CA2145556A1

CA2145556A1 - Knee brace apparatus with continuous rotating and pivoting action hinge structure

Info

Publication number: CA2145556A1
Application number: CA 2145556
Authority: CA
Inventors: James H. Taillon
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-30
Filing date: 1995-03-27
Publication date: 1995-10-01
Also published as: GB9506224D0; AU1616295A; GB2288435A

Abstract

A knee brace includes upper and lower frames attached to the thigh and calf of a leg. Hinge units are secured to the frames in alignment with the sides of the knee. Each hinge unit includes a first hinge member having a cam opening with a first cam surface and a second cam surface extending from a common connection end outwardly to outer ends. A second hinge member includes spaced followers spaced in accordance with the length of the cams. The hinge members abutt with the followers within the cam opening in alignment with a common connection end and one of the outer ends. As the knee bends, the hinge members rotate relative to each other about the one follower with the outer moving on the cam surface to the outer end thereof. In a further knee bend, the hinge members rotate about the second follower with the first follower moving along its cam surface to the common connection. The hinge members do not include any linear movement.

Description

-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 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 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 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:

_ 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 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.

214~556 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 214~S6 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 ~- 2145556 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 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 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 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 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 , 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 21 i5556 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.

2l45556 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.

,,_, 21~S556 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 21 1~556 `~., 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.

Claims

1. A knee brace device for securement to the leg of a person, comprising a first hinge unit adapted to be connected to the medial side of the leg in alignment with knee for moving with the flexing of the knee, a second hinge unit adapted to be connected to the lateral side of the knee for movement with the flexing of the knee, said first and second hinge units each including a multiple cam and follower assembly aligned with the knee and establishing a sequential relative first rotation of each hinge unit about a first fixed pivot axis unit for a first selected flexing of the knee followed by a second rotation of each hinge unit about a second spaced fixed axis during a second selected flexing of the knee from said first selected flexing, said hinge units establishing only said first and said second rotations of said first and second hinge units during said first and second selected flexing of the knee and without substantive linear motion within the hinge units during the flexing of the knee.

2. The knee device of claim 1, wherein each of said hinge units including an upper leg link and a lower leg link having overlapping ends in alignment with the knee, one of said upper and lower leg links having a first cam wall and a second cam wall and the other of said links having a first cam follower engaging said first cam wall and a second cam follower engaging said second cam wall of said links.

3. The knee brace device of claim 2, wherein said cam walls having a common end aligned and spaced from said first pivot axis, said cam followers and cam walls having a first position with the brace in an in-line position and preventing reverse rotation of the brace from the in-line position.

4. The knee brace device of claim 2, wherein the ends of said cam walls define stops limiting the rotation on said hinge units and thereby the leg of the knee.

5. The knee brace device of claim 2, wherein said cam walls are curved walls of a predetermined length defining the maximum movement of each follower, said curved walls being connected to each other at a common end, said cam walls extending outwardly therefrom with the opposite ends of said cam walls located in spaced relation to each other with respect to said common end in accordance with a equilateral triangle and whereby the first cam follower and said second cam follower are maintained in precise constant linear spacement as a result of the sequential rotation of said followers about each other.

6. The knee brace device of claim 1, wherein said total motion of said knee and hinge unit is in the range of 120 degrees, said first rotation about said axis being inclusive of 60 degrees and said second rotation being inclusive of a final 60 degrees of said 120 degrees.

7. The knee brace device of claim 2, wherein said first cam wall and said second cam wall are curved walls having identical curvatures with the curvature of said first wall having as its center the axis of the second cam follower at the end of the first knee movement from the full extended position of the knee and said second cam wall having as a center the axis of the first cam follower in the extended position of the knee.

8. The knee brace device of claim 2, wherein said cam walls are formed as opposed walls of a single cam opening in said one of said links.

9. The knee brace device of claim 2, wherein said one of said links includes a cam opening including said first and second cam walls as a first arcuate cam wall and a second spaced arcuate cam wall, the other of said links having said first and second cam follower secured thereto and located abutting said first and second arcuate cam walls, each of said cam walls being of a generally similar length and said cam followers abutting a first end of the corresponding cam walls with the leg in a first position.

10. The knee brace device of claim 1, including first and second annular pads located respectively abutting said first and second hinge units.

11. The knee brace device of claim 10, including a releasable connection of said pads to said hinge units.

12. The knee brace device of claim 1, including an elastic leg sleeve having a central knee portion, a thigh portion and a calf portion, said sleeve having a back wall with an elongated lateral slit in the central knee portion about equal to the width of the back of the knee.

13. The knee brace device of claim 12 wherein said sleeve includes a first seam extending from above said slit downwardly past the end of the slit and laterally across and beneath the slit to the bottom end of the sleeve, and a second seam extending from laterally beneath said slit upwardly past the end and laterally outwardly of said slit to the upper end of said sleeve.

14. The knee brace device of claim 1, wherein said first and second hinge units each includes an upper rigid plate member and a lower rigid plate member, the medial hinge unit including a first rigid link secured to said lower rigid plate member, and including an outwardly angled portion and an upwardly extended portion aligned with the knee axis to locate the first rigid link adjacent the side of the knee, the lateral hinge unit including a second rigid link having a first flat portion secured to said lower rigid plate member and having a second flat portion extending from said first flat portion, said second flat portion being located adjacent the lateral side of the knee, said upper portions of said first and second rigid links being connected to said upper rigid plate members to form said first and second hinge units.

15. The knee brace device of claim 14, wherein each of said upper rigid plate member includes a lower bifurcated arm defining the upper rigid link telescoped over the aligned upper portion of said second flat portion, each of said cam and follower assembly being mounted within said telescoped portions of said first and second links.

16. The knee brace of claim 15, wherein one of said upper and lower leg links having a first cam wall and a second cam wall and the other of said upper and lower leg links having a first cam follower engaging said first cam wall and second cam follower engaging said second cam wall.

17. A mechanical hinge for a knee brace unit, said mechanical hinge including a thigh link and a calf link with overlapping end portions, a first of said overlapping end portions having first and second opposed arcuate cam openings with cam walls extending from a common connection and to a first pivot axis and to a second pivot axis and defining first and second and third follower locations, the second of said overlapping portions having first and second cam followers rotatably secured in spaced relation to the second link in accordance with two of said follower locations and located within said cam openings with said first cam follower located at said fixed pivot axis and with said second cam follower at said common connection with the links located in alignment corresponding to an extended position of the leg and knee, said first axis being located essentially in alignment with the pivot axis of the knee and relative pivoting of the leg on the knee pivot axis establishing pivoting within the hinge unit and attached links with the knee and with said links pivoting about said first pivot axis and said first cam follower whereby said second cam follower moves on the radius of said second cam wall to said second pivot axis and then defines a second fixed pivot axis and during further pivoting of the leg and knee said first cam follower moving on the radius of said first cam wall to define a continuous pivoting and rotating hinge movement essentially corresponding to the movement of the interconnected knee without linear motion within the hinge.

18. A rotational hinge unit for a knee brace device comprising first and second rigid support elements having overlapping integrated rigid integral link members, said link members being spaced in generally abutting relation for relative pivotal movement relative to each other between an extended position and an angulated position essentially corresponding to the flexing motion between an extended leg position and a maximum flexed and bent knee position, said first link member having first and second cam walls with an interrelated curvature and spacing, said second link member having first and second follower elements projecting laterally therefrom engaging said first and second cam walls respectively and having a first position wherein said first follower engages a first end of said first cam wall and defines a pivot axis for rotation of said first link member during a first selected angular movement of the knee from an extended leg position, said second follower engaging said second cam wall and moving along said second cam wall during said rotation about said first follower and engaging the end wall of said second cam wall at the end of said first selected angular movement of the knee and defining a fixed second pivot axis about which said link members pivot during pivoting of the knee beyond said first selected angular movement, said cam walls being constructed and arranged whereby said hinge unit establishes only said first and second pivoting movement of said link member about said first and second axis and without substnatially relative linear movement of said links and essentially follows the pivoting of the knee about its internal axis as a result of the sequential pivot axes support.

19. A knee brace apparatus comprising a femoral shell having a medial femoral upright and a lateral femoral upright, a tibial shell having a medial tibial upright and a lateral tibial upright, attachment units for interconnecting of said femoral shell to a leg above a knee and said tibial shell to the leg below the knee, said femoral uprights and said lateral tibial uprights of said shells having overlapping portions for alignment with the knee, hinge units interconnecting the overlapping portions, each of said hinge units comprising a cam assembly including a cam opening secured to one of said uprights and cam follower units secured to the other of said overlapping portions of said uprights, each of said cam openings including a first cam wall and a second cam wall located in opposed spaced relationship and having a common end connection, each of said cam walls extending as a curved surface wall opening in the same direction from said common connection and spaced from each other, each of said cam walls terminating in the outer end in an end wall forming a stop wall, the cam follower units including first and second cam followers having a circular periphery abutting the first and second cam walls and rotatably secured to the other of said uprights for movement along said first and second cam walls respectively, said cam followers being mounted with a first of said cam followers being located within the cam opening in engagement with the first cam wall adjacent its stop wall and with the second cam follower located in the common connection of said cam walls and with said location being established with the uprights located in relationship to each other with the knee in a fully extended position, said cam followers and cam walls forming a continuous pivoting and rotational motion within the hinge unit with the movement of the knee and wherein the hinge unit pivots about the axis of the first cam follower during initial movement of the knee from the fully extended position and with relative movement between the cam followers and the cam walls moving the second cam follower along the second cam wall into engagement with the stop wall of the outer second cam wall and at that time establishing a new pivot position for said cam followers wherein the hinge unit now pivots around the second cam follower in response to further bending of the knee, said hinge units establishing a continuous pivoting and rotation movement without linear motion within the hinge unit.

20. The apparatus of claim 19, wherein each of said attachment units, comprising a frontal rigid frame assembly consisting of left and right side rigid elements having adjacent inner sides interconnected by an adjustable releasably clamp unit, the outer sides of each rigid element having interconnecting straps for securing of the frame assembly about the leg, said clamp unit being adjusted to firmly affix the frame assembly over the sleeve, said upper and lower frame assemblies attached to the upper and lower leg portion with the axis of said first cam follower member substantially aligned with the pivot axis within the knee.

21. The apparatus of claim 20, wherein said right and left side rigid elements have a substantial curvature generally corresponding to the curvature of a leg portion to which it is to be attached and with the overlapping portions of said uprights formed as an integrated part of the corresponding elements.

22. The apparatus of claim 20, wherein said straps include non-elastic connecting members secured to upper and lower portions of the rigid elements.

23. The knee brace device of claim 19, wherein each of said attachment units include a three point strap assembly including first and second strap connectors secured in vertical spacement to said first thigh frame and a single third connector secured to the second thigh frame generally centrally of said first and second connectors, a strap member fixedly secured to one of said first connector and passed through said third connector and having a free end, and a releasable unit securing said free end to said second connector.

24. The knee brace device of claim 23, wherein said releasable unit is a pivoted buckle releasably clamping said free end within said second connector.

25. The knee brace device of claim 23, wherein each of said first and third connectors includes a rectangular eyelet having a width corresponding to the width of said strap.

26. The knee brace device of claim 25, wherein said releasable unit includes a clamp unit for releasable securing said free end therein.

27. A knee brace device including a structure for supporting a mechanical pivot structure moving in simulation of the knee joint of the leg, comprising:
a hinge unit including an upper hinge member adapted to be secured to the thigh of the leg and a lower hinge member adapted to be secured to the calf of the leg, a first pivot member and a second pivot member secured to said hinge members in predetermined spaced relation, a first arcuate path for movement of said first pivot member in the hinge member adjacent said first pivot member, a second arcuate path in the hinge member adjacent said second pivot member, each of said paths having a first end member and a second end member in said in-line position of the leg and hinge unit, said arcuate paths being oriented and located with said first pivot member at said first end member of said first arcuate path and said second pivot member being located at said first end member of said second arcuate path, said arcuate paths and said pivot member locations being constructed and arranged whereby pivotal movement of the knee from said in-line orientation results in movement of the second pivot member pivot member in said second arcuate path about said first pin to the second end member of said second arcuate path and preventing movement of said first pivot member from said first end member during a selected bending of the knee and hinge members and thereafter allowing said first pivot member to move in said first arcuate path about said second pivot member.

28. The knee brace device of claim 27, having upper leg and lower leg attachment units connected to said upper hinge member and connected to said lower hinge member, respectively, each of said attachment units including upright frames for abutting the opposite sides of the legs and including back flexible straps secured to the rear portions of said upright members to secure the back side thereof to the leg and a front V-shaped strap having a single point attachment to the one upright and a two point attachment to the second upright, said V-shaped strap being fixed to a first point of said two point attachment and adjustably secured to the second point and passing through said single point attachment.

29. The knee brace device of claim 28, wherein each of said frames is contoured to substantially conform to the shape of the leg, said upper frames including a generally rectangular portion with a slight concave side leg portion and a small front leg portion connected to said side leg portion by a smooth curved wall and having said hinge members integrally connected by a curved connecting portion to said upper frames.

30. The knee brace device of claim 29, including a hinge plate having a flat mount portion and an offset flat hinge portion joined to said mount portion by an inclined portion, and said outer lower frame is a substantially rectangular frame with side and front portions and has a recess in said side portion to receive said flat mount portion and an outwardly offset recessed portion to receive said inclined portion and thereby locate the offset flat hinge portion with said upper frame and said upper hinge members.

31. The knee brace device of claim 30, including a pad member secured to the inner side of each of said first and second hinge units and abutting the adjacent knee in the secured position on a knee.

32. The knee brace device of claim 27, including an upper attachment frame and a lower attachment frame, each of said frames being U-shaped and having a base and a pair of side legs, said upper attachment frame secured to the leg with the base spaced from the knee and said side legs extended downwardly on the opposite sides of the leg toward the knee, said lower attachment frame secured to the leg with the base spaced downwardly of the knee and the side legs extended upwardly along the opposite sides of the leg toward the knee, and said hinge unit having said upper and lower members secured to the upper and lower side legs of said frames.

33. The knee brace device of claim 32, wherein said frames are rigid frames shaped to abut the leg, and with said side legs terminating in overlapping ends in alignment with the knee, said pivot members and said arcuate paths being secured as a part of said side legs.