Patent Publication Number: US-2012040810-A1

Title: Apparatus and methods for stretching the lower leg

Description:
BACKGROUND 
     In general, this application relates to an apparatus and methods for stretching the posterior portion of the lower leg, and more particularly to an apparatus and methods for providing stabilized ankle joint dorsiflexion while controlling hindfoot, midfoot, and forefoot pathomechanics. 
     Loss of dorsiflexion range of motion in the ankle (secondary to posterior compartment tightness) may contribute to painful pes planovalgus (PPV) or flatfoot, subsequent posterior tibial tendon dysfunction, and other problems. When dorsiflexion is compromised by posterior compartment tightness, the paths of least resistance during tibial progression over the foot are excessive hindfoot valgus and midfoot collapse with forefoot abduction. 
     Passive range of motion stretching is frequently prescribed for symptomatic PPV patients. When passive stretching occurs, without controlling the pathomechanics of PPV, the posterior compartment is not isolated and the midfoot is loaded into a collapsed position. This results in suboptimal outcomes from passive range of motion stretching with the potential for symptom exacerbation. 
     Stretching is also implicated for patients with equinovarus. Equinovarus foot and ankle condition is commonly associated with anterior compartment strength compromise (e.g., clubfoot, Charcot Marie Tooth disease, cerebral vascular accident, etc.). As the anterior compartment may be overpowered by the posterior compartment, limited dorsiflexion range of motion may result. The associated varus posture of the foot and ankle associated with these conditions necessitates hindfoot and forefoot control during passive stretching of the posterior compartment. 
     Accordingly, there is a need to improve the control over the pathomechanics of PPV and equinovarus under passive range of motion stretching. 
     BRIEF SUMMARY 
     An apparatus and method for stretching the muscles of the lower leg are generally disclosed. More particularly, an apparatus and methods for stabilizing the foot while stretching the posterior compartment of the lower leg are disclosed. The methods include dorsiflexion wherein the feet are positioned so that the forefoot and hindfoot are inverted or everted while the posterior compartment is simultaneously stretched. 
     In one embodiment, an apparatus for stretching the posterior compartment of the lower leg is provided and includes a body having a dome-shaped continuous outer surface. The outer surface includes a rounded upper section and a plurality of walls. The upper section supports at least a portion of a foot. The plurality of walls extend downwardly from the upper section and includes a sidewall that also supports at least a portion of the foot. 
     In another embodiment, a method is provided for stretching the posterior compartment of the lower leg. The method includes providing a body having a continuous dome-shaped outer surface and positioning a portion of a foot on a rounded upper section and a sidewall of the outer surface. 
     In another embodiment, a method is provided for stretching the posterior compartment of the lower leg. The method includes providing a first body having a continuous dome-shaped outer surface and a second body having a continuous dome-shaped outer surface; positioning at least a portion of a first foot on a first upper section and a first sidewall of the outer surface of the first body; and positioning at least a portion of a second foot on a second upper section and a second sidewall of the outer surface of the second body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Having thus described embodiments of the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  is a top perspective view of an apparatus for stretching a lower leg in accordance with an embodiment. 
         FIG. 2  is a bottom plan view of an apparatus for stretching a lower leg as shown in  FIG. 1 . 
         FIG. 3  is a front elevation view of an apparatus for stretching a lower leg as shown in  FIG. 1  and further illustrating feet positioned on an outer surface of the apparatus in accordance with an embodiment. 
         FIG. 4  is a side cross-sectional view of an apparatus for stretching a lower leg as shown in  FIG. 3 . 
         FIG. 5  is a rear view of an apparatus for stretching a lower leg as shown in  FIG. 1  and further illustrating feet positioned on the apparatus in accordance with an embodiment. 
         FIG. 6  is a left side elevation view of an apparatus for stretching a lower leg illustrating a foot positioned on the lower leg stretcher in accordance with an embodiment. 
         FIG. 7  is a rear view of an apparatus for stretching a lower leg as shown in  FIG. 6 . 
     
    
    
     DESCRIPTION 
     The following description and examples illustrate some exemplary embodiments of the disclosed apparatus and methods for stretching the lower leg. Those of skill in the art will recognize that there may be numerous variations and modifications of the apparatus and methods that may be encompassed by the scope of this disclosure. Accordingly, the description of the exemplary embodiments is not intended to limit the scope of the apparatus and methods for stretching the lower leg. 
     In order to facilitate an understanding of the various aspects of the apparatus and methods for stretching the lower leg, the following are defined below. 
     The term “hindfoot” as used herein refers without limitation to the posterior portion of the human foot. For example, the hindfoot may include the areas of the foot comprising the subtalar joint and the adjacent bones and soft tissue. The term “midfoot” as used herein refers without limitation to the section of the human foot that includes the tarsometatarsal joints and adjacent bones and soft tissue. The term “forefoot” as used herein refers without limitation to the section of the foot that includes the metatarsophalangeal joints and adjacent bones and soft tissue. 
     The term “medial longitudinal arch” or “arch” as used herein refers without limitation to the section of the human foot that includes the calcaneus, talus, navicular, cuneiforms, and the first three metatarsal bones. 
     The term “lower leg” as used herein refers without limitation to the portion of the human leg below the knee. For example, the lower leg may include leg, ankle, and foot portions. 
     The term “posterior compartment” as used herein refers without limitation to the area of the leg comprising the gastrocnemius, plantaris, and soleus muscles. All three of these muscles are connected to the Achilles tendon or calcaneal tendon. The posterior compartment may also include the muscles of the deep posterior compartment, such as the flexor digitorum longus, flexor hallicus longus, and tibialis posterior muscles. 
     The term “inverted position” as used herein refers without limitation to turning the foot or a portion of the foot medially or toward the midline of the body so that the sole of the foot is facing in an inward direction. 
     The term “everted position” as used herein refers without limitation to turning the foot or a portion of the foot laterally or away from the midline of the body so that the sole of the foot is facing in an outward direction. 
     In  FIG. 1 , an apparatus for stretching the lower leg is illustrated, and generally designated at  10 . The lower leg stretcher  10  comprises a body  12  having an outer surface. The outer surface of the body  12  is dome-shaped and includes a rounded upper section  14  and a plurality of walls. The plurality of walls extend downwardly from the upper section  14 . As shown in  FIGS. 1 and 2 , the walls comprise a front wall  16 , sidewalls  18   a ,  18   b , and a rear wall  20 . The front wall  16 , sidewalls  18   a ,  18   b , and rear wall  20  slope down from the top rounded section  14  to a rim  22 . 
     In some embodiments, the stretcher  10  is made of a rigid material such as hard plastic or any combination or mixture of materials that do not compress, deform, or collapse under body weight. In other embodiments, the stretcher  10  is made of a flexible material(s) of varying durometers such as rubber, silicon, ethylene vinyl acetate foam, or combination thereof. In the illustrated embodiment, the leg stretcher  10  is formed from a single unitary plastic piece such that the stretcher  10  is easy and cost effective to manufacture, ship, and store. The upper section  14  and the walls ( 16 ,  18   a ,  18   b ,  20 ) define an inner cavity  24 . The lower leg stretcher  10  is formed by molding, extrusion, thermoforming, coating, or by any other manufacturing method or combination of methods. In the illustrated embodiment, the rim  22  is square-shaped, but may also be, for example, round-shaped, triangle-shaped, or any other shape. In the embodiment shown, the stretcher  10  is lightweight, stackable, and cost effective to manufacture as a minimal amount of material is needed to form a hollow body. In other embodiments, the body  12  may be solidly formed. For example, stretcher  10  may be configured such that a planar surface extends along the entire bottom area of body  12 . In some embodiments, the body  12  may be solidly formed from a rigid material such as a plastic or a flexible material(s) of varying durometers such as rubber, silicon, ethylene vinyl acetate foam, or combinations thereof. The unitary construction of the stretcher  10  allows the user to stretch the lower leg with very little complications or instructions. 
     As best seen in  FIG. 2 , the rim  22  extends along the bottom edges of front wall  16 , sidewalls  18   a ,  18   b , and rear wall  20  and along the perimeter of the inner cavity  24 . For example, the rim  22  may extend from the bottom edge of the walls ( 18   a ,  18   b ,  16 ,  20 ) at varying distances. The rim  22  supports and stabilizes the stretcher  10  on a working surface such as a floor. The rim  22  may optionally be secured to a platform, to the floor, or to the working surface. For example, the rim  22  may be nailed or glued to a platform or a base support for additional stability. In some embodiments, a non-slip or gripping material is applied to the portion of the rim contacting a surface to impart slip resistance to the stretcher  10 . 
     In  FIG. 3 , a textured material  28  is shown covering the surface of the stretcher  10 . However, the outer surface of leg stretcher  10  may be smooth as illustrated in  FIG. 1 . The textured material  28  is a polymer, a synthetic rubber (e.g. neoprene), a natural rubber, or any other material or combination of materials suitable for imparting slip resistance or surface texture. In some embodiments, the textured material  28  provides cushioning, slip resistance, or foot placement guidance. Textured material  28  is applied directly to the outer surface of the body  12  by dip coating, spray coating, adhering, or by any other means for depositing the material on the outer surface of the stretcher  10 . In some embodiments, textured material  28  covers the entire outer surface of the leg stretcher  10 . In other embodiments, the coating only covers a portion of the outer surface of the stretcher  10 . For example, a rubber coating may only cover the surface portions on which the foot is to be placed or a number of rubber cut outs may be spaced out and glued onto the surface of the leg stretcher  10 . 
     In other embodiments, embedded texture is formed in the outer surface of the body  12 . For example, the plastic outer surface of the body  12  may be formed with dimples, ridges, or any other type of surface texture to prevent a user&#39;s foot from slipping. In other embodiments, indentations or raised markings for user guidance are formed in the outer surface of the stretcher  10 . For example, the outer surface of the body  12  may be imprinted with an indentation in the shape of a foot or arrows or text to provide stretching or foot placement instructions. 
     As shown in  FIG. 4 , the upper section  14  is elevated higher than the walls ( 16 ,  18   a ,  18   b ,  20 ) forming a bisected teardrop profile. The rear wall  20  slopes downwardly from the upper section  14  more gradually than the front wall  16  making the front wall  16  steeper than the rear wall  20 . 
     In use, a user positions one or both feet on the outer surface of the stretcher  10 . In the illustrated embodiments, the foot is positioned so that the toes of a forefoot  30  are directed toward front wall  16  and the heel of a hindfoot  32  is directed toward rear wall  20  ( FIGS. 4 and 5 ). In this way, the forefoot  30  is positioned at a higher elevation than the hindfoot  32  enabling an appropriate dorsiflexion load to be imposed when the forefoot  30  and the hindfoot  32  are in contact with the outer surface of the body  12 . The dorsiflexion load and concurrent passive stretch of the posterior compartment may be increased as the user progresses their center of mass anteriorly. For example, the user may simply lean forward and may optionally touch a wall or other supporting structure for balance as one or both feet are positioned on the stretcher  10 . A user may also increase the dorsiflexion load by placing a portion of the hindfoot  32 , such as the heel, on the ground and the forefoot  30  on the wall ( 16 ,  18   a ,  18   b , or  20 ) of the stretcher  10 . 
     In  FIG. 5 , a right foot  26   a  is positioned on the right sidewall  18   a  and a left foot  26   b  is positioned on the left sidewall  18   b  (see also, e.g.,  FIG. 3 ). In this position, the sidewalls  18   a ,  18   b  support the forefoot  30  and the hindfoot  32  in an inverted position. Positioning the forefoot and the hindfoot in inversion so that the sole of the foot faces inward corrects for any eversion of the foot that may occur in patient with PPV (i.e. flatfoot). 
     The upper section  14  is convex-shaped and supports at least a portion of a medial longitudinal arch  34  as shown in  FIG. 4 . The sidewalls  18   a ,  18   b  support another portion of the medial longitudinal arch  34 . Alternatively, a foot may be positioned on the outer surface of the body  12  such that the medial longitudinal arch  34  is completely supported by the upper section  14  and/or sidewall  18   a  or  18   b . In either embodiment, the medial longitudinal arch  34  is supported to prevent collapse. 
     In some embodiments, the sidewalls  18   a ,  18   b  support a portion of the forefoot  30  and hindfoot  32  of the right foot  26   a  and left foot  26   b . In other embodiments, the front wall  16  and rear wall  20  each support a portion of the forefoot  30  or hindfoot  32  of the right foot  26   a  and/or left foot  26   b  (see,  FIG. 4 ). For example, the support of the foot on front wall  16  and rear wall  20  may depend on the size of the user&#39;s foot, the size of the stretcher  10 , or the position of the foot. A user with a larger foot may extend over a greater distance on the surface of front wall  16  and/or rear wall  20  compared to a user with a smaller foot size. The length, width, and height of stretcher  10  and the relative size of each section may, for example, be optimized for maximum support of a user&#39;s foot or feet. 
     In one embodiment, the entire plantar surface (i.e. the sole) of the foot is in contact with the outer surface of stretcher  10 . For example, a user with PPV may position their feet on stretcher  10  such that the portion of the plantar surface of the foot corresponding to a fallen arch is supported in addition to the rest of the sole. In this way, the corrective loads are comfortably distributed over the broadest possible surface area. 
     In  FIGS. 6 and 7 , a right foot  26   a  is positioned on the left sidewall  18   b , front wall  16 , and rear wall  20 . The left sidewall  18   b  slopes downwardly from the upper section  14  such that the hindfoot  32  as well as the forefoot  30  of the right foot  26   a  are everted or turned outward from the midline of the body. In the illustrated embodiment, the left side wall  18   b  supports at least a portion of the right foot  26   a  in an everted position. In another embodiment, the right side wall  18   a  supports at least a portion of the left foot  26   b  in an everted position. In other embodiments, at least a portion of the right foot  26   a  and/or left foot  26   b  are positioned on the upper section  14  in an everted position. This positioning ensures that the forefoot  30  and hindfoot  32  of users with equinovarus conditions are everted during the passive stretch of the posterior compartment. 
     Depending on the position of the foot, the upper section  14  supports at least a portion of the forefoot  30  and hindfoot  32  of the right foot  26   a  and/or left foot  26   b . For example, a user may place their left foot on the right sidewall of the stretcher  10  while placing their right foot on the ground or on an elevated platform located adjacent to the stretcher  10 . The supporting foot, for example, may be placed on a platform such that the supporting foot is at the same height as the foot engaging the stretching apparatus to promote balance and ensure optimal stretching of the lower leg. In other embodiments, a user positions one foot on one of the stretcher  10  and the other foot on another of the stretcher  10 . For example, a user may place their right foot on the left sidewall of a first stretcher and place their left foot on the right sidewall of an adjacent second stretcher. In this way, both posterior compartments of the lower legs are stretched at the same time and the user is able to remain balanced on both apparatuses during the stretch. The dorsiflexion load may be increased by shifting the user&#39;s center of mass forward. The two stretchers may be, for example, fastened together or secured to the floor or a supporting structure for added stability. The stretchers may be positioned adjacent to each other at varying distances. 
     While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other changes, combinations, omissions, modifications and substitutions, in addition to those set forth in the above paragraphs, are possible. Those skilled in the art will appreciate that various adaptations and modifications of the just described embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.