Patent Publication Number: US-2006010580-A1

Title: Headstand assisting implement

Description:
FIELD OF THE INVENTION  
      The present invention relates to the general field of implements for performing physical exercise and is particularly concerned with a headstand assisting implement.  
     BACKGROUND OF THE INVENTION  
      The word “yoga” is derived from the Sanskrit “yeung”, meaning to join. In Hindu philosophy, yoga is used to attain spiritual insight and harmony. In Western countries, the term yoga is often used interchangeably with “hatha yoga”.  
      The practice of “hatha yoga” involves performing various physical postures and relaxation exercises. The yogic physical exercises are called Asanas, a term which means steady pause. This is because Yoga Asanas are typically meant to be held for some time. Yoga Asanas typically focus on the health of the spine, its strength and flexibility.  
      Although there are probably millions of Asanas, twelve selected pauses are considered as basic postures. Known as the “king of Asanas” because of its many benefits, the headstand is the first of the twelve basic Asanas. The headstand consists in balancing on the crown of the head also referred to as the Sahasrara chakra.  
      The headstand is considered by many to be a panacea for countless human ills. Benefits of performing the headstand includes: a) reversal of venous flow, thus flushing out areas of stagnant or collected blood; b) reversal of the flow of cerebro-spinal fluid, resulting in formation of new cerebro-spinal fluid in the region of the intracerebral ventricles; c) activation of the carotid sinus barorereceptors, resulting in increased discharge from the parasympathetic nervous system, thus lowering heart rate and blood pressure; d) strengthening of the paravertebral musculature; e) improvement of balance as a result of the establishment of new neural circuitry by the new demand for balance placed on the cerebellum and vestibular apparatus; f) improvement in concentration; g) improvement in endurance; and h) improvement in relaxation and general well being.  
      Although not necessarily considered an advanced Asana, the headstand nevertheless requires some level of experience and may be potentially hazardous. Indeed, when performing a headstand, the cervical spine, in particular, may be subjected to important stresses that may potentially lead to serious injury.  
      Some believe that the headstand should not be performed by individuals having cervical spondylosis, blocked arteries, osteo-arthritis of the neck or shoulders, backache, premenstrual stress or high blood pressure. Furthermore, it is typically recommended to get help from a yoga practitioner to perform the headstand in a correct and safe manner.  
      There exists several methods for performing a yoga headstand. Typically, the sequence is initiated by coming onto the elbows and knees about 6 inches away from a wall. The hands are then placed to the outside of the triceps muscles to establish a beginning arm position. The elbows are then released and the fingers interlocked creating a “V” stance with the forearms. The crown of the head is then rested on the floor.  
      The toes are then tucked under and, while inhaling, the hips are lifted and the legs straightened. The neck must be maintained in proper alignment throughout the procedure.  
      Once this initial position has been established, one foot is placed in front of the other, preferably the stronger leg forward. It is typically recommended that most of the weight should rest on the elbows and not on the crown of the head. However, this may actually train the bad habit of having the mechanical axis of the spine anterior to the anatomic axis.  
      The abdominal muscles and the pelvic floor muscles are contracted and, slowly, one leg at a time, the individual floats the feet up resting the legs on the wall. When headstand is taught in this way, the weight does not rest on the crown of the head, but rather rests on the elbows. It is recommended to keep the legs together and the toes spread.  
      When practiced as described in the foregoing it is only when the neck is very strong and the individual has been practicing for many years that he or she can then place the full weight of the body on the head. As the headstand posture is practiced, from the starting position the abdominal muscles may be engaged first and both legs then slowly floated up together until in the inverted headstand position. Eventually, as the posture is established, the individual can move away from the wall and attempt it in a free-stand position. Typically, the posture is held for 5 to 10 deep breaths. Many other sequences may be used to achieve a proper headstand.  
      Typically, most people recommend that most of the weight be distributed onto the hands and/or forearms in order to “protect” the spine. However, it is believed that by maintaining most of the weight on the forearms and/or hands, the spine may in fact become more vulnerable since the mechanical axis of the body is shifted forward of the cervical spine. By shifting the mechanical axis away from the anatomic axis of the vertebral column, the spine and its surrounding musculature become at risk for both acute and chronic injury. Furthermore, the advantage of aligning the body weight with the trabeculae of the vertebral bodies, which combined with the intervertebral discs can withstand very high compressive forces, is lost if the mechanical and anatomic axis are not aligned.  
      When the headstand is performed with the mechanical axis of the spine substantially aligned with the anatomic axis, the weight of the body is concentrated in a small area of a part of the cranium, commonly referred to as the crown, where it is in contact with the floor. The sustentation polygon or surface within which the centre of gravity of the body must project in order to maintain the body in the inverted position without falling over is relatively small. Furthermore, the surface of the cranium in contact with the ground has a somewhat convex configuration which further reduces the overall stability of the position.  
      Sway or imbalance is magnified when one attempts to maintain the mechanical axis and the anatomic axis concentrated in such a small area. Furthermore, in the inverted and erect position, the body becomes a long lever arm such that movements caused by relatively small forces become magnified. Such small forces can reach significant levels to a point that imbalance is created by the sway.  
      This sway must be countered by muscular forces in order to maintain the body in the headstand position. These forces, in turn, can reach relatively high levels and are transmitted in the form compensatory flexion, extension and rotary motion at the vertebral bodies. These motions and forces can result in disc bulging or herniation.  
      Hence, it would be desirable to provide a headstand assisting implement allowing an intended user to assume the inverted and erect position associated with conventional headstands wherein the mechanical and anatomic axes are in a substantially co-linear relationship relative to each other but without the hereinabove mentioned disadvantages associated with such a position. In other words, it would be desirable to provide a headstand assisting implement that could allow an intended user to perform a headstand wherein involvement of the forearms is minimized and wherein the need for providing compensatory movements to maintain balance is also minimized.  
     SUMMARY OF THE INVENTION  
      It is a general object of the present invention to provide a headstand assisting implement adapted to assist an intended user in ergonomically performing a headstand.  
      In accordance with the present invention, there is provided a headstand assisting implement for assisting an intended user while the intended user performs a headstand, the intended user having a head including a cranium, the headstand assisting implement comprising: an implement body, the implement body defining a ground contacting surface for resting on a ground surface and a substantially opposed cranium contacting surface for contacting the cranium of the intended user; the cranium contacting surface being provided with a cranium receiving concavity, the cranium receiving concavity being configured and sized for substantially fittingly receiving a predetermined portion of the cranium of the intended user so as to ergonomically support the cranium of the intended user when the intended user performs the headstand.  
      Conveniently, the cranium receiving concavity has a substantially ovoid configuration when seen from a top view, the ovoid configuration of the cranium receiving concavity defining a concavity long axis extending substantially longitudinally across the cranium receiving concavity and a substantially perpendicular concavity short axis extending transversally across the cranium receiving concavity, the concavity long and short axes being sized so that the outline of the cranium receiving concavity corresponds substantially to the outline of the predetermined portion of the cranium of the intended user.  
      Preferably, the cranium receiving concavity defines a concavity main section and a concavity auxiliary section, the concavity main section being located substantially centrally relative to the cranium receiving concavity; the concavity auxiliary section being located peripherally relative to the concavity main section, the radius of curvature of the concavity auxiliary section being greater then the radius of curvature of the concavity main section;  
      In at least one embodiment of the invention, the concavity main section is hollow. In another embodiment of the invention, at least a portion of the concavity main section and the concavity auxiliary section are made out of different materials.  
      Preferably, the implement body is made out of an integral piece of substantially resiliently deformable body material.  
      Advantages of the present invention include that the proposed implement allows an intended user to perform a headstand with reduced risks of injury. The proposed implement is also intended to provide a greater sense of comfort, security, stability and capability to an intended user practicing headstands.  
      In turn, the improved comfort, security, stability and capability enable the body of an intended user to maintain headstands for a longer period of time. It also enables the intended user to place the body in a variety of headstand positions.  
      The proposed implement is designed so as to allow the body of the intended user to maintain its mechanical axis substantially in line with the anatomic axis during performance of the headstand.  
      Also, the proposed implement is designed so as to act as an interface between the crown of the head of the intended user and the ground surface and to provide an enlarged contact surface with the ground surface.  
      Still furthermore, the proposed implement is designed so as to provide self-alignment features adapted to reduce the need for the intended user to exert muscular tension in an attempt to maintain balance. In other words, the proposed implement is designed so as to improve the stability of the intended user when the latter is in the headstand position.  
      Also, the proposed implement is designed so as to be usable by a wide range of users having a relatively wide range of anthropometric values in terms of head size and configuration.  
      Yet, still furthermore, the proposed implement is designed so as to be manufacturable using conventional forms of manufacturing and conventional materials so as to provide an implement that will economically feasible, long-lasting and relatively trouble-free in operation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Various embodiments of the present invention will now be disclosed, by way of example, in reference to the following drawings in which:  
       FIG. 1 , in a perspective view, illustrates a headstand assisting implement in accordance with an embodiment of the present invention;  
       FIG. 2 , in a top view, illustrates the headstand assisting implement shown in  FIG. 1 ;  
       FIG. 3 , in a partial perspective view with sections taken out, illustrates some of the features of the headstand assisting implement shown in  FIGS. 1 and 2 ;  
       FIG. 4 , in a longitudinal cross-sectional view taken along arrows IV-IV of  FIG. 2 , illustrates some of the features of the headstand assisting implement shown in  FIGS. 1 through 3 ;  
       FIG. 5 , in a longitudinal cross-sectional view similar to that of  FIG. 4 , illustrates a headstand assisting implement in accordance with a second embodiment of the present invention;  
       FIG. 6 , in a longitudinal cross-sectional view similar to that of  FIGS. 4 and 5 , illustrates a headstand assisting implement in accordance with a third embodiment of the present invention;  
       FIG. 7 , in a transversal cross-sectional view, illustrates a headstand assisting implement in accordance with an embodiment of the present invention, the headstand assisting implement being shown used by an intended user in the headstand position, the intended user being shown in phantom lines and part of the vertebral column of the intended user being shown in full lines;  
       FIG. 8 , in a transversal cross-sectional view, illustrates a headstand assisting implement in accordance with an embodiment of the present invention, the headstand assisting implement being shown with the head of an intended user resting thereon, the head being shown in phantom lines and in an angular offset relationship relative to a vertical axis, part of the cervical spine of the intended user being shown in full lines. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIG. 7 , there is shown, in a transversal cross-sectional view, a headstand assisting implement in accordance with an embodiment of the present invention generally indicated by the reference numeral  10 . The implement  10  is shown being used by an intended user  12  performing a headstand.  
      The intended user  12  has a head  14  supported by a neck  16  extending from a torso  18 . The intended user  12  also has a pair of arms including forearms  20  and a pair of legs  22  extending from the torso  18 .  
      In  FIG. 7 , the intended user  12  is shown performing a typical yogic posture or Asana wherein the legs  22  are crossed and wherein the back of the head  14  is placed in the hollow of the palm (not shown). It should, however, be understood that the implement  10  could be used for performing other types of headstands without departing from the scope of the present invention. Furthermore, although the implement  10  was primarily designed for use in practicing yoga or the like, it should be understood that the implement  10  could be used in other contexts and for practicing other types of activities such as gymnastics, general physical conditioning or the like without departing from the scope of the present invention.  
      The head  14  of the intended user  12  includes a cranium. As is well known in the art, when seen from the top, the human cranium typically has a substantially ovoid or egg-shaped outline or configuration. When seen from the front or the rear, the top portion or crown  24  of the human cranium typically has a substantially rounded and convex configuration or outline. Although  FIGS. 7 and 8  illustrate a cranium having a crown portion  24  with specific anthropometric parameters, it should be understood that the implement  10  is intended to be used by individuals having a variety of cranium anthropometric parameters without departing from the scope of the present invention.  
       FIGS. 7 and 8  also schematically illustrate part of the vertebral column  26  of the intended user  12 . As is well known in the art, the vertebral column includes vertebrae  28  and intervertebral discs  30  positioned therebetween.  
      The headstand assisting implement  10  includes an implement body  32 . The implement body  32  defines a crown contacting surface  34  for resting on a ground surface  36 . The implement body  32  also defines a substantially opposed cranium contacting surface  38  for contacting the cranium of the intended user  12 .  
      As illustrated more specifically in  FIGS. 4, 5  and  6 , the cranium contacting surface  38  is provided with a cranium contacting concavity  40 . The cranium receiving concavity  40  is configured and sized for substantially fittingly receiving a predetermined portion of the cranium of the intended user  12  so as to ergonomically support the cranium of the intended user  12  when the latter performs a headstand.  
      As illustrated more specifically in  FIG. 2 , the cranium receiving concavity  40  has a substantially ovoid configuration when seen from a top view. The ovoid configuration of the cranium receiving concavity  40  defines a concavity long axis  42  extending substantially longitudinally across the cranium receiving concavity  40 . The ovoid configuration of the cranium receiving concavity  40  also defines a substantially perpendicular concavity short axis  44  extending transversely across the cranium receiving concavity  40 . The concavity long and short axes  42 ,  44  are sized so that the outline of the cranium receiving concavity  40  corresponds substantially to the outline of the predetermined portion of the cranium of the intended user  12 .  
      Typically, the cranium receiving concavity  40  is configured and sized for substantially fittingly receiving the so-called crown portion  24  of the cranium of the intended user  12 . Preferably, the crown portion  24  intended to contact the cranium receiving concavity  40  is defined as extending between the two parietal bones and the posterior portion of the frontal bone, the center of the cranium receiving portion being the native fontanelle.  
      The cranium receiving concavity  40  is configured and sized for substantially fittingly accommodating the crown portion of an intended user having anthropometric parameters located between that of the 5 th  and 95 th  percentile of human craniums. Typically, the concavity long axis  42  has a value of approximately between 12.5 centimetres and 14 centimetres and the concavity short axis  44  has a value of approximately between 10 centimetres and 11.2 centimetres.  
      As illustrated more specifically in  FIGS. 4 through 6 , the cranium receiving concavity  40  typically has a substantially flattened parabolic configuration when seen in a longitudinal cross-section taken about the oval long axis  42 . Typically, the profile of the surface of the cranium receiving concavity along the concavity short axis  44  also has a substantially parabolic configuration.  
      As illustrated more specifically in  FIGS. 1 and 2 , the cranium receiving concavity  40  defines a concavity main section  46  and a concavity auxiliary section  48 . The concavity main section  46  is typically located substantially centrally relative to the cranium receiving concavity  40  while the concavity auxiliary section  48  is typically located peripherally relative to the concavity main section  46 .  
      As illustrated more specifically in  FIGS. 4 through 6 , the radius of curvature of the concavity auxiliary section  48  is greater than the radius of curvature of the concavity main section  46 . The concavity main section  46  defines a main section radius of curvature  50  while the concavity of the auxiliary section  48  defines an auxiliary section radius of curvature  52 . Typically, the main section radius of curvature has a value of approximately between 20 cm and 22 cm while the concavity of the auxiliary section radius of curvature  52  has a value of approximately between 36 cm and 51 cm.  
      As seen more specifically in  FIG. 2 , the concavity main section  46  also has a substantially ovoid configuration. The ovoid configuration of the concavity main section  46  defines a main section long axis extending substantially longitudinally across the concavity main section  46  and a substantially perpendicular main section short axis extending substantially transversely across the concavity main section  46 . Typically, the main section long axis has a value of approximately between 6.25 centimetres and 7 centimetres while the main section short axis has a value of approximately between 5 centimetres and 5.6 centimetres.  
      The cranium receiving cavity  40  defines a concavity peripheral edge  54 . As illustrated more specifically in  FIG. 4 , the level difference between the concavity peripheral edge  54  and the nadir of the cranium receiving concavity  40  defines a concavity depth  56 . Typically, the concavity depth  56  has a value between 1.6 centimetres and 1.8 centimetres.  
      The distance between the nadir of the cranium receiving concavity  40  and the ground contacting surface  34  defines a body minimal thickness  58 . Typically, the body minimal thickness  58  has a value of approximately between 0.635 centimetres and 1.0 centimetre.  
      Typically, the concavity peripheral edge  54  has a substantially rounded configuration or contour. The concavity peripheral edge  54  hence defines a corresponding peripheral edge radius of curvature  60 . The peripheral edge radius of curvature  60  typically has a value of approximately between 0.3 centimetres and 0.5 centimetres.  
      The implement body  32  includes a body peripheral surface  62  extending between the concavity peripheral edge  54  and the ground contacting surface  34 . The body peripheral surface  62  tapers generally inwardly in a direction leading from the ground contacting surface  34  to the concavity peripheral edge  54 .  
      The body peripheral surface  62  extends at a peripheral-to-ground contacting surface angle  64  relative to said ground contacting surface  34 . Typically, the peripheral-to-ground contacting surface angle  64  has a value of approximately between 65 degrees and 90 degrees.  
      The implement body  32  is preferably made out of an integral piece of a substantially resiliently deformable body material. Typically the body material is a polymeric or elastomeric resin. Typically, the body material is a Urethane polymer sold under the Trademark Gel or Evergreen #10-A (non toxic) or other substantially similar suitable material. Typically, the body material provides substantially the following characteristics: a viscosity of approximately 600 PCS, an elongation of approximately 1.000%, a tensile strength of approximately: 200 PSI and a tear of approximately PLI 25 PI.  
      As illustrated more specifically in  FIGS. 3 through 6 , at least the cranium receiving concavity  40  and typically both the cranium receiving concavity  40  and the body peripheral surface  62  are coated with a coating material having a coating material friction co-efficient equal to or lower then that of Lycra (a trademark). Typically, the coating material is a coating layer or film  66  of Lycra or similar material adhesively or otherwise secured to the implement body  32 .  
      In use, as illustrated in  FIGS. 7 and 8 , the implement  10  is adapted to ergonomically support the crown portion  24  of the cranium of the intended user  12  when the latter performs a headstand. The configuration and size of the cranium receiving concavity  40  allows the latter to act as a socket for substantially fittingly receiving the crown portion of the cranium.  
      The combination of the dimensional characteristics of the implement  10  and of the type of material chosen for forming the implement body  32  allows the implement  10  to functionally accommodate a wide range of crown section configurations and sizes. Indeed, the selected dimensional characteristics and degree of resiliency of the material synergistically combine to provide a tight fit to intended users having a wide range of anthropometric characteristics.  
      The concavity main section  46  is configured and sized for contacting the portion of the cranium of the intended user  12  that would contact the ground surface  36  if the implement  10  were not used and if the body of the intended user  12  was properly balanced along a substantially vertical axis  68 . The concavity main section  46  is intended to provide that portion of the crown section of the intended user  12  with a somewhat more ductile or soft contacting surface than that of the ground surface  36 .  
      The concavity auxiliary section  48  is adapted to provide a greater contact surface with the cranium of the intended user  12  then that which would have been in contact with the ground surface  36  should the implement  10  had not be used and the intended user  12  has nevertheless been in a balanced vertical position. Hence, the contact surface with the cranium is increased by the concavity auxiliary section  48 .  
      The contact surface with the ground surface  36  is also increased by the implement  10  since the body peripheral surface  62  tapers generally inwardly in a direction leading from the ground contacting surface  34  towards the concavity peripheral edge  54 . The body peripheral surface  62  is configured and sized for increasing the contact area of the cranium of the intended user  12  transmitted by the implement  10  to the ground surface  36  without interfering with surrounding structures such as the forearms  20  of the intended user  12 . Indeed, as shown in  FIG. 7 , the implement  10  is configured and sized so as to leave a clearance between the implement  10  and the forearms  20  of the intended user when the latter uses the forearms  20  for additional support.  
      The radius of curvature of the concavity auxiliary section  48  allows the latter to be angled relative to the ground surface  36  so as to provide a reaction force against the weight of the intended user  12 , the reaction force having a horizontally extending vector segment so as to further help in stabilizing the intended user  12  in the proper position. Furthermore, as illustrated more specifically in  FIG. 8 , the resiliently deformable nature of the body material from which the implement body  32  is made is such that the implement body  32  is adapted to controllably deform upon the axis  70  of the vertebral column  26  deviating from the vertical axis  68 . This controlled deformation of the implement body  32  protects the spine and, more specifically, the intervertebral discs by mitigating and taking up the bulging that would normally occur during compensatory adjustment as a result of body sway during the headstand.  
      Furthermore, the resilient nature of the body material from which the implement body  32  is made is such that, upon deformation, the implement body  32  will tend to resiliently spring back to its original configuration hence creating self-aligning biasing forces that will tend to bias the vertebral column axis  70  towards the vertical axis  68  as indicated by arrow  72  in  FIG. 8 . These inherent self-aligning forces, in turn reduce the need for compensatory movement and/or forces emanating from the user body that could potentially lead to injury.  
      In order to further increase the comfort associated with the use of the implement  10 , the resilient nature of the body material from which the implement body  32  is made synergistically combines with the dimensional characteristics of the concavity peripheral edge  54  taking into consideration other parameters from both the intended user  12  and the implement  10 .  
      The body minimal thickness  58  is also designed taking into consideration the nature of the body material from which the implement body  32  is made so as to prevent the head contacting surface  38  from contacting the ground surface  36  and/or prevent the implement body  32  adjacent the head contacting surface  38  from being compressed to the point of having a modulus of elasticity having a value over a predetermined threshold that would make use of the implement  10  uncomfortable.  
      Referring more specifically to  FIG. 5 , there is shown a headstand assisting implement in accordance with an alternative embodiment of the invention generally indicated by the reference numeral  10 ′. The implement  10 ′ is substantially similar to the implement  10  and, hence, similar reference numerals will be used to denote similar components.  
      One of the main differences between the implements  10  and  10 ′ resides in that at least part of the concavity main section  46  of the implement  10 ′ is hollow. In other words, a central aperture  74  extends through the implement body  32  in the region of the concavity main section  36 .  
      Referring now more specifically to  FIG. 6 , there is shown a headstand assisting implement in accordance with a third embodiment of the present invention, generally indicated by the reference numeral  10 ″. The implement  10 ″ is substantially similar to the implements  10  and  10 ′ and, hence, similar reference numerals will be used to denote similar components.  
      One of the main differences between the implement  10 ″ and the implements  10  and  10 ′ resides in that at least part of the concavity main section  46  and the concavity auxiliary section  48  are made out of different materials.  FIG. 6  illustrates a situation wherein an insert  76  made out of a different material is used. Preferably, at least part of the concavity main section  46  is made out of a material having a lower modulus elasticity than that from which the concavity auxiliary section  48  is made.  
      Typically, at least the concavity main section is made out of a material having a modulus elasticity having a value of approximately between 100 and 400 kPA and at least part of the concavity auxiliary section  48  is made out of a material having a modulus elasticity having a value of approximately between 10 and 40 kPA.  
      Typically, the modulus elasticity of the concavity main and auxiliary sections  46 ,  48  is substantially similar to or lower than the corresponding modulus elasticity of the nucleus pulposus and annulus fibrosus of a physiologic intervertebral disc.