U.S. patent application number 12/816226 was filed with the patent office on 2011-12-15 for ergometric chair apparatus.
Invention is credited to Betty A. Augustat.
Application Number | 20110304192 12/816226 |
Document ID | / |
Family ID | 45095652 |
Filed Date | 2011-12-15 |
United States Patent
Application |
20110304192 |
Kind Code |
A1 |
Augustat; Betty A. |
December 15, 2011 |
Ergometric Chair Apparatus
Abstract
The present invention and method is for a chair disposed upon a
surface that is designed for a female anatomy; the chair includes a
seat having proximate and distal end portions forming a first
convex surface with a chord plane intersecting, the having a length
shorter than its width. The chair also includes a back having first
and second end portions that form a second convex surface, wherein,
a second lateral measure on the second end is less than a first
lateral measure on the first end. The seat plane and an extension
axis that is perpendicular to the surface are relatively positioned
to one another to form an acute angle to one another, such that a
user's femur bone lengthwise angles downward from hip to knee
toward the surface while the user's shoulders arch rearward thus
aligning the user's hip joint and shoulder joint vertically for
better posture.
Inventors: |
Augustat; Betty A.;
(Broomfield, CO) |
Family ID: |
45095652 |
Appl. No.: |
12/816226 |
Filed: |
June 15, 2010 |
Current U.S.
Class: |
297/452.23 |
Current CPC
Class: |
A47C 1/03255
20130101 |
Class at
Publication: |
297/452.23 |
International
Class: |
A47C 7/00 20060101
A47C007/00 |
Claims
1. A chair adapted for a female anatomy, wherein said chair is
adjacent to a surface, comprising: (a) a seat having a proximate
end portion and a distal end portion forming a first substantially
convex arcuate profile surface there between, said seat also
including a length substantially parallel to said first
substantially convex arcuate profile surface and a first distance
substantially transverse to said length, said first substantially
convex arcuate profile surface formed from a first partial arc of a
first radius, said first radius being greater than said length, in
addition said first substantially convex arcuate profile surface
including a first seat tangential point on said proximate end
portion and a second seat tangential point on said distal end
portion, wherein said first seat tangential point and said second
seat tangential point are at a second distance apart forming a seat
plane; (b) a back having a first end portion and a second end
portion, said first and second end portions forming a second
substantially convex arcuate profile surface, said back also
including a dimension substantially parallel to said second
substantially convex arcuate profile surface and a first measure
and a second measure both being substantially transverse to said
dimension, wherein said second measure on said second end portion
is less than said first measure on said first end portion, said
second substantially convex arcuate profile surface formed from a
second partial arc of a second radius, said second radius being
greater than said dimension, in addition said second substantially
convex arcuate profile surface including a first back tangential
point on said first portion and a second back tangential point on
said second portion, wherein said first back tangential point and
said second back tangential point are at a third distance apart
forming a backplane; (c) said seat plane and an extension axis that
is perpendicular to the surface are relatively positioned to one
another to form an acute angle to one another at an intersection
point positioned therebetween said first seat tangential point and
said second seat tangential point; (d) said seat and back are
relatively positioned such that a span from said first seat
tangential point to said first back tangential point is at least
equal to half of said dimension; (e) a support base disposed
between said seat and the surface; and (f) a support structure
disposed between said seat and said back.
2. A chair adapted for a female anatomy according to claim 1,
wherein said acute angle is in the range of about fifty-five to
eighty-five (55-85) degrees.
3. A chair adapted for a female anatomy according to claim 1,
wherein said length is in the range of about thirteen (13)
inches.
4. A chair adapted for a female anatomy according to claim 3,
wherein said first distance is in the range of about sixteen (16)
inches.
5. A chair adapted for a female anatomy according to claim 3,
wherein said second distance is in the range of about eleven (11)
inches.
6. A chair adapted for a female anatomy according to claim 1,
wherein said dimension is in the range of about seven (7)
inches.
7. A chair adapted for a female anatomy according to claim 6,
wherein said third distance is in the range of about six (6)
inches.
8. A chair adapted for a female anatomy according to claim 1,
wherein said first measure is in the range of about twelve (12)
inches.
9. A chair adapted for a female anatomy according to claim 8,
wherein said second measure is in the range of about four (4)
inches.
10. A chair adapted for a female anatomy according to claim 2
further comprising a high friction surface disposed upon said
seat.
11. A chair adapted for a female anatomy according to claim 2
further comprising a memory foam disposed upon said seat.
12. A chair adapted for a female anatomy, wherein said chair is
adjacent to a surface, comprising: (a) a seat having a proximate
end portion and a distal end portion forming a first substantially
convex arcuate profile surface there between, said seat also
including a length substantially parallel to said first
substantially convex arcuate profile surface and a first distance
substantially transverse to said length, said first substantially
convex arcuate profile surface formed from a first partial arc of a
first radius, said first radius being greater than said length, in
addition said first substantially convex arcuate profile surface
including a first seat tangential point on said proximate end
portion and a second seat tangential point on said distal end
portion, wherein said first seat tangential point and said second
seat tangential point are at a second distance apart forming a seat
plane; (b) a back having a first end portion with a transition to a
second end portion, said first and second end portions forming a
second substantially convex arcuate profile surface, said back also
including a dimension substantially parallel to said second
substantially convex arcuate profile surface and a first measure
and a second measure both being substantially transverse to said
dimension, wherein said second measure on said second end portion
is less than said first measure on said first end portion, said
second substantially convex arcuate profile surface formed from a
second partial arc of a second radius, said second radius being
greater than said dimension, in addition said second substantially
convex arcuate profile surface including a first back tangential
point on said first portion and a second back tangential point on
said second portion, with a maximum said second radius extension
portion positioned therebetween said first and second back
tangential points, wherein said first back tangential point and
said second back tangential point are at a third distance apart
forming a backplane; (c) said seat plane and an extension axis that
is perpendicular to the surface are relatively positioned to one
another to form an angle of about seventy-five (75) to eighty-seven
(87) degrees to one another at an intersection point positioned
therebetween said first seat tangential point and said second seat
tangential point; (d) said seat and back are relatively positioned
such that a span from said first seat tangential point to said
first back tangential point is about six (6) to nine (9) inches;
(e) a support base disposed between said seat and the surface; and
(f) a support structure disposed between said seat and said
back.
13. A chair adapted for a female anatomy according to claim 12
wherein said seat proximate end portion and said transition are
positioned about fourteen (14) to seventeen (17) inches apart.
14. A chair adapted for a female anatomy according to claim 12
wherein said seat proximate end portion and said maximum second
radius extension portion are positioned about eight (8) to eleven
(11) inches apart.
15. A chair adapted for a female anatomy according to claim 12
wherein said seat proximate end portion and said maximum second
radius extension portion are positioned with an overlap of about
two (2) inches parallel to the surface.
16. A method of using chair adapted for a female anatomy, wherein
said chair is adjacent to a surface, comprising the steps of: (a)
providing a chair that is adapted for a female anatomy that
includes a seat having a proximate end portion and a distal end
portion forming a first substantially convex arcuate profile
surface therebetween, said seat also including a length
substantially parallel to said first substantially convex arcuate
profile surface and a first distance substantially transverse to
said length, said first substantially convex arcuate profile
surface formed from a first partial arc of a first radius, said
first radius being greater than said length, in addition said first
substantially convex arcuate profile surface including a first seat
tangential point on said proximate end portion and a second seat
tangential point on said distal end portion, wherein said first
seat tangential point and said second seat tangential point are at
a second distance apart forming a seat plane, further included is a
back having a first end portion with a transition to a second end
portion, said first and second end portions forming a second
substantially convex arcuate profile surface, said back also
including a dimension substantially parallel to said second
substantially convex arcuate profile surface and a first measure
and a second measure both being substantially transverse to said
dimension, wherein said second measure on said second end portion
is less than said first measure on said first end portion, said
second substantially convex arcuate profile surface formed from a
second partial arc of a second radius, said second radius being
greater than said dimension, in addition said second substantially
convex arcuate profile surface including a first back tangential
point on said first portion and a second back tangential point on
said second portion, with a maximum said second radius extension
portion positioned therebetween said first and second back
tangential points, wherein said first back tangential point and
said second back tangential point are at a third distance apart
forming a backplane, a support base disposed between said seat and
the surface, and a support structure disposed between said seat and
said back; (b) adjusting said seat plane to an extension axis that
is perpendicular to the surface such that they are relatively
positioned to one another to form an acute angle from between about
fifty-five (55) to eighty-five (85) degrees to one another, wherein
said angle is taken at an intersection point positioned
therebetween said first seat tangential point and said second seat
tangential point, determination of said angle will be based upon a
user's leg length, seat height above the surface, and the user's
comfort level in said adjusting of said angle; (c) adjusting said
seat and back such that they are relatively positioned to one
another to result in a selected span from said first seat
tangential point to said first back tangential point, said selected
span being based upon the user sitting in said chair after
completing said angle adjusting step and measuring a distance from
said first seat tangential point to a small of the back of the
user, wherein said maximum second radius extension portion is
positioned to be in contact with the small of the back of the user
at said selected span; and (d) adjusting said maximum second radius
extension portion in a selected reach parallel to the surface to be
positioned in contact with the small of the back of the user while
the user is sitting in said chair after completing said angle
adjusting step and said span adjusting step.
Description
FIELD OF INVENTION
[0001] The present invention relates to ergonomic seats or chairs,
and more particularly to chairs that help support workers to reduce
fatigue when performing tasks while seated for prolonged durations
of time.
BACKGROUND OF THE INVENTION
[0002] There exists a need to provide ergonomic support to workers
using chairs to assist in decreasing fatigue, helping in the
prevention of musculoskeletal disorders (MSDs), and related issues
that result from pronged durations of time spent it a seated
position. In the increasing sedentary environment of the modern
workplace, recent trends emerged showing an increase in chronic
medical problems, such as musculoskeletal disorders (MSDs) and an
increase in worker fatigue arising when workers sit for prolonged
durations of time performing tasks that require the worker to sit.
These problems are, in part, due to the growing dependence on
computers to perform tasks in offices and increasing levels of
automation in the work place that reduce the amount of manual labor
in the workplace. Over time, chair design has remained largely
unchanged, by not providing for the differing needs of office
workers.
[0003] The negative impact of inadequate ergonomic support provided
to workers during extended time periods of seating manifests
primarily in two ways. The first is an increased load on the health
care system, typically due to an increase in MSDs and similar
ailments. The second significant impact is a loss of worker
productivity through lowered worker efficiency related to loss of
concentration and absenteeism in connection with the treatment of
MSDs or related ailments. Additionally, extended time periods of
sitting without beneficial ergonomic support leads to a decrease in
efficiency once a worker becomes fatigued. Fatigue due to extended
time periods of sitting can cause the worker to take more frequent
breaks effectively spending less time performing work, a higher
incidence of work errors, and decline in worker attitude, all
combining to drive up the cost of labor to the employer.
Additionally, with an aging work force, employers will likely
experience additional heath benefit costs as older workers become
more prone to MSDs and other ailments. These relatively large costs
can be circumvented through preventative steps taken by the
employer to help reduce the number of MSDs and other ailments in
the workplace due to inadequate ergonomic support of workers, as
well as increasing the productivity of workers. These preventive
measures may include proactive steps such as stretching and other
therapeutic activities in the workplace. However, reliance on such
proactive steps alone is insufficient. It is difficult to ensure
employees participate in such proactive measures, and it may prove
difficult to encourage such behavior. As a result, providing
workers with ergonomic chairs capable of passively assisting the
workers from becoming prone to MSDs, other related ailments, and
fatigue is preferable. The relatively small investment of properly
designed chairs will allow passive assistance to the worker to
combat the aforementioned emerging health problems of the modern
office environment.
[0004] The prior art recognizes the problems of workplace fatigue
and chronic injury related to prolonged time periods of sitting.
The prior art employs a variety of techniques in an attempt to
assist in alleviating seating fatigue and helping to prevent the
onset of MSDs and other related ailments. The use of a contoured
back structure combined with an adjustment mechanism is a common
attempted solution in the prior art. However, the use of a back pad
in conjunction with a means of adjustment presents difficulty in
assisting workers in overcoming undesirable ergonomic conditions
associated with extended time periods of sitting. First, the
adjustment mechanism can be complicated to operate. Moreover, the
adjustment mechanism presents a potential failure point in that the
adjustment mechanism may break preventing adjustments from being
made. Also, the range of adjustment may allow the worker to adjust
the back into a position that may be comfortable temporarily, but
after continuous use lead to fatigue. This requires the worker to
either continually adjust the back, or alternatively, adjust the
back to a comfortable starting position and continue to work
despite the onset of fatigue, precursors to MSDs, or other related
ailments. Adjustable back designs may also lead to an impediment of
the full range of motion of the seated worker while performing job
tasks. Furthermore, chairs are commonly too big or too small for
the worker using them, leading to inappropriate sitting positions
that can cause fatigue also.
[0005] An example of a prior art solution employing an adjustable
seat back is in U.S. Pat. No. 6,394,547 B1 to Vik, that discloses a
seat back support that is positioned between the 2nd lumbar and the
11th thoracic vertebrae of the worker. The seat back in Vik
provides a horizontal and vertical component of force normal to the
workers' back that acts upon the worker's back. Vik attempts to
provide a simple and inexpensive ergonomic chair that provides
adequate support to a worker even when the worker leans back in the
chair. Vik accomplishes this end by employing an adjustable back
affixed in a cantilever fashion to a seat that is positioned
between the 2nd lumbar and the 11th thoracic vertebrae of the
worker. While Vik accomplishes providing the worker with back
support, Vik fails to teach a dimensional relationship between the
back, hips, and legs of the worker. Moreover, Vik does not address
any problems related to the seat of the chair, nor does Vik provide
any assistance in alleviating MSDs or other ailments related to the
soft tissue of the worker's legs and posterior. Also, because Vik
targets a specific region of the back, and the design explicitly
requires that the back pad contact the worker at a specific
location, workers may either be unfamiliar with where to position
the back pad, or find the position uncomfortable and fail to use
the pad correctly.
[0006] Further, a prior art example that includes an adjustable
backrest is U.S. Pat. No. 5,624,158 to Adat et. al., that discloses
a seat backrest that is adjustable in vertical height and contour
in both the curvature of upper and lower portions of the backrest.
Additionally, Adat et. al. provides adjustable lateral support to
the worker. Adat et. al does recognize the need to provide freedom
of movement in the worker's upper body; however, the adjustment
mechanisms in Adat et. al. are complicated and involves several
adjustment points, as well as several mechanisms for adjustment.
The various mechanical adjustment structure in Adat et. al. are all
prone to unreliability issues after repeated use. While Adat et.
al. provides a plurality of adjustments to the worker, Adat et. al.
also presents difficulty in that the worker must spend time fine
tuning the adjustment at various points to achieve a comfortable
backrest position. Note that Adat et al., has no criterion
disclosed as to set the various backrest adjustments for specific
issues related to extended sitting fatigue and discomfort.
[0007] Similarly, in U.S. Pat. No. 6,626,494 B2 to Yoo, a chair is
disclosed with an adjustable backrest assembly that is adjusted by
the worker to a desired position. However, there is no limitation
on the adjustment to the backrest in Yoo, making the backrest
infinitely adjustable. This could lead to continual adjustments by
the worker, tending to prevent correct positioning. Moreover,
because the worker can be unfamiliar with what backrest position is
necessary to correctly align the spine, Yoo presents an opportunity
for the worker to adjust the chair backrest into a less desirable
or possibly detrimental position. Without supervision by a person
qualified to determine the correct orthopedic position of the
chair, Yoo does not solve the need to provide ergonomic
support.
[0008] A further prior art reference that attempts to simplify the
adjustment of the chair backrest is U.S. Pat. No. 7,147,282 B2 to
Hatcher et. al., that incorporates the adjustment structure into
the backrest support structure. Hatcher et. al. allows adjustments
to be made by the worker without having to awkwardly reach behind
or underneath the worker to make adjustments to the chair backrest.
As Hatcher et. al. only provides backrest depth adjustment with
respect to the seat, the issues of multiple adjustments with
multiple potential reliability issues is solved, however the need
still exists to correctly position the lower body of the worker to
the chair backrest. Further, in Hatcher et al., there is no method
disclosed on how to set the various adjustments of the backrest for
specific MSD disorder issues from prolonged sitting.
[0009] Similarly, in U.S. Pat. No. 6,938,956 B1 to Piretti
discloses a double backrest support structure for a chair with the
desired solution of proper back support. Piretti discloses
structure to provide lumbar support to the worker through the use
of two separate backrest members that, like Adat et. al., employ a
variety of adjustment mechanisms to provide the worker with desired
back comfort. The adjustments in Piretti provide greater complexity
to the worker using the chair and can allow the worker to adjust
the chair backrest members to a less desirable ergonomic position.
Additionally, in Piretti the added adjustment mechanism complexity
adds to the overall cost and time required to manufacture and
assemble the chair, making the design less feasible for mass
production. Piretti has no teachings related to specific settings
for the backrest in response to particular extended sitting fatigue
problems experienced by the worker.
[0010] Continuing in the prior art, a chair having again two back
support portions that are each independently adjustable is
disclosed in US. Pat. No. 7,040,703 B2 to Sanchez. In Sanchez,
separate back support members attach each chair back support to the
seat of the chair. Such an arrangement in Sanchez only complicates
the existing problem of adjustment complexity, as to adjust the
back portions to the desired position to promote ergonomic support,
there are an increasing number of adjustments that need to be made
by the worker, thus increasing the time required to make the
adjustments and increasing the difficulty in getting the chair back
support positioned to a beneficial or desirable position. Moreover,
Sanchez represents increasing complexity in the manufacturability
and assembly of chairs leading to increased costs of production.
Also as in Piretti, Sanchez has no disclosure of a method for
selecting various adjustments to better accommodate chronic fatigue
problem a worker has from extended periods of sitting.
[0011] Similarly, in U.S. Pat. No. 6,655,731 B2 to Martin disclosed
is an adjustment mechanism that leads to complex adjustments and
difficulty in replicating the desired position. In Martin, both the
chair seat and chair back are adjustable rotationally about a
parallel pair of axes of each the chair seat and chair back. The
chair seat and chair back are also adjustable by adjusting the
chair seat and chair back to various discrete adjustment positions
that are provided along the horizontal and vertical members of the
frame of the chair. While the arrangement in Martin does provide
increasing versatility for a variety of workers, the limited
adjustment ability leads to incorrect adjustments, as well as an
inability to reproduce or replicate a desirable adjustment setting
once the setting has been realized. Also, Martin lacks specific
teaching as to how to set the various adjustments in accordance
with the various worker ailments resulting from prolonged sitting
periods.
[0012] Another common solution in the prior art is the use of a
seat that may have a specific size or contour. While the use of a
seat of a specific shape or size does not present the
aforementioned problems of the adjustable back, the particularity
of each shape may not be accommodating to all workers. This
requires a plurality of designs or manufacturing techniques to
accommodate different workers. In this respect, some prior art has
sought to assist male or female genders through various differing
forms specific to either male or female genders. While particularly
shaped seats may alleviate some MSDs and other ailments related to
the soft tissue of the posterior of the workers, the designs do not
provide for any specialized support for the worker's back. Thus
there is also a need to provide specifically designed chairs that
accommodate gender specific anatomy, for instance, the anatomy of a
woman's body. As the shape of a woman's body is unique, a chair
design should similarly reflect and conform to the specific needs
of women.
[0013] A prior art reference that discusses the need to use
specific structure for chairs that differ with respect to men and
women is in U.S. patent application publication number 2002/0175553
A1 to Steifensand. Steifensand discloses two species of chairs that
differ based upon the gender of the worker. While Steifensand
discloses a shorter seat for the female species of the chair,
Steifensand fails to provide an adapted chair back for the female.
Therefore, while Steifensand recognizes the need for specifically
designed chairs for the differing body contours of the male and
female worker, the invention in Steifensand falls short of
adequately providing a chair back that is designed specifically for
the female gender.
[0014] Similarly, in U.S. Pat. No. 5,110,183 to Jeanes, III teaches
how the different anatomy of female and male genders effect the
proper design of chairs. Jeanes, III uses tables of data compiled
to represent the respective anatomies of males and females.
Additionally, Jeanes, III discloses that a shorter seat in the
distance that is parallel to the femur bone is preferable to a
longer seat for the anatomy of a female. However, Jeanes, III
attempts to solve the problem of discomfort for the infirm or
persons confined to a wheelchair; therefore, Jeanes, III does not
disclose a desirable position of the back of a worker that is
performing tasks. Jeanes, III provides a chair that is suited for
reclining or converting to a prone position. Thus, Jeanes, III is
not feasible for a worker that is required to perform tasks.
Moreover, Jeanes, III teaches away from using any contour of the
seat or back, but instead teaches of using a flat, planar surface
for both the back and seat portions of the chair. Jeanes, III also
fails to provide a specific back to seat relationship desirable to
promote correct ergonomics.
[0015] Next in U.S. Pat. No. 6,193,313 B1 to Jonsson provides a
unique seat structure that predisposes the worker to a position in
which the legs, hips, and back are aligned in a particular way.
However, Jonsson teaches that it is desirable to pivot the worker's
hips toward the chair backrest such that the worker's back is
driven positionally into the lumbar support of the chair. Jonsson
accomplishes this position by the structure of the seat alone. The
invention in Jonsson tends to create a position that leads to a
slouching posture where the top of the worker's spine is arched so
that the worker's shoulders are positioned forward of the hips of
the worker creating a position that leads to fatigue. In addition
the posture Jonsson induces may promote discomfort in the lower
portion of the worker's back.
[0016] Another prior art example of the use of contour to provide
ergonomic support comes in U.S. Pat. No. 7,077,469 B2 to Badia i
Farre that includes a seat surface designed to be straddled by the
worker such that the legs of the worker are positioned so that the
worker's legs are disposed on opposite sides of the seat.
Additionally, Badia i Farre incorporates voids in the seating
surface to accommodate the male genitals of the worker to prevent
soft tissue contact with the seat. Again, due to the unconventional
method of straddling the seat, a worker may not feel comfortable
with using the Badia i Farre seat. Additionally, workers that use
the design in Badia i Farre may find it difficult to mount and
dismount the seat. Further, especially for women, the wearing of a
dress as opposed to slacks would preclude the use of this
straddling of the seat.
[0017] Other prior art solutions take on unconventional designs
that position workers in fundamentally different positions than a
traditional chair. One such position includes providing ventral
support to the worker. These designs can lead to complexity and
difficulty in use, especially when the worker mounts or dismounts
the chair. As an example the following prior art references use
either dorsal or ventral support structures to help induce correct
ergonomic position. One such reference is U.S. Pat. No. 4,650,249
to Serber. Serber discloses an office chair that uses a ventral
support in combination with a seat to help induce correct ergonomic
position. However, in Serber such an arrangement where ventral
support is used, the positioning of the support can lead to
interference with the work task movements performed by the worker,
as well as difficulty sitting on the chair and returning to a
standing position. However, this type of office chair design being
introduced decades ago has not meet with much market acceptance
most likely due to the difficulty of the worker mounting and
dismounting the chair, the lack of seating position flexibility,
and the potential interference of the chair with desks and other
office equipment. These problems are also present in U.S. Pat. No.
7,104,606 B2 to Congleton et. al. Congleton et. al. discloses a
chair that is convertible from ventral to dorsal support. Again, in
Congleton et. al. when in the dorsal support arrangement, the seat
and back do not properly orient the hips of the worker and when in
the ventral support arrangement, the issues of sitting and standing
from the chair arise, much like in Serber.
[0018] Similarly, U.S. Pat. No. 7,090,303 B2 to Kropa discloses a
chair that supports the worker ventrally by providing a rest that
contacts the worker's abdomen and allows the worker to perform
tasks in front of the worker. The primary problem Kropa addresses
is the ability to rehabilitate lower leg injuries while seating
through the use of abductor and adductor type movement attachments
that allow the legs to be exercised while seated. However, in Kropa
again, the design presents challenges for using the chair in that
worker mounting and dismounting the chair becomes awkward with the
addition of the abductor and adductor type movement extensions.
Also, due to the ventral support of the worker in Kropa, the design
may limit the number of workers willing or able to use such a
design, especially as related to limitations to use of the workers
hands and arms. Again, Kropa does not teach a method of setting
adjustments in response to worker fatigue stemming from extended
periods of sitting.
[0019] There exists a need to provide a chair that assists in
positioning a worker in a manner that promotes prevention of MSDs,
other related ailments, and reduces fatigue by utilizing the shape
of the seat and back in addition to the position of the seat and/or
back with respect to each other. Such a chair should be simple and
inexpensive to produce and use without excess adjustability that
adds complexity to the overall design. Such a design should also
accommodate the varying sizes of workers, yet also be able to serve
a large portion of the working population effectively, without
drastic changes in the design or use of the chair. One such
solution to the dichotomy of providing a chair to serve a specific
shape, yet also be useful to a large population of workers may be
to provide a chair designed especially for the unique anatomy of
the female gender. The design of a female specific chair would
allow for a large population of workers to be accommodated, while
still tailoring the chair to the specific needs that a female
anatomy presents. Additionally, to further assist in the reduction
of MSDs, related ailments, and fatigue, it is desirable to perform
a series of tests to determine what position is most desirable for
a worker to take while working for an extended duration of time.
Such tests should focus on the ability to reduce fatigue, and seek
to determine the optimal position to provide ergonomic support to a
worker. An objective measure for fatigue should be developed to
accurately measure what size and relative position should be
realized in the seat and back to accommodate a worker. Also, to
overcome the problems in the prior art of common workers having
difficulty in adjusting a chair into a desirable position, a method
should be developed whereby a worker can properly and simply adjust
a chair into the optimal position by following steps to properly
orient the workers body prior to extended durations of time.
SUMMARY OF THE INVENTION
[0020] The present invention is for a chair that is adapted for a
female anatomy; the chair includes a seat having a proximate end
portion and a distal end portion that forms a first substantially
convex arcuate profile surface therebetween on the seat. The seat
also including a length that is substantially parallel to the first
substantially convex arcuate profile surface and a distance
substantially transverse to the length, with the first
substantially convex arcuate profile surface formed from a first
partial arc of a first radius, the first radius being greater than
the length. In addition, the first substantially convex arcuate
profile surface includes a first seat tangential point on the
proximate end portion and a second seat tangential point on the
distal end portion, wherein the first seat tangential point and the
second seat tangential point are at a first distance apart forming
a seat plane.
[0021] Further included in the chair is a back having a first end
portion and a second end portion, the first and second end portions
forming a second substantially convex arcuate profile surface, the
back also including a dimension substantially parallel to the
second substantially convex arcuate profile surface and a first
measure and a second measure both being substantially transverse to
the dimension. Wherein, the second measure on the second end
portion is less than the first measure on the first end portion,
with the second substantially convex arcuate profile surface formed
from a second partial arc of a second radius, the second radius
being greater than the dimension. In addition, the second
substantially convex arcuate profile surface including a first back
tangential point on the first portion and a second back tangential
point on the second portion, wherein the first back tangential
point and the second back tangential point are at a second distance
apart forming a back plane.
[0022] The seat plane and an extension axis that is perpendicular
to the surface are relatively positioned to one another to form an
acute angle to one another at an intersection point positioned
therebetween the first seat tangential point and the second seat
tangential point, in addition the seat and back are relatively
positioned such that a span from the first seat tangential point to
the first back tangential point is at least equal to half of said
dimension. Further, a support base is disposed between the seat and
the surface, and a support structure disposed between the seat and
the back.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 shows a prior art side elevation view of a female
chair user sitting in a typical conventional technology office
chair, wherein it can seen that the femur bone lengthwise portion
of the leg is parallel with the support surface with the back
posture somewhat hunched over noting that the shoulder joint is not
vertically aligned of the hip joint adding toward poor posture
which is shown skeletally in FIGS. 2 and 3;
[0024] FIG. 2 side elevation view of a skeletal structure from FIG.
1, with the female chair user sitting in a typical conventional
technology office chair, wherein it can seen that the Femur bone
lengthwise portion of the leg is parallel with the support surface
with the back posture somewhat hunched over making for poor
posture, noting that the pivotal movement of the Femur bone in the
hip joint is limited to about sixty (60) degrees, thus from the
standing position as shown in FIGS. 4 and 5, the user leg upper
portion can move from standing to sitting through an arc of about
sixty (60) degrees or in other words about thirty (30) degrees
short of the standard sitting position on the Femur bone lengthwise
being at ninety (90) degrees to the back bone as shown in FIGS. 1,
2, and 3, thus the Femur bone lengthwise must bend the pelvis and
the back bone for the last thirty (30) degrees of movement to
achieve the ninety (90) sitting position in FIGS. 1, 2, and 3, this
results in the situation wherein the discs have unequal spacing as
between the bones, see especially FIG. 3, which can be termed a
Kyphosis operational state, wherein the pressure placed upon the
disc increases significantly from their uneven edge loading, being
up to a 400% increase in disc pressure from the standing position
in FIGS. 4 and 5 to the high forward leaning positions for the back
as seated in FIGS. 1, 2, and 3;
[0025] FIG. 3 shows expanded view 3-3 from FIG. 2 detailing out the
femur bone, pelvic, and discs area, wherein it can be more clearly
seen that the femur bone being parallel to the support surface
causes the pelvic bone to rotate counter clockwise putting the
discs in a hunched-over position in an arcuate posture opposite
from that of the standing position as shown in FIGS. 4 and 5, with
this being combined with the conventional chair user tending to
lean somewhat forward causes the portions of the discs adjacent to
the femur to be compressed axially more than the portion of the
discs oppositely positioned, resulting in the undesirable
aforementioned increase in disc pressure which can be termed the
Kyphosis operational state;
[0026] FIG. 4 shows a side elevation view of a skeletal section of
a normal human in a standing position, showing the most natural
posture of the upper portion of the femur bone, the pelvis and the
backbone, wherein the backbone is in a Lordosis operational state
with the lumbar curve in its natural state, or more importantly
that the discs of the back have equal spacing around their entire
periphery as between the disc and the bone resulting in more equal
pressure placed upon the discs which is desirable, as when the
discs have unequal spacing as between the bones, which can be
termed the Kyphosis operational state, see FIGS. 2 and 3, wherein
the pressure placed upon the disc increases significantly, being up
to a 400% increase in disc pressure from the standing position to
high forward leaning positions for the back;
[0027] FIG. 5 shows expanded view 5-5 from FIG. 4 detailing out the
femur bone, pelvic, and discs area, wherein it can be more clearly
seen that the femur bone position in the normal standing attitude
resulting in the pelvic bone is in its natural positional state
putting the discs in the evenly spaced state around their entire
periphery, wherein the backbone is in the Lordosis operational
state with the lumbar curve in its natural state;
[0028] FIG. 6 shows a side elevation view of a skeletal section of
a normal human in a laying on their side relaxed position, such
that there is no gravitational force on the skeletal structure that
would be bearing upon the feet upward, as in a normal standing
attitude, thus this relaxed on the side laying position showing the
most natural default positional posture of the upper portion of the
femur bone, wherein the femur bone is at one-hundred and
thirty-five (135) degrees of angle from the back bone, plus the
pelvis and the backbone, wherein the backbone again is in what can
be termed the Lordosis operational state with the lumbar curve in
its natural state, or more importantly that the discs of the back
have equal spacing as between the disc and the bone resulting in
more equal pressure placed upon the discs which is desirable, as
opposed to again as when the discs have unequal spacing as between
the bones, which can be termed the Kyphosis operational state,
wherein the pressure placed upon the disc increases significantly
being up to a 400% increase in disc pressure from the standing
position to high forward leaning positions for the back;
[0029] FIG. 7 shows expanded view 7-7 from FIG. 6 detailing out the
femur bone, pelvic, and discs area, wherein it can be more clearly
seen that the femur bone position in the normal laying on the side
position resulting in the pelvic bone is in its natural positional
state putting the discs in the evenly spaced state around their
entire periphery, wherein the backbone is in the Lordosis
operational state with the lumbar curve in its natural state;
[0030] FIG. 8 shows a perspective view of the present invention of
the chair adapted for the female anatomy, noting the downward
sloping seat away from the back to the support surface to allow the
user's knees to be positioned below the hip, wherein the chair back
has a great amount of spacing away from the seat to allow for a
slight back arching, further to accommodate space for the user's
buttocks, and the back having an upper narrow portion to
accommodate non binding movement of the user's shoulder blades as
the user's arms are moved for work motions, i.e. using a keyboard
and the like, further a foot rest is shown, that is formed as a
partial periphery chord segment that has a radial arcuate section
for receiving a user's heel;
[0031] FIG. 9 shows a front elevation view of the present invention
of the chair adapted for the female anatomy, again noting the
downward sloping seat away from the back to allow the user's knees
to be positioned below the hip, wherein the back has a great amount
of spacing away from the seat to allow for a slight back arching,
further to accommodate space for the user's buttocks, and the back
having an upper narrow portion to accommodate non binding movement
of the user's shoulder blades, further the foot rest is shown, that
is formed as the partial periphery chord segment that has the
radial arcuate section for receiving the user's heel;
[0032] FIG. 10 shows a side elevation view of the present invention
of the chair adapted for the female anatomy, again noting the
shorter in length from the rear proximal portion to the front
distal portion downward sloping seat at an angle going from the
rear of the seat to the front of the seat, again to allow the
user's knees to be positioned below the hip, wherein the back has a
span of spacing away from the seat to allow for the user to have
the slight back arching, further to accommodate space for the
user's buttocks, wherein the chair back is positioned to nest in
the small of the back of the user to further support a better
skeletal posture for the user sitting in the present invention
chair, further the foot rest is shown, that is formed as the
partial periphery chord segment that has the radial arcuate section
for receiving the user's heel;
[0033] FIG. 11 shows the same side elevation view as FIG. 10, with
the user in position in the chair with their legs between the hip
and knee being angled downward toward the floor surface, plus
showing the span of the free and open space as between the seat and
back for the user's hips and lower back open space to slightly arch
rearward, further to accommodate space for the user's buttocks, and
the chair back nesting in the small of the user's back for support
on the user's skeletal structure to approach the more ideal back
positioning as shown in FIGS. 2 and 3, further the foot rest is
shown, that is formed as the partial periphery chord segment that
has the radial arcuate section for receiving the user's heel;
[0034] FIG. 12 shows the same side elevation view as FIG. 11, with
the addition of a skeletal cross section of the user in position in
the chair with their legs or the femur bone between the hip and
knee being angled downward toward the floor surface, plus showing
the span of the free and open space as between the seat and back
for the user's hips and lower back open space to slightly arch
rearward, further to accommodate space for the user's buttocks, and
the chair back nesting in the small of the user's back for support
on the user's skeletal structure to approach the more ideal back
positioning as shown in FIGS. 6 and 7, further, the positional
relationship of the femur to the pelvis to the discs is also shown,
that is between the Lordosis and Kyphosis positions as previously
described, further the foot rest is shown, that is formed as the
partial periphery chord segment that has the radial arcuate section
for receiving the user's heel;
[0035] FIG. 13 shows a compilation of raw data samples taken of
women for the scope of distances as between their waist and their
shoulder blades with a quasi somewhat bell shape statistical
variance curve of variation of this measured distance, wherein it
was shown that the majority of the thirty (30) test sample subjects
came in at a distance of about 8.06 inches, this was done to
determine the range of adjustment movement vertically of the back
and for the upper of second portion narrowing of the back to
accommodate clearance for the user's shoulder blades;
[0036] FIG. 14 shows another compilation of raw data samples taken
on a group of thirty (30) participants for the scope of distances
from their waist to the curve or the small of their backs for
determining placement of the maximum second radius extension
portion or largest protrusion portion of the back to enable the
nesting of this protrusion portion in the small of the back for the
user, the mean distance for the waist to small of the back distance
was 1.83 inches; and
[0037] FIG. 15 shows a further compilation of raw data samples also
taken on a group of thirty (30) participants for the scope of
distances from the bottom of the chair of seat portion to their
waists, for the purpose of enabling the measurements as taken in
FIGS. 13 and 14 to be associated with the chair structure itself,
wherein the distance from the bottom of the chair seat portion to
the users waists had a mean of 8.23 inches.
REFERENCE NUMBERS IN DRAWINGS
[0038] 30 Ergometric chair apparatus adapted for a female anatomy
[0039] 35 Seat [0040] 40 Proximate end portion of seat 35 [0041] 45
Distal end portion of seat 35 [0042] 50 First substantially convex
arcuate profile surface [0043] 55 Length substantially parallel to
the first substantially convex arcuate profile surface 50 [0044] 60
First distance substantially traverse to the length 55 [0045] 65
First radius [0046] 70 First partial arc of the first radius 65
[0047] 75 First seat tangential point [0048] 80 Second seat
tangential point [0049] 85 Second distance [0050] 90 Seat plane
[0051] 91 Support base in-between the seat 35 and the surface 210
[0052] 95 Back [0053] 100 First end portion of back 95 [0054] 101
Foot rest [0055] 102 Partial periphery chord segment of the foot
rest 101 [0056] 103 Radial arcuate section of the foot rest 101
[0057] 105 Second end portion of back 95 [0058] 110 Second
substantially convex arcuate profile surface [0059] 115 Dimension
substantially parallel to second substantially convex arcuate
profile surface 110 [0060] 120 First measure of back 95 [0061] 125
Second measure of back 95 [0062] 130 Second radius [0063] 135
Second partial arc of the second radius 130 [0064] 140 First back
tangential point [0065] 145 Second back tangential point [0066] 150
Third distance [0067] 155 Back plane [0068] 156 Support structure
between the seat 35 and the back 95 [0069] 160 Transition from the
back first end portion 100 to the back second end portion 105
[0070] 165 Maximum second radius extension portion [0071] 170
Overlap as between the seat proximate end portion 40 and the
maximum second radius extension portion 165 [0072] 175 Extension
axis that is perpendicular to the surface 210 [0073] 180 Acute
angle [0074] 181 Femur bone center line inclination angle that is
complementary to the acute angle 180 [0075] 182 Femur bone center
line parallel to surface 210 in the prior art [0076] 185
Intersection point of the acute angle 180 [0077] 186 Inline user
shoulder joint and hip joint vertical alignment [0078] 187 Lateral
offset of the user shoulder joint and hip joint vertical alignment,
either forward or rearward [0079] 190 Span from the first seat
tangential point 75 to the first back tangential point 140 [0080]
200 High friction surface of seat 35 [0081] 205 Memory foam of seat
35 [0082] 210 Surface [0083] 215 User [0084] 216 Heel of the user
215 [0085] 217 Buttocks of the user 215 [0086] 220 Female anatomy
[0087] 225 Leg length of user 215 [0088] 230 Waist of the user 240
or the small of the user's 240 back [0089] 235 Seat height above
the surface 210 [0090] 240 User sitting in the chair 30 [0091] 245
Distance from the first seat tangential point 75 to the small 230
of the user's 240 back [0092] 250 Horizontal measurement of the
buttocks 217 to the user's 240 waist 230 or small of the user's
[0093] 240 back [0094] 255 Waist to shoulder blade distance of the
user 240 [0095] 265 Bottom of chair or seat 35 to waist of the user
240 distance [0096] 270 Distance from the maximum second radius
extension portion 165 to transition 160
DETAILED DESCRIPTION
[0097] With initial reference to FIG. 1 shown is a prior art side
elevation view of a female chair user 240 sitting in a typical
conventional technology office chair, wherein it can seen that the
femur bone lengthwise portion of the leg is parallel 182 with the
support surface 210, with the back posture somewhat hunched over,
noting that the shoulder joint is forward 187 of the hip joint,
adding toward poor posture which is shown skeletally in FIGS. 2 and
3.
[0098] Continuing, as the basis for FIGS. 2, 3, 4, 5, 6 and 7, in a
study completed by German orthopedic surgeon , Hanns Schoberth in
1962, x-rays were taken in showing that the femur has about sixty
(60) degrees of pivotal movement in relation to the pelvis, meaning
that when an individual moves into a seated position requiring a
ninety (90) degree angle of femur movement from standing for
instance, in relation to the pelvis necessitates that the pelvis
and the lumbar curve must accommodate the additional thirty (30)
degrees of movement, with this additional bending occurring between
the 4.sup.th and 5.sup.th lumbar discs, see FIGS. 2 and 3. Thus, in
FIGS. 4 and 5 shown is a side elevation view of a skeletal section
of a normal human in a standing position, showing the most natural
posture of the upper portion of the femur bone, the pelvis, and the
backbone, wherein the backbone is in what could be termed a
Lordosis operational state with the lumbar curve in its natural
state, or more importantly that the discs of the back have equal
spacing as between each of the disc and the bone adjacent sets,
resulting in a more equal pressure distribution placed upon each of
the discs which is desirable. This is as opposed to when the discs
have unequal spacing as between the bones, which can be termed the
Kyphosis operational state, see FIGS. 2 and 3, wherein the pressure
placed upon each disc can increase significantly being up to a 400%
increase in disc pressure from the standing position to undesirable
high forward leaning positions for the back.
[0099] Further, referring specifically to FIGS. 6 and 7 in a study
conducted by American orthopedic surgeon J. J. Keegan in 1953, in a
series of x-rays of people laying on their sides in documenting the
movements in the lumbar section of the spinal column, FIGS. 6 and 7
show a side elevation view of a skeletal section of a normal human
in a relaxed laying on their side position, such as resting in a
bed, such that there is no gravitational force on the skeletal
structure in its normal vertical axis, i.e. as in standing, thus
FIGS. 6 and 7 showing the most natural default positional posture
of the upper portion of the femur bone, wherein the femur bone
lengthwise is positioned at one-hundred and thirty-five (135)
degrees of angle from the back bone as shown. Thus in FIGS. 6 and
7, as shown in the pelvis and the backbone positioning, wherein the
backbone again is in what can be termed a Lordosis operational
state with the lumbar curve in its natural state, or more
importantly that the discs of the back have the desirable equal
spacing as between each of the disc and the bone adjacent sets
resulting in a more equal pressure distribution placed upon the
discs which is desirable, again as opposed to when the discs have
the undesirable unequal spacing as between the adjacent bones,
which can be termed the Kyphosis operational state, see FIGS. 2 and
3, wherein the pressure placed upon the disc increases
significantly being up to a 400% increase in disc pressure from the
standing position to high forward leaning positions for the back,
see FIGS. 1, 2, and 3.
[0100] Referring again to FIGS. 2 and 3, for the side elevation
view of a skeletal structure from FIG. 1, with the female chair
user 240 sitting in a typical conventional technology office chair,
wherein it can seen that the Femur bone lengthwise portion of the
leg is parallel 182 with the support surface 210 with the user's
240 back posture somewhat hunched over making for poor posture,
noting that the pivotal movement of the Femur bone in the hip joint
is limited to about sixty (60) degrees, as previously discussed,
thus from the standing position as shown in FIGS. 4 and 5, the user
215 leg upper portion can move from standing to sitting through an
arc of about sixty (60) degrees or in other words about thirty (30)
degrees short of the standard ninety (90) degree sitting position
on the Femur bone lengthwise being positioned at ninety (90)
degrees as shown in FIGS. 1 and 2. Thus, as FIGS. 2 and 3 show, the
Femur bone lengthwise must bend the pelvis and the back bone for
the last thirty (30) degrees of movement to achieve the ninety (90)
sitting position as shown in FIGS. 1 and 2, this results in the
situation wherein the discs have unequal spacing as between the
adjacent bones, which can be termed the Kyphosis operational state,
wherein the pressure placed upon the disc increases significantly
being up to a 400% increase in disc pressure from the standing
position to high forward leaning positions for the back in the user
240, see FIGS. 1, 2, and 3.
[0101] Yet further, in FIG. 8 shown is a perspective view of the
present invention of the chair 30 adapted for the female anatomy
220, noting the downward sloping chair seat 35 away from the chair
back 95 to allow the user's 240 knees to be positioned below their
hip, wherein the chair back 95 has a great amount of spacing via a
span 190 away from the seat 35 to allow for the slight back arching
of the user 240, further to accommodate space for the user's 240
buttocks 217, and the chair back 95 having an upper narrow portion
or second measure 125 to accommodate non binding movement of the
user's 215 shoulder blades. Further a foot rest 101 is shown, that
includes a partial periphery chord segment 102 and that has a
radial arcuate section 103 for receiving a user's 215 heel 216, see
FIG. 11. Continuing, FIG. 9 shows a front elevation view of the
present invention of the chair 30 adapted for the female anatomy
220, again noting the downward sloping chair seat 35 away from the
chair back 95 to allow the user's 240 knees to be positioned below
their hip, wherein the chair back 95 has a great amount of spacing
or span 190 away from the chair seat 35 to allow for the user 240
back to slightly arch to form a type of swayback curve at the small
230 of the user's 240 back bone, further to accommodate space for
the user's 240 buttocks 217, and the chair back 95 having an upper
narrow portion or second measure 125 to accommodate non binding
movement of the user's 240 shoulder blades. Further a foot rest 101
is shown, that includes a partial periphery chord segment 102 and
that has a radial arcuate section 103 for receiving a user's 215
heel 216, see FIG. 11.
[0102] Continuing, FIG. 10 shows a side elevation view of the
present invention of the chair 30 adapted for the female anatomy
220, again noting the shorter in length 55 from the rear proximal
portion 40 to the front distal portion 45 downward sloping angle
180 seat at an angle 181 going from the rear 40 of the seat 35 to
the front 45 of the seat 35, again to allow the user's 240 knees to
be positioned below the hip, wherein the chair back 95 has a span
190 of spacing away from the seat 35 to allow for user 240 slight
back arching or creating the small of the back 230 curve, wherein
the chair back 95 is positioned to nest in the small of the back
230, allowing free space for the user's 215 buttocks 217 to not be
impeded by the chair back 95, resulting in the user 240 being able
to further support a better skeletal posture for the user 240
sitting in the present invention chair 30, see also FIGS. 11 and
12. Further a foot rest 101 is shown, that includes a partial
periphery chord segment 102 and that has a radial arcuate section
103 for receiving a user's 215 heel 216, see FIG. 11. Continuing,
FIG. 11 shows the same side elevation view as FIG. 10, with the
user 240 in position in the chair 30 with their legs between the
hip and knee being angled 181 downward toward the floor surface
210, plus showing the span 190 of the free and open space as
between the seat 35 and back 95 for the user's 240 hips and lower
back open space to slightly arch rearward 230 allowing free space
for the user's 215 buttocks 217, and with the chair back 95 nesting
in the small 230 of the user's 240 back for support on the user's
240 skeletal structure to approach the more ideal back positioning
as shown in FIGS. 6 and 7. Further a foot rest 101 is shown, that
includes a partial periphery chord segment 102 and that has a
radial arcuate section 103 for receiving a user's 215 heel 216, see
FIG. 11.
[0103] Next, FIG. 12 shows the same side elevation view as FIG. 11,
with the addition of a skeletal cross section of the user 240 in
position in the chair 30 with their legs or the femur bone between
the hip and knee being angled downward 181 toward the floor surface
210, plus showing the span 190 of the free and open space as
between the seat 35 and back 95 for the user's 240 hips and lower
back open space to slightly arch rearward 230, allowing free space
for the user's 215 buttocks 217, and with the chair back 95 nesting
in the small 230 of the user's 240 back for support on the user's
240 skeletal structure to approach the more ideal back positioning
as shown in FIGS. 6 and 7, further, the positional relationship of
the femur to the pelvis to the discs is also shown, that is between
the Lordosis and Kyphosis positions as previously described. Thus
given that the user's 215 upper legs and femur bone angle downward
181 helps reduce the thirty (30) degree angle that the pelvis must
normally take up, as shown in FIGS. 2 and 3, thus helping to
alleviate the uneven disc pressure as shown in FIGS. 2 and 3, with
there being a comfort limit as to how large of an angle 181 can be
tolerated without the user 215 sliding forward in the seat 35.
Further a foot rest 101 is shown, that includes a partial periphery
chord segment 102 and that has a radial arcuate section 103 for
receiving a user's 215 heel 216, see FIG. 11.
[0104] Further, FIG. 13 shows a compilation of raw data samples
taken of women for the scope of distances as between their waist
and their shoulder blades 255 with a quasi somewhat bell shape
statistical variance curve of variation of this measured distance
255, wherein it was shown that the majority of the thirty (30) test
sample female subjects came in at a distance of about 8.06 inches
as between the waist and shoulder blades 255, this was done to
determine the range of adjustment movement vertically of the back
95 and for the upper of second portion 105 narrowing second measure
125 of the chair back 95 to accommodate clearance for the user's
240 shoulder blades. Next, FIG. 14 shows another compilation of raw
data samples taken on a group of thirty (30) female participants
for the scope of distances being horizontal measurements of the
user's 240 buttocks 217 to the user's 240 waist 230 or small of the
back defined as distance 250 for determining placement of the
maximum second radius extension portion 165 or largest protrusion
portion of the chair back 95 to enable the nesting of this
protrusion portion 165 in the small of the back 230 for the user
240, wherein the mean distance for the waist to small of the back
distance 250 was 1.83 inches. Next, FIG. 15 shows a further
compilation of raw data samples also taken on a group of thirty
(30) female participants for the scope of distances from the bottom
of the chair or seat 35 portion to their waists 265, for the
purpose of enabling the measurements as taken in FIGS. 13 and 14 to
be associated with the chair 30 structure itself, wherein the
distance 265 from the bottom of the chair seat 35 portion to the
users 240 waists had a mean of 8.23 inches. Note that the dimension
for the 265 measurement, the seat thickness is included, thus in
say taking a measurement from the seat proximal end portion 40 or
the first set tangential point 75, upward the seat thickness should
be subtracted from dimension 265, being about four (4) inches.
[0105] Broadly, as best shown in FIGS. 8 through 12, the present
invention is for a chair 30 that is adapted for a female anatomy
220; the chair 30 includes a seat 35 having a proximate end portion
40 and a distal end portion 45 that forms a first substantially
convex arcuate profile 50 surface therebetween on the seat 35. The
seat 35 also including a length 55 that is substantially parallel
to the first substantially convex arcuate profile surface 50 and a
distance 60 substantially transverse to the length 55, with the
first substantially convex arcuate profile surface 50 formed from a
first partial arc 70 of a first radius 65, the first radius 65
being greater than the length 55. In addition, the first
substantially convex arcuate profile surface 50 includes a first
seat tangential point 75 on the proximate end portion 40 and a
second seat tangential point 80 on the distal end portion 45,
wherein the first seat tangential point and the second seat
tangential point are at a second distance 85 apart forming a seat
plane 90, best shown in FIG. 10.
[0106] The concept here is that the length 55 is shorter than a
conventional office chair seat to allow the user's 240 legs to
angle 181 more toward the surface 210 with seat support focused in
the area of the user's 240 hip joint as opposed to a longer more
conventional seat 35 length 55, as shown in FIGS. 1 and 2, that
would put pressure on the user's 240 leg just behind the knee, thus
restricting the desired angle 181, as best shown in FIG. 11. In
addition, the seat 35 convex arcuate profile surface 50 further
facilitates angle 181, as the seat 35 surface 50 allows somewhat of
a "roll off" i.e. the distal end portion 45 curves even more
towards the surface 210 than does the seat 35 area adjacent to an
intersection area 185 which would be more parallel to the angle
181, again see FIG. 11, as opposed to a conventional chair that has
a relatively flat seat surface that is parallel to the surface 210,
as shown in FIGS. 1 and 2.
[0107] Further included in the chair 30 that is adapted for a
female anatomy 220 is a back 95 having a first end portion 100 and
a second end portion 105, the first 100 and second 105 end portions
forming a second substantially convex arcuate profile surface 110,
the back 95 also including a dimension 115 substantially parallel
to the second substantially convex arcuate profile surface 110 and
a first measure 120 and a second measure 125 both being
substantially transverse to the dimension 115, as best shown in
FIGS. 8, 9, and 10. Wherein, the second measure 125 on the second
end portion 105 is less than the first measure 120 on the first end
portion 100, with the second substantially convex arcuate profile
surface 110 formed from a second partial arc 135 of a second radius
130, the second radius 130 being greater than the dimension 115. In
addition, the second substantially convex arcuate profile surface
110 including a first back tangential point 140 on the first
portion 100 and a second back tangential point 145 on the second
portion 105, wherein the first back tangential point 140 and the
second back tangential point 145 are at a third distance 150 apart
forming a backplane 155. As the back 95 is designed to nest into or
adjacent to the small of the back 230 of the user 240, as shown in
FIG. 11, thus with the back 95 being of minimal size to support the
small of the back 230 while leaving a larger span 190 as between
the seat 35 and the back 95 accommodating room for the somewhat
swayback user 240 posture going from their hip joint to their lower
back to allow for additional body adjustment movement to achieve
what is shown in FIG. 11, primarily with the user's 240 shoulder
joint and hip joint being in a vertical alignment 186 in moving
more toward a better skeletal posture as shown in FIGS. 4, 5, 6,
and 7.
[0108] Continuing on the chair 30 that is adapted for a female
anatomy 220, the seat plane 90 and an extension axis 175 that is
perpendicular to the surface 210 are relatively positioned to one
another to form an acute angle 180 to one another at an
intersection point 185 positioned therebetween the first seat
tangential point 75 and the second seat tangential point 80. In
addition the seat 35 and back 95 are relatively positioned such
that a span 190 from the first seat tangential point 75 to the
first back tangential point 140 is at least equal to half of the
dimension 115, to accommodate the measurement distances 255, 250,
and 265 based upon data taken as shown in FIGS. 13, 14, and 15 all
as previously described, wherein the span 190 is a larger dimension
i.e. the distance as between the seat 35 and back 95 is greater
than a typical conventional chair, see FIG. 1, wherein the chair in
FIG. 1 doesn't allow the user as much freedom of movement to adjust
for better posture, further not allowing for hardly any buttocks
217 rearward clearance, thus aiding in promoting the undesirable
slouching forward of the user's 215 back as previously
described.
[0109] Preferably the seat 35 and back 95 are relatively positioned
such that the span 190 from the first seat tangential point 75 to
the first back tangential point 140 is about six (6) to nine (9)
inches, based upon the data in FIGS. 13, 14, and 15, as opposed to
a conventional office chair in FIG. 1, wherein the span is in the
range of zero (0) to four (4) inches, that would severely restrict
the freedom of movement as between desirable positioning of the
user's 240 femur, pelvis, and back bone or spine. Continuing, on
the back 95 positioning, based upon the data in FIGS. 13, 14, and
15, for the chair 30 adapted for a female anatomy 220 wherein the
seat proximate end portion 40 and the maximum second radius
extension portion 165 are positioned at a preferred distance 245 of
about eight (8) to eleven (11) inches apart, as shown in FIG. 11,
to best position the back 95 to be nested in the user's 240 small
of their back 230. Further, in looking at the lateral positioning
of the back 95, the chair 30 adapted for a female anatomy 220,
wherein the seat proximate end portion 40 and the maximum second
radius extension portion 165 are positioned with a preferable
overlap distance 170 of about two (2) inches being parallel to the
surface 210, as best shown in FIG. 7, as this is to better ensure
positioning of the back 95 to be nested in the user's 240 small of
their back 230, to better accommodate the desired shoulder joint
and hip joint vertical in-line alignment 186, as shown in FIG.
11.
[0110] Alternatively looking at FIG. 10 in particular for the acute
angle 180 for the chair 30 adapted for a female anatomy 220, the
preferred acute angle 180 is in the range of about fifty-five to
eighty-five (55-85) degrees. This particular range for the acute
angle 180 is derived from FIGS. 2, 3, 4, 5, 6, and 7 and in
particular FIGS. 2, 3, 4, and 5 for the sixty (60) degree range of
Femur bone movement in the hip joint before the pelvis and back
bone have to move (causing the previously described undesirable
uneven spacing of the back bone disc sets), thus the sixty (60)
degree movement falls within the range fifty-five to eighty-five
(55-85) degrees for the acute angle 180. Also looking at FIGS. 6
and 7, the one hundred-thirty-five (135) degree angle for the Femur
from the back bone would result in acute angle 180 being forty-five
(45) degrees which is just out of the preferred range. However,
there are practical considerations to make as when the user 240 is
seated in the chair 30 as shown in FIGS. 11 and 12, to take the
acute angle 180 to a lower number such as forty-five (45) degrees
would risk the user 240 uncomfortably sliding forward out of the
chair, even with a high friction surface seat 35 covering 200
and/or memory foam 205/or seat 35 surface sculpting for the user
240, thus the past need for the kneeling chair like Serber U.S.
Pat. No. 4,650,259, as previously discussed in the field and
background section, utilized knee and abdominal ancillary supports
to better allow the complementary angle 181 (to acute angle 180) as
shown in FIG. 11, such that as angle 181 is to be increased to
beyond, for instance greater than thirty-five (35) degrees, wherein
the user 240 could stay in the seat with these ancillary supports
that add their own problems of cramping and soreness to the user
from pressure against their knee and abdominal area used as
supports.
[0111] Further, these ancillary supports were not popular with
users as these ancillary supports caused additional problems with
abdominal and knee cramping, nerve irritation, and just plain
getting in the way in front of the desk, keyboard, computer, and
the like, plus causing awkward and difficult movement to get in and
out of the chair by the user 240. Thus the acute angle 180
preferred range of range fifty-five to eighty-five (55-85) degrees
is the most practical while trying to allow for angle 181 to fall
within the desired range of thirty-five (35) to five (5) degrees,
with the ideal being thirty (30) degrees as per the Hanns Schoberth
study previously discussed, for improved skeletal posture without
the need for ancillary support devices as previously described that
do not have much popularity. Further in a modified embodiment for
the chair 30, the acute angle 180 could have a narrowed range of
position of about seventy-five (75) to eighty-seven (87) degrees,
thus resulting in complementary angle 181, in FIG. 7 being in the
range of three (3) to fifteen (15) degrees.
[0112] As shown in FIGS. 8 through 12, a support base 91 is
disposed between the seat 35 and the surface 210, wherein the
support base 91 has conventional castors, conventional vertical
height adjustment, and further the foot rest 101 that includes the
partial periphery chord segment 102, with the radial arcuate
section 103, and further an angular 180 seat 35 adjustment that can
be of a frictional clamping type, or a ratcheting mechanism, or a
dowel pin that is received in a plurality apertures, or a suitable
equivalent. Additionally, also as shown in FIGS. 8 through 12, a
support structure 156 is disposed between the seat 35 and the back
95 that controls the positional relationship as between the seat 35
and the back 95 as previously described to effectuate the distance
245 and the horizontal measurement 250, via conventional adjustment
mechanisms of frictional clamping, or dowel pins that are received
in a plurality apertures, or a suitable equivalent.
[0113] Continuing to a number of preferred specifics for the chair
30 for a female anatomy 220 are the dimensions that are based upon
the data gathered from FIGS. 13, 14, and 15 for the group of thirty
(30) female participants the following is given; the length 55 is
in the range of about thirteen (13) inches, noting that this
dimension is shorter than a conventional office chair, which is in
the range of eighteen to twenty (18-20) inches, to allow for the
user's 240 knees to drop below their hips, as shown in FIGS. 11 and
12, as a first step toward minimizing the pelvis and backbone
bending causing uneven disc loading as shown in FIGS. 2 and 3, thus
moving toward the more ideal pelvis/backbone positioning shown in
FIGS. 4 and 5. Further, on the chair 30 adapted for a female
anatomy 220 the first distance 60 is in the range of about sixteen
(16) inches, however, this first distance 60 could be a larger
distance and not affect the function of the chair 30 and the second
distance 85 is in the range of about eleven (11) inches, being the
distance between the first tangential point 75 and the second
tangential point 80 on the seat 35 that is used as intersection
points to develop the seat plane 90.
[0114] Continuing, on the chair 30 adapted for a female anatomy 220
the dimension 115 is in the range of about seven (7) inches, noting
that this is the height of the chair back 95, that is also smaller
than a conventional office chair, that are in the range of eleven
(11) to eighteen (18) inches, thus the present invention has a
shorter back 95 for several reasons, being to accommodate a female
anatomy 220 based upon the data in FIGS. 13, 14, and 15, and as
previously discussed the desired function of the back 95 is to nest
in the small of the back 230 of the user 240 dictating that the
back is smaller than a conventional office chair, further this
nesting of the back 95 in the small of the user's back 230
facilitates the skeletal posture approaching that of FIGS. 4 and 5.
In accordance, on the back 95, the third distance 150 is in the
range of about six (6) inches, being the distance between the first
back tangential point 140 and the second back tangential point 145
to form the back plane 155.
[0115] Continuing on the back 95, as another feature unique to the
female anatomy 220 also based upon the data in FIGS. 13, 14, and
15, the back is narrower at its upper or second end portion 105 to
accommodate a narrower distance as between a female's shoulders and
shoulder blades and to again allow for more freedom of movement in
settling into the desired skeletal posture of FIGS. 4 and 5. Thus
on the back 95 the first measure 120 is in the range of about
twelve (12) inches as best shown in FIG. 9, and then transitioning
160 to the second measure 125 is in the range of about four (4)
inches, which allows the females more narrowly spaced shoulder
blades full freedom of movement as compared to a males wider spaced
shoulder blades, noting that the conventional office chair has a
back width in the range of twelve (12) to sixteen (16) inches
typically without any narrowing at the upper portion being a
consistent width over its entire height. Also, on the back 95,
distance 270 in going from the maximum second radius extension
portion 165 to the transition 160 defines on the back 95 the
distance from the small of the back 230 of the user 240 to the
start of the shoulder blades of the user 240, thus distance 270 is
equal to distance 255 plus distance 265 less distance 245 which
equals about two and one-half (2-1/2) inches. Further, based upon
the data in FIGS. 13, 14, and 15, for the chair adapted 30 for a
female anatomy 220, preferably wherein the seat proximate end
portion 40 and the transition 160 are positioned being the
combination of 255 and 265 about fourteen (14) to seventeen (17)
inches apart, as shown in FIG. 11.
[0116] A few other optional useful features of the chair 30 adapted
for a female anatomy 220 would include a high friction surface 200
disposed upon the seat 35. Wherein the preferred materials of
construction for the high friction surface 200 would include
velvet, velour, a thick nap fabric, and the like to help resist the
tendency for the user 240 to slide forward on the seat 35 due to
the acute angle 180, and its complementary angle 181, as best shown
in FIGS. 10 and 11 respectively. In addition, optionally, the seat
35 can include a memory foam 205 disposed upon the seat 35 as shown
in FIG. 9, which could be combined with a sculpted seat again to
better resist the tendency for the user 240 to slide forward on the
seat 35 due to the acute angle 180, and its complementary angle
181, as best shown in FIGS. 10 and 11 respectively.
METHOD OF USE
[0117] Referring in particular to FIGS. 4, 5, 6, 7, 11, and 12, a
method of using a chair 30 adapted for a female anatomy 220,
wherein the chair 30 is adjacent to a surface 210 is disclosed,
comprising the steps of: firstly providing a chair 30 as previously
described. A next step of adjusting the seat plane 90 to an
extension axis 175 that is perpendicular to the surface 210 such
that they are relatively positioned to one another to form an acute
angle 180 from between about fifty-five (55) to eighty-five (85)
degrees to one another, wherein the angle 180 is taken at an
intersection point 185 positioned therebetween the first seat
tangential point 75 and the second seat tangential point 80. The
determination of the angle 180 will be based upon a user's leg
length 225, seat height above the surface 235, and the user's
comfort level in said adjusting of the angle 180 in not
uncomfortably sliding forward on the inclined seat 35, however as
also previously discussed the ideal angle 180 is sixty (60) degrees
for zero pelvis and lumbar backbone flexing meaning that the discs
are not unevenly loaded as previously discussed, however, even if
the user 240 has some sliding forward discomfort, they should set
the angle 180 as close to sixty (60) degrees as possible for
maximum posture benefit, see FIGS. 10 and 11.
[0118] A further step of adjusting the seat 35 and back 95 such
that they are relatively positioned to one another to result in a
selected span 190 from the first seat tangential point 75 to the
first back tangential point 140, the selected span 190 being based
upon the user 240 sitting in the chair 30 after completing the
previous angle 180 adjusting step and measuring a distance 245 from
the first seat tangential point 75 to a small 230 of the back of
the user 240, wherein the maximum second radius extension portion
165 is positioned to be in contact with the small 230 of the back
of the user 240 at the selected span 190, as shown in FIGS. 11 and
12. A next step of laterally adjusting the maximum second radius
extension portion 165 in a selected measurement 250 parallel to the
surface 210 to be positioned in contact with the small 230 of the
back of the user 240 while the user is 240 sitting in the chair 30
after completing the angle 180 adjusting step and the span 190
adjusting step, as best shown in FIGS. 11 and 12, wherein as
previously described the maximum second radius extension portion
165 is to be nested in the small 230 of the back of the user 240 to
facilitate the user's shoulder joint and hip joint to be in
vertical alignment 186 as best shown in FIGS. 11 and 12.
CONCLUSION
[0119] Accordingly, the present invention of a chair apparatus
adapted for a female anatomy and method of using the same has been
described with some degree of particularity directed to the
embodiments of the present invention. It should be appreciated,
though, that the present invention is defined by the following
claims construed in light of the prior art so modifications the
changes may be made to the exemplary embodiments of the present
invention without departing from the inventive concepts contained
therein.
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