CA 02243058 1998-07-14
ERGONOMICAL LEG SUPPORT SYSEM
FOR A MEDICAL EXAMINATION TABLE
This invention relates to an ergonomical
leg support system for use with a medical
examination table and more particularly to an
5 ergonomical leg support system that is largely
automatically adjustable for various users.
It is known to have a leg support system
on medical examination tables, often referred to
as stirrups. The stirrups are heel supports that
10 are usually supported horizontally outward from
the top of the examination table. The stirrups
can be extended longitudinally and are used for
gynecological examinations. Users of the stirrups
often refer to them negatively and find them
15 extremely uncomfortable. It is very important for
women to have annual gynecological examinations.
However, women sometimes forgo these examinations
because of the discomfort experienced in using
stirrups.
20 It is an object of the present invention
to provide a leg support system for use with a
medical examination table where the system has
outer thigh supports in combination with foot
rests, the outer thigh supports being largely
25 automatically adjustable so that the system can
accommodate users of various sizes and support the
legs of a user in a relatively comfortable
position compared to previous devices.
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An ergonomical leg support system is used
with a medicJal examination table having a top. The
system has two outer thigh supports, each thigh
support being connected to a compressible connector.
There are two foot rests. There are connecting means
connecting 'the system to the table and elongated
members intE=rconnecting and supporting the thigh
supports, foot rests and connecting means. The
connecting means and elongated members comprise a
support frame to support the footrests and thigh
supports.
In the drawings:
Figure 1A is a perspective view of a leg
support system with frame connected to a
conventional medical examination table, footrests
and thigh s~~pports extending from the frame;
Figure 1B is an enlarged perspective view
of part of vhe leg support system of Figure 1A;
Figure 2A is a sectional side view of a
compressiblE=_ strut;
Figure 2B is an exploded perspective view
of the comp:ressible connector with dotted lines to
show an interior;
Figure 2C is an exploded side view of the
compressiblc= connector.
Figure 3 is a perspective view of a
rotational :rod end;
Figure 4 is a perspective view of a padded
thigh support ;
Figure 5 is a sectional side view of a
padded footrest;
Figure 6 is a bottom view of a footrest;
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Figure 7A is an end view of a support arm
containing notches for various positions as viewed
from an end of the examination table;
Figure 7B is a side view of the support 5
arm of Figu~~e 7A;
Figure '7C is a top view of the support arm
of Figure 7~~; and
Figure 8 is a perspective view of a
bracket.
There is shown in Figures 1A and 1B, a
perspective view of an ergonomical leg support
frame 2 releasably connected to an end 4 of a
medical examination table 6 having a top 8. The top
8 is the upper surface of the table on which a
patient rests. The top surface can be flat or have
a raised position. The top surface is usually
padded. The=_ medical examination table 6 is only
partially shown (schematically with dotted lines)and
has an end '10 with openings 11 therein to
receive posies 12 of the system 2. The posts 12
provide releasable connecting means between the
frame 2 and the examination table 6. The leg
support sysi~em could be designed as an integral
part of the examination table, but is preferably
releasably connected thereto. For medical
examination tables that do not have the openings
11 or similar variations thereof, the connecting
means of the frame can be easily redesigned by
simple mechanical changes to accommodate
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examination tables that are different from the
examination table partially shown in Figure 1.
Rigidly affixed to each of the posts 12 on either
side of the frame 2 are support arms 14, 16. The
support arm 14, is affixed to an end of one of the
posts 12. Each of the support arms 16 supports
one end 18 c~f a compressible connector 20. The
compressibls~ connector 20 rotatably supports a
plate 22 through a pivotal bracket 24 that has a
pin 26 extending through an opening (not shown) of a
rod end 28. The plate 22 preferably has padding (not
shown in Figure 1) thereon. The plate 22,
compressiblE~ connector 20, pivotal bracket 24 and
rod end 28 comprise an outer thigh support 21.
The posts 12 extend through brackets 30 of the
frame 2. The brackets 30 have two openings 32 (only
one of which is shown in Figure 1). One of the
openings 32 is sized to receive each of the posts 12
and the opening 32 is designed to receive
elongated members 34, which, in turn support rods
36, which in turn support foot rests 38 on either
side 40, 42 of the frame 2. Bands 44, 46 are
longitudina:Lly adjustable by means of a slot 48
and extend between the elongated members 34 to add
stability to the frame 2 and to allow for tables of
different widths.
Each of the two thigh supports 21
preferably lzas five degrees of freedom as follows:
(i)rotational movement about the x, y and z
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axes as well as translational movement
along the support arm 16 and an imaginary
longitudinal axis (not shown) of the
compressible connector 20.
5 From Figure 1B, it can be seen that the
compressible connector 20 has a loop 49 at one end
and a rod end 28 at an opposite end. At an outer
end of the loop 49, there is located a collar 58
having a spring-mounted pin 60 slidably mounted
10 therein and extending therefrom. The pin 60 has a
handle 62 located thereon with a spring (not
shown) located within the collar 58 to force the
pin 60 and handle 62 inward when the handle 62 is
not subjected to any external force. When the
15 handle 62 is pulled outward, the pressure of the
spring (not shown) is overcome and the pin moves
outward from the loop 49.
In Figure 2A, there is shown a sectional
side view of the compressible connector 20. The
20 compressible connector 20 has an outer section 52
and an inner section 54. The two sections 52, 54
are mounted coaxially so that the smaller section
54 slides within the outer section 52. The outer
section 52 has an outer end 19. A spring 56 is
25 located within the inner section 54 so that the
compressible connector 20 will contract
longitudinally under external pressure and expand
when the pressure is released or reduced. In
place of the spring 56, a gas strut or gas
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cylinder could be used. Preferably, the
compressible connector 20 is designed so that it
is fully compressed when ten pounds of force have
been placed longitudinally on the connector 20
5 from the plate 22 (not shown in Figure 2A) and is
fully extended when the weight is removed from the
plate 22. Preferably, the compressible connector
20 will begin to contract when five pounds of
force have been placed longitudinally on the
10 connector 20 from the plate 22.
The outer section 52 contains an axially
located piston 53 with a transverse pin 57
extending therethrough. When the outer sections
52, 54 slide relative to one another the pin 57
15 slides within a slot 55 in the inner section 54,
55. The slot limits the movement of the two
sections 52, 54 relative to one another.
The rod end 28 contains a circular
opening 64 with a bearing 66 mounted therein. The
20 opening 64 is designed to receive the pin 26 of
the pivotal bracket 24. The bearing 66 preferably
permits a total of approximately seven and
one-half degrees of movement in two directions
about one axis and approximately seven and
25 one-half degrees of movement in two directions
about another axis and adds two degrees of freedom
to the plate 22 (not shown in Figure 2A). The two
axes are orthogonal to one another. The pin 26
and pivotal bracket 24 represent another degree of
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freedom of the plate 22. The bearing 66 provides
a universal joint between the pin 26 and the
compressible connector 20. Figures 2B and 2C use
the same reference numerals as Figures 2A.
5 In Figure 3, there is shown a perspective
view of the rod end 28 with the opening 64
extending through the bearing 66 that is mounted
in the loop 68. As can be seen, a cylindrical
section 70 has a screw thread 71 thereon.
10 In Figure 4, there is shown a perspective
view of a part of a padded thigh support 72 having
a wood base 73, a layer of hard foam 74 and a
layer of soft foam 75. Preferably, a layer of
vinyl (not shown) surrounds the thigh support.
15 In Figure 5, there is shown a sectional
side view of the padded foot rest 38 which also
has a wood base 77, a layer of hard foam 78 and a
layer of soft foam 79. Preferably, the foot rest
38 is surrounded by a layer of vinyl 80.
20 The plate 22, bracket 24, rod end 28, pin
26, compressible connector 20, loop 48, collar 58,
pin 60 and handle 62 comprise an outer thigh
support 21.
In Figure 6, there is shown a bottom view
25 of the foot rest 38. Preferably, the foot rest 38
is oversized by approximately 50~ when compared to
the foot of a typical user. The foot rest 38 has
two brackets 82, 83 mounted at an angle on said
bottom so that the foot rest 38 extends outward
CA 02243058 1998-07-14
and slightly upward from the elongated member 36.
The bracket 83 is slightly shorter than the
bracket 82 to obtain the proper angle.
In Figure 7A, there is shown an end view
5 of the posts 12 and support arms 14, 16 that are
rigidly connected to one another as viewed from
the end of the examination table. The support arm
14 is at an angle 13 to the post 12. The angle 13
is approximately one hundred and twenty-nine
10 degrees plus or minus five degrees. The support
arm 16 contains a plurality of openings 84 therein
to receive the pin 60 shown in Figure 2 so that
the outer thigh support can be moved
longitudinally to any of the positions represented
15 by the openings 84 simply by pulling on the handle
62 shown in Figures 1A and 1B. When the handle 62
is released, the pin will retract and if the outer
thigh support is in the desired position along the
length of the support arm 16 the handle is
20 released and the outer thigh support is releasably
locked in that position.
The same reference numerals are used in
Figures 7B and 7C as used for Figure 7A. Figure
7B is a side view and Figure 7C is a top view of
25 the support arms 14, 16. An angle 15 between the
support arms 14, 16 when viewed from the side of
post 12 is approximately one hundred and forty-two
degrees plus or minus five degrees. An angle 17
between the support arms 14, 16 when viewed from a
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CA 02243058 2000-OS-11
top of the post 12 is approximately one hundred
and twenty-:four degrees plus or minus five
degrees.
In Figure 8, there is shown the bracket 30
containing openings 32 for receiving the posts 12
and the elongated members 34. Openings 86 are
designed to receive set screws (not shown) for the
posts 12.
The leg support system of the present
invention i:~ designed to be suitable for all women
lying in the=_ range of the fifth to ninety-fifth
percentiles of women in height, whether the women
are heavy o:~ light. The pad portion of the thigh
supports ha:~ a curvature to provide additional
comfort. The thigh supports support the outer
thighs without applying external force to the knee
or hip joints. Preferably, the pads of the thigh
supports me<~sure approximately six inches by
approximate:Ly four inches. The length,
orientation, and location of the support arms were
determined »sing regression analysis. The
positive z <axis was defined to lie parallel to the
length of the table in a direction which points from
the head of the table to the foot of the
table. The j~ositive y axis was defined to be the
upward direction. The origin was located twenty
centimetres below the center line of the surface of
the table directly beneath the pudendum positioned
at a reference paint, shown as R.P. in Fig 1A of an
imaginary p;~tient. The positive x access was
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defined to be parallel to the width of the table in
the left direction for a patient on the table. The
following e<~uations were obtained by regression
analysis:
y = 1.26592 + 10.274 (1)
x = 0.674512 + 7.258 (2)
2. 5 :'.-~ z ~5. 0 (3)
Equations (1) and (2) describes the
movement of the surface of the thigh pad in space.
Equation (3) defines the endpoints of the line in
equat ions ( 1 ) and ( 2 ) .
The spring 56 in the compressible
connector i:~ preferably designed so that the pad
portion of i~he thigh support will compress more for
a patient with heavier thighs than it will
compress for a patient with lighter thighs. The
pad portion of the thigh supports are free to
rotate around the pivot point within a suitable
and limited range of angles. Rotation around the
axis parallE~l to the femur is preferably centred
at seventy degrees from the horizontal. Rotation
about the a:~is which is normal to the plane which
is tangent ~'o the surface of the thigh of a
patient at i~he location of the pad is preferably
limited to plus or minus eight degrees from the
resting position of the pad. Freedom to rotate
within this limited range accommodates women with
different lengths of legs and different
femur-tibia ratios. Rotation about the line with
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the greates~~ gradient which lies in the plane
tangent to ?she surface of the thigh of a patient
at the loca~~ion of the pad is limited to plus or
minus eight degrees from the resting position of
the pad.
Since a patient's legs are preferably
abducted thirty-four degrees and rotated outward
ten degrees at the hip, the patient's feet will
angle outwa~_rd slightly more than thirty-four
degrees. The foot rests are therefore angled at
thirty-four degrees from an imaginary center line
plane (x=0) through the examination table, as shown
in Figure 1~~ in dashed outline. In order to support
the outward rotation of the leg of a patient, the
foot rests <also tilt outwards at an angle of ten
degrees. ThE=_ foot rests are located in a fixed
position anc3 in order to accommodate women of
various sizes, the foot rests have pads with a size
of approximately one and half times the width and
the length .required for the average woman.
Preferably, each foot rest is approximately sixteen
inches long and six inches wide. The foot rests are
preferably ~~ositioned at a level below the top
surface of vhe examination table, thereby causing a
vertical drop from the buttocks to the heels of a
patient.
The leg support system of the present
invention h;~s several advantages. The thigh
supports support approximately ten degrees of
outward rot,~tion at the hi.p of a patient. The leg
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support system causes the patient to be in a rest
position without any static muscle contractions.
The thigh supports do not apply pressure on the
knee joint and they do not apply pressure behind
5 the leg, which increases circulation. The thigh
supports of the present invention are not load
bearing. The leg support system increases
visibility of and access to the external
genitalia.
10 The foot rests are located far enough
away from an end of the examination table that the
degree of flexion at the knee of a patient using
the leg supports is approximately ninety degrees.
This is much less than the degree of flexion when
15 using typical stirrups.
The physical comfort achieved by the leg
support system of the present invention provides
psychological comfort to the patient as well. As
women are able to achieve a greater degree of
20 relaxation, the reluctance to arrange regular
gynecological examinations will dissipate.
The leg support system of the present
invention is designed to automatically adjust for
women of different sizes because the thigh
25 supports compress more for patients who are
heavier than for patients who are lighter.
Preferably, there is one manual adjustment on each
side as well. Variations, within the scope of the
attached claims, will be readily apparent to those
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skilled in the art. The leg support system can be
an add-on feature to an existing examination table
or it can be made integral with an examination
table. The compressible connector can be designed
g in various different ways to achieve the same
result or described in the present application,
but is preferably designed as described.
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