of  FIG. 1  of the drawings, the straps  51  through  55  extend around the padded foot, ankle and lower leg of the patient. They are secured to the base  34  and the struts by slots such as slot  44  in strut  36  or by D-rings, such as D-ring  46  or pivoted D-ring  48 . The straps are provided with mating hook and loop material on their overlapping surfaces so that they are readily adjustable. The integrally formed D-ring  48  will be discussed in greater detail hereinbelow. 
   The strut  36  is reduced in thickness in the area  62  to increase the flexibility of the strut, to readily accommodate patients with large lower legs. However, to insure orthopaedic stability and support, a stop mechanism  64  is provided. As disclosed in greater detail hereinbelow (see  FIG. 17 ), the stop mechanism  64  has two surfaces spaced apart by a narrow space. Accordingly, as the walker is being fitted to a person with a large lower leg, the upper portion of the strut  36  may easily flex outward. However, if in use, the strut  36  is flexed beyond a predetermined distance or angle, preferably at least equal to 15 degrees but less than 30 degrees, the two spaced surfaces at reference numeral  64  engage, and there is much higher resistance against further deflection, and increased support for the leg. 
   Concerning the straps  51  and  52 , they each have one end permanently secured to a D-ring, with the D-ring  66  for strap  52  being visible. The free ends of straps  51  and  52  pass through D-rings  48  and  46 , respectively and then fold back and engage facing surfaces of the straps by hook and loop securing material. The other straps  53 ,  54  and  55  similarly extend around the assemblies in a generally conventional manner with slots in the struts and/or hook and loop material on the outer surfaces of the struts holding the straps in place. 
     FIGS. 2 through 7  are various views of the walker as shown in  FIG. 1 , with  FIG. 7  showing the patterned bottom layer of the outer sole, or outsole  38  for increased friction and traction. The outsole is bonded to the plastic base  34  by adhesive, and the outsole extends around and up the sides of the plastic base. 
   As shown to advantage in  FIGS. 8 and 9  of the drawings, the upper edge of the outsole  38  has a ridge  72  which interlocks with a mating peripheral recess  74  in the base. This configuration increases traction and resists delamination of the outsole from the base. Instead of the simple ridge and groove as shown, more complex interlocking stuctures may be employed; and the ridge and groove may be reversed. 
   Referring to  FIGS. 8 and 9  of the drawings, the cored openings  76  which extend inwardly to a thin central web, and the cores  78 , are clearly shown. Referring back to  FIGS. 1 ,  2  and  4  of the drawings, note that the outsole  38  covers the entry to the cored openings  76 . This has the advantage of preventing ingress of mud or other foreign material. 
   It may also be noted that the outward extent of the walker base  34  in the area  80  just above the peripheral recess  74  is greater than the outward extent in area  82  just below recess  74 , by a predetermined thickness equal to the thickness of the outsole  38 . This configuration presents a smooth exterior in the area where the outsole  38  mates with the base  34 ; and has the advantages of avoiding protrusions which might catch on objects as the patient walks and also presents a pleasing aesthetic appearance. It also avoids the need for additional components for closing the ends of the cored areas  76 . 
     FIG. 10  is a top plain view of the outsole  38  with the heel area to the left as shown in  FIG. 10  and the toe area to the right. This is a view of the inside of the outsole  38 , and includes a large number of hollow doughnut shaped protrusions  90 , and upwardly extending walls or ridges  92 . These protrusions and walls extend upwardly from the continuous underlying surface of the outsole  38 ; and they provide additional resiliency particularly in the heel area, where the heel strike portion of a walking stride could otherwise provide a shock to the injured lower leg or foot of the patient. It is also noted that the closed wall protrusions trap air between the lower portion of the outsole and the mating surface of the base  34 , thereby increasing the resiliency and buoyancy provided by the outsole. It is also noted that the outsole  38  is preferably adhesively bonded to the base  34 . 
     FIG. 11  is a side view of the walker of  FIG. 1  with the padding straps and D-rings removed. Apart from matters previously mentioned, the line  94  represents the mating surfaces between the strut  36  and the walker base  34 . 
     FIG. 12  is a plan view of the inside of a long strut which is, by way of example and not of limitation, about 13 inches long. It includes openings or slots  44 , and recesses  96  to reduce the weight of the assembly. As indicated in earlier figures of the drawings, the slots  44  receive straps, such as strap  55  for holding the walker securely onto the patient. 
   The short strut  102  shown in  FIG. 13  of the drawings is about 6½ inches long, and, with its laterally extending wings  132  and  134 , is about 4½ inches wide. 
   The lower end of the long strut  36  has a triple locking mechanism including three prongs, the two outer prongs  104 , and a central locking prong  06 . The short strut  102  has an identical three prong locking mechanism including the two outer prongs  104 ′ and the central locking prong  106 ′. 
     FIG. 14  is a perspective view of the locking mechanism at the lower end of the struts. Note that, in addition to the three locking prongs,  104 ,  106 , the struts have two thin outwardly extending longitudinal flanges  108  which mate with the longitudinal grooves or slots  110  on the strut support (see  FIG. 15 ). Incidentally, it may be noted from  FIG. 14  that the prongs  104 , 106  are thicker than the flanges  108 , so that, as shown in  FIG. 15 , the ends of the prongs  104  do not slide in the grooves or slots  110 , but ride on the outer edges of these slots  110 . Incidentally the central portion  112  of the central locking prong  106  is of significantly reduced thickness, so that it may readily bend in the direction perpendicular to the plane of the strut, as indicated by arrow  114  in  FIG. 14 . 
     FIG. 15  shows the strut  36  partially assembled into the base  34 , with the flanges  108  mating with slots or grooves  110 . The outer prongs  104  are severely bent inward, and the central locking prong  106  is bent up out of the plane of the paper. The locking shoulders  114  are available to receive the outwardly extending surfaces  116  of the outer prongs  106  (see  FIG. 14 ). 
   The fully locked position of the strut  36  is shown in  FIG. 16 , with the prongs  104  having surfaces  116  locked over the locking shoulders  114 . The final locking step is accomplished by pressing the central locking prong  106  firmly into the space between the outer prongs  104  so that its outwardly extending protrusions  116  (see  FIG. 14 ) interlock with recesses on the facing surfaces of the outer prongs  104 . 
   As noted above, with both the long and the short walkers having identical locking mechanisms, a walker of either type may be formed using a common base, and the desired long or short struts. 
   Attention is now directed to  FIG. 17  which should be considered along with  FIGS. 3 and 11  of the drawings. As mentioned above, the struts such as strut  36  may be thinned down in area  62 , to increase flexibility to readily accommodate patients with varying size lower legs. However, following deflection in the direction indicated by arrow  122 , the surfaces  124 , 126  engage, and provide the desired orthopaedic structural support. This combination of initial flexibility and subsequent increased stiffness and reduced flexibility both accommodate varying size lower legs, and also provides the desired orthopaedic support. 
   Referring now to the short walker strut of  FIG. 13  and the cross-sectional view of  FIG. 18 , taken along plane  18 - 18  of  FIG. 13 , the short strut  102  is provided with laterally extending wings  132  and  134 , with vertically extending lines of weakness or so-called “living hinges”  136 . In practice two struts such as strut  102  are mounted on a walker base, with padding around the ankle of the type shown in  FIGS. 1-6 , but somewhat shorter, commensurate with the height of the struts. Straps are mounted to the struts and to the padding preferably using the hook and loop principle; and the wings  132 ,  134  on the short struts, are flexed to make a close supporting fit with the size of the foot and ankle of the patient. 
     FIGS. 19 and 20  relate to the integrally moulded pivotal D-ring of the type shown at  48  in  FIG. 1  of the drawings. In  FIG. 19 , the “D-ring”  48  has an opening  142  for receiving a strap, and two integrally molded flaps  144  and  146 . The flap  144  has an integrally molded pivot pin  148  formed thereon; and the flap  146  has a variable size opening  150 . As indicated in  FIG. 20  the opening  150  has outwardly directed cuts so that the rounded head  152  of pin  148  can snap through the hole. The side walls of the hole will then snap back and engage the reduced diameter section of the pin and retain the pin in its closed position, normally locked into a hole in an orthopaedic walker or support as indicated in  FIG. 1  of the drawings. 
   In closing, it is noted that specific illustrative embodiments of the invention have been shown in the drawings and described in detail hereinabove. It is to be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. Thus, by way of example and not of limitation, the locations of the rib  72  and the recess  74  may be reversed with the rib on the base and the recess on the periphery of the outsole. Also, the outer prongs on the locking mechanism may be made thinner to fit into the grooves or slots on the strut supports of the base. In addition, the struts may be formed of aluminum over-molded with plastic, as one alternative to the use of fiber-glass impregnated nylon. In another area, the stop for reducing strut flexibility be included in the junction between the struts and the base, with one of the two mating stop surfaces being on the base, and the other stop surface being on the strut, and with the strut-to-base joint being somewhat flexible. Further, the outsole may be more permanently affixed to the walker base by over-molding the bottom of the base with the outsole, and having the outsole interlock into openings or recesses in the base. Also, the struts, either long or short, may be provided with slots, or integrally molded outwardly extending D-ring type structures for receiving straps. Accordingly the present invention is not limited to the specific embodiments shown in the drawings, or described in detail hereinabove.