Abstract:
An appendage cover ( 10 ) for at least partially covering a portion of an appendage ( 14 ) of a user to permit the appendage to slide upon a selected support surface is disclosed. The appendage cover includes an outer surface ( 16 ) of a first material, the outer surface oriented to engage the support surface when worn upon the appendage. The first material has a low coefficient of friction to permit the appendage to slide upon the support surface and to impede the adhering of the outer surface to the support surface. The appendage cover further includes an inner surface ( 18 ) of a second material, the inner surface oriented to engage the appendage. The second material has a high coefficient of friction to permit the appendage to adhere to the outer surface to impede the sliding of the appendage relative to the inner surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 60/463,756 filed on Apr. 16, 2003, entitled “Appendage Cover,” the disclosure of which is hereby expressly incorporated by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to rehabilitative devices, and more particularly to appendage covers adapted to permit the covered appendage to selectively glide upon a surface.  
         BACKGROUND OF THE INVENTION  
         [0003]    In the healthcare industry, a patient of limited mobility is often transferred from one location to another, such as from a wheelchair, bed, toilet, or car to another location. Although such an operation appears benign on the surface, it has been discovered that injuries can occur to both healthcare workers and their patients during the performance of the transfer. Potential for injury during the transfer is present in many forms, however one specific source of injury in particular has not been addressed by previously developed safety aids. More specifically, it has been found that during the transfer, a patient&#39;s foot of a weak or paralyzed leg sticks or catches on the floor, causing stress on the hip, knee, and ankle joints. As the healthcare worker continues to transfer the patient, the patient&#39;s foot remains “adhered” to the floor as the patient is rotated and moved from the wheelchair to the bed, resulting in the patient&#39;s leg becoming twisted, stepped upon, folded under the patient, etc. Adherence of the foot potentially causes injury to the patient, such as sprains, strains, and/or fractures. Additionally, the adherence of the foot upon the floor significantly increases the difficulty of the transfer, which can result in an increase in injuries to the healthcare workers. Thus, healthcare workers are subject to injury during transfer operations, especially back injuries.  
           [0004]    It also been discovered that injuries can occur to patients while using a wheelchair, most notably when a leg of the user has lost some degree of mobility, such as a result of a stroke. For example, it has been found that during the use of the wheelchair, a patient often propels the wheelchair with the unaffected leg while either dragging the weakened leg or supporting the weakened leg with a leg rest. In the situation of the weakened leg being rested upon the floor surface, a sole of a shoe worn by the user, or other such foot covering, has a tendency to adhere or grab the floor. The user is then injured as the foot is impacted and or twisted as the wheelchair continues to move forward.  
           [0005]    Further, during the rehabilitation of an appendage, such as a foot or a hand, it is often desirable to slide the limb along a surface during performance of a rehabilitation exercise. However, it has been discovered that the skin of the appendage or appendage cover, such as a shoe, tend to grab or stick upon the surface, resulting in excess frictional forces and a jerking motion as the skin or appendage cover grabs and releases from the surface. These excess frictional forces decrease the range of motion that the patient is able to swing the limb through, thus decreasing the effectiveness of the exercise. Further, the resisting friction forces may be too great, potentially preventing the patient from even performing the exercise.  
           [0006]    Thus, there exists a need for an appendage cover that permits the appendage to glide upon a variety of surfaces.  
         SUMMARY OF THE INVENTION  
         [0007]    An embodiment of an appendage cover formed in accordance with the present invention for reducing surface friction of a weak or paralyzed appendage of a person to permit the appendage to glide upon a surface is disclosed. The appendage cover includes a body portion for covering at least a portion of the appendage. The body portion includes a grip surface positioned to engage the appendage and hold the body portion stationary relative to the appendage. The body portion also includes a glide surface positioned to slide upon the surface during movement of the person. The glide surface has a predetermined coefficient of friction sufficient to enable the appendage to glide upon the surface when (1) the appendage is resting upon the surface and (2) not bearing the weight of the user and further sufficient to permit the appendage to remain immobile upon the surface when the appendage is bearing at least a portion of the weight of the user.  
           [0008]    An alternate embodiment of an appendage cover formed in accordance with the present invention for reducing surface friction of a weak or paralyzed appendage of a person to permit the appendage to glide upon a surface is also disclosed. The appendage cover includes a body portion for covering at least a portion of the appendage. The body portion includes a grip surface positioned to engage the appendage and hold the body portion stationary relative to the appendage. The body portion further includes a glide surface positioned to slide upon the surface during movement of the appendage. The glide surface formed from a fabric of a predetermined fineness rating to enable the appendage to glide upon the surface when (1) the appendage is resting upon the surface and (2) not bearing the weight of the user and further sufficient to permit the appendage to remain immobile upon the surface when bearing at least a portion of the weight of the user.  
           [0009]    A second alternate embodiment of a foot cover formed in accordance with the present invention for reducing surface friction of a weak or paralyzed leg of a person to permit a foot of the leg to glide upon a surface is further provided. The foot cover includes a body portion for covering at least a portion of a shoe donned by the foot. The body portion includes a grip surface positioned to engage the shoe and hold the body portion stationary relative to the shoe during use. The body portion further includes a glide surface positioned to slide upon the surface during movement of the leg, the glide surface formed from a fabric having a fineness rating of less than 400 denier.  
           [0010]    A third alternate embodiment of an appendage cover formed in accordance with the present invention for at least partially covering a portion of an appendage of a user to permit the appendage to slide upon a selected support surface is disclosed. The appendage cover includes an outer surface oriented to engage the support surface when the appendage cover is worn upon the appendage, the outer surface having a predetermined coefficient of friction sufficient to permit the appendage to slide upon the support surface and to impede the adhering of the outer surface to the support surface. The appendage cover also includes an inner surface oriented to engage the appendage, the inner surface having a selected coefficient of friction higher than the predetermined coefficient of friction to permit the inner surface to adhere to the appendage to impede the appendage from moving relative to the inner surface. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The foregoing aspects and many of the attendant advantages of this invention will become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
         [0012]    [0012]FIG. 1 is an isometric view of one embodiment of an appendage cover formed in accordance with the present invention, depicted worn upon a foot of a user;  
         [0013]    [0013]FIG. 2 is a top plan view of the appendage cover depicted in FIG. 1, the appendage cover depicted in a flat, laid out position;  
         [0014]    [0014]FIG. 3 is an elevation view of the appendage cover depicted in FIG. 2;  
         [0015]    [0015]FIG. 4 is a bottom plan view of the appendage cover depicted in FIG. 2; and  
         [0016]    [0016]FIG. 5 is a cross-sectional view of the appendage cover depicted in FIG. 2, the cross-sectional cut taken substantially through section 5-5 of FIG. 2. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    [0017]FIGS. 1-5 depict an illustrated embodiment of an appendage cover  10  formed in accordance with the present invention. Although the illustrated embodiment of the present invention is described as implemented for use as a cover for a foot of a user, those skilled in the relevant art will appreciate that the disclosed appendage cover  10  is illustrative in nature and should not be construed as limited to application with the foot of a user. It should therefore be apparent that the appendage cover  10  has wide application, and may be used in any situation where reducing the coefficient of friction of a body part, such as a hand, an elbow, a portion of a limb remaining after amputation, etc., is desirable. It should also be noted that for purposes of this disclosure, terminology such as forward, aft, left, right, etc. should be construed as descriptive and not limiting.  
         [0018]    Referring to FIG. 1 and generally described, the appendage cover  10  reduces surface friction and thereby allows a weak or paralyzed foot  14  to glide safely with the body, helping to eliminate stress placed on the hip, knee and ankle joints. The appendage cover  10  helps to reduce the risks of fracture, sprains, strains, and surprise twists caused when the foot  14  of a patient catches or sticks to the floor. The appendage cover  10  may be used to enhance transfer ease, ambulation speed and distance, leg control, joint protection, and active muscle capability. The appendage cover  10  of the illustrated embodiment is designed to enable the caregiver easier and safer transfers, and to maximize patient mobility. The appendage cover  10  of the illustrated embodiment is durable, lightweight, portable and easy to use.  
         [0019]    Referring to FIGS. 1-5 and focusing on the structure of the appendage cover  10 , the appendage cover includes a flexible cover  12  adapted to substantially cover a foot  14  of a user, the flexible cover  12  removably coupled to the foot  14  by an attachment assembly  20 . The flexible cover  12  includes an outer layer  16  and an inner layer  18 . The outer layer  16  is suitably formed from a flexible material having a low coefficient of friction. The coefficient of friction is selected to permit the foot  14  of a moderate (50% to 75%) or maximum (75% to 100%) weakened leg to slide easily upon a surface, most notably flooring surfaces, without grabbing or “adhering” thereto while the foot  14  is in a non-load bearing position, i.e. a position wherein the limb bears substantially only the weight of the limb itself.  
         [0020]    On the other hand, the coefficient of friction of the outer layer  16  is preferably not too low so as to permit the foot to bear the weight of the user without slipping out from under the user. In one embodiment, the leg is able to be angled up to about 10 degrees relative to the support surface while bearing the weight of the user before the foot slips out from under the user. In another embodiment, the leg is able to be angled up to about 15 degrees relative to the support surface and bear the weight of the user before the foot slips out from under the user. In another embodiment, the leg is able to be angled up to about 20 degrees relative to the support surface and bear the weight of the user before the foot slips out from under the user. In still another embodiment, the leg is able to be angled up to about 30 degrees relative to the support surface and bear the weight of the user before the foot slips out from under the user.  
         [0021]    Preferably the outer layer  16  is made from a fabric, one suitable material being a nylon fabric, having a fineness rating of between about 100 denier and about 400 denier, with a preferred fineness rating of 200 denier. Although the outer layer  16  of the illustrated embodiment is described as a fabric made from a specific material, it should be apparent to those skilled in the art that the outer layer  16  may be formed from any number of materials, all of which are suitable for use with and within the spirit and scope of the present invention.  
         [0022]    The inner layer  18  is suitably formed from a flexible material having a high coefficient of friction, the coefficient of friction selected to adhere to the foot  14  or a shoe enclosing the foot  14 , such that the appendage cover  10  grips the foot and does not slide relative to the foot  14  during use. One suitable material for the inner layer  18  is a synthetic rubber, such as DUPONTS® neoprene. Although the inner layer  18  of the illustrated embodiment is described as made from a specific material, it should be apparent to those skilled in the art that the inner layer  18  may be formed from any number of materials, all of which are suitable for use with and within the spirit and scope of the present invention.  
         [0023]    Referring now to FIGS. 1, 2, and  4 , the attachment assembly  20  includes an ankle attachment device  22 , a hindfoot attachment device  24 , and a midfoot attachment device  26 . The ankle attachment device  22  couples the appendage cover  10  to the ankle or leg  28  of the user. The ankle attachment device  22  of the illustrated embodiment includes a left strap  30  and a right strap  32 , each extending perpendicularly outward from a longitudinal axis of the appendage cover  10  at the aft end of the appendage cover  10 . The right strap  32  may be joined to the left strap  30  around the leg  28  of the user through the use of a well known hook and loop fastening system. More specifically, the right strap  32  may include a portion of hook fabric  34  that engages a portion of loop fabric  36  disposed on the left strap  30 , thereby removably coupling the appendage cover to the leg  28  of the user.  
         [0024]    The hindfoot and midfoot attachment devices  24  and  26  are substantially similar in construction and operation to the ankle attachment device  22  described above with exception to their location on the appendage cover  10 . As the name implies, the hindfoot attachment device  24  is coupled in proximity to a heel of the user, such that the left and rights straps, when coupled to one another, encircle the hindfoot portion of the foot, i.e. over the astragalus and/or scaphoid bones of the foot  14 . The midfoot attachment device  26  is coupled forward of the hindfoot attachment device  24 , such that the left and right straps of the midfoot attachment device  26 , when coupled to one another, encircle the midfoot portion of the foot, i.e. over the metatarsal bones of the foot  14 .  
         [0025]    Although the attachment assembly  20  is described as formed from straps  30  and  32  utilizing a hook and loop fastening system for coupling the straps to one another, it should be apparent to those skilled in the art that the attachment assembly  20  may utilize any number of well known fastening systems for coupling the straps to one another, such as buckles, buttons, clips, etc. Further, although the illustrated embodiment utilizes an attachment assembly  20  having straps for coupling the appendage cover  10  to the foot  14  of the user, it should be apparent to those skilled in the art that the other attachment assemblies are suitable for use with the present invention. For instance, the attachment assembly  20  may suitably include laces, zippers, elastic material, etc. for removably coupling the flexible covering  12  to the foot  14  of the user and are therefore within the spirit and scope of the present invention.  
         [0026]    Referring to FIG. 2, the appendage cover  10  further includes indicia  37  to mark the preferred placement of the heel upon the appendage cover  10  when donning. The indicia  37  may be visual indicia and/or physical indicia. Moreover, the indicia  37  may be formed in any number of manners, such as by printing an outline of the preferred location of the heel upon the inner layer  18  or sewing a line of stitching in a rough outline of the periphery of a heel as an indicator of the preferred location of the heel upon the inner layer  18 .  
         [0027]    Still referring to FIG. 2, the appendage cover  10  further includes a left tether and a right tether  38  and  40  respectively. The tethers  38  and  40  are formed from a loop of thread passing through the flexible cover  12  and encircling a small portion of the flexible cover  12 , “bunching up” the fabric in the location of the tethers  38  and  40 . The tethers  38  and  40  thus aid in forming a hinge  42  in the flexible cover  12 , the hinge  42  providing a preferential fold line. The hinge  42  thus aids in the folding of the rear portion of the flexible cover  12  up behind the ankle during donning of the appendage cover  10 . Further, the tethers  38  and  40  create a reduced width portion  44  of the flexible cover  12 , which aids in providing a visual indication of where the heel of the foot should be placed by providing a rounded section in the flexible cover  12  which generally matches the round shape of the heel of the foot.  
         [0028]    Referring to FIGS. 1 and 2, in light of the above description of the structure of the appendage cover  10 , the operation of the appendage cover  10  will now be described. In donning the appendage, the user lays the appendage cover  10  in a flat, laid out position as depicted in FIG. 2, with the inner layer  18  facing the foot of the user and the outer layer  16  laying against a supporting surface, such as a floor. The user, possibly with assistance of a healthcare worker, places the heel of the foot in the location indicated by the indicia  37 , i.e. just forward of the hinge  42 . The ankle attachment device  22  is fastened around the leg  28  of the user. A tongue  46  of the appendage cover  10  is then folded back upon the foot  14  so as to cover the top of the user&#39;s foot. The hindfoot and the midfoot attachment devices  24  and  26  are then fastened around the foot  14  of the user, thereby securing the tongue  46  against the foot of the user, and removably coupling the appendage cover  10  to the foot of the user.  
         [0029]    Once donned, the outer layer  16  provides a reduced friction surface such that the foot may be easily slid upon most surfaces, such as most floor coverings, as the weight of the user is born by the users arms, other leg, and/or the healthcare worker. The low coefficient of friction of the outer layer  16  aids healthcare personnel in transferring a patient from one location to another, such as transferring a patient from a wheelchair to a bed. More specifically, the appendage cover  10  permits transfers to be performed without the foot of the patient grabbing or adhering to the floor during the transfer, thus reducing the potential for injury to the patient and healthcare workers as described above. However, the coefficient of friction of the outer layer  16  is sufficient to permit the outer layer  16  to grip the surface when the foot is in a load bearing position and supporting a least a portion of the weight of the user so that the foot does not slip out from under the user.  
         [0030]    Further still, the outer layer  16  facilitates the performance of rehabilitative exercises by reducing the friction forces exerted upon the foot when slid upon a surface during performance of an exercise. More specifically, the appendage cover  10  permits the foot  14  to slide upon a surface, such as a floor, during rehabilitative exercises with reduced effort, thereby increasing limb mobility during the exercise. For instance, in one exercise, a user lays upon a pad and swings their leg to the left and right in a pendulum like manner upon the pad. Due to the reduction of friction, the arc which the user is able to swing the leg through is increased, enhancing the rehabilitative quality of the exercise. In some cases, the appendage cover  10  reduces the amount of friction to a point that permits the user to slide the foot across an exercise surface wherein such movement was previously impossible without the application of the appendage cover  10 .  
         [0031]    The low coefficient of friction of the outer layer  16 , which permits a foot  14  wearing the appendage cover  10  to slide without grabbing upon a floor, is also advantageous for a wheel chair bound person. More specifically, the appendage cover  10  permits a user to push or slide ahead a covered foot  14  in front of the wheelchair when the foot falls off of a foot support platform of the wheelchair or when a foot support platform is not used. During such use, the appendage cover  10  impedes a shoe worn by the user, or other such foot covering, from adhering to or grabbing the floor resulting in the foot being impacted and or twisted as the wheelchair continues to move forward.  
         [0032]    Although a few examples of exemplary uses of the appendage cover  10  are described for illustrative purposes, it should be apparent to those skilled in the art that the appendage cover  10  may be used for any activity where movement of an appendage with reduced friction upon a surface is desired.  
         [0033]    The appendage cover  10  of the illustrated embodiment is an one-size-fits-all device. It may be worn upon a large foot, a small foot, a foot covered by a shoe, sock, or other covering, or upon an uncovered foot. As should be apparent to those skilled in the art, the attachment assembly  20 , in coordination with the tongue  46 , permits the appendage cover  10  to adapt to many different sizes of feet. Although the illustrated embodiment is depicted as an one-size-fits-all device, it should be apparent to those skilled in the art that alternately, the appendage cover  10  may also be suitably formed in any number of sizes, each size selected to correspond to a selected size of a foot.  
         [0034]    Further still, although the appendage cover  10  of the illustrated embodiment is described as formed for covering a foot of a user, it should be apparent to those skilled in the art that the appendage cover  10  may alternately be formed to be donned upon alternate areas or appendages of the body. For instance, the appendage cover  10  may be alternately formed to cover a hand, wrist, elbow, head, back, ankle, calf, knee, thigh, leg, back, etc. of a user. It should be apparent to those skilled in the art that the size, shape, orientation, etc. of the flexible cover and attachment assembly may be varied from the illustrated embodiment to better accommodate the coupling of the appendage cover  10  to the desired portion of the body. Further, for the purposes of this detailed description, the term appendage includes any articles of clothing or other objects worn by the appendage such as a sock or a shoe covering a foot.  
         [0035]    Further still, although the illustrated embodiment is depicted as worn upon the foot of the user, it should be apparent that the illustrated appendage cover  10  may be donned upon alternate areas of the user, such as about the hand, wrist, elbow, etc. of the user without modification.  
         [0036]    While the illustrated embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.