Abstract:
The pneumatic Achilles wrap comprises a wrap including at least one strap for fastening the wrap around the foot and around the ankle. The wrap positions an arch cell which contains a dynamic volume of air within the wrap under a human foot. The arch cell is fabricated from a flexible material and is in communication with a conduit member. Upon application of external pressure to the arch cell, air is expelled from said air cell through said conduit member. The wrap also positions a tendon cell which contains a dynamic volume of air within the wrap against the Achilles tendon. The tendon cell is in communication with the arch cell via the conduit member. The tendon cell is also fabricated from a flexible material. Upon the expelling of air from said arch cell, the air enters through the conduit member into the tendon cell which exerts a greater pressure against the Achilles tendon.

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention relates to a compression wrap for pneumatically applying dynamic pressure to the Achilles tendon. 
     2. Description of Related Art 
     Active people commonly experience the ache and debilitating effects of posterior heel pain as a result of three commonly accepted causes: Haglund syndrome, Achilles tendinitis/osis and Sever&#39;s disease. 
     Haglund syndrome is characterized by a painful soft tissue swelling where the Achilles tendon attaches to the calcaneum (heel bone). Haglund syndrome can often result in the development of a bony deposit on the back of the calcaneum or in the inflammation of the bursa, the fluid filled sac that decreases friction between the Achilles tendon and the calcaneum, which is known as retrocalcaneal bursitis. It is believed that Haglund syndrome results from the repetitive application of trauma or stress to the Achilles tendon. 
     Achilles tendinitis and tendinosis describe two classifications of tendon injury around the Achilles. Tendinosis refers to non-inflammatory intratendinous degeneration which is initially asymptomatic. Tendinitis describes symptomatic degeneration of the tendon associated with inflammation. Stanish has referred to these tendon classifications as non-union soft-tissue injuries. It is believed that non-union soft-tissue injuries are caused by inadequate perfusion of the local tissues. The affliction is characterized by soft tissue swelling, tenderness to the touch and roughening about the Achilles tendon known as crepitus. Those suffering from Achilles tendinitis/osis also experience pain with active pointing and passive raising of the foot. 
     Sever&#39;s disease results from a sclerosis or thickening and irregularity of the growth plate known as the calcaneal apophysis. It is believed that Sever&#39;s disease results from inflammation of the soft tissues of the heel following an injury. Sever&#39;s disease may cause a number of conditions including retrocalcaneal bursitis, traction apophysitis, which is the separating of the tendon from the bone, and osteochondrosis of the calcaneal apophysis which is irritation and inflammation of the bone and cartilage in the heel. Those suffering from Sever&#39;s disease experience pain down the back of the heel with passive raising of the foot, rapid and repetitive pointing of the foot and a springly gait. Sever&#39;s disease is aggravated by running and jumping. 
     These conditions are often treated by use of heel lifts which normally are foam pads approximately 0.25 inches thick; oral pain relievers; shoe inserts; anti-inflammatory medications; rest; ultrasound; various physical therapy treatments; and flexibility exercises. Surgical procedures such as diagonal removal of a heel bone known as oblique calcaneal osteotomy; removal of a deep and superficial retrocalcaneal bursae; cleaning and tendon repair are sometimes required for effective treatment. 
     U.S. Pat. No. 4,841,957 in the name of Wooten, et al. describes a U-shaped pad for applying compression around the affected area of the heel. However, the device disclosed in the Wooten patent only applies static pressure to the affected area of the Achilles tendon. We have reason to believe that a dynamic pulsating pressure would be more effective in remedying maladies associated with the Achilles tendon. 
     Nitric oxide is known to be released with a change in sheer stress in blood flow against the endothelial cells lining the veins. Our studies indicate that pulsating pressure accelerates venous velocity. Other studies show that acceleration of venous velocity increases sheer stress. A recent study,  Modulation of Tendon Healing by Nitric Oxide , authored by George A. C. Murrell and others indicates that nitric oxide is present during tendon healing, and that the inhibition of nitric oxide reduces the healing response. While the tendons are avascular, the small nitric oxide molecule is known to pass through vessel walls. Nitric oxide acts as a vasodilator, providing greater fluid and nutrition to local tissues. 
     The results indicated by testing the present invention supports the belief that application of a dynamic, pulsating pressure around the sides of the Achilles tendon provides relief and healing to those suffering from maladies afflicting the Achilles tendon. 
     United Kingdom patent No. 817,521 discloses an apparatus for facilitating the blood circulation in the extremities of the human body. The device shown in this patent is cumbersome making the same difficult and time consuming to attach to the lower leg of the wearer. A further disadvantage in the use of this device resides in the fact that the inflatable cushions must be inflated from an external source, such as a pump. 
     U.S. Pat. No. 5,348,530 discloses a pneumatic ankle brace with a bladder and foot pump arrangement. The device of this patent is of rather complicated construction and requires use of a detachable hand-held pump. 
     U.S. Pat. No. 4,841,956 discloses a device adapted to be mounted to the lower leg and foot of a person for inducing venous blood flow in the leg. This device includes a pulse generator and programmable distributor necessitating a non-ambulatory position for the wearer during use. 
     U.S. Pat. No. 4,628,945 discloses a self-inflating ankle brace including air bags with resilient, compressible filler material. This patent discloses only a brace. 
     SUMMARY OF THE INVENTION 
     The present invention provides relief to those who are suffering from posterior heel pain. 
     Therefore, an object of the invention is to provide an Achilles wrap which includes a device for applying pulsating pressure to the Achilles tendon. 
     Another object of the invention is to utilize a foot cell to pulse pump pressure to the area around the Achilles tendon. 
     A further object of the invention is to provide an Achilles wrap which provides pulsating pressure to the Achilles tendon by use of a V-shaped pad which envelopes the Achilles tendon. 
     An even further object of the invention is to utilize an ankle wrap made of a flexible, stretchable material to which a strip of a plurality of hooks can easily attach, so that strips of a plurality of hooks attached to an arch cell and an Achilles tendon cell can be used to locate the arch cell and tendon cell anywhere on the ankle wrap to facilitate positioning. 
     The foregoing advantages are achieved by the pneumatic Achilles wrap of the present invention. The Achilles wrap comprises a wrap including at least one strap for fastening the wrap around the foot and around the ankle. The wrap is preferably made of a stretchable, flexible material to which a strip of a plurality of hooks readily attaches. The wrap positions an arch cell which contains a dynamic volume of air within the wrap under the arch of the foot. The arch cell preferably includes a strip of a plurality of hooks for attachment to the wrap. The arch cell is fabricated from a flexible material and is in communication with a conduit member. The tendon cell is preferably V-shaped to envelop the Achilles tendon and includes a strip of a plurality of hooks for attachment to the wrap. Upon application of external pressure to the arch cell, air is expelled from said air cell through the conduit member. 
     Both the tendon cell and the arch cell are fabricated from a flexible material defining pockets containing open-cell foam pads. Upon the expelling of air from said arch cell, the air passes through the conduit member into the tendon cell which exerts a greater pressure against the Achilles tendon. The arch and tendon cells are self-inflating. Thus, an external pump is not required. 
     The present invention in its various aspects has only been summarized briefly. For a better understanding of the present invention and its objects and advantages, reference should be made to the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings which are part of the disclosure illustrate the present invention. 
     FIG. 1 is a perspective view of the wrap assembly of the present invention. 
     FIG. 2 is a side elevational view of the wrap assembly of FIG. 1 wrapped around a human foot. 
     FIG. 3 is a perspective view of the wrap assembly of FIG. 1 including the pneumatic system of the present invention with portions cut away for illustrative purposes. 
     FIG. 4 is a cross-sectional view of an Achilles tendon cell taken along line  4 — 4  in FIG.  3 . 
     FIG. 5 is a cut away view of the tendon cell of the present invention. 
     FIG. 6 is a side view of the present invention shown in FIG. 3 wrapped around the human foot with the pneumatic system in partial phantom. 
     FIG. 7 is a graph of the pressure the present invention applies to the Achilles tendon. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention comprises an Achilles wrap which accommodates a pneumatic system. FIG. 1 depicts the Achilles wrap  10  of the present invention which can be worn on either foot of a human being. The Achilles wrap  10  is made up of a woven filament material which is flexible, stretchable and adaptable to attachable engagement by a plurality of hooks, such as VELCRO hooks. The Achilles wrap  10  comprises four separate straps. 
     A foot strap  12  is the longest of the straps, with a first end  14  and a second end  16 . A tab  18  containing a plurality of hooks, such as VELCRO hooks, is connected and preferably stitched to the first end  14  of the foot strap  12  with the hooks facing inwardly. A tab  20  is connected and preferable stitched to the second end  16  of the foot strap  12  which also contains a plurality of hooks which face outwardly. 
     The Achilles wrap  10  also includes a first ankle strap  24  and a second ankle strap  26 . The first ankle strap has a first end  27  to which a tab  28  with a plurality of hooks such as VELCRO hooks facing inwardly is connected and preferably stitched. The second ankle strap  26  has a first end  32  to which a tab  34  containing a plurality of hooks facing outwardly is connected and preferably stitched. The first ankle strap  24  and the second ankle strap  26  both have second ends  38 ,  40  connected and preferably stitched to each other at an obtuse angle defining a lower vertex  42  and upper vertex of  43 . 
     The Achilles wrap  10  further includes a heel strap  46  which has a first end  48  and a second end  50 . The first end  48  of the heel strap  46  is connected and preferably stitched to a proximal side  52  of the first ankle strap  24 . The second end  50  of the heel strap  46  is connected and preferably stitched to a proximal side  54  of the second ankle strap  26 . The foot strap  12  has a proximal side  56 , the central portion of which is connected and preferably stitched to a central portion of a distal side  58  of the heel strap  46 . 
     The relationship of all the straps in the Achilles wrap  10  is configured to accommodate the ankle  60 , the heel  62 , the Achilles tendon  63  and the left or right foot  64  of a human being as shown in FIG.  2 . The plurality of hooks contained on each of the tabs  18 ,  20 ,  28 ,  34  are disposed to facilitate engagement of the hooks on the tabs to the woven filament material comprising the respective straps  12 ,  24 ,  26 . The foot strap  12  and the ankle straps  24 ,  26  are fastened around the foot  64  and ankle  60 , respectively, to secure the Achilles wrap  10  on the foot. The angled relationship of the first and second ankle straps  24 ,  26  facilitate the upper vertex  43  to contact a heel  62  at a lower elevation than the top side of the foot  64  where the first end  27  of the first ankle strap  24  and the first end  32  of the second ankle strap  26  come together as shown in FIG.  2 . 
     The pneumatic system  70  shown in FIG. 3 comprises an Achilles tendon cell  72  and an arch cell  74  in connection with each other. As shown best in FIG. 4 the tendon cell  72  comprises a first wall  75  and a second wall  76  each made of plastic. Each wall of the tendon cell is preferably made of a polyurethane coating  82  applied to a nylon ply  84 . The two walls  75 ,  76  are sealed together with the polyurethane coating  82  inside along the common edges thereof on all but one side, preferably by radio frequency welding, to form a bi-fold pocket  78 . The pocket  78  in the tendon cell  72  contains a generally V-shaped metal support  86  which is sufficiently ductile to allow adjustment of the angle defined by the legs of the support  86 . As seen in FIG. 4, the support includes leg portions  86   a  and  86   b  joined by a medial vertex portion  86   c . Of course, the support  86  can be considered as U-shaped. 
     The nylon ply  84  of the first wall  75  and the second wall  76  comprised of the nylon plies is fuzzy to the touch. Two strips  87 ,  88  of a plurality of hooks such as VELCRO hooks are attached to the nylon ply  84  of the first wall  75  to facilitate attachment of the tendon cell  72  to the woven filament material of the first ankle strap  24  and the second ankle strap  26 , respectively. The Achilles tendon cell  72  takes on the folded shape of the V-shaped support  86  and thereby can receive the heel  62  of a human foot  64 . 
     Referring to FIG. 5 which shows a rear cut-away view of the tendon cell  72 , a plastic film overlay  89 , which preferably comprises transparent polyurethane, is sealed, preferably by radio frequency welding, along a seam  90  to the polyurethane coating  82  of the second wall  76 . The seam  90  isolates a medial non-inflatable or uninflated zone  92  between a first lateral compartment  94  and a second lateral compartment  96 . Both the compartment  94  and the compartment  96  are in communication with each other, and each contains an open-cell foam  98 ,  100  of about 0.2 inches thick which provides self-inflation and cushioning features. The seam  90  hermetically seals the overlay  89  to the polyurethane coating  82  of the second wall  76  to form air-tight lateral compartments  94 ,  96 . 
     The second wall  76  of the tendon cell  72  contains a first neck portion  102 . The transparent plastic film overlay  89  has a second neck portion  104  which is registered with and is sealed to the first neck portion  102  with a tunnel therebetween for receiving an inlet tube  106 . The inlet tube  106  is hermetically secured between the first neck portion  102  and the second neck portion  104  and serves as a duct to bring air into the medial and lateral compartments  94 ,  96  of the tendon cell  72 . 
     The arch cell  74 , best shown in FIG. 3, comprises two generally oval or elliptical walls, a base wall  110  and a top wall  112 , each made from the same material as the walls  75 ,  76  of the tendon cell  72 . Thus, each wall  110 ,  112  has an inner polyurethane coating applied to an outer nylon ply. The outer surface of the base wall  110  of the arch cell  74  has a strip  116  of a plurality of hooks, such as VELCRO hooks, attached thereto for detachable engagement of the arch cell with the woven filament material of one of the straps. Hence, the arch cell  74  can be secured anywhere on the Achilles wrap  10 ; the arch cell is preferably secured to the central upper portion of the foot strap  12 . The inner polyurethane coating on the top wall  112  is sealed to the inner polyurethane coating on the base wall  110  around the edges thereof to provide a hermetically sealed pocket. The arch cell  74  contains an open-cell foam pad  120  of about 0.5 inches thick. The foam pad  120  is self-inflating, as disclosed in U.S. Pat. No. 4,628,945 referred to above which is assigned to the assignee of the present invention, and which is incorporated herein by reference. 
     The base wall  110  and the top wall  112  of the arch cell  74  each has corresponding neck portions  121 ,  122  sealed to each other with a tunnel therein for hermetically receiving an outlet tube  123 . The outlet tube  123  is removably coupled by a connector  124  to the inlet tube  106  to provide an air-tight pneumatic system comprising the arch cell  74  and the tendon cell  72 . 
     The Achilles wrap  10  with the arch cell  74  and the tendon cell  72  attached thereto are wrapped around the foot  64  as shown in FIG.  6 . The inlet tube  106  and the outlet tube  123  should be positioned along the inside of the foot  64 . When weight from the foot  64  bears upon the arch cell  74 , air is quickly expelled from the arch cell  74  to the tendon cell  72  to increase the pressure on the Achilles tendon  63 . When weight on the arch cell  74  is removed, the self-inflating foam pad  120  in the arch cell  74  expands the walls  110 ,  112  of the arch cell  74  to increase the volume of the arch cell  74 . The increased volume creates a vacuum which quickly sucks air from the tendon cell  72  back into the arch cell  74  thereby decreasing the pressure that the tendon cell  72  bears on the Achilles tendon  63 . 
     Walking while wearing the Achilles wrap  10  produces a rapid change in pressure which enhances the magnitude of the pulsation on the sides of the heel  62 , thereby increasing the velocity of blood flow in the foot  64  and the leg. This results in an increase in vascular sheer stress and, we believe, the release of nitric oxide. Hence, the pulsating compression at the sides of the heel  62  may enhance diffusion of nitric oxide into the Achilles tendon  63 . The pulsating pressure applied by the tendon cell  72  to the Achilles tendon  63  while walking is shown in FIG.  7 . The abscissa represents skin pressure in mmHg; the ordinate represents walking time in seconds. 
     The arch cell  74  fits into the arch  130  of the foot  64  between the tarsal head and the calcaneus metatarsal. Confining the arch cell  74  to this portion of the foot facilitates insertion of the foot with the wrap  10  in the wearer&#39;s shoe and permits the arch cell to function as a dynamic orthotic comfortably supporting the arch  130  with resilient pressure. We believe that the arch cell  74  under the arch  130  also acts as a dynamic pump enhancing the flow of blood in the foot  62  and leg which may well be a source of nitric oxide. 
     The tendon cell  72  envelopes the back of the heel  62  and thus the Achilles tendon  63 . The inflation of the tendon cell  72  is confined by the V-shaped metal support  86  that prevents outward expansion and directs the energy of pulsation inwardly to the sides of the Achilles tendon  63 . As previously stated, the metal comprising the support  86  is sufficiently flexible to permit manual reshaping to conform to the angle of the individual&#39;s heel  62  and the Achilles tendon  63  but rigid enough to withstand the pressure of the inflated tendon cell  72  without distortion. The preferred material for the support is aluminum alloy 6061T4 in 0.32 inch gauge. 
     The pressure from the tendon cell  72  is confined to the sides of the Achilles tendon  63  instead of the back of the Achilles tendon  63  by dividing the tendon cell  74  into two lateral compartments  94 ,  96  which are, as previously discussed, separated by a medial uninflated zone  92 . Both the lateral compartment  94  and the lateral compartment  96  are inflated with air flowing through the inlet tube  106  and traversing but not inflating the uninflated zone  92 . Without the uninflated zone  92 , inflation would cause the support  86  to push away from the heel  62 . Under such conditions, compression against the sides of the Achilles tendon  63  would be lost because the only counter force to the rearward expansion of the tendon cell  72  would be the inner side of the first and second ankle straps  24 ,  46  wrapped around the ankle  60 . The ankle straps  24 ,  26  would have to be unacceptably tight and inelastic to be effective as a counter force. 
     To utilize the Achilles wrap  10 , the wrap  10  is laid open on a surface. The tendon cell  72  is attached to the first and second ankle straps  24 ,  26  by engaging the strips VELCRO type  88 ,  89  on the tendon cell  72  to the first and second ankle straps  24 ,  26 , respectively. The support  86  is bent to accommodate the angle presented by the heel  62  of the foot. The arch cell  74  is attached to the foot strap  12  by engaging the VELCRO type strip  116  with the woven filament material of the foot strap  12 . The arch cell  74  should be positioned so the neck portions  121 ,  122  of the cell  74  are pointing toward the inside of the foot  64 . Once the arch cell  74  is positioned on the foot strap  12 , the ankle strap is secured around the ankle  60  so the tendon cell  72  receives the Achilles tendon  63  of the foot. The ankle strap is secured around the ankle by engaging the hooks on the tabs  28 ,  34  to the woven filament material of the ankle straps  24 ,  26 . Because the tabs  28 ,  34  with the plurality of hooks are facing in opposite directions, the tab  34  on the second ankle strap  26  with the hooks facing outwardly goes in the inside of the first ankle strap  24  and the hooks on the tab  28  of the first ankle strap  24  facing inwardly is applied to the outside of the second ankle strap  26 . Therefore, both tabs  28 ,  34  are secured to respective ankle straps  24 ,  26 . No weight should be put on the arch cell  74  until the ankle straps  24 ,  26  are secured. 
     Upon securing the ankle straps  24 ,  26 , the foot  64  can be placed on the arch cell  74  and the foot strap  12  secured around the foot. The first end  14  and the second end  16  of the foot strap  12  each have tabs  18 ,  20  with a plurality of hooks facing in opposite directions, so the second end  16  is positioned inwardly of the first end  14 . Thus, the hooks on tab  18  on the first end  14  engage the woven filament material on the second end  16  and the hooks on the tab  20  on the second end  16  engage the woven filament material of the first end  14 . After the Achilles wrap  10  is wrapped around the foot  64  and secured, the inlet tube  106  can be coupled to the outlet tube  23  via the connector  124 . By applying pressure to and removing pressure from the arch cell  74 , the tendon cell  72  applies dynamic pressure to the heel  62  as previously described. 
     It will be appreciated that the detailed description and the examples relate to the preferred embodiment by way of example only. Many variations of the invention will be obvious to those knowledgeable in the field, and such obvious variations are within the scope of the invention as described and claimed, whether or not expressly described.