Note: Descriptions are shown in the official language in which they were submitted.
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KNEE BRACE APPARATUS WITH CONTINUOUS ROTATING
AND PIVOTING ACTION HINGE STRUCTURE
Background Of The Invention
The present invention relates to an
orthopedic knee brace apparatus for a stabilization and
support of a human knee joint and particularly to such a
knee brace device having a continuous rotational and
pivotal action hinge structure.
Knee brace devices have been provided for
many years. Recent developments have been accelerated
due to the significant increase in professional and
amateur sports involving significant stresses on the
human knee. The medical profession has long recognized
that the knee joint is one of substantial complexity and
due to the structure of the knee and the stresses placed
thereon, has been a significant source of serious injury.
The more recent knee brace devices have generally
included a polycentric hinge unit connected to various
upper and lower leg attachment elements. The hinge unit
is located in alignment with the knee, with a similar
hinge unit provided to the interior and exterior sides of
the knee. The modern hinge structure has been related to
the realization of the knee action which includes both
pivotal and lateral movements resulting in a change in
the axis rotation in moving through the complete flexure
of the knee. Such devices are used in various
applications to protect the knee from injury and/or to
stabilize previously injured knee joints.
The prior art generally discusses the action
of the knee as including an initial sliding motion
followed by pivoting motion. For example, U.S. Patent
4,890,607 to Townsend defines a knee as requiring a
mechanical joint which must produce an initial rearward
movement of the tibia relative to the femur within the
joint followed by a single axis pivot type rotational
movement. U.S. Patent 4,603,690 to Skeen discloses a
sliding pivot knee joint which produces a rearward
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sliding of the tibia relative to the femur for a
predetermined distance during an initial range of
flexion. Similarly, U.S. Patent 4,723,539 to Townsend
discloses a similar structure using a pair of compound
arcuate paths each of which includes a straight line
portion. However, the constraining action and location
of the pivot points does not properly follow the pivotal
movement of the knee with its axis of rotation and the
like and thus requires the sliding action with the link
structure.
The complexity of available knee brace
devices vary widely with attendant variation in costs,
and effectiveness of the devices. Further, the available
systems may not produce a comfortable orthosis, as well
as the desired support and stability of the knee,
particularly throughout the total range of motion.
Notwithstanding the existing past and present
interest and activity in connection with the development
of knee brace devices, there is a continuing need and
demand for a more simple, reliable and effective knee
brace unit which can be produced with a cost efficiency.
Summary Of The Present Invention
The present invention is particularly
directed to a relatively simple hinge structure
consisting of rotational and pivotal movement within the
hinge structure to follow the normal knee movement as
well as an improved upper and lower leg attachment unit
and system for attaching of the knee brace device to a
person's leg. The present invention provides joint
stability throughout the full range of motion, with
excellent medial and lateral support and protection.
Applicant has discovered that the link
structure need not provide for any constraining action
with a resulting linear motion within a hinge structure
by appropriate forming of a camming structure within the
hinge structure in accordance with the actual pivoting
action of the knee. In particular, the initial pivotal
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movement of the knee and thus of the constraining linkage
structure should provide for a continuous pivotal and
rotational movement initially about an axis corresponding
to the rotational axis within the knee. Subsequently, a
posteriorly shifted axis for continued pivotal and
rotational movement is created for the final flexing of
the knee. An initial rotational movement is made about
the knee axis in the initial pivoting of the knee,
followed by an immediate posterior shifting of the axis
with continued rotation thereon for the subsequent
pivoting of the knee. This results in a true continuous
pivoting action without any offset or sliding motion
within the linkage of the hinge unit; producing an
improved stabilized knee brace device. More
particularly, the knee brace device generally includes
first and second brace members connected to each other by
biaxial hinge joint units, and particularly
interconnected to each other by a first and second axes
members. In a preferred construction, the pivot axes are
located with respect to each other in a normal fully
extended position with at least the initial axis of
rotation substantially aligned with the axis of the knee
and extending substantially normal thereto. The second
pivot axis unit is spaced therefrom and defines the
radius for the initial rotational movement of the knee;
pivoting in-line with the knee axis. This distance also
defines the amount of shift to the second pivot point.
The rotational movement pivots the second axis unit to a
stop member which defines the limit of first pivoting
movement of the second axis, which then becomes the
second operative rotating axis for further rotation and
flexing of the knee. Thus, generally in accordance with
known phenomena, general flexor limits of 120 to 135
degrees are conventional for the normal knee. In
accordance with a preferred construction of this
invention, for a 120 flexor knee brace the axes are
located on the apexes of an equilateral triangle with the
~. 21g5556
one apex aligned with the knee axis in fully extended leg
position.
In a further aspect of this invention, first
and second biaxial hinge units of the leg are integrally
formed with or permanently affixed to a rigid upper leg
frame unit and a rigid lower leg frame unit. Each of the
leg frame units is generally similarly constructed and
includes a pair of substantially rigid frames with a
center portion of the frames including an adjustable
attachment structure and with outwardly spaced arms
pivoting upwardly and downwardly therefor. Each frame is
formed, as a precontoured, anatomical frame member to
conform to the leg with a comfortable fit and is secured
to the leg with the adjustable clamp to the front of the
lS leg and with the upper and lower arms extending from the
center about the leg with the end portions of the lower
frame arms overlapping and aligned with the knee joint.
The biaxial hinge units are secured to overlapping end
portions of the frame arms. Strap members firmly secure
the upper and lower aligned end portions of the pair of
rigid frames in place to secure the frame units to the
thigh or upper leg member and to the calf or lower leg
member. The adjustable attachment structure provide for
proper location of the frame units in firm
interengagement to the leg. For optimum construction, an
elastic sleeve, which is preferably contoured and
anatomically tailored to comfortably fit the leg, is
first assembled over the knee joint. The rigid frame
units are then similarly attached to the upper and lower
part of the leg, with the special biaxial hinge units in
alignment with the knee joint.
More particularly, each hinge joint structure
or unit, in a preferred embodiment of the knee brace
device, is formed within the upper frame by overlapping
hinge structure at the knee and in particular alignment
with the knee joint. A pair of cam followers are
rotatably affixed to the one leg member and the cam
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opening unit is secured to leg member, with the special
rotational cam opening located with the cam followers
operatively therein. The cam opening generally includes
two arcuate paths extending in aligned, laterally spaced
relation and in similar opposed arcuate paths. The first
and second cam follower are located within the first and
second arcuate cam paths, with the followers located in a
first position in an extended knee portion and movable
therefrom in sequence along the respective arcuate cam
openings during flexure of the knee, with the cam
follower's sequentially establish first and second pivot
axis for the biaxial hinge unit. The first cam follower,
in the extended knee position, is substantially aligned
with the knee axis. As the knee flexes, the knee hinge
pivots about the first cam follower and the second cam
follower moves in and with an arcuate motion through the
arcuate cam opening and follows the natural motion of the
knee. At a selected angle, the second follower reaches
the end of its arcuate cam opening and is now restrained
against further rotation about the first cam follower.
The second cam follower then defines a second and new
rotational axis, and further flexing of the knee results
in the first follower pivoting and rotating about the
second follower. Again, the rotational movement of the
first follower about the axis of the second follower is a
directed rotational movement with proper flexing movement
of the knee.
In a practical and effective embodiment, the
arcuate paths have identical radii and extend at an
obtuse angle within a cam opening and in the same
direction from a common apex connection to individual end
pivot locations or stops. The second cam follower is
aligned with the common overlapping arcuate apex while
the first follower is secured at the opposite end of the
first arcuate path which in use, is substantially located
in alignment with the knee axis with the leg fully
extended. For a 120 degree knee movement, the three
21 ~555 6
follower locations generally define an equilateral
triangle with angles of sixty degrees.
The orientation of the cam opening and the
initial orientation of the cam members only requires that
at least one axis be located substantially in alignment
with the knee axis in the original elongated or extended
position of the person's leg. The pivot joints are thus
spaced and oriented such that the joint pivots on the
spaced first cam follower axis during an initial 60
degree rotation, with the second follower pivoting about
the first axis and moving from the common pivot
connection into alignment with the second pivot axis. At
that time, the second pivot follower becomes the pivot
axis for further pivoting movement and flexure of the
knee joint. During this latter movement, the first
follower pivots about the second follower and moves to
the common pivot connection. The knee has now moved
between the normal limits of 120 degrees, with the hinge
unit supporting and limiting the knee joint. Applicant
has found that the pivot or cam opening can be formed as
a single generally heart-shaped configuration with the
common point of the base of the heart-shaped opening and
the two pivot axes to the opposite sides of the outer or
head portions of the heart-shaped opening.
Alternatively, simple arcuate paths generally on a
similar orientation can be provided.
For other extended knee action brace devices,
such as 135 movement, the sizes of the pins are changed
to vary the relative angular movement of the pins. As
previously noted, the hinge joint is preferably formed
with the hinge links integrally formed with the opposite
aligned arms of the aligned rigid frames but may be
separately formed and appropriately attached as a part to
rigid frame members.
In a preferred construction, the pivot hinge
links are formed with the first link having a cam opening
of an appropriately shaped configuration. The opposite
2l~sss6
or second link is formed with a bifurcated end adapted to
telescope over the cam portion of the first link. The
pair of cam followers are secured one each to an opposite
side arm of the bifurcated end, and each preferably
s includes a bushing secured to the link by a pin with the
bushing located within the cam opening.
The hinge unit, particularly in the
combination of the unique biaxial hinge unit, the elastic
sleeve and rigid contoured frames for leg attachment of
the knee brace device, has been found to provide a
particularly effective knee brace device without the
complexity associated with the prior art devices which
assert the necessity of including linear cam movement to
provide a tracking of the actual knee movement. The
hinge unit permits production tolerances such that the
device can be commercially produced as a cost effective
knee brace unit while providing high lateral and pivotal
knee motion including flexure and/or extension of the
knee joint such that an injured knee is properly
protected and to essentially minimize possible injury to
the user by either extending or flexing of the knee joint
beyond the normal permissible limits. Further, the
biaxial knee orthosis is readily formed with excellent
joint stability and having the strength of a single axis
unit and the performance of the multi-axis design. Thus,
with the new knee brace device, the knee can move in
accordance with a normal healthy knee joint within
necessary permissible safe limits and a damaged knee
joint can be protected and strengthened within the
desired limited motion.
Brief Description Of The Drawings
The drawings furnished herewith illustrate a
best mode presently contemplated for carrying out the
invention or more fully described hereinafter.
In the drawings:
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_
Fig. 1 is a pictorial view of a knee brace
device constructed in accordance with the teaching of the
present invention;
Fig. 2 is a front elevational view of the
5knee brace device shown in Fig. 1;
Fig. 2a is a view similar to Fig. 2
illustrating an alternate embodiment.
Fig. 3 is an enlarged side elevational view
of the brace unit illustrated in Figs. 1-2;
Fig. 4 is a sectional view of the brace unit
taken generally on line 4-4 of Fig. 3;
Fig. 5 is a sectional view taken generally on
line 5-5 of Fig. 4;
Fig. 6 is a sectional view taken generally on
line 6-6 of Fig. 4;
Fig. 7 is an enlarged vertical section
through the hinge unit in the extended leg position;
Fig. 8 is a sectional view taken generally on
line 8-8 of Fig. 7;
Fig. 9 is an exploded pictorial view of the
linkage shown in Figs. 3 and 4;
Fig. lOa through lOc are diagrammatic views
illustrating the continuous pivotal movement within the
linkage illustrated in Figs. 1-10;
Fig. 11 is a view of a sleeve covering the
knee and leg beneath the knee brace;
Fig. 12 is an exploded view of the sleeve
more clearly illustrating the construction;
Fig. 13 is a view of an alternate embodiment;
Fig. 14 is a pictorial view illustrating an
alternate embodiment of a knee brace device in place;
Fig. 15 is an exploded view of the knee brace
device;
Fig. 16 is a view of the thigh element of the
35knee brace device; and
Fig. 17 is a view similar to Fig. 16 of the
calf element of the knee brace device.
21~5556
Description Of The Illustrated Embodiment
Referring to the drawings and particularly to
Figs. 1-3, a knee brace device 1 is illustrated applied
to the leg 2 of a person, with the leg 2 only
fragmentarily shown in a diagrammatic illustration in
Fig. 1. The knee brace device 1 generally includes an
upper leg attachment unit 3 for attaching thereof to the
upper thigh or femoral portion 4 of the leg 2. A similar
lower leg attachment unit 5 secures the knee brace device
1 to the calf or tibial portion 6 of the leg 2, with the
knee 7 disposed therebetween. Each of the attachment
units 3 and 5 is similarly constructed and includes an
outer or lateral hinge unit 8 and an inner or medial
hinge unit 9. The hinge units 8 and 9 are secured to
adjacent end portions of attachment units 3 and 5 as
hereinafter described to form supporting hinge joints
aligned with the knee 7. The lateral and medial hinge
units 8 and 9 are essentially aligned with each other
and, as hereinafter more fully developed, establish a
pivotal supporting brace which essentially follows the
pivotal movement and action associated with flexing of
the knee. The hinge units 8 and 9 are similarly and
specially constructed with an internal biaxial camming
action which includes a continuous pivotal and rotational
movement within the hinge structure without the usual
constraining slide action of the prior art while
maintaining a very simple and compact pivot action.
The present invention is thus particularly
directed to special construction of a unique biaxial
hinge unit to eliminate the sliding action and the
resulting constraining hinge action taught by the prior
art. The present invention is also particularly directed
to the special construction of the attachment units 3 and
5 with contoured rigid support members to provide a
comfortable, firm and effective interconnection of the
knee brace device, with the hinge units 8 and 9 properly
located and maintained in alignment with the knee 7.
21g5SS6
--10--
In a preferred construction, an elastic knee
sleeve 10 is telescoped over the knee and adjacent leg
portions for receiving of the attachment units 3 and 5.
The sleeve 10 is specially contoured to
closely follow fit the knee, calf and thigh of the
patient. The sleeve 10 is formed with the thigh portion
slightly offset from in-line aligned with the knee
portion and more closely conform to the natural position
of the leg. Although any suitable soft elastic material
can be used, applicant has found that a soft neoprene
with an outer surface fabric and inner surface fabric as
at lOa (as shown in Fig. 12) provides a particularly
satisfactory sleeve.
The sleeve device unit in one aspect of the
present invention is specially contoured and anatomically
tailored to fit tight and stay in place. The elastic
sleeve contributes to the comfortable support of the knee
within the contoured knee brace device.
Referring to the upper leg or thigh
attachment unit 3 for purposes of description, the unit 3
includes a left rigid frame 12 and right rigid frame 13,
of a similar construction.
The upper thigh frames 12 and 13 are
similarly formed rigid frames formed of a suitable
plastic or other rigid material. Referring to frame 13
of unit 3 (with the corresponding elements of frame 14
identified by corresponding primed numbers) and
particularly Figs. 2, 3 and 5, the frame 13 includes an
upper portion 14 for attachment to the leg and an
extended lower portion or arm 15 aligned with the knee
joint. The upper portion 14 is generally rectangular in
shape and is located to cover about the front half of the
side of the thigh and extend over a small extent of the
front portion. The upper portion has the side portion
formed with a slight lateral curvature and an integral
front distinct curved portion 14a of substantially
shorter extent which extends on to the front of the leg.
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--11--
The arm 15 is integrally formed to the lower
end and rearward portion of the frame upper portion and
extends into alignment with the knee. The upper portion
14 and arm 15 for both the interior and the exterior
frames are connected by smooth inward curved connection
16, and with the arm 15 set slightly inwardly of the
portion 14 as shown in Fig. 4, such that the frames 12
and 13 have a contour for fitting of the orthosis to the
structure of the leg and knee. Each arm 15 and 15' of
the upper frames 13 and 14 is formed as a bifurcated arm
forming a hinge opening parallel to the side of the knee
joint and directly forming a first hinge link of the
biaxial hinge units 8 and 9.
Adjustable straps 17 and 17a are secured to
the rear edge portion of the rear frame portions 14 and
14'. Straps 17 and 17a are in vertically spaced relation
to on the frames and extend around the leg to form a
posterior attachment of the frames. The straps 17-17a
may be formed with suitable releasable end attachment
elements and are shown as elements sold under the
trademark "Velcro". The opposite ends of the straps 17
and 17a are looped through corresponding vertically
spaced openings 18 and 18a, and 18' and 18a' in the left
and right frame members 12 and 13, and folded back on
themselves to support the frame to the rear side of the
leg.
Adjustable attachment units 19 and l9a
interconnect the forward ends and edges of the rigid
frames 12 and 13 of unit 3 to provide for firm
interengagement of the frame unit 3 to the leg.
The attachment unit 19 includes a strap 20
passed through an eyelet unit 21 on frame 13 and an
opening in frame 12. The eyelet unit 21 includes a
rectangular metal loop 22 releasably attached to the
frame 13 and particularly portion 16 by a button unit.
The button unit includes a triangular plate 23 having one
side hinged on an arm of the loop 22 and a latch button
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-12-
23a is pinned to frame 13 to receive the latch plate 23
and releasably attaches the upper unit 3 to the leg.
The straps 17-17a provide a general position
of the frames 12-13 relative to the leg and the
attachment strap units 19 and l9a provide a positive and
releasable attachment of the frames 12-13 to the leg.
Attachment strap units 19 and l9a are readily
assembled with a relatively loose fit with the adjustable
straps 17 and 17a first drawn up to locate the rigid
frames to the upper leg portion. The adjustable
attachment units 19 and l9a are tightened to firmly and
appropriately locate and secure the frames in place, with
the arm 15 and 15' aligned with the knee to form a hinged
link at hinge units 8 and 9.
The lower frame members 25 and 26 of
attachment unit 5 are formed as similar generally
rectangular rigid members. Each frame member 25 and 26
is located just below the knee. Referring to frame 25,
the frame is curved and contoured to fit the side of the
calf and has a small front lip 27 which extends slightly
onto the front side of the leg.
The frames 25 and 26 are attached to the
lower leg as follows.
The attachment for the lower frames 25-26
includes a pair of spaced front straps 28 and 28a
including a front loop and button unit 29 essentially
identical to the unit 21 disclosed and applied to the
upper frames 12-13. The back straps 30 and 30a are
secured to the frame 25 and 26 using a Velcro strap unit.
However, the upper strap 30 is located immediately below
the knee and is specially fastened using eyelet units 31
and 31' secured one each to the aligned edge portions of
the frames 25 and 26.
The lower frames 25-26 are secured to the
calf of the leg in downwardly spaced relation to the arms
15 and 15' of the upper frames 12-13, and with the side
portions accurately aligned therewith. Hinge plate
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-13-
members 32 and 33 are secured to the aligned upper ends
of the frames 25-26. The plate members 32 and 33 extend
upwardly from the frames into the aligned bifurcated end
and particularly openings of the upper arms 15 and 15' to
form the second links of the hinge units 8 and 9. The
plate members thus are contoured and shaped to extend
from the frames with appropriate offset to contour the
plate members 32 and 33 to the contour of the knee
structure, and are coupled to and within the arms 15 and
15', as more fully described hereinafter.
Prior to description of the hinge units 8 and
9, an alternate and preferred frame attachment system for
releasable connection of the frames to the leg is
illustrated in Fig. 2a.
Each front frame attachment unit, in the
preferred construction shown in Fig. 2a, is a releasable
three point anterior strap unit connecting the front, or
anterior portions of the frames 12 and 13 and frames 25
and 26. Referring to frames 12 and 13, a strap 34 of a
suitable webbing has one end secured to the lower end of
the interior frame 12. The strap 34 is secured to the
frame 12 by an eyelet 34a and extends across the leg
above the knee and passes through an eyelet and button
unit 34b, which is similarly affixed to the center of the
right frame member 13. The free end of the strap 34
extends back over the thigh to a releasable buckle unit
34c to lock the strap in place. The buckle unit 34c is
of a standard construction including a pivoted plate-like
buckle secured by a pivot pin to a base plate. The base
plate is secured to the frame 13. In the open position,
the strap moves freely through the buckle and is locked
in place by pivoting the buckle into abutment with the
base plate.
Referring again to Figs. 1, 2 and 4, the
plate members 32 and 33 are secured to the frames and
project upwardly into the arms 15 and 15' and form links
of the pivot units 8 and 9. The plate members 32 and 33
~ 21~5556
are specially spaced to the contour of the leg and knee
structure, as follows.
In particular, the exterior coupling plate
member 33 has a flat mounting or plate portion 35 located
within a formed offset recess 35a in the uppermost end of
the calf frame 26. The plate portion 35 is secured
thereto by a pair of rivets 36 and 36a located in
vertically spaced relation. The upper rivet 36 secures
the eyelet unit 31' to the upper end of the frame for
receiving of the upper Velcro securement strap 30. The
plate member 32 extends upwardly from the frame 25 as a
flat plate 37, with an outward angle, into the bifurcated
opening in the frame arm 15' and forms the link for
coupling to the arm or link 15.
The hinge plate member 32 for the interior is
a shaped plate and similarly includes a lower flat plate
portion 38 located within a formed offset recess 39 in
the upper end of frame 32. The plate portion 38 is again
riveted to the frame by rivets 40 and 40a, with the upper
rivet 40 simultaneously securing the eyelet unit 31 in
place. The plate member 32 has a relatively sharp angled
and integral plate portion 42 projecting outwardly within
the upper portion of the frame 25. The frame 25 has a
correspondingly shaped offset 43. An integral plate
portion 44 extends upwardly from the inclined portion 42
into the hinge opening of the upper frame arm 15 and
forms a hinge link of the hinge unit 9. The frame and
hinge plate is thus again matched to the contour of the
knee.
Both the upper and lower frame units 3 and 5
are thus similarly attached to the leg 2 with the hinge
links formed by arms 15 and 15' and arms 37 and 44 of
hinge units 8 and 9, all generally contoured to the leg
and knee and thereby accurately and precisely aligned
with the knee joint. The fixed interconnection of the
supporting rigid frames of units 3 and 5 permits accurate
location of the hinge units 8 and 9 relative to the knee
, 21g~556
-15-
structure. This provides precise location of the knee
brace to the knee as particularly described for the
optimal sequential fixed pivoting within the hinge
structure in accordance with the teaching of the present
invention.
Although any suitable attachment system can
be used to affix the hinge units to the frame, the rigid
frame extension, such as illustrated in Figs. 1-5, is
preferred to provide a highly reliable and effective
system for the support of the hinge units.
Each of the hinge units 8 and 9 is
essentially of an identical construction and are
correspondingly oriented with respect to the pivoting and
rotational axis related to the knee. Conse~uently, the
hinge unit 9 will be described in detail with
corresponding elements of the hinge unit 8 identified by
generally similar primed numbers.
Generally, in the illustrated embodiment of
the invention, the hinge unit 8 includes the integral
thigh link or arm 15 extending as a part of the thigh
attachment frame and, in the illustrated embodiment,
forming an integral part thereof. The link 44 is defined
by the upper end of the plate 32 and projects from the
lower frame into the arm 15. The two hinge arms or limbs
15 and 44 are in overlapping relationship and coupled to
form a continuous rotational camming connection as
follows.
In the illustrated embodiment of the
invention, the thigh or femoral link 15 is shown
including the bifurcated lower end defining spaced plate-
like members. The lower or tibial hinge link 44 projects
upwardly as a single arm into the bifurcated arm. A cam
opening and cam followers are secured to the hinge links
to provide a continuous pivotal movement during flexing
of the knee. In the illustrated embodiment, a cam
opening 45 is formed within the hinge link 44 First and
, 2145556
-16-
second pivot followers 47 and 48 are secured to the walls
of arm 15 and located within such cam opening. The cam
opening 46 and the cam follower units 47 and 48 are
specially formed to define a continuous rotational motion
between the links 15 and 32, with two spaced and
sequentially fixed axes of rotation.
The illustrated cam opening 46 is generally
an equilateral triangle in configuration with each of two
adjacent sides curved to define curved guides having cam
surfaces 49 and 50 separate by the obtuse angle of 60,
and connected to each other by curved corners. The pair
of cam followers 47 and 48 are aligned with the cam
surfaces 49 and 50 and are adapted to provide sequential
rolling engagement with the adjacent cam surfaces 49 and
50 during the rotation of hinge arms 15 and 44 and as the
knee flexes.
As more fully developed hereinafter, two
sides of the opening function as cam surfaces or walls
while the third side functions to close the cam opening
and define rotational stop limits of the cam followers at
the opposite ends of the two operative cam walls 49 and
50. The third wall 51 may therefore be of a different
configuration as long as it does not interfere with the
camming motion provided by the two opposite cam walls.
In the illustrated embodiment of the
invention, each of the follower units 47 and 48, which
may be any suitable type, is preferably constructed as a
low friction rolling support, as illustrated in Figs. 7-
9. In a typical practical application, a roller bushing
52 having a radius corresponding to the corner curvature
at the ends of the cam walls 49 and 50. The bushing is
drilled and to receive an elongated attachment nut
forming an elongated nut and a shaft 52a. The nut shaft
-52a is preferably a stainless steel shaft which extends
from the exterior through the bifurcated arm 15 with an
interior clamp bolt 53 threaded into the elongated nut
shaft 52a. The shaft 52a has a smooth bearing surface
~_ 2145556
-17-
within the opening in the arm to support the roller
bushing 52.
Simple pin members as well as any other cam
and follower system can of course be provided and
interconnected in place of the bushing structure, within
the teaching of the present invention.
In the initial extended full extension of the
wearers leg as shown in Figs. 3 and 4, the follower units
47 and 48 are located in the two adjacent apexes or
corners 54 and 55 of the cam opening as shown in Fig. 10.
The radius of curvature of the cam walls 49 and 50 are
identical and the follower units 47 and 48 are of a
corresponding construction.
More particularly, in the illustrated
embodiment of the invention, the cam opening 46 is formed
within the bifurcated arm 15 with a common apex or corner
54 of the cam opening located as an upper most end of the
opening. The cam opening is oriented about the corner 54
located centrally between and forwardly of corners 55 and
56, which are vertically aligned with the corner 55
located above corner 56. The curved walls 49 and 50
extend downwardly and laterally from corner 54 at thirty
degrees to a perpendicular line from corner 55 to the end
wall between corners 54 and 56.
In an extended leg position, follower 47 is
located in the common upper corner 55 and the second
follower 48 is located in the corner 54. In the
illustrated embodiment, the cam opening orientation is
such that the leg is held with the thigh biased
rearwardly of an in-line vertical position relative to
the calf and lower leg. Further, flexing of the leg from
this in-line position results in the hinge members and
therefore the upper and lower leg members pivoting about
the axis 57 of the follower 48 located at the corner 54
substantially midway between the axes of the corner 55
and the corner 56. The follower 47 moves along the cam
wall 29. In flexing and pivoting of the lower or calf
21~555 6
-18-
portion of the leg, the hinge unit 9 and particularly
link 44 which is attached to the calf or lower portion of
the leg, will pivot clockwise about the axis 57 of the
first follower 48 during the first sixty (60) degrees of
rotation of the knee joint. The pivoting motion or
movement of the tibia link causes relative movement of
the second cam follower 47 along the cam wall 29, with
the follower 47 and its roller rolling downwardly to the
corner 56 at the lower end of cam wall 29. When the knee
has pivoted through sixty (60) degrees of rotation, the
follower 47 engages the end of the cam surface or wall 29
as shown in Fig. lOb. The cam follower 47 is now held in
place and defines a second pivot axis 57a as the
rotational axis for the subsequent 60 degree rotation of
the knee and interconnected link. Thus, the link
continues to pivot and rotate with the leg, but with the
cam follower 48 now riding up the cam wall 30 to the
common corner 55, as shown in Fig. lOc.
Thus, with the present invention, a
continuous rotational movement of the knee and the
interconnected and identically arranged pivot units 8 and
9 is created without any constraint within the linkage
which requires a lateral, sliding motion such as taught
in the prior art systems. The continuous rolling and
rotational action maintains a positive and reliable knee
support while permitting the desired movement of the
knee. The hinge structure is simple and can be readily
constructed to provide a reliable and long life hinge
system.
With the elements firmly strapped to the leg,
the inner surface of the overlapping knee brace elements
or pivot angle elements are close spaced to the opposite
sides of the knee. Suitable padding is preferably
attached into the inside of the overlapping rigid
elements of the pivot unit. In the illustrated
embodiment of the invention, releasably mounted knee pads
58 and 59' are illustrated attached to the inner face of
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each arm 15 and 15'. Each knee pad 58' is similarly
constructed with an inner base fabric 58a for the Velcro
attachment to the inner face of arm 15. The pad 58 is a
circular donut secured to the periphery of the pad and is
suitably expanded with air, a soft resilient filler 59 or
the like to provide a cushioned support abutting the
knee. The pad 58 is attached to the Velcro fabric in any
suitable manner by an adhesive or the like for attachment
to the "Velcro" liner affixed in alignment with the hinge
unit.
The structure of sleeve 10, in accordance
with the preferred and commercial embodiment of this
invention, is constructed to comfortably support the knee
brace and the knee action as defined by the hinge units 8
and 9. The illustrated sleeve 10 has a front circular
opening 60 adapted to be aligned with the knee cap 60a.
The sleeve's cross section at that location generally
corresponds to the circumference of the knee. Different
sized sleeves preferably are provided related to the
general size of the knee, for example, between an extra
small and double extra large sleeves with the gradations
therebetween. The upper or thigh part of the sleeve 10
extends outwardly generally in accordance with the
conventional anticipated expansion of the thigh related
to the size of the knee. The calf or bottom part of the
sleeve similarly expands, with a lesser expansion related
to the slight expansion of the calf portion adjacent the
knee.
The sleeve 10 is formed with the thigh
portion slightly offset from in-line aligned with the
knee portion and more closely conform to the natural
position of the leg as set by the original in-line
orientation of the knee brace.
In addition as shown in Figs. 11 and 12, a
popliteal window or opening 61 is formed in the backside
of the sleeve 10 in alignment with the knee opening.
Generally, in accordance with a unique teaching of this
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invention, the opening 61 is formed as an elongated slit-
like opening with the bottom and top walls 62 and 63 of
the elongated opening curved slightly outwardly to define
a relatively vertically narrow opening extending
throughout the back width of the knee structure.
Further, the sleeve 10 is formed with the split and
seamed walls to the opposite side of the elongated
opening 61. A lower seam 64 extends at an angle from
slightly above and outwardly of the opening 61 and
downwardly past the edge and beneath the opening to the
bottom opening edge of the sleeve 10. The second seam 65
is on the opposite side of the elongated opening 61 and
extends from below and beneath the opening 61 upwardly
past the edge and outwardly of the opening to the upper
opening edge of the sleeve lO. This unique sleeve
construction with the diagonally opposed seams and
popliteal window avoids bunching and migration of the
sleeve upon the knee, and maintains a comfortable knee
brace support.
The various frame members 12, 13, 25 and 26
are also in the practical construction secured by a
releasable coupling to the sleeve 10. In the illustrated
embodiment of the invention, a plurality of "Velcro"
attachment units 66 are secured to the inner face of the
frames 12-13 and 25-26. The fabric surface lOa of the
sleeve provide direct attachment of the frame members to
the sleeve by units 66.
The knee brace device is formed with a
plurality of Velcro fastener elements secured to the
inside of the formed leg attachment elements or units,
at least one Velcro element and preferably two vertically
spaced Velcro elements are provided. The Velcro elements
attached to the outer fabric surface lOa of the soft
liner to secure the knee liner in place relative to the
knee brace with the appropriate openings aligned with the
knee. The special liner is used having a frontal part
secured to a side and back part by the locating seams.
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The seams are generally located in alignment with the
coupling portions of the back edge of the leg attachment
frames. The frame members of the brace can thus be
appropriately located on the knee with the rear straps
drawn up followed by the tightening of the front locking
strap.
The attachment unit 68 are also applied over
inner elements of the hinge units and support protective
pad units overlying the hinge units 8 and 9.
In the first embodiment, the pivot pin
elements move through successive 60 angles to effect the
total angular orientation or pivoting movement of the
knee through 120. Other angular limits may be provided.
For example, to establish a 135 movement the pivot hinge
units in a modified hinge unit may be formed with
different radii and particularly in a ratio of 2 to 1, as
shown in Fig. 13.
In Fig. 13, follower pins 70 and 71 are again
shown within a generally triangular cam opening 72. Cam
opening 72 includes a first cam path 73 extending from
the first pivot stop wall containing pin 70. The path 73
extends toward a second path 74 for the second pivot pin
71. The first pin 70 is shown as twice the size of the
second pivot pin 71. The angular path 74 projects from
the location 75 of pin 71 through an angle equal to 90
of the leg movement to a second stop location 76. The
second pin 71 moves along such path 74 as it pivots about
the pin 70 and terminates in abutment with the end of
arcuate path.
The second pin 71 is half the diameter of the
first pin and moves through an angle of 90 in response
to the movement of the angle of 90 of the knee bending
from an in-line orientation.
Thereafter, the first pin 70 moves along its
path 73 about pin 71 through an angle equal to 45 of
knee movement and engages an offset stop wall 77.
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The end wall of the first path 73 for the pin
70 thus extends into an intermediate portion of the
second path and is particularly located downwardly along
the second path 74 from the initial starting or first end
location of the pin 71.
Thus, the angular movement for different than
degree movements can be effected readily through
orientation and structure of the pins including the pin
sizes and the angular path of movement of the respective
pins.
An alternate embodiment of a knee brace
device 80 is shown in Figs. 14-17, inclusive. Referring
to Figs. 14-17, the knee brace device 80 includes a thigh
or upper U-shaped attachment element 81 and a calf or
lower U-shaped attachment 82 for attaching of the device
io a leg 83. The upper element 82 is attached with the
base 84 on the front of the legs 83 and the side legs 85
and 85a extending down along the side to the knee 86.
Suitable straps 87 pass through opening in the back edge
of the side legs and secure the element 81 to the thigh
of the leg 83. The bottom or calf element 82 is secured
to the calf of the leg with the base 88 of the U-shaped
element located spaced from the knee 86 of the side legs
89 and 89a extended upwardly along the side of the leg to
the knee 86 and into overlapping relation to the
depending legs 85 and 85a of element 81. Straps 90 and
goa pass through openings in the legs 89 and 89a to
secure the calf element 82 in place. An upper strap 90
passes through openings 91 in the back or inner edge of
side legs 89 and 89a. Strap 90 passes around the front
and back of the leg. Strap 90 passes through opening 92
in the front edge of the side legs 89 and 89a and extend
across the front of the leg. The side legs of elements
81 and 82 overlaps with the biaxial hinge unit built into
the side overlapping legs. The elements 81 and 82, as
shown in Figs. 16 and 17, may be formed as flat elements
and subsequently shaped to fit the leg. The elements are
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preferably rigid plastic elements, and may be assembled
on the leg with the sleeve and the inner cushion or
protective units secured in alignment with the hinge
units 93 as disclosed in the previous embodiments.
The structure of the attachment assembly and
the hinge assembly are shown in a preferred and practical
embodiment featuring aspects of the teaching of this
invention. The particulars may be varied within the
basic teaching of a biaxial hinge providing pivoting and
rotational positioning as previously disclosed herein.
For example, although shown with the upper leg attachment
including an integral hinge link, a separate hinge link
may be used attached to the upper element. The various
embodiments are also disclosed with one cam opening,
which may be formed with separate first and second curved
paths without the connecting base wall between the two
curved pivoting walls for the pivoting members. The
structure of the illustrated cam followers may also be of
any suitable construction which permits the desired
movement within the cam openings.
The hinge members with the cooperating
follower cam paths can thus be formed in the integral
arms or separate limbs or as separate elements secured to
overlapping arms or limbs. The above examples are only
given as typical variations and are not limiting of the
scope of possible constructions within the scope of the
accompanying claims defining the various aspects and
features of the knee brace device of the present
invention, and the various preferred and unique aspects
thereof within the teaching herein.
