Abstract:
The pneumatic Achilles sleeve assembly comprises a sleeve and at least one strap for fastening the sleeve around the ankle. The sleeve assembly positions an arch cell which contains a dynamic volume of air within the sleeve 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 sleeve assembly also positions a tendon cell which contains a dynamic volume of air within the sleeve 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 OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to a compression sleeve for pneumatically applying dynamic pressure to the Achilles tendon, and to the sole of the foot, particularly at the arch.  
           [0003]    2. Description of Related Art  
           [0004]    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.  
           [0005]    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.  
           [0006]    Achilles tendinitis and tendinosis describe two classifications of tendon injury around the Achilles tendon. 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.  
           [0007]    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 springy gait. Sever&#39;s disease is aggravated by running and jumping.  
           [0008]    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.  
           [0009]    Plantar fasciitis is an inflammation of the fascia along the bottom of the foot. The fascia are sheets of fibrous tissue beneath the surface of the skin that enclose muscles or muscle groups and separate muscular layers. Plantar faciitis can be quite painful to an individual but can be soothed by massages that increase circulation to the plantar fascia.  
           [0010]    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.  
           [0011]    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.  
           [0012]    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.  
           [0013]    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.  
           [0014]    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.  
           [0015]    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.  
           [0016]    U.S. Pat. No. 4,678,945 discloses a self-inflating ankle brace including air bags with resilient, compressible filler material. This patent discloses only a brace.  
           [0017]    U.S. Pat. No. 6,322,530, assigned to the instant assignee and incorporated herein by reference in its entirety, discloses a wrap made of a plurality of stretchable flexible straps. The straps wrap around the foot to hold in place one aircell positioned in the vicinity of the Achilles tendon and another aircell positioned in the vicinity of the arch of the foot, the two aircells being operatively connected to one another through a conduit member. As the user walks and steps on the aircell at the arch, that aircell is compressed, and the pressure in the aircell at the Achilles tendon is increased. As the user step off the arch aircell, the airflow is reversed, and air travels back from the Achilles tendon aircell to the arch aircell, ready for the next cycle. This device provides effective pneumatic compression of the Achilles tendon, but can be difficult for the user to apply and adjust properly.  
         SUMMARY OF THE INVENTION  
         [0018]    The present invention provides relief to those who are suffering from posterior heel pain or from plantar faciitis.  
           [0019]    Therefore, an object of the invention is to provide an Achilles sleeve which includes a device for applying pulsating pressure to the Achilles tendon and to the arch area of the foot.  
           [0020]    Another object of the invention is to utilize a foot cell to pulse pump pressure to the area around the Achilles tendon.  
           [0021]    A further object of the invention is to provide an Achilles sleeve assembly that provides pulsating pressure to the Achilles tendon by use of a aircell that envelopes the Achilles tendon.  
           [0022]    An even further object of the invention is to provide an Achilles sleeve assembly having a flexible stretchable sleeve with an inelastic strap around the ankle area to facilitate positioning of the sleeve on the foot and ankle.  
           [0023]    The foregoing advantages are achieved by the pneumatic Achilles sleeve assembly of the present invention. The Achilles sleeve assembly comprises a sleeve, the sleeve comprising a foot portion that envelopes the circumference of the foot in the area of the arch of the foot, and an ankle portion that can be opened and closed at the ankle by means of an inelastic strap to allow easy entry of the foot into the sleeve. The foot portion includes a pocket on the inner surface thereof disposed against the arch of the foot, the pocket being configured to accommodate an arch cell that contains a dynamic volume of air. The arch cell is fabricated from a flexible material and is operatively connected to a conduit member. The tendon cell is shaped to envelop the sides of the Achilles tendon and is disposed on the rear inner surface of the ankle portion of the sleeve. The tendon cell also is operatively connected to the conduit member. Upon application of external pressure to the arch cell, air is expelled from the arch cell through the conduit member and into the tendon cell.  
           [0024]    Both the tendon cell and the arch cell are fabricated from a flexible material defining pockets containing open-cell foam pads. When air is expelled 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.  
           [0025]    A better understanding of the present invention and its objects and advantages can be had by making reference to the following detailed description taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    The drawings which are part of the disclosure illustrate the instant invention.  
         [0027]    [0027]FIG. 1 is a perspective view of the sleeve of the instant invention;  
         [0028]    [0028]FIG. 2 is a plan view of the sleeve assembly of the invention showing the aircells connected by the conduit and showing the strap;  
         [0029]    [0029]FIG. 3 is a rear view of the sleeve of the instant invention in which the strap is open;  
         [0030]    [0030]FIG. 4 is a perspective view of the sleeve assembly of the instant invention in which the ankle strap is open;  
         [0031]    [0031]FIG. 5 is a plan view of the fabric blank used to form the sleeve of the instant invention;  
         [0032]    [0032]FIG. 6 is a side view of the present invention placed on a human foot with the pneumatic system in partial phantom;  
         [0033]    [0033]FIG. 7 is a cross-sectional view taken along line  7 - 7  in FIG. 2 showing the Achilles tendon cells, the strap and the ankle portion of the sleeve assembly; and  
         [0034]    [0034]FIG. 8 is a graph of the pulsating pressure the instant invention applies to the Achilles tendon. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]    The following is a description of a preferred embodiment of the instant invention.  
         [0036]    The instant invention comprises a sleeve assembly that accommodates a pneumatic system. FIG. 4 depicts the sleeve assembly  10  of the present invention that can be worn on either foot of a human being. The sleeve assembly  10  comprises a sleeve  12  preferably made of a flexible stretchable material, such as neoprene. Sleeve  12  comprises a foot portion  14  and an ankle portion  16 .  
         [0037]    As shown in FIG. 1, foot portion  14  is in the form of a cuff  18  that surrounds the circumference of the foot in the region of the arch. The cuff  18  has a distal end  20  which is in the form of an opening through which the forefoot extends, and a proximal end  22  that defines an opening through which the heel of the foot extends. The inner surface  24  of cuff  18  has a pocket  26  provided thereon so as to be juxtaposed against the arch of the foot when the sleeve assembly is applied to a user. The pocket  26  is configured to receive aircell  30 , described in greater detail below. Pocket  26  can be attached by peripheral seam  27  to surface  24  by known means such as stitching, gluing, or welding. Pocket  26  can be made of a neoprene foam thicker than the neoprene of sleeve  12  to further promote comfort for the user. In one embodiment, seam  27  will have a gap  28  along one side of sufficient size to allow aircell  30  to be inserted into pocket  26 , so that aircell  30  need not be in position when pocket  26  is being stitched, glued, or welded to inner surface  24 . A neck portion  29  will be of sufficient size to allow the passage therethrough of the air conduit member, described below.  
         [0038]    Ankle portion  16  of sleeve  12  includes a rear portion  40  that covers the posterior surface of the ankle region including the Achilles tendon, and first and second side flaps  42 ,  44  extending laterally from either side of said rear portion  40 . First and second side flaps  42  and  44  wrap around the front of the user&#39;s ankle when the sleeve assembly is in place on a user. FIG. 5 illustrates the blank from which sleeve  12  can be made. It may be seen that each of first and second side flaps  42  and  44  terminates at inner edges  43  and  45  respectively. These edges  43  and  45  are fastened together by stitching, welding, gluing, or other known means to form a seam  47  that runs vertically along the back of the user&#39;s ankle when the sleeve assembly  10  is in position on a user. A strip of fastening material  46  is disposed on the inner surface of rear portion  40  in the general area of the Achilles tendon. Hook or loop material sold under the trademark VELCRO® can be used for this purpose. A second patch of hook or loop material  48  is affixed to the outer surface of first side flap  42 . It is preferred that hook bearing material be used for both strip  46  and patch  48 .  
         [0039]    The sleeve assembly of the instant invention further comprises an ankle strap  50  formed of an inelastic material and having a plurality of hooks or loops on one side thereof. If patch  48  comprises hooks, then strap  50  will comprise loops  52 . Strap  50  has a first end  54  fixedly secured to the outer surface of first side flap  42 , rearward of second patch  48 . First end  54  of strap  50  can be secured to the outer surface of first side flap  42  at securement site  51  by known means such as stitching, gluing, or welding. First side flap  42  has a slit  49  disposed rearward of the site of securement  51  of first strap end  54  to first side flap  42 . Slit  49  is long enough to allow the width of strap  50  to pass therethrough.  
         [0040]    The sleeve assembly of the instant invention further comprises a pneumatic system  60  comprising arch aircell  30 , described in more detail below, and tendon aircell  62 . In the illustrated embodiment, tendon aircell  62  is generally in the shape of an inverted “U”, with two downwardly extending compartments  77   a ,  77   b  and a central portion  78  therebetween. As best shown in FIG. 7, tendon cell  62  comprises a first wall  64  and a second wall  67  each made of plastic. First wall  64  is preferable made of nylon ply  65  coated on one surface with polyurethane  66 ; in the construction of the tendon cell of the instant invention, the nylon side forms an exterior surface of the cell and the polyurethane is on an inside surface. Second wall  67  can be formed of polyurethane. Pieces of open-cell foam material  69   a ,  69   b  of about 0.2 inches thick are disposed between first wall  64  and second wall  67  in each of the compartments  77   a ,  77   b . A third wall  70  comprises nylon ply  72  and polyurethane coating  74 . Third wall  70  is juxtaposed against second wall  67 , with polyurethane coating  74  facing polyurethane second wall  67 . The three walls  64 ,  67  and  70  are sealed together along their common edges at edge seal  63 , preferably by radio-frequency welding, with one surface of polyurethane wall  67  in contact with polyurethane coating  66 , and polyurethane coating  74  in contact with the opposite surface of polyurethane wall  67 . The first wall  64 , second wall  67 , and third wall  70  are also sealed together at central portion  78  of tendon air cell  62 , except for one small area extending between the downwardly extending compartments  77   a ,  77   b . This unsealed area forms a channel  79  between the two compartments through which air can flow.  
         [0041]    First wall  64 , second wall  67 , and third wall  70  each have a neck portion in alignment with the others. The neck portions are sealed together at their edges with a tunnel therebetween for receiving a tendon inlet tube  90 . The tendon inlet tube  90  is hermetically secured between the neck portions of first wall  64  and second wall  67 , and serves as a duct to bring air into the compartment  77   a , through channel  79 , and into compartment  77   b.    
         [0042]    Third wall  70  has two slits  73 ,  75  therein disposed substantially on either side of tendon aircell  62 , each slit  73 ,  75  being long enough to accommodate the width of strap  50 . Strap  50  passes through slit  49  of ankle portion  16  of sleeve  12 , then through slit  73  of tendon aircell  62 . Strap  50  further extends between second wall  67  and third wall  70 , and then through slit  75 . Strap  50  then continues along the inner surface of second side flap  44 , and is fixedly attached to outer edge  57  of second side flap  44  at attachment site  58 . The attachment between strap  50  and side flap  44  can be made by stitching, gluing, welding, or other known means. The second end  56  of strap  50  extends beyond attachment site  58 , for engagement with patch  48  on first flap  42 . Third wall  70  of tendon cell  62  also has on its outer surface a strip of hook and loop material  71  sized and positioned to engage hook and loop strip  46  on the inner surface of ankle portion  40 .  
         [0043]    The arch cell  30  comprises two generally oval or elliptical walls, a bottom wall  32  and a top wall  34 , each preferably made of nylon coated on one side with polyurethane. The walls  32  and  34  are placed in registry with the polyurethane coated surfaces facing one another, and are sealed to one another around the edges thereof to provide a hermetically sealed aircell. The aircell  30  contains a piece of open-cell foam  35  of about 0.5 inches thick. The foam pad  35  is self-inflating, as disclosed in U.S. Pat. No. 4,628,945, which is assigned to the assignee herein and incorporated herein by reference.  
         [0044]    The base wall  32  and the top wall  34  of arch cell  30  each has corresponding neck portions  36 ,  38  sealed to each other with a tunnel therein to form neck  29  for hermetically receiving outlet tube  39 . The outlet tube  39  is removably coupled by a connector  92  to inlet tube  90  to provide an air-tight pneumatic system comprising the arch cell  30 , the tendon cell  62 , and the connecting conduit.  
         [0045]    When weight from the user&#39;s foot bears upon arch cell  30 , air is quickly expelled from the arch cell  30  to the tendon cell  62  to increase the pressure on the Achilles tendon. When weight on the arch cell  30  is removed, the self-inflating foam piece  35  in the arch cell  30  expands the walls  32 ,  34  of the arch cell  30  to increase the volume of the arch cell. The increased volume creates a vacuum which quickly sucks air from the tendon cell  62  back into the arch cell  30  thereby decreasing the pressure that the tendon cell  62  bears on the Achilles tendon.  
         [0046]    Walking while wearing the pneumatic Achilles sleeve assembly  10  of the instant invention produces a rapid change in pressure which enhances the magnitude of the pulsation on the sides of the heel, thereby increasing the velocity of blood flow in the foot and the leg. This results in an increase in vascular shear stress and, we believe, the release of nitric oxide. Hence, the pulsating compression at the sides of the heel may enhance diffusion of nitric oxide into the Achilles tendon. The pulsating pressure applied by the tendon cell  62  to the tendon is shown in FIG. 8. The abscissa represents skin pressure in mmHg; the ordinate represents walking time in seconds.  
         [0047]    The arch cell  30  fits into the arch of the foot between the tarsal head and the calcaneus metatarsal. Confining the arch cell  30  to this portion of the foot facilitates insertion of the foot with the sleeve assembly  10  into the wearer&#39;s shoe and permits the arch cell  30  to function as a dynamic orthotic comfortably supporting the arch with resilient pressure. We believe that the arch cell  30  under the arch also acts as a dynamic pump enhancing the flow of blood in the foot and leg, which may well be a source of nitric oxide. The pulsating pressure to the arch of the foot may also provide treatment for plantar fasciitis.  
         [0048]    The tendon cell  62  envelops the back of the heel and thus the Achilles tendon. The inflation of the tendon cell  62  is confined to the inflatable compartments  77   a ,  77   b . The inflation of the tendon cell  62  is confined by the inelastic strap  50  that extends behind the tendon cell  62  and is secured fixedly in place by the user by attachment of loops  52  to patch  58 , thus preventing outward expansion of the tendon cell and directing the energy of pulsation inwardly to the sides of the Achilles tendon.  
         [0049]    The pressure from the Achilles tendon cell  62  is confined to the sides of the Achilles tendon rather than the back of the Achilles tendon by dividing the tendon cell  62  into two compartments  77   a ,  77   b  separated by a medial uninflated zone  78 . Both of the compartments  77   a  and  77   b  are inflated with air flowing from inlet tube  90  into compartment  77   a , through channel  79 , and into compartment  77   b . Without the uninflated central portion  78 , inflation could cause the second and third cell walls  67  and  70  to push away from the heel. Under such conditions, pressure against the sides of the Achilles tendon would be lost.  
         [0050]    To use the Achilles sleeve assembly  10  of the instant invention, the first and second side flaps  42 ,  44  are opened and separated. The user puts the foot into the sleeve  12  through cuff  18  until arch cell  30  is positioned beneath the user&#39;s arch. The first side flap  42  is folded over the front of the user&#39;s ankle. The second side flap  44  is folded over the front of the user&#39;s ankle and, depending on its length and the size of the user&#39;s ankle, over first side flap  42 . The loop-bearing side  52  of strap  50  is pressed in place against patch  48  on the outside of first flap  42  to secure the sleeve assembly in place. When this is done, the tendon cell  62  will be correctly positioned against the Achilles tendon without any additional adjustment by the user. Further, arch cell outlet tube  39  and tendon cell inlet tube  90  will already be connected by connector  92  and in their proper positions. Although no further adjustment of the pneumatic system is required, the tubes can be disconnected at connector  92  to adjust the pressure in the system and then reconnected, as may be desirable for certain users, or under certain conditions such as high altitudes.  
         [0051]    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.