Abstract:
An improved running shoe is disclosed that dissipates the impact forces of the heel step by utilizing a pressurized inner bladder designed for bi-directional collapse. The shoe comprises a rear portion for accommodating a heel, a forward portion for accommodating toes, a shoe sole; and a compressible bladder. The compressible bladder is preferably contained within said shoe sole and partially inflated. The inner bladder has a heel portion extending proximate to an outside end of the rear portion of the shoe but tapered inward at the impact point and a toe portion extending proximate to an outside end of the forward portion of the shoe. The inner bladder collapses at the heel upon the initial heel step, significantly reducing the heel step impact forces. The heel step section of the inner sole is then re-pressurized utilizing the natural forward motion of the toe step. Preferred embodiments of the shoe include accordion pleats around the heel and a rounded heel to further dissipate impact forces.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/987,001 (“the &#39;001 application”) filed May 1, 2014. The &#39;001 application is hereby incorporated by reference in its entirety for all purposes, including but not limited to, all portions describing various aspects of the present invention, those portions describing shoe design in general as background and/or for use as specific embodiments of the present invention, and those portions describing other aspects of manufacturing and testing shoes that may relate to the present invention. 
     
    
     STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       REFERENCE TO A MICROFICHE APPENDIX 
       [0003]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    The present invention relates to shoes. More particularly, the present invention relates to a shoe that dissipates the harmful impact forces of the heel step. 
         [0006]    2. Description of the Related Art 
         [0007]    The continued popularity of running as an exercise has spawned numerous innovations in running shoes. Many of these innovations are sourced to the fact that the initial heel step impact is the cause of the most running related injuries. In general, these innovations have evolved primarily in varying forms of cushioning. In addition, this heel step impact problem has also spawned the use of various forms of air bladders in shoes. 
         [0008]    Addressing cushioning, there is significant evidence that additional cushioning, in whatever form, does not significantly reduce the occurrence of injury due to impact and specifically the initial heel contact impact. Recent studies described in the relevant literature, such as “Cushioned Running Shoes Don&#39;t Reduce Injuries” from the Mar. 13, 2014, issue of Runners World, “Shoe Cushioning: All or Nothing?” from the Jun. 2, 2011, issue of Competitor Magazine, and “Study: Shock Absorbing Running Shoes Don&#39;t Reduce Injury Risk” from the Oct. 13, 2013, issue of Red Orbit, demonstrate the failure of the prior art cushioning to effectively reduce running related injury. 
         [0009]    Addressing bladders, there have also been many different models of bladder arrangements used in shoes that were intended to dissipate the heel step shock. However, these bladder systems, whether air or other fluid, tend to be limited in coverage area and/or dependent upon valves, etc. Also, the prior art bladders tend to be mounted with the same prior art feature of a rigid outer heel perimeter which junctures vertically downward with the hard heel horizontal bottom to form a perpendicular hard juncture at the “corner.” This perpendicular hard juncture is where the initial heel step makes contact with the ground and in actuality, serves as a reinforcement. In other words, the direct heel step impact point meets the ground at its&#39; stiffest angle. This hard juncture reinforcement significantly neutralizes any intended prior art bladder or cushion shock dissipation. 
         [0010]    As shown in  FIG. 22 , the prior art shoes were generally fitted with a flat bottom heel of heavy resilient material with an outer horseshoe shape and a hard “vertical to horizontal” corner. This heel is commonly layered with a midsole which provides additional stiffness. As will be recognized by those of skill in the art, prior art shoes also utilized hard plastic heel counters internal liners  55  such as are shown in  FIG. 17 . These prior art shoes had a hard heel column  56  created by the combination of the outsole, midsole, and hard heel counter. An example of such prior art shoe is shown in  FIG. 22  approximating the point of impact  65  against the hard heel juncture and heel counter stiff perpendicular train  66 . This view is presented with a nominal impact angle  63  of 22 degrees. The summation of the conventional prior art design is a stiff perpendicular heel column with little or no collapsibility and thus little or no shock dissipation at the exact point where it is critically needed. 
         [0011]    As can be seen, it would be advantageous to have a running shoe, or more specifically a shoe system, that could effectively reduce the impact shock on the wearer&#39;s heel by absorbing the culpable heel step shock to reduce the occurrences of injury. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    The present invention is an improved running shoe, or shoe system, that dissipates the impact forces of the heel step. Preferably, dissipation of impact forces occurs through utilization of a pressurized inner bladder designed for bi-directional (up and down) collapse. Another aspect of dissipating impact forces involves the use of accordion pleats at the outer shoe heel. Yet another aspect of dissipating impact forces involves the use of a recessed, rounded heel. 
         [0013]    In a particular embodiment, the inner pressurized bladder is located between a midsole of a shoe and an insole of the shoe, and extends from the rear heal area of the shoe to the forward toe area. The pressurized bladder, which is preferably inflated with air, collapses at the heel upon the initial heel step, significantly reducing the heel step impact forces. The heel step section of the bladder is then re-pressurized utilizing the natural forward motion and weight shift of the toe step which compresses the fluid backward into the heel section. The bladder may be of resilient elastomer construction or other material with similar properties. 
         [0014]    In a particular embodiment, a series of accordion pleats are located on the midsole at the outer shoe sides. The accordion pleats collapse on initial heel step impact to dissipate impact forces during the heel step and rebound to the original shape during the toe step. The accordion pleats are preferably press formed into both sides of the midsole above the heel. 
         [0015]    In a particular embodiment, a recessed rounded heel is utilized to dissipate impact forces of the heel step. This rounded heel is recessed away from the back of the heel and rounded to eliminate the hard heel juncture and therefore facilitate a smoother, softer impact point. In a particular embodiment, a semi-flexible heel counter is provided to bear the vertical load and shock at points away from the heel step impact point. Preferably, the semi-flexible heel counter includes flexible ribs along the side of the counter generally perpendicular to the impact direction of the heel step. 
         [0016]    In a preferred embodiment, an inner bladder, in conjunction with a series of side accordion pleats and a recessed, rounded heel are utilized together to dissipate impact forces from the heel step. Capitalizing on the compressible nature of the bladder; the heel section of the bladder and the accordion pleats will preferably be re-pressurized by the natural forward motion of the toe step, thus imparting pressure back to the heel section. A most preferred embodiment comprises this system design to dissipate the energy, all utilizing the same, auto-compression source. 
         [0017]    Additional advantages of the invention are set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0018]    A better understanding of the present invention can be obtained when the following detailed description of the disclosed embodiments is considered in conjunction with the following drawings in which: 
           [0019]      FIG. 1  is a side view of an embodiment of a running shoe made in accord with the present invention; 
           [0020]      FIG. 2  is side view of an embodiment of a pressurized bladder for a running shoe made in accord with the present invention; 
           [0021]      FIG. 3  is a top view of an embodiment of a pressurized bladder for a running shoe made in accord with the present invention; 
           [0022]      FIG. 4  is a side view of an embodiment of a running shoe made in accord with the present invention in a heel impact position; 
           [0023]      FIG. 5  is a side view of an embodiment of a running shoe made in accord with the present invention in a toe compression position; 
           [0024]      FIG. 6  is a graph comparing impact forces on a conventional running shoe as compared to the estimated forces on an embodiment of the present invention; 
           [0025]      FIG. 7  is a perspective view of an embodiment of the bottom of the rounded heel with an apex at the maximum point of impact; 
           [0026]      FIG. 8  is a side view of an embodiment of a recessed, rounded heel; 
           [0027]      FIG. 9  is a perspective view showing an embodiment having accordion pleats, oriented to culminate to an apex point; 
           [0028]      FIG. 10  is an embodiment of the accordion pleats in the pressurized, upright position; 
           [0029]      FIG. 11  is an embodiment of the accordion pleats in collapse due to the heel step downward force and the ground force upward force; 
           [0030]      FIG. 12  is an alternative embodiment of the pleat design utilizing sealed tubing; 
           [0031]      FIG. 13  is a side view of a shoe embodiment with accordion pleats having a downward sweep to absorb ground forces at the point of impact and an impact patch; 
           [0032]      FIG. 14  is another perspective of the embodiment of  FIG. 13 ; 
           [0033]      FIG. 15  is perspective view of an embodiment of an insertable bladder retainer tabs; 
           [0034]      FIG. 16  is a cutaway view of a shoe system embodiment shown from the back presenting a midsole, a bladder, an insole above the bladder and accordion pleats; 
           [0035]      FIG. 17  a side view of a prior art hard plastic heel counter; 
           [0036]      FIG. 18  is a side view of an embodiment of a softer heel counter with an open lower back and flexibility ribs to remove a layer of stiffness such as was inherent in the prior art. 
           [0037]      FIG. 19  is a back view of the embodiment of  FIG. 18 ; 
           [0038]      FIG. 20  is a side view of an embodiment of a heel counter approximating some impact distortion at the flexibility ribs and at the open lower back. 
           [0039]      FIG. 21  is a side view of the an embodiment illustrating the heel step at impact angle and the respective positions of the rounded, recessed heel, the impact patch, and the accordion pleats to absorb the impact forces; 
           [0040]      FIG. 22  is a side view of a common prior art type shoe illustrating the point of impact against the hard heel juncture and heel counter stiff perpendicular train; 
           [0041]      FIG. 23  is another shoe embodiment with a smaller, thinner bladder and smaller impact angle suitable for walking or power walking; 
           [0042]      FIG. 24  is another shoe embodiment cross section showing a bladder with a support bias to one side suitable for supporting pronation (medial side) or supination (lateral side) symptoms; 
           [0043]      FIG. 25  is another shoe embodiment cross section with a wider foot print and side channels for added stability; 
           [0044]      FIG. 26  is another shoe embodiment cross section showing a vertically elongated bladder heel for compensating for a short leg or other possible gait afflictions. 
           [0045]      FIG. 27  is another shoe embodiment with a slimmer profile bladder and more relaxed impact angle suitable for standard, lace-up walking shoes. 
           [0046]      FIG. 28  is another shoe embodiment with a slimmer profile for hiking boot applications. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0047]    The natural motion of running, whether male or female, can be divided into two distinct segments; the heel step followed by the toe step. The heel step is more time concentrated and therefore provides a significant instantaneous impact. The subsequent toe step is a time-gradual, weight shift rolling motion, which is devoid of any significant impact forces. The present invention comprises a shoe and/or a shoe system that counters the initial and harmful heel step impact. 
         [0048]    As shown in  FIGS. 1 ,  2  and  3 , in particular shoe embodiments, a compressible air bladder  12 , comprises a rear containment portion  10 , preferably extending from the rear heel of the shoe, and a forward containment section  13  extending into the toe portion of the shoe, which acts to significantly dissipate the energy of the heel step impact. The maximum impact point on the bladder  12  is shown as impact point  11 . Another embodiment of the bladder is shown in  FIG. 15 . In preferred embodiments, bladder  12  extends from a point proximate to the rearmost portion of the heel of the shoe to a point proximate to the forward most portion of the shoe. 
         [0049]    A bi-directional dissipation of the heel impact occurs with the compression of the heel into the top of the bladder  12  and simultaneous absorption of the ground force upward into the bottom of the bladder  12 . This bi-directional compression forces the bladder fluid from the heel section  10  of bladder  12 , and thus the pressure, to the front toe section  13  of the bladder  12 . The natural motion of the toe step then transfers this pressure energy back to the heel section  10  of the bladder  12 , thus re-pressurizing the inner air bladder heel section  10 . This, in effect, is a reciprocating motion that transfers pressure from the heel section to the toe section with the heel step and then back to the heel section with the toe step. 
         [0050]      FIG. 1  depicts a side view of one embodiment of running shoe with an inlay of a pressurized bladder.  FIGS. 4 and 5  demonstrate the flow of pressure of the embodiment of  FIG. 1 .  FIG. 4  is a side view of the heel step with the point of impact, with downward force  15 , and upward force  16 , and the direction of the pressure flow  17  inside the inner bladder  12 . The heel section  10  of the pressurized inner bladder  12  preferably has a larger air cavity than the toe section  13  and this larger volume dissipates of the heel step forces.  FIG. 5  is a side view of the toe step (weight roll), with downward force  18 , and upward force  19 , and the opposite direction of the pressure flow  20  inside the bladder  12 . 
         [0051]      FIG. 6  compares a conventional shoe impact chart with an overlay of an estimated soft heel impact of an embodiment of the present invention. This conventional shoe test chart shows the impact peak (Impact Transient)  21  and also a larger slower peak  22 , sometimes called the “Active Peak;” both in standard Force vs. Time units. However, the so called “Active Peak” does not create the concentrated force like the Impact Peak as the Active Peak is more of a rolling, weight motion. The present invention centers on dissipation of the heel step Impact Peak, as this is the primary cause of injuries. While this chart shows an estimated 40% reduction in impact forces  23 , it is expected that actual testing of preferred embodiments may show an even greater reduction of the impact forces. As will be recognized by those of skill in the art, this chart can be refined by a properly configured, momentum based, test based on particular embodiments. 
         [0052]    The bladder  12  is preferably formed from rubber or a resilient elastomer with similar properties. In particular embodiments, the bladder  12  can be formed from an inner layer and an outer layer to form a double ply bladder. Two layers of the bladder preferably can be cemented and stitched or even double stitched for durability. Preferably, the bladder  12  can withstand and hold a pressure of at least about 20 psig (plus or minus ten percent). 
         [0053]    Preferably, pressurized bladder  12  is sized to the entire length of the foot. By way of an example, using a size 10 male foot as a model, the heel section  10  of an embodiment of the bladder  12  calculates to a volume of about 10 in 3  where the toe section  13  is about 8 in 3 . While the toe section  13  is preferably longer and wider, the heel section  10  of this embodiment is deeper creating a larger volume. This depth facilitates the dissipation of the heel step energy. Sizing the toe section  13  to the entire length and width of the foot facilitates the capture of the entire toe step energy to re-compress the heel section  10 . This particular embodiment design has a natural self-corrective factor in that the toe step, while not as voluminous, is actually three to four times longer in execution time than the heel step. In other words, the toe step has more time to re-pressurize the heel step section  10  of the bladder  12 , prior to the next cycle. 
         [0054]    Utilizing an average standing foot print area and an average weight, the estimated working pressure of a preferred embodiment of the bladder is about a nominal 20 psig. The working fluid is preferably air, but other inert compressible gases such as nitrogen and the like can also be utilized. In addition, different air pressure values are preferably not required for different weight classes. There is a natural correction factor in that lower weight classes will normally have smaller foot prints and thus smaller bladders. This is a self-correction to a standardized inner pressure. As will be recognized by persons of skill in the art, the working pressure target can all be verified and refined utilizing properly configured, momentum based, testing for particular embodiments. 
         [0055]    As shown in  FIGS. 13 and 14 , another aspect of the invention is the utilization of accordion pleats  41  to dissipate the energy of the heel step impact. Accordion pleats  41  may be a stand-alone impact reduction device or, preferably, serve as an enhancement of the aforementioned bi-directional compression of the bladder  12 . Accordion pleats  41  comprise a series of folds of medium soft elastomer which are pressed into both sides of the heel portion of the shoe above at the impact point. In preferred embodiments, accordion pleats  41  comprised three to four folds, but in others may comprise as few as two or more than four. Accordion pleats  41  act as a bellows on impact to facilitate maximum impact absorption. The accordion pleats  41  are preferably formed with a downward sweep to coincide with the maximum ground force impact point as shown. 
         [0056]    As shown in  FIGS. 10 and 11 , accordion pleats  33  (or  41  in  FIG. 13 ) will collapse with the force of the heel step and will be stretched back to the upright position, preferably with the bladder  12  back pressure from the toe step (FIGS.  10 , 11 ).  FIG. 10  depicts an embodiment of accordion pleats  33  adjacent, but not fused, to the bladder  12 . Under normal internal heel pressure, the pleats  33  are expanded as bladder  12  is expanded to a normal height  34 .  FIG. 11  shows the embodiment of the pleats  33  compressed due to the heel step action  36 . When the bladder  12  is again pressurized by the toe step action, the top of the bladder again expands with the pressure and “stretches” the accordion pleats  33  back to the upright, pressurized position. 
         [0057]    To further enhance the collapse, the accordion pleats  33  may be graduated such that the bottom and thus the first contact pleat is greater in height than the second pleat and so on. This would enhance shock dissipation by allowing for a more natural decay of the impact. The accordion pleats  33 , in effect, spread the impact contact time and thus decrease the peak impact force. One natural decay rate is a 0.6 power so that with a first (bottom) pleat height of “P,” the next pleat height would be 0.6P and the third pleat height would thus be 0.36P. Once again, this can be verified and refined by testing on a properly configured, momentum based, test stand for particular embodiments. 
         [0058]    An alternative embodiment of accordion pleats is shown in  FIG. 12  utilizing sealed tubing  37  to absorb the initial impact and then expand upon the re-compression of the bladder. Tubing  37  may be rubber or other material with similar properties. As will be recognized by those of skill in the art, the sealed tubing, preferably rubber, can be a more efficient manufacturing option, depending upon circumstance available to the manufacturer. 
         [0059]    Another aspect of the invention is an impact patch  40 . As shown in  FIG. 13 , an impact patch  40  can be combined with a downward sweep of the accordion pleats  41  for increased absorption of the impact.  FIG. 14  depicts impact patch  40  and the downward sweep of the accordion pleats  41  from another view point. As will be recognized by those of skill in the art, the normal impact point between the shoe and the ground is between the back heel center line and the outer edge of the lateral side of the heel. Impact patch  40 , which preferably comprises a harder rubber or similar material, is located at the normal impact point on the shoe. 
         [0060]    Another aspect of the invention is the development of a recessed, rounded heel to significantly dissipate the energy of the heel step impact as shown in  FIG. 21 . In this embodiment, the heel is rounded, from the back of the heel to the bottom of the heel, essentially eliminating the hard heel juncture or “corner.” The rounded, recessed heel design can be a significant contributor to the dissipation of impact forces. The rounded heel section also eliminates the prior art “hard juncture” contact point and serves to accommodate the accordion pleats at the requisite strategic impact angle. In the preferred embodiments, the rounded heel has a minimum radius of curvature equivalent to about 0.5 inches. The rounded heel is generally rounded across the entire back of the shoe and may continue somewhat toward the sides. 
         [0061]      FIG. 8  shows the off-set of the rounded heel. This rounded heel point is preferably recessed away from the back of the shoe  29  to concentrate the impact dissipation designs to the maximum angle of impact  28 . Again, this rounded heel eliminates the common heel outer band hard juncture which has no capacity for collapse and therefore no capacity to dissipate energy. Eliminating the stiff heel hard juncture of prior art shoes by utilizing the rounded heel significantly enhances the compression characteristics of the shoe. 
         [0062]    Another aspect of the invention is a semi-flexible heel counter. As shown in  FIGS. 18 and 19 , particular embodiments of the invention utilize an embodiment of a heel counter  70  that it bears the vertical load and shock at points away from the heel step impact point. The heel counter is preferably manufactured from a thin, semi-firm rubber or material having similar properties. Preferably, the heel counter  70  has an open portion  57  along the bottom and flexibility ribs  58 . Preferably, flexibility ribs  58  along the sides of the heel counter  70  are pressed in a direction perpendicular to the impact direction for additional enhanced shock absorption. Flexibility ribs  58  preferably comprise thin indentations or channels in the heel counter  70  that break the continuity of the counter and therefore create small zones of additional flexibility.  FIG. 21  illustrates the heel step at the impact angle and the respective positions of the impact patch  61  and the downward sweep of the pleats  64  to absorb the impact force  62 . This view is presented with a nominal impact angle  63  of about 22 degrees. As will be recognized by those of skill in the art, the embodiments utilizing the semi-flexible heel counter  70  eliminate the prior art stiffness column at the hard heel juncture (as shown in  FIGS. 17 and 22 ). 
         [0063]    Particular shoe embodiments utilize a midsole, preferably formed of a soft elastomer in a single piece. The midsole  52  can be shaped to form an internal shell for the bladder  53  (bladder  12  from earlier FIG&#39;s.) such as can be seen in  FIG. 16 . That is, the midsole  52  can be formed as an outer air bladder contour or support surface. Additionally, particular embodiments of the midsole  52  can have the accordion pleats  51  form pressed into the inner and outer walls above the heel. In such embodiments, midsole  52  thickness can be reduced significantly as compared to the prior art due to the removal of material to accommodate the heel section of the bladder  53 . This has the added advantage of replacing solid weight material with virtually weightless air. In preferred embodiments, bladder  53  is placed between the midsole  52  and an insole  50  and is formed to fit snugly on top of the midsole. The midsole  52  is preferably contoured to the larger heel section to match the bladder heel section. This particular midsole embodiment arrangement, which includes the accordion pleats  51  has the added advantage of being press formed in one unitized piece. The midsole bottom is preferably be formed to accommodate the larger heel section. The midsole  52 , including the accordion pleats  51 , can thus be pressed in one piece and joined to the insole  50  with Velcro. This insole joint  49  assists to raise the accordion pleats  51  on toe step compression and thus prepare the accordion pleats  51  for the next heel step impact. 
         [0064]    In this regard,  FIG. 15  depicts a bladder embodiment  45  ( 53  in  FIG. 16 ) formed to fit snugly on top of the midsole  52 . An arch section  46  can be custom sized to address various arch problems. Preferably, bladder  45  is insertable into the midsole and can be secured to the midsole  52  cavity utilizing Velcro tabs  47  above the bladder heel section  48 . This bladder to midsole joint  49  need not be air tight but merely secure, as the pressure is within the bladder  45 . 
         [0065]    Various embodiments allow for bladder  45  to be inserted in various ways. In some embodiments, bladder  45  is inserted in permanent manner during on assembly and affixed between the midsole and insole. In other embodiments, bladder  45  can be inserted through a side zipper or through the upper opening. Due to the extra size of the bladder heel section, the most preferred embodiment allows insertion and removal of bladder  45  through an upper opening thereby making it readily replaceable. 
         [0066]    Particular embodiments may utilize an outsole comprising a slightly more flexible grade of blown rubber than is conventionally utilized to remove another layer of the hard heel juncture column. However, the outer sole impact patch contact area preferably maintains the conventional carbon rubber as it must withstand the impact. The impact  40  patch will preferably be formed of carbon rubber or other durable material to withstand the heel impact. 
         [0067]    Particular shoe embodiments and the various shoe features discussed herein may utilize materials of construction such as are readily known to those of skill in the art. Contemporary materials (rubber derivatives, leather, canvas, EVA, polyvinyl chloride, proprietary derivatives etc.) can be used in except as were specifically described herein, for example as with the semi-flexible heel counter and outsole. 
         [0068]    As an alternative, an apex may be utilized on the shoe heel bottom to withstand the contact at the impact point and reduce the common hard heel circumference outer band. This apex also collapses and provides more dissipation of the initial heel impact forces. The apex replaces the common hard heel outer band of the prior art shoes which is stiff and therefore has no capacity to dissipate impact energy.  FIG. 7  shows an alternate embodiment of the bottom of the heel with a strategic apex point  26 . The bottom of the shoe heel, near the convergence of the accordion pleats, forms an apex strategically located at the maximum impact point  26 . Preferably, the apex is a triangle shaped hard rubber patch to provide a more resilient impact surface point for wear. It is noted that the apex design, along with the recessed heel, eliminates the common prior art, hard, outer heel perimeter (hard juncture), which has virtually no flexibility and therefore no dissipation characteristics. The compressible nature of accordion pleats  27  offers additional impact dissipation which converges near the apex point  26 . Preferably, the apex is located between the heel center and the lateral edge to coincide with the impact point. 
         [0069]    While each of the aspects described above can be utilized independently, in the most preferred embodiments the bladder, accordion pleats, and rounded heel combine to dissipate the heel impact by utilizing compression. That is, the bi-directional heel step dissipation, the accordion pleats, and the off-set rounded heel, combine to provide optimum heel step impact dissipation. In addition, the compressive nature of the inner bladder also serves to recharge (re-pressurize) the elements above at each running step. 
         [0070]    As described, these embodiments of the present invention primarily address the sport of running and the accompanying running injuries. However, the present invention is applicable to footwear utilized in other fields including, but not limited to, walking, football and other running sports, therapeutic walking and other foot or leg therapies, hiking, and various military applications. In addition, the compressive nature of the inner bladder can be shaped in different configurations to address different problems, for example, to also relieve pronation problems, while at the same time dissipating the initial impact. 
         [0071]    For example, three additional shoe style embodiments are show in  FIGS. 23 ,  27  and  28 . In  FIG. 23 , a shoe embodiment is shown with a more shallow or thinner bladder and smaller impact angle suitable for walking or power walking. This embodiment preferably has fewer accordion pleats  67 , for example two or three, and an impact angle of approximately 10 degrees as opposed to the running impact angle of a nominal 20 degrees. This smaller impact angle  68  is sufficient for a smooth step while at the same time offering the impact dissipation necessary for walking. In  FIG. 27 , a shoe embodiment is shown with a smaller, thinner bladder  79  and a more relaxed impact angle suitable for standard, lace-up walking shoes. To maintain the common shoe appearance, this embodiment can be implemented with or without accordion pleats and can be fitted with a dark rubber heel that gives the appearance of leather. As will be recognized by one of skill in the art, there is sufficient absorption in the bladder heel to absorb normal walking impact. In  FIG. 28 , another shoe embodiment is shown with a shallow profile bladder  80  that can be utilized for hiking boot applications. This embodiment is shown without accordion pleats but retains support for a soft leather heel. As will be recognized by those of skill in the art, there is sufficient absorption in the bladder heel to absorb normal hiking impact. 
         [0072]    Examples of shoe embodiments directed to therapeutic issues are shown in  FIGS. 15 ,  24 ,  25 , and  26 . In  FIG. 15 , an arch section  46  is shown that can be reduced or enlarged to address different arch types and arch problems. In  FIG. 24 , a heel portion of a shoe embodiment is shown illustrating a bladder with a support bias to one side suitable for supporting pronation (medial side) or supination lateral side) symptoms. Utilizing the enclosed compressed fluid, bladders can be formed to off-set the effects of pronation or supination by compensating with the shape of the inner heel on the medial or lateral side. As will be recognized by those in the art, this example demonstrates but one of the possibilities for biomechanical applications. In  FIG. 25 , a heel portion of another shoe embodiment is shown with a wider foot print and side channels  73  for added stability. Side channels  73  are channels protruding more to the medial and lateral sides of the heel. This extra volume and breadth provides more stability if needed. Because bladder  74  is filled with a compressed fluid, the bladder  74  will form into the proper spaces within the midsole  73 . As noted previously, the insole can be secured with Velcro strips. In  FIG. 26 , a heel portion of another shoe embodiment is show with a vertically elongated bladder heel section  78  for compensating for a short leg or other possible gait afflictions. As will be recognized by those of skill in the art, this concept can be expanded to bladders that can minimize limps by reverse-engineering the limp and forming a bladder that will adequately compensate. Preferably for such embodiments, midsole  77  is formed in one piece and includes the accordion pleats  69 . These are but a few examples of the utility of enclosed, expandable, compressed air bladders to relieve and alleviate a wide range of bio-mechanical problems. 
         [0073]    While the terms used herein are believed to be well-understood by one of ordinary skill in the art, definitions are set forth to facilitate explanation of certain of the presently-disclosed subject matter. 
         [0074]    Following long-standing patent law convention, the terms “a”, “an”, and “the” refer to one or more when used in this application, including the claims. Thus, for example, reference to “a pleat” includes a plurality of such pleats, and so forth. 
         [0075]    Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently-disclosed subject matter. 
         [0076]    As used herein, the term “about,” when referring to a value or to an amount of a dimension, mass, weight, time, volume, percentage, etc., is meant to encompass variations of in some embodiments plus or minus 20%, in some embodiments plus or minus 10%, in some embodiments plus or minus 5%, in some embodiments plus or minus 1%, in some embodiments plus or minus 0.5%, and in some embodiments plus or minus 0.1% from the specified amount, as such variations are appropriate to perform the disclosed methods or employ the disclosed compositions. 
         [0077]    The term “comprising”, which is synonymous with “including” “containing” or “characterized by” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. “Comprising” is a term of art used in claim language which means that the named elements are essential, but other elements can be added and still form a construct within the scope of the claim. 
         [0078]    As used herein, the phrase “consisting of” excludes any element, step, or ingredient not specified in the claim. When the phrase “consists of” appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole. 
         [0079]    As used herein, the phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps, plus those that do not materially affect the basic and novel characteristic(s) of the claimed subject matter. With respect to the terms “comprising”, “consisting of”, and “consisting essentially of”, where one of these three terms is used herein, the presently disclosed and claimed subject matter can include the use of either of the other two terms. 
         [0080]    As used herein, the term “and/or” when used in the context of a listing of entities, refers to the entities being present singly or in combination. Thus, for example, the phrase “A, S, C, and/or O” includes A, S, C, and O individually, but also includes any and all combinations and subcombinations of A, S, C, and O. 
         [0081]    As used herein, proximate means near, but not necessarily at a specific point. Thus for example on end of a bladder is proximate to the outside of the heel, if a portion of the bladder is located in the heel area and extends into the rearmost fifty percent of the heel, or more preferably into the rearmost 20 percent of the heel. Similarly, a portion of the bladder is proximate to the front of the toe portion if a portion of the bladder is located in the toe portion and extends into the forward most fifty percent of the toe section, or more preferably into the forward most twenty percent of the toe section. 
         [0082]    It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The foregoing disclosure and description are illustrative and explanatory thereof, and various changes in the details of the illustrated apparatus and construction and method of operation may be made without departing from the spirit in scope of the invention which is described by the following claims.