US20060010580A1

US20060010580A1 - Headstand assisting implement

Info

Publication number: US20060010580A1
Application number: US11/159,868
Authority: US
Inventors: Raymond Long
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-24
Filing date: 2005-06-23
Publication date: 2006-01-19
Also published as: CA2510695A1

Abstract

A headstand assisting implement for assisting an intended user while the latter performs a headstand includes an 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 is provided with a cranium receiving concavity 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.

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^thand 95^thpercentile 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.

Claims

1. A headstand assisting implement for assisting an intended user while said intended user performs a headstand, said intended user having a head including a cranium, said headstand assisting implement comprising:

an implement body, said implement body defining a ground contacting surface for resting on a ground surface and a substantially opposed cranium contacting surface for contacting said cranium of said intended user;

said cranium contacting surface being provided with a cranium receiving concavity, said cranium receiving concavity being configured and sized for substantially fittingly receiving a predetermined portion of said cranium of said intended user so as to ergonomically support said cranium of said intended user when said intended user performs said headstand.

2. A headstand assisting implement as recited in claim 1 wherein said cranium receiving concavity has a substantially ovoid configuration when seen from a top view, said ovoid configuration of said cranium receiving concavity defining a concavity long axis extending substantially longitudinally across said cranium receiving concavity and a substantially perpendicular concavity short axis extending transversally across said cranium receiving concavity, said concavity long and short axes being sized so that the outline of said cranium receiving concavity corresponds substantially to the outline of said predetermined portion of said cranium of said intended user.

3. A headstand assisting implement as recited in claim 2 wherein said concavity long axis has a value of approximately between 12.5 cm and 14 cm and said concavity short axis has a value of approximately between 10 cm and 11.2 cm.

4. A headstand assisting implement as recited in claim 1 wherein said cranium receiving concavity is configured and sized for substantially fittingly accommodating said predetermined portion of said cranium of an intended user having anthropometric parameters located between that of the fifth and ninety fifth percentile of human craniums.

5. A headstand assisting implement as recited in claim 2 wherein said cranium receiving concavity has a substantially flattened parabolic configuration when seen in a longitudinal cross-section taken about said oval long axis.

6. A headstand assisting implement as recited in claim 1 wherein said cranium receiving concavity defines a concavity main section and a concavity auxiliary section, said concavity main section being located substantially centrally relative to said cranium receiving concavity; said concavity auxiliary section being located peripherally relative to said concavity main section, the radius of curvature of said concavity auxiliary section being greater then the radius of curvature of said concavity main section.

7. A headstand assisting implement as recited in claim 6 wherein the concavity main section has a main section radius of curvature and the concavity auxiliary section has an auxiliary section radius of curvature, the main section radius of curvature has a value of approximately between 20 and 22 centimetres and the concavity auxiliary section radius of curvature has a value of approximately between 3.6 and 5.1 centimetres.

8. A headstand assisting implement as recited in claim 6 wherein said concavity main section has a substantially ovoid configuration, said ovoid configuration of said concavity main section defining a main section long axis extending substantially longitudinally across said concavity main section and a substantially perpendicular main section short axis extending substantially transversally across said concavity main section.

9. A headstand assisting implement as recited in claim 8 wherein said main section long axis has a value of approximately between 12.5 cm and 14 cm and said main section short axis has a value of approximately between 10 cm and 11.2 cm.

10. A headstand assisting implement as recited in claim 6 wherein said concavity main section is hollow.

11. A headstand assisting implement as recited in claim 6 wherein at least a portion of said concavity main section and said concavity auxiliary section are made out of different materials.

12. A headstand assisting implement as recited in claim 6 wherein at least a portion of said concavity main section is made out of a material having lower modulus of elasticity then that from which said concavity auxiliary section is made.

13. A headstand assisting implement as recited in claim 6 wherein at least a portion of said concavity main section is made out of a material having a modulus of elasticity of approximately between 100 and 400 kPA and at least a portion of said concavity auxiliary section is made out of a material having a modulus of elasticity of approximately between 10 and 40 kPA.

14. A headstand assisting implement as recited in claim 1 wherein said cranium receiving concavity has a concavity peripheral edge, the level difference between said concavity peripheral edge and the nadir of said cranium receiving concavity defining a concavity depth, said concavity depth having a value of between 1.6 cm and 1.8 cm.

15. A headstand assisting implement as recited in claim 1 wherein the distance between the nadir of said cranium receiving concavity and said ground contacting surface defines a body minimal thickness, said body minimal thickness having a value of approximately between 0.635 cm and 1.0 cm.

16. A headstand assisting implement as recited in claim 1 wherein said cranium receiving concavity has a concavity peripheral edge, said concavity peripheral edge having a substantially rounded configuration, the radius of curvature of said concavity peripheral edge having a value of approximately between 0.3 cm and 0.5 cm.

17. A headstand assisting implement as recited in claim 1 wherein said implement body includes a body peripheral surface extending between said concavity peripheral edge and said ground contacting surface, said body peripheral surface tapering generally inwardly in a direction leading from said ground contacting surface to said concavity peripheral edge.

18. A headstand assisting implement as recited in claim 17 wherein said body peripheral surface extends at a peripheral-to-ground contacting surface angle relative to said ground contacting surface, said peripheral-to-ground contacting surface angle having a value of approximately between 65 degrees and 90 degrees.

19. A headstand assisting implement as recited in claim 1 wherein said implement body is made out of an integral piece of substantially resiliently deformable body material.

20. A headstand assisting implement as recited in claim 19 wherein said body material is a urethane gel.