CA2186227C

CA2186227C - Multi-functional dynamic splint

Info

Publication number: CA2186227C
Application number: CA002186227A
Authority: CA
Inventors: Mark Deharde; Kenneth A. Patchel
Original assignee: Ultraflex Systems Inc
Current assignee: Ultraflex Systems Inc
Priority date: 1994-03-22
Filing date: 1995-03-22
Publication date: 1999-09-28
Anticipated expiration: 2015-03-22
Also published as: CA2186227A1; WO1995025489A1

Abstract

A dynamic splint has a bi-directional torsional dynamic tension unit (348) fastened between first and second struts (308,388) to selectively deliver force opposing either extension or flexion. The tension unit (348) is mounted about a pivot post (34) and can be rotated between two positions. In the first position, the power unit is locked relative to the first strut (308) and the torsion spring opposes relative movement of the second strut (388) in a first direction. In the second position, the tension unit (348) is locked relative to the second strut (388). In this second position, the tension unit (348) opposes movement of the first strut (308) relative to the second strut (388), providing torsion in an opposite direction from that of the first position. Self-aligning contour plates (334) on the struts conform to the anatomy and provide a mechanical interlock to bony prominence on the patient's limbs.

Description

~ Wo 95/25489 2 1 8 6 2 2 7 r~ 9~
M[JLTI-FTJNCTIONAL DYNAMIC SPLINT
FiPl~l of til!~ Tnylonhl~n Th~ present invention relates to splint assemblies generahy, and more ~ ally to a dynar~ic splint adapted to exert an adjustable force or tension at a body joint.
s T`~ of ~h Tnvf nh- n In recent ye~rs, dramatic advances have been made m the d~ of ' t, compæt ' for correcting common and debilitating injuries to body joints such as fingers, wrists, knees, elbows and the like. Perhaps the greatest advances have been ~nade in the design of orthotic bræe units which counteract instabilities im a joint 10 by reimforcing tbe joint as a whole to prevent unwanted motion. Such orthotic devices are typically formed with a mechanical joint supported by a pair of bræing members. The mechanica1 joint is defined by a pair of side bars, each of which has a hinge-like pivoting joint irl its [niddle with the top and bottom ends of the side bars being connected to bracing members which fit around a body portion above and below the joint to be supported. These 15 devices operate generally by confining tbe movement of the joint as it bends so that unwanted motions are eliminated or at least minimized. The most commonly known orthoses ar~ orthotic knee bræes of the type commonly used by atbletes who have suffered injuries to l-ither the ligaments that h..~l. - the lower femur and upper tibia, o} to the bones themselves, which result in knee ~ iti,~c Joint instability is not the only debilitating condition of a body joint which requires correction. The operation of a body joint may be impaired in a manner which inhibits the operation of the joint in ~ "~ extension or flexion. For example, a flexion contræture prevents full extension of the joint, while an extension contracture prevents the joint from being bent or flexed to the full extent. Obviously, the treatment of a flexion 25 contracture or an extension contracture requires more tban the mere support against instability provided by many CUII~llLiUII~I] orthotic devices.
To ~reat flexion and extension ~, spring-biased splint units have been developed to provide a force across a body joint. These splint devices provide tension which operates in opposition to a flexion or extension contracture and thereby not only WO 95/25489 ~ 2 ~ 8 6 2 2 7 provide support in instances where muscular wea~ness e~ists, but also enhance r~h~h~ .m One type of ~nown adjustable spring-loaded splint includes a pair of lower struts and a pair of uppe} struts of tubular ~ rir ~ ;. . . which are pivotally ~
Spring biasing units mounted witbin the tubular struts are adapted to apply an adjustable force at the pivot point which tends to align tbe two pivoted struts. Such an adjustable splint mechanism is iUustrated by U.S. Patent Nos. 4,397,308; 4,485,808; 4,508,111;
4,538,600 and 4,657,000 to George R. Hepburn.
Although known adjustable splints operate effectively to apply tension across ajoint, they are relatively heavy and bulky and ~ ly impede to some extent free activityat the affected joint. The heavv tubular strut assemblies used in prior art splints are generaDy not coextensive from the com ecting pivot point, and thus may be brought into only parallel rather than axially a1igned ~ It is impossible to contour these heavy struts to corlform to the limb of a user, and the degree of pivotal movement within which the applied force is linear is generally smaU. Such splints generally use straight line springing against a cam. The rotational force applied by the cam is extremely non-linear due to the changing moment arm on the cam surface. This variation prevents the application of a constant therapeutic force and requires constant adjustment to the spring force through the desired range of motion.
FinaUy, with known prior art adjustable splints, the bias adjustment mechanism fo}
the splint is difficult to reach, and the degree of adjustment is often difficult to ascertain.
Accurate adjustment of the bias for such prior art units with the splint in place is not easily j~,,"",l,lj.h .l~andthebiasstructureemployeddoesnotfacilitatepolycentriciointstructures of the type better suited to the motion of certain joints, such as the knee.
In general, prior art splints have been constructed for force application in either a flexion or contraction direction, but not both. However, U.S. Patent 4,370,977 to Mauldin shows a knee brace with a spring comnected to a hinge member which may be used to resist motion in either direction. Resistance in one direction is l, ~r ,, ,, .~,l to resistance in the opposite direction by removing a ll~u~b~w~ and the torsion spring, and reinstaUing the torsion spring in different holes on the binge portion. However, ' ~ of this type do not provide an even adjustment of force capability, and reversing the direction of force appiication requires complexity in the operations required to reverse the device.
U.S. Patent 5,052,379 to Airy et al. shows a brace with frame sections connectedby a pivot joint whicb resists relative movement of the frame sections in either or both _ .. _ , . ..

WO 95125489 2 1 ~ 6 2 2 7 r~

directions about the pivot axis. A removably connected torsion spring provides t_e resistive force. Tl~is reference, however, uses different torsion springs to impose the resistance desired, rather tban changing the position of a single torsion spring.
c of thP I
.

S It is a primary object of the present invention to provide a novel and improved dynamic extension or flexion spiint for the treatment of joint ~.UII~ ,tlJ~ which is easily applied to a body member in the area of the joint to be treated and which is both compact and ~
Another primary object of the present invention is to provide a mechanism for lû applying an accurate adjustable force with near-constant ]inearity opposing movement of a body joint, consistent reset-ability and easy read-ability.
Another object of the present invention is to provide a novel and improved dynamic extension or flexion splint having opposed strut assemblies which l flat strut members ,~dapted to be contoured in place to conform to a body member. This permits 15 ~ ,;,,, the fit of the splint for greater comfort.
A iurther object of the present invention is to provide a novel and imp}oved dynamic extension and/or flexion splint having opposed strut assemblies which may be easily removed from a strut assembly support unit. Each strut assembly includes two elongated stiut members which slide into pockets on either side of the joint to be treated.
Yet another object of the present invention is to provide a novel and improved dynamic extension and/or flexion splint which provides a full range of motion for a joint u..d~- . The spiint hl~,UI~. ' strut members which pivot at a mechanical joint through the ma~imum anatomical range plus 10 Il~ At~ iull. Tension is applied to the strut members by a torsion or power-spring type of biasing unit with near iinear force . I, .,,.. i~ mounted at the mechanical joint, and the spring tension is adjustable by means of a bias adjustment mechanism which is also located at the mechanical joint. Thus, the tension applying spring and the bias adjustment are both located entirely at the mechanical joint for the splint.
A further object of the present invention is to provide a novel and improved dynamic 30 extension and/or flexion spiint having a polycentric joint mechanism whuch is adapted to provide g~eater than the full anatomical range of motion. Elongated strut members are wossl2s489 21 8 6227 r~ Jv o-lss ~
mounted on the joint for pivotal motion about two spaced paTallel pivot axes. Each strut member is biased by a separate spring, and the bias of plural springs is ~ ly adjusted by a bias adjustment ' An indicator at the mechanica'l joint provides an indication of the degree of bias which is set into the springs.
A still fu ther object of the present invention is to provide a dynamic extension and/or flexion splint having a~ adjustable spring mechanism which is reversible to provide either flexion or extension resistance.
Another object of the present invention is to provide an adjustable-bias dynamicextension and/or flexion splint with a visible indicator showing the relative magnitude of the bias force applied.
A further object of the present invention is to provide an adjustable-bias dynamic extension and/or flexion splint wherein the bias force is produced by a mechanism in a housing located at the joint, and a visible indicator of the relative magnitude of the bias force is provided when different inscribed portions of a member rotating upon bias force adjustment become visible t'nrough an aperture as a result of the rotation.
It is also an object of the present invention to provide a dynamic extension and/or flexion splint, having portions attachable to a human body on each side of a body joint and applying a bias force to the joint, which also has a mechanism for selectively negating the bias force during attachment or removal of the splint.
Another object of the present invention to provide a dynamic extension and/or flexion splint, having portions attachable to a human body on each side of a body joint and applying a bias force of adjustable maglutude to the joint, which also has a mechanism for selectively negating the bias force during attachment or removal of the splint without changing the maglutude adjustment setting the bias force to be applied.
It is also an object of the present invention to provide a dynamic splint which is designed to be easily attached to a body joint in a flexible manner that ~ r-- for deviations in tne geometry of the joint and permits attachment of the splint even to damaged or swollen joints.
Another object of the present invention is to provide a dynamic splint with pivotable self-aligning pads that, . for swelling amd variations in patient bone and tissue structure.

~ WO 95/2~48!~ 2 1 8 6 22 7 i~3 It is also aA object of the present invention to provide a dynamic splint with pivotable self-alignillg pads located to rest against bony J~ ACeS such as joint condyles and thereby preveAt migration of the splint along tAe limb during _ L ' A iurther object of the present invention is to provide a dynalnic ankle splint with 5 a dynamic cradle for applying an adjustable torsional load to the ball of the foot to correct inversion and eversion of the ankle.
Yet another object of the present invention is to provide a dynamic wrist splint wbich is attached to the forearm, and applies a bias force to the b2nd through a novel palm interface.
It is also an object of the present invention to provide a dynarnic wrist splint which distributes fo}ces over a large area of the palm.
A further object of the present invention is to provide a dynamic wrist splint which adjusts over the wrist's arc of rotation to ~,ol~roll~bly distribute forces over the palm.
Anl~ther important object of the invention is to provide a dynamic splint having a bi-directional power unit that can be readily switched between flexion and extension force modes.
It is also an object of the invention to provide a reversible power unit with a spring fastened between first and second struts to selectively deliver force opposing eitAer extension or flexion.
Another object of the invention is to provide a reversible bi-direction power unit which is mounted about a hinge pin amd can be selectively rotated between two positions to apply forcP, in one of two directions. In the first position, the power unit is locked relative to a first strut and a spring in the power unit opposes relative movement of a second strut in a first direction. In the second position, the power unit is locked relative to the second strut, and the spring opposes movement of the first strut relative to the second strut, applyimg force in the opposite direction from the force provided iA the first position.
Another object of the present invention is to provide a novel universally sized soft cuff/strap ~lesign for a dynalnic splint that simplifies set-up and provides infinite adjustment capability for iAcreased comfort and p~l[OIIII~I-,~. Infinitely adjustable telescoping struts are also provided to facilitate custom fitting ~iuc~mpr~
Another object of the invention is to provide an improved cam locking mechanism for selecti~ely disabling the torsional force of the power unit when domling or doffing the spliAt.

wo ss/zs489 2 1 8 6 2 2 7 r~
These, and other objects of the present invention are 3r , " ' ' by providimg anadjustable splint having a pair of elongated strut assemblies which each incorporate a pivotal joint between the ends thereof. These strut assemblies are supported on opposite sides of a body joint by a strut support unit which is mountable on a body member and which locates 5 the pivotal joint in alignment with a body joint. Each strut assembly includes a first elongated strut member and a second elongated strut member which extend from the pivotal joint. The elongated strut members of each strut assembly are flat units which may be contoured to match the contour of the body member upon which the splint is moumted. The pivota~ joint operates to commect one end of the first and second strut members for pivotal 10 movement about a pivot axis between a first extended position where the elongated strut members extend outwardly from opposite sides of the pivotal joint and a second closed position where the first and second strut members extend outwardly in close proximity from the same side of the pivotal joint. A bias unit is provided at the pivotal joint to oppose pivotal movement of the strut members in a first direction and to aid such pivotal movement 15 in a second opposite direction. The magnitude of the bias is adjustable by a mechanism which is also located at the pivotal joint, while the range of motion provided by the joint can be altered by spring loaded pins which operate as stops for the strut members. The relative magnitude of bias provided is indicated in a preferred i l ' by numericmarkings on a rotating member of the adjustment mf ~-~icm The portion of the rotating 20 member having the appropriate magnitude marking is visible through an aperture in the housing. A pin lock mechanism is provided for locking the strut members to prevent relative movement thereof and to temporarily prevent the application of force by the bias unit during attachment and removal of the splint.
Specific preferred el.lb, ' of the invention include a dynamic ankle splint 25 ;,~ a correction çradle. The correction cradle applies a torsional force to the foot, thus permitting correction of inversion and eversion of the ankle in ~..,; ", ~i.", with correction of ~i.":~il~. .;..,~ and plantar flexion. A dynanuc wrist splint attaches to the forearm and provides a novel palm interface which adjusts to apply force over a large area of the palm deperlding on the angular position of the hand. A flexion strap is provided at 30 the back of the hand for applying flexion forces.
In a preferred c.lll.~" t, a bi-directional power unit, which may employ a torsional spring, is fastened between first and second struts to selectively deliver force opposing either extension or fiexion. The power urlit is mounted about a hinge pin and can .. . ... .. . . .. . _ ... . .. ..

~ wo9s/2s489 2186227 r_.,n~

be rotated between two positions. In the first position, the power unit is locked relative to the first strut and tbe torsion spring opposes relative movement of the second strut in a first direction. In the second position, the power unit is locked relative to the second strut. In this seconl~ position, the torsion spring opposes movement of the first strut relative to the 5 second strlt. However, because of the rotation and re-locking of the power unit, the second position pl ovides force in the opposite direction from the force provided in the first position .
As a result, a single dynamic splint can be used in both flexion and extension modes.
Additional features of the dynamic splint include pivoting seLf-aligning contour plates on the struts that conform to tbe anatomy and provide a mechanical interlock to bony 10 I,.ul.fll.~ on the patient's limbs, such as the maLleoli and femoral condyles. As a result, superior bracing stability is acbieved and the tendency of splints to migrate downward during ambulation is eliminated. A novel single cuff/strap design simplifies set-up and provides illfinite adjustment capability for increased comfort and l~ r.~ Infinitely adjustable telescoping struts are also provided to facilitate custom fitting ~
An improved cam locking mechanism disables the torsional force of the power unitwhen donning or doffing the splint. ~;O - ly, this cam locking mechanism is also useful in locking the splint in a .~,.~. ~. ., . ~i position to protect the affected limb against movement and damage during ... ' _' Th~ dynamic splints disclosed permit of a defined tolerable force level with near constant linearity over a ~vide range of motion of a body joint. The dynamic splints are ~ , useful for ~ llyl~Lic of range-of-motion and mobility, particular in post-operative cases.
RriPf ~,~c~ ;rm of rht DrAwir~c Figure I is a view in side elevation of the dynamic extension splint of the present invention;
Figure 2 is a plan view of a strut assembly for the dynamic extension splint of Figure ;
Figure 3 is a sectional view of the strut assembly of Figure 2;
Figure 4 is a view in front elevation of the strut assembly of Figure l;
Figure 5 is a sectional view of a biasing spring assembly used in the strut assembly of Figure 3;

wo ssl2s4ss : 2 ~ 8 6 2 2 7 ~ 199 Figure 6 is a view in side elevation of a second ~ ' ' of the dynamic e~tension splint of the present invention;
Figure 7 is a sectional view of a strut assembly for the dynamic extension splint of Figure 6;
S Figure 8 is a sectional view of the strut assembly of Figure 2 showing a range of motion stop assembly;
Figure 9 is a sectional view of a spring loaded pin used in the range of motion stop assembly of Figure 8;
Figure 10 is a partial plan view of the strut assembly of figure 8;
Figure 11 is a partial plan view of a strut assembly for the dynamic extension splint of Figure 6 showing a range of motion stop assembly;
Figure 12 is a partial sectional view of the strut assembly of Figure 11;
Figure 13 is a side view of a locking pin according to the present invention, installed through the housing and into the strut assembly to prevent relative rotation of the struts;
Figure 14 is a side elevation of am ankle brace according to the present invention ill-,UlUUl.l~ a novel foot pronation/supination cradle;
Figure 15 is a front elevation of the ankle brace of Figure 14;
Figure 16 is a side view of a wrist brace according to the present invention i.lCul~luldli.lg a novel palm interface structure;
Figure 17 is a top view of the wrist brace of Figure 16;
Figure 18 is a top view of another .~ L ' of the wrist brace of the present invention, ihlcul~uld~ g a modified palm imterface design;
Figure 19 is a bottom view of the wrist brace of Figure 18 showing the palm interface thereof in greater detail;
Figure 20A is an assembly drawing of am improved cam locking mechaoism for a dynamic splint, and Figure 20B is a side view of the cam locking mechanism shown in Figure 20A;
Figure 21 is an assembly drawing of an alternative design locking mechanism for a dynamic splint;
Figure 22A is an assembly drawing showing one side of a dynanuc splint with pivoting contour plates amd infùlitely telescoping struts according to the present invention, and Figure 22B is a detail drawing of a pivoting contour plate;

~ WO 95/2548'A~ 2 1 8 6 2 2 7 r~ J~
g Figure 23A is a top view of the bi-directional dynamic tension unit according to tbe present in~ention;
Figure 23B is a cross-sectional view showing the assembly of the bi-directional dynalnic tension unit of Figure 23A;
S Figure 24 is a plan view of a proximal strut of the l.~ ;.,.. A1 dynamic splint of the present invention;
Figure 25 is a plan view of a distal strut of the 1,:1;,~ dynamic splint of the prese~lt in~ention;
Figure 26A shows the bi-directional power unit connectPd for flexion operation, and 10 Figure 263 shows the bi-directional power unit connected in position for extension operation;
Figure 27A shows an improved single cuff/strap assembly according to the presentinvention, and Figure 27B shows the assembly of Figure 27A installed on the adjustable dynamic splint of Figure 22.
15 l~P~'Ti~ti~lTI of thP Preferred r...l..~i;
Referring now to Figures l-S, the dynamic extension and/or flexion splint of thepresent invention indicatPd generally at 10 includes a suspension sleeve 12 formed from neoprene foam or similar material having some elasticity. The suspension sleeve is adapted to fit snugly around a limb or other body member in the area of a joint and operates to 20 position a mechanical joint assembly 14 in alignment with a body joint. Suspension sleeve 12 provides a slight ~,OUI~ OII to the body member in the area of the affected body joint.
This c. ~ and heat associated therewith, facilitates tissue nutrition which facilitates tissue growth.
A p~air of mechanical joint assemblies 14 are mounted upon opposite sides of the25 suspension sleeve 12 as illustratPd in Figure 4, and each mechanical joint assembly includes first arld second strut members 16 and 18 which extend outwardly from a mechanical joint - 20 which is a hinge structure. The strut members 16 and 18 are removably received in open ended, spaced pockets 22 and 24, ~,~liv~ly, and a pair of such pockets are secured to each of ~wo opposite sides of the suspension sleeve 12. These pockets may be formed 30 of le_ther or similar material, and operate to facilitate removal of a mechanical joint assembly 14 therefrom. When the mecharlical joint assembly is in place within the pockets woss/2s489 2 ~ 8 622 7 æ ;md 24, the mechanical joint 20 wiU be retained in position at the side of a body joint to be treated. Adjustable posterior straps 26 and 28 and anterior straps 30 and 32 are secured to the pockets 22 and 24. The cnnnhin~ n of an anterior and posterior strap is positioned on either side of the mechanical joint 20, and these straps cooperate to surround S the limb of a user on either side of a joint to be treated. Such amterior and posterior straps msure that optimum therapeutic c;rf~li~ is obtained from the spring tension provided by the mechanical jomt 20.
The mechanical joint 20 is formed at ends of the strut members 16 and 18 which are pivoted about a pivot post 34. These pivoted ends of the strut members are bifurcated to 10 provide an enclosure for am adjustable spring mechanism used to tension the mechanical joint 20. Thus, the first strut member 16 consists of a flat, elongate strut section 36 which, as it approaches the mechanical joimt 20, is split into an upper leg 38 and a lower leg 40.
The upper leg extends paraUel to and is spaced from the lower leg by a bridging section 42.
Similarly, the second strut member 18 includes a flat, elongate strut section 44 having a 15 bifurcated end with a lower leg 46 which extends paraUel to but is spaced from an upper leg 48 by a bridging section 50. The upper and lower legs 38 and 40 and the upper and lower legs 46 amd 48 are arcuate in ....,1~" ,.1;.~,., as iUustrated by the lower legs 40 and 46 shown in Figure 5. The upper legs 38 and 48 substantiaUy match the lower legs m As illustrated in Figure 3, the legs 46 and 48 fit within the legs 38 and 40, and are moumtedforpivotalmovementbythepivotpost34whichexh~ndsll,---1:~-.,--,,h Thispivotpost creates a pivotal axis which is substantiaUy ~ to the Inn~ih~ axes 52 and 54 of the stlut sections 36 and 44, ~li\~.,ly.
A gear housing 56 is secured to the outermost surface of the upper leg 38, and operates to enclose a gear 58 mounted upon one end of the pivot post 34. This gear meshes with an adjustment screw 60 which is mounted for rotation in the gear housing 56. The adjustment screw has threads which engage the teeth of the gear 58 in known manner to rotate the gear amd thereby rotate the pivot post 34. However, when the adjushment screw 60 is stationary, it locks the gear and the pivot post to the upper leg 38 and the lower leg 40. However, the lower leg 46 and upper leg 48 are moumted for pivotal movement about the pivot post 34.
As wiU be noted from Figure 3, the pivot post extends completely through the upper legs 38 and 48 and the lower legs 40 and 46, and is held in place by a removable clip 62 ~ woss/2s48s 2186227 r~.,u~ 13~
which engages a groove in the pivot post. This removable clip may be formed by a spring clip, washer, or other known removable clip means, which can be removed from a groove in the pivot post 34 to facilitate disassembly of the mechanical joint 20. This permits a circular leaf-spring 64 to be mounted about the pivot post 34 between the lower and upper legs 46 and 48. One end 66 of this circular leaf-spring is secured within a central slot 68 formed in the pivot post 34, while an opposite end 70 of the leaf-spring is hooked about a post 72 which extends between the lower leg 46 and tbe upper leg 48. A second post 74 extends between the upper leg 38 and the lower leg 40, and this post is engaged by a step 76 formed in the periphery of the lower and upper legs 46 and 48 when the flat elongate strut sectiolls 36 and 44 are in tbe extended position of Figure 2.
The degree of tension set into the circular leaf-spring 64 may be indicated by indicia 132 on the gear 58 which cooperates with a stationary indicator 134 formed on the gear housing 56. Specifically, gear 58 may be marked about its periphery with a series of numbers or other markings indicating the relative tension existing on the spring when that marking occupies a defined position. Stationary indicator 134 may take the form of an aperture in gear housing 56 through which indicia 132 (i.e. the numbers or other markings) are visible.
As ~ill be noted from Figure 5, when ~he flat elongate strut sections 36 and 44 are pivoted toward one another in the direction of the arrows in Figure 5, the steps 76 will move away from the post 74 and the pivotal movement will be opposed by the tension of the circular leaf-spring 64. Thus, the flat, elongate strut sections move from an extended position wi~h the steps 76 in contact with the post 74 against the bias of the spring 64 to a second closed position wherein the first and second strut members come into contact and extend from the bottom side of the mechanical joint 20 in Figure 5. As the flat elongate strut sections 36 and 44 are pivoted back to the extended position shown in Figure 2, the pivotal movement is aided by the bias of the spring 64. It is obvious that this bias may be adjusted by rotating the adjustment screw 60 which in turn engages and rotates the gear 58 to rotate the pivot post 34. Depending upon the direction of rotation of the pivot post, the convolutions of the spring 64 will be tightened or loosened to adjust the bias of the spring.
It is noteworthy that the flat elongated strut sections 36 and 44 are formed from aluminum or similar lightweight, bendable material. Not only does this make the dynamic extension splint 10 light and compact, but it also permits the strut sections to be bent to conform to the outer contour of the limb of a user after the splint is in place to enhance wo gs/25489 2 1 8 6 2 2 7 ~

comfort. Also, since the mech<mical joint 20 can be ~ I-lr-1 by removing the spring clip 62, the spring 64 can be reversed to reverse the direction in which the spring aids or opposes pivotal movement. This facilitates therapeutic use of the dynamic extension splint 10 to provide either flexion or extension resistance. The spring ~orce can also be reversed by the means described below in connection with Figures 23 through 27.
Referring now to Figures 6 and 7, a second . l-o~ of the dynamic splint of the present invention is indicated generally at 78. For purposes of ri~ ~rnrri~n structulal dements of dynamic splint 78 wbich are identical in structure and operation to those previously described in connection with dynamic splint 10 will be designated with like reference numerals. Also, in Figure 6, only one side of dynamic splint 78 is illustrated, but it should be recognized that the first and second strut members and mechanical joint shown in Figure 6 are provided on both sides of the suspension sleeve 12 as shown in Figure 2.
Dynamic splint 78 includes a suspension sleeve 12 which differs from that of Figure 1 in that it is provided with an opening 80 to receive the patella or another portion of a body joint to be treated. The sleeve also includes pull straps on either side connected to one end of the pocket 22. These pull straps, one of which is indicated at 82, are used to pull the sleeve 12 over a hmb or a body member.
Dynamic splint 78 differs from dynalnic splint 10 mainly in the structure of themechanical joint, for the splint 78 includes a polycentric mechanical joint 84. This polycentric joint includes two spaced pivot pins 86 and 88 instead of the single pivot post 34 of Figure 3. Each of these pivot pins extends tbrough one of the bifurcated ends of the strut members 16 and 18. It will be noted that these bifurcated ends do not overlap, as illustrated in Figure 3, but imstead, are spaced arart by the pivot pins 86 and 88. Thus, as illustrated in Figure 7, the first strut member 16 includes the flat elongate strut section 36, and a bridging section 90 which extends between a lower leg 92 and an upper leg 94.
Similarly, the second strut member 18 includes the flat, elongate strut section 44 and a bridging section 96 which extends between a lower leg 98 and am upper leg 100. The bridging sections 90 and 96 space the lower legs 92 and 98 an equal distance from the upper legs 94 and 100, and circular leaf-springs 102 and 104 are moumted about the pivot pirls 86 and 88 between the upper and lower legs of the first amd second strut members. One end 106 of the spring 102 is hooked about a post 108 that extends between the lower leg 98 and the upper leg 100 of the second strut member 18, while an opposite end 110 of the spring 102 is secured within a slot 112 formed in the pivot pin 86. Similarly, one end 114 of the ... . _ _ _ _ _ _ _ . _ _ _ _ . ... .

~ W0 95~2s489 2 1 ~3 ~ 2 2 7 ~ 5J
spring 104 is hooked about a post 116 which extends between the lowe} leg 92 and upper leg 94 of the first strut member 16, while a second end 118 of the spring is secured within a slot 120 formed in the piYot pim 88.
- A housing 122 extends over the bifurcated ends of the first and second strut members 16 a~d 18 and encloses the polycentric mechamical joint 84. The pivot pins 86 and 88 extend outv~ardly on either side of the housing and on one side are clipped in place by the remoYable clips 62. The opposite ends of the pivot pins extend outwarlly beyond the housing 122, and bear meshed gear members 124 and 126. These gear members operate to gear the pivot pins 86 and 88 together, and one gear member is mounted on the end of each of the pivot pins to rotate therewith. Secured to the end of each pivot pin and projecting above the respective gear members 124 and 126 is a tool engaging adjustment knob, with two such adjustment knobs being indicated at 128 and 130. These adjustment knobs inclu~le a plura~ity of flat surfaces for ~"~ . 1 with a wrench-type tool that is used to turn the gear members 124 and 126. For example, if the tool engages the adjustment knob 130 and turns the gear 126 in the direction of the arrow in Figure 6, then both of the pivot pins 86 and 88 are turned by an equal amount due to the mesh between the gears 126 and 128. This adjusts the bias of the springs 102 and 104 an e~ual amount, and the degr~ee of tension set into the springs may be indicated by indicia 132 on the gear member 124 which coop.~rates with a stationary indicator 134 formed on the housing læ.
To l~ck the gear members 124 and 126 in a desired position, a small locking gear136 is provided on the end of an elongate slide member 138 which slides in a slot 140 formed in the housing 122. The locking gear 136 has teeth which engage the teeth of the gear members 124 and 126 to lock these gears in place. To unlock these gears for purposes of bias :~'; t, the slide member 138 is moved to the left in Figure 6 to disengage the gear 136. The slide member may be . ' ' by means of a knob 142 provided on the end thereof opposite to the locking gear 136.
The housimg 122 is formed with i ~ c 144 and 146 to engage the first and second strut members 16 and 18. These ' provide stops for the strut members in the extended position shown in Figure 6. However, the two strut members may be 30 moved together to the leh in Figure 6 for a full 180 due to the polycentric co,L~ ,tiul. of the mechanical joint 84. As the strut rnembers pivot, the pivotal movement is tr,msmitted by the posts 108 and 116 to the springs 102 and 104, and these springs oppose pivotal movement between an extended and a closed position in one direction while aiding pivotal wo s~/2s4sg 2 1 8 6 2 2 7 ~ ~ 99 moYement in the opposite direction. The bias of the two springs may be adjusted equally by rotating one of the gear members 124 or 126 to accomplish rotation of the opposite gear for an equal amount and therefore rotation of the pivot pms 86 and 88.
As m the case of the spring 64, the springs 102 and 104 can be reversed by S removing the clips 62 and .I; _~,I.li,.~ the mechanical joint 84. Thus the dynamic extension sp~int 78 can be configured to provide either flexion or extension resistance.
The dynamic extension splints 10 and 78 may be provided with an adjustable rangeof motion stop assembly to limit the degree of motion a body member is permitted to make around a body joint. For many types of injuries, it is beneficial to rehabilitate the body joint in stages with the degree of motion permitted by the splints being increased as free motion in a previous stage is achieved. With reference to Figures 8-10, the mechanical joint assembly 14 for the dynamic extension splint 10 includes an arcuate line of spaced holes 150 and 152 formed in the legs 38 and 40 Ic~li~ly. A hole 150 is aligned with a i,.P hole 152 to receive one of the spring biased pins 154 or 156 extending fromopposite ends of a stop 158. The stop 158 includes a stop housing 160 that retains the pins 154 and 156 which are biased outwardly from the ends of the stop housing by a spring 162.
The stop housing extends across the legs 46 and 48 so that when the pins extend into selected holes 150 and 152, the stop 158 will engage the legs 46 and 48 to limit the relative pivotal movement of the strut members 16 and 18. To remove or adjust the position of the stop 158, the pins 154 and 156 are ~rr~cc~A into the stop housing 160 so that the stop can be disengaged from the holes 150 and 152.
The dynamic extension splint 78 shown in Figures 11 and 12 is also provided witha range of motion stop assembly including a plurality of arcuately arranged spaced holes 164 and 166 formed in the upper amd lower edges Ic~li~. ly of the housing 122. As shown in Figure 12, which is a view of a portion of the mechanical joint 84 with the springs 102 and 104 removed for purposes of illustration, two stops 158 are positioned to span the distance between the upper and lower edges of the housing 122, with a stop eA-tending in front of each of the bifurcated ends of the strut members 16 and 18. The spring biased pins 154 and 156 for each stop extend into a hole 164 and 166 IC~Li~. ly in the housing 122.
Thus, each stop limits the range of pivotal movement of a strut member 16 or 18 depending upon where the stop is positioned in the line of holes 164 or 166.
Figure 13 is an exploded view of a preferred ~ " - of the mechanical joint 20 which provides a locl~ing means for relieving the action of the bias mechanism during * WO 95/2548!~ 2 1 ~ 6 2 2 7 ~ 99 installation and removal of dynamic extension splint 10. In this, ~ t, mechanical joint 20 has a hole 170 through housimg 56 of mechanical joimt 20. A hole 172 of si~e and shape similar to that of hole 170 is formed im strut member 18, which rotates relative to housing 56 and strut member 16 as explained previously. Holes 170 and 172 are formed 5 at the same distance from the axis of rotation of strut member 18 (i.e. pivot post 34, not shown) so that holes 170 and 172 are aligned, at one point in the rotation of strut member 18 relative to housing 56, along a locking pin insertion axis 174 paraUel to the axis of rotation of strut member 18. At the poimt of alignment of holes 170 and 172, locking pin 176 can be inserted through both holes 170 and 172 to prevent relative motion of strut members 16 and 18. Locking pin 176 comprises knob 178 and elongated pin 180. Of course, a l~lurality of holes 170 or holes 172 could also be provided to provide several points of a]ignment at which strut members 16 and 18 could be locked together. Also, holes 170 and 172 and locking pin 176 can be provided on either one or both of the twomechanica~ joints 20 of a given dynamic extension splimt 10, as desired.
In use, locking pin 176, together with holes 170 and 172, can be used to remove the bias force provided by mechanical joint 20 during attachment and removal of dynamic extension splimt 10 from the affected body part. The elimination of the bias force during attachment and removal simplifies the attachment and removal process, L~ ,ul~ly when larger bias forces are being applied. Specifically, any bias force ~ tending to act against the forces needed to disengage . I of dynamic extension splint 10 from the affected body part will be nP~ i7P~l This i "-~ ;"" of bias forces also prevents any springing back of strut members 16 or 18 when one of strut members 16 or 18 is released from the affected body part and the other is stiU attached. Such springing action as a result of bias forces during removal of the device could aggravate the injuries being treated with dynamic e~:tension splint 10, or cause fur~her injuries. Of course, bias force could also be reduced by adjusting the tension on mechanical joints 20. EIowever, the use of locking pin 176 pern~its complete elimination of the bias force without disturbirlg the desired bias force setting.
Referring now to Figure 14, an ankle splint according to the present invention is shown generally at 182, attached to a human ankle 184 connecting leg 186 to foot 188 having toes 190. Ankle splint 182 comprises two strut members 16, one on each side of leg 186, which are rotatably connected via mechanical joints 20 (which is of a type described ]?reviously) to strut members 18, one on each side. Strut members 18 are W0 95125489 2 ~ 8 6 2 2 7 P~ lll ''^~199 rotatably conDected by fasteners 195 to arms 193 which are rotatably connected by pins 192 to a central cradle 194 which supports a foot carriage 196. Foot carriage 196 is commected to travel in an arc relative to cradle 194 along slot 212. Fasteners 214 loosely connect foot carriage 196 to cradle 194 to penTut this arc-like movement. Fasteners 214 are preferably of nylon or incorporate nylon bearing washers to facilitate sliding of carriage 196 along slot 212. A spring 218 is moumted between attachment 216 (moumted on carriage 196) and a tensioDing bolt 220 mounted through slot 212 and held in position along slot 212 by nut 222.
Fasteners l9S can be loosened to laterally adjust the angle of arms 193 to, for deviations in alignment of the foot. Fasteners 195 will then be tightened to hold arms 93 finnly to strut members 18.
Strut members 16 are attached to leg 186 by extension straps 204 and flexion straps 205 which pass through opposite holes 210 at the front and back IC.~U~ly of one of the two strut members 16, and are then attached to similar straps 204 and 205 æsociated in the same manner with the strut member 16 on the other side of leg 186. 'îhe attachment of straps 204 and 205 is preferably by hook-and-loop fasteners, such as Velcro, although other types of strap commecting h^rdware could also be used. Optionally, a heel cup 198 may be provided for further stâbiliziDg ankle splint 182 with respect to ankle 184. A strap 200 connects heel cup 198 to ankle splint 182 via a snap 202 or other appropriate fastening me ns. Cuffs 206 are imstalled on leg 1 86 under straps 204 to prevent chafing aDd increase comfort during use. Cuffs 206 are made from a three-part laminate comprising a central layer of split neoprene, am outer layer of loop material for use with hook-and-loop fasteners, and an inner non-allergenic padding and liDing layer. Cuffs 206 have loop fastener material section 207 attached to tbe inner layer of cuffs 206 at am edge 211 thereof parallel to the 1~ axes of strut members 16. Cuffs 206 will be provided in an oversi^~e cl~c~, and may then be cut at the end opposite from edge 21 1 bearing loop fastener material section 207, to fit tbe particular patient's body part. Loop fastener material section 207 will engage the outer layer of cuffs 206 at any point about cuffs 206, &us providing a cu,lLu,uuu~ly-adjustable snug fit around leg 186. Strut member 18 may be provided with a pad 208 of sheepskin or other soft material. Strut members 16 are of aluminum or other relatively soft metal to facilitate bending of strut members 16 by the installer to conform to the shape of leg 18~
-wO 9s~2s4s) 2 1 8 6 2 2 7 A ~

Figure lS, which is a front. l view of ankle splint 182, shows more clearly the bending of strut member 16 to conform strut member 16 to the shape of leg 186. As a further attlchment means, strut members 16 have hook fastener material 209 attached to their inner surfaces, and hook fastener material 209 engages the loop fastener material on S the outer kayers of cuffs 206 to hold strut members 16 in position with respect to cuffs 206.
Carriage 196 receives the ball of foot 188. Of course, the ~ ,., of cuffs 206 c~m be changed depending on the arFliratit)n Either a plurality of smaller cuffs 206 or one larger cuff 206 cam be provided in the mounting area of ankle splint 182.
Anl~e splint 182, through the bias force provided by mechanical joints 20, provides therapy for correction of both plantar flexion _nd .1. ., ~ ;. ", limitations. As will be seen, the bias fc,rce provided by spring 218 acting on carriage 196 also permits correction of inversion and eversion of the foot. Since inversion or eYersion accompany a large percentage of ankle :' " ankle splint lg2 provides a major advance in totl dynanuc th!erapy for the lower leg, ankle, and foot.
Referring now to Figure 15, it will be seen that spring 218 is of the type having t vo arms æ4 and 226 e~tending outw_rdly from a central biasing device, such as a wire coil, which provides a ffirce biasing arms 224 and 226 toward a rest position in which arms 224 and 226 ar~ separated. Arm 224 is connected to attachment 216 of carriage 196, and arm 226 is comlected to tensioning bolt 220. The arms 224 and 226 may pass through holes provided in attachment 216 and tensioning bolt 220, or may be attached in some other UI way. Depending on the positioning of tensioning bolt 220 anywhere along slot 212, spring 218 provides a variable biasing force tending to move carriage 196 in one or the other direction along slot 212. As carriage 196 moves along slot 212, it rotates in an arc relative to ankle 184, tending to rotate the end of foot 188 in the region of toes 190 rekative to ankle 184. Also, due to the share of cradle 194, the ball of the foot 188 tends to move up or down relative to ankle 184 as it rotates under the influence of spring 218.
Thus, cradle 194, carriage 196, spring 218, and their associated ~ , in, ;_ with the other: 1 of ankle splint 182, comprise a me_ns for applying a bias force tending to rotate foot 188 laterally relative to ankle 184, while at the same time applying 30 a bias force tending to move the end of foot 188 up or down relative to ankle 184. The cradle 194 is designed to be reversible im its connection to arms 193 to r~ bothleft and right feet.

Figure 16 shows a wrist splint ~30 designed according to the invention. An elastic neoprene cuff 206 similar to the cuffs 206 described previously is attached about forearm 232, and flexion straps 234 and extension straps 236 are attached about cuff 206, using hook-and-loop fastener material or other adjustable attaching methods, to connect two strut members 16 located on the sides of forearm 232. Each strut member 16 is fixed to a mechanical joint 20. Struts 238 are attached to mechanicsl joint 20 to rotate relative thereto and to be biased in one direction or the other depending on the assembly of mechanical joint 20, as described previously. Each strut 238 has a series of adjustment holes 240 spaced along its length. Depending on the size of the patient's hand 248, axial pin 242 will be 10 irlstalled through and between two Cu~ adjustment holes 240, one on each strut 238. Axial pin 242 is a structural member which connects struts 238 to hold struts 238 palallel. Axial pin 242 also provides an attaching point for a palm strap 244, and defines an axis about which palm strap 244 rotates. Strap 246 is attached to axial pin 242 or palm strap 244 across the back of hand 248. In this i ' ' t, straps 244 and 246 are 15 preferably made of fairly rigid material, such as thin aluminum. In actual use, straps 244 and 246 will be padded for comfort with sheepskin or other appropriate padding material as described previously with respect to other ~ c ' However, to avoid obscuring structural parts in the drawing, tbis padding material is not shown in Figure 16.
In use, palm stlap 244 trimsmits the bias force of mechanical joints 20, where 20 ~ , to oppose exterlsion of the wrist. S;~,..irl~lLly, the dist~nce between palm strap 244 amd mechanical jomt 20 is adjustable by installation of axial pin 242 in different pairs of adjustment holes 240. Also, palm strap 244 rotates about axial pin 242 during extension of the wrist, so tbat palm strap 244 maintains its location relative to the palm of hand 248.
This rotating action is important, since the distance between the palm and mechanical joints 25 20 will vary during movement of the hand about the axis extending between mechanical joints 20. The rotating motion of palm strap 244 provides a means for dynamically adjusting the location of palm strap 244 in the palm in response to changes in the orientation of hand 248.
Strap 246 transmits the bias force of mechimical joints 20 to oppose flexion of the 30 wrist when mechanical joints 20 are adjusted to provide a flexion-opposing bias force.
Figure 17 is a top view of the wrist splint 230 of Figure 16 showing a dorsal support 250 mounted along the dorsal side of forearm 232 and held in place by flexion straps 234.
The rounded end of dorsal support 250 is placed " '~/ to the side of the styloid _ _ _ _ . .. _ . _ . . . . . . .. . . . .

woss/2s48s r~""~A"g9 2 ~ 86227 process, toward the center of the wrist. Preferably, dorsal support 250 has hook fastener rnaterial mounted on its underside to connect with the loop fastener material on the exterior of cuff 206, thus fulther holding dorsal support 250 in place relative to the wrist. Dorsal - support 250 is of aluminum or other bendable rigid material. Dorsal support 250 provides S additional rigidity and support for the attachment of wrist splint 230 to forearm 232 when wrist splint 230 is applied to oppose extension of the wrist. In particular, during extension of the wrist, the dorsal support 250 delivers the '( of the wrist splint 230 to the wrist axis at an optimal point. Dorsal support 250 will not be used when wrist splint 230 is configured to oppose flexion of the wrist.
10 Figure 18 shows a preferred 1.. ~ .. of a wrist splint generally at 251. The attachment of wrist splint 251 to foreann 232 is substantially similar to that previously described with reference to Figures 16 amd 17 for wrist splint 230, amd will not be repeated here. Wrist splint 251 differs from wrist splint 230 im that relatively short strut members 252 are attached to mechanical joints 20 to rotate relative thereto, biased by the bias force exerted by mechanical joint 20 as described previously. Elongated rigid arms 254 are attached to each of the strut members 252 through one end of arms 254 by fasteners 256.
Fasteners 256 may be hex head screws, and are chosen so that they may be loosened, permitting arms 254 to rotate about the axis defined by the length of fasteners 256, and then tightened to hold arms 254 at a desired angle with respect to strut members 252.The ends of arr~s 254 not attached to strut members 252 are attached through slots 255 to opposite ends of an elongated rigid crossbar 258 through slot 259 by additional fasteners 256 which, as described above, can be loosened to permit adjustment of the angles between arms 254 and crossbar 258, and tightened to hold arms 254 and crossbar 258 relatively ir~nobile. A palm strap 260 is attached at opposite ends to opposite ends of crossbar 25~ to rotate about an axis parallel to the central lo.~g;l~ 1 axis of crossbar 258.
The ~ r~ provided by slots 255 amd 259 permit adjustment of the length of the moment arm from the wrist axis to the palmar crease to suit the individual patient. In addition, theangularadjustabilityofthestructureshownallows~ .1 forradialand ulnar deviation.
Figure 19 is a bottom view of wrist splint 251 of Figure 18 amd shows the palm interface of wrist splint 251 in greater detail. Palm strap 260 is a flexible strap, which may be made from heavy nylon fabric and provided with metal fasteners or snaps for rotatable attachment to crossbar 258. A palm pad 262, shaped to fit the palm with a cutout region wosst2s4ss 21 8 622 7 r~

to: the thumb, is attached to palm strap 260. Palm pad 262 is preferably made of a fairly rigid yet flexible material, such as urethane. Palm strap 260 and palm pad 262 may be reinforced with thin aluminum inserts to provide added rigidity and structulal strength. The aluminum inserts can be bent to provide a uniform loading across the concave surface of the transverse arch. Palm strap 260, palm pad 262, and crossbar 2',8 will gerlerally be covered with lambs wool or other padding materia'l (not shown) when wrist splint 251 is in use.
In use, the wrist sphnt 251 shown in Figures 18 and 19 can be adjusted to c~mrPnc~tp for differences in angle between hand 248 a~ad forearm 232 by adjusting the relative angles of strut members 252, arms 254, and crossbar 258 before tightening fasteners 2',6. As am additional comfort feature, palm pad 262 provides a means for distributing tbe bias force provided by mechanica' joints 20 over a larger area of the palm. The flexible I l ,,.. ". t. .; `I ;~ ~ of palm strap 260 and palm pad 262 combine with the rotation of palm strap 260 relative to crossbar 258 to provide a dynamically self-adjusting force ~ trihllti~n apparatus throughout the range of motion of hand 248.
It is a particular feature of all of tbe designs discussed and shown previously that the split cuffs and straps are not located on the joint itself. Thus, . ' ~ are never applied directly to the joint. In many cases, the affected joint will have been injured and may be painful or swollen. Thus, this feature permits use of the dynamic splint of the present invention even during the early recovery stages of an injury to the affected joint.
As noted previously, the mechamical joints in the dynamic splints of the presentinvention preferably allow full range of motion of the affected joint, plus 10% in either direction. This design provides a substantial advantage in that the joint is not;,-,- -- ~1.;1; . .J
during use of the splints, and everyday activities can be performed if necessary while wearing the splints. Full movement of the affected body parts during wearing of the splints enhances blood flow and thus tissue health. In addition, a full rmge of motion prevents stiffness in the direction other than that being treated. Thus, the dynamic splints of the present invention will not create a flexion limitation by limiting motion in the flexion direction during treatment of am extension problem.
Figure 20 shows a cam locking mechanism 270 which is ~ uLuly useful with the dynamic splint of the present invention. Cam locking mechanism 270 comprises a first strut 274, pm receiving detents 272, pivot pin 276, second strut 278, housing member 280, cam 282, locking pin 2M, elastomeric ~ring or rubber band 286, camsh~ 288, locking knob ~ wo ss/2s4ss 2 ~ ~ 6 2 2 7 r~ 99 290, and attachment posts 292. The cam locking mechanism 270 will preferably be integrated with a force mechanism of the type disclosed above or a bi-directional force mechanism operating about pivot pin 276, but for the sake of clarity the force mechanism is omitted f~om the view in Figure 20.
S Housing member 280, along with a housing member 294 attached to or formed integrally ~ith second strut 278, serves to enclose the operating parts of cam locking mechanism 270. Housing member 280 is fixed to second strut 278 and spaced therefrom by a plurali~y of attachment posts 292. Pivot pin 276 is held in place between second strut 278 and hollsing member 280, either through attachment to second strut 278 and housing member 280 or preferably by floatmg insertion in holes provided in these two parts. A
plurality of pin receiving detents 272 are disposed periodically about first strut 274, which may be eith~ } a proximal or distal strut of the splint. Pin receiving detents 272 are provided on first stru~ 274 adjacent housing member 294 as shown in Figure 20. Preferably, another set of pin receiving detents 272 similar in appearance to the detents shown is attached to 15 first strut 274 in parallel, spaced I ~;"h;~, with the pin receiving detents shown, so that the second set of pin receiving detents is adjacent housing member 280. In this way, locking pin 284 is held at each end by a detent 272 when the cam locking mechanism 270 is actuated. Although two sets of detents preferred, for the sake of clarity, only one set of detents 272 is shown in Figu}e 20A. Figure 20B is a side view of the mechanism of Figure 20 showing the second set of detents 272 provided on strut part 293 which is fixed to strut 274 by rivets or other suitable: ~ ' The spring of the adjustable forcespring device of the present invention may be located in area 295 behween strut 274 and strut part 293 around pivot pin 276 in the manner described elsewhere in the ~1~ ; i ;. I ;
Again, the details of the adjustable force spring device omitted from Figure 20B in order to more cle~rly show the parts and operation of the cam locking mechanism 270.
An elongated slot 296 is provided in housing member 294 and a CU~ Ulldillg elongated slot is provided in housing member 280 (not shown~. Locking pin 284 extends between housimg members 280 amd 294 and is held lhvlcl,vh~vvn~ The ends of locking pin 284 reside in elongated slot 296 and the Cullc ~ ' v elongated slot in housmg member 280, permitting translation movement of locking pin 284 along the elongated slots. Cam 282 is fixed to camshaft 288 which is rotatably attached to housing members 280 and 294 Iv*~vvli~vly. Camshaft 288 passes through housing member 280 and locking knob 290 is fixed to camshaft 288 on the outside of housing member 280. Carn 282 is shaped so that WO 95125489 2 ~ 8 6 2 2 7 as cam 282 is revolved, locking pin 284 is forced to move along the elongated slots into locking O v with one of the pin receiving detents 272. Preferably, the cam 282 on one side of the splvnt is constructed as a mirror image of the cam 282 on the opposite side of the same splint. In this way, one of the cams will be actuated by ~..,.,t. ..1~ Lwij~e 5 rotation and the cam on the opposite side of the limb will be actuated by clockwise rotation.
In this way, turning both locking knobs 290 forward will lock both sides of the splint, and turning the Lnobs backward will unlock the splint. It has been found empirically that this mode of operation is more intuitive for patients than having the knobs both turn~hX,L~ c or both turn clockwise.
Rubber band 286 biases locing pin 284 against cam 282, so that locking pin 284 is held away from pin receiving detents 272 e~cept when cam 282 is turned to force locking pin 284 into ~ with pin receiving detents 272. Thus, by turning the locking knob290, the patient can activate cam locking mechanism 270 to lock the relative positions of the struts 274 and 278 in one of a plurality of ~ ' ' positions. The cam lockingmechanism 270 is ~u li~,ul~u 1~ useful in disabling the torsional force of the power unit when donning or doffing the splint. ~ , this cam locking mechanism is also useful in locking the splint in a ~ lt ' position to protect the affected limb against movement and damage during ' ' In many cases, it may be desirable to prevent any movement of the affected joint while the patient is moving around. For e~ample, in some cases walking on an injured knee joint might result in p~un or further damage if recovery has not progressed to the point where the joint can bear the forces of ~mh~ n In such cases, it may be preferable to lock tbe splint to prevent amy flexion or extension of the leg if the patient will be walking with the splint installed. The struts can then be easily unlocked to apply force to the joint after the patient is sitting down and ready for therapy.
Cam locking mechanism 270 is auvaul~geuu~ over the pin locking mechanism disclosed above in tbat it is self-contained and has no removable parts which could become lost or fall out during :Imh~ n Cam locking mechanism 270 has excellent structural strength and can thus be locked to bear the weight of the patient during ambulation and prevent movement, facilitating the adv ~ mode of use described above.
Figure 21 shows an alternative design locking mechanism for a dynamic splint. Asshown in Figure 21, struts 278 and 274 are commected for mutual rotation about pivot mechanism 276. Pivot mechanism 27~ is preferably a hollow pivot mechanism with acentral hole 277 sized to receive pivot post 34. Strut 274 is provided with detents 300 at _ _ _ _ . _ _ . .. . . _ . . _ . . . . , . .. ... . . .. . . . .. _ .. . . _ . _ . . .

WO 95~2548!~ 2 ~ 8 6 2 2 7 r~ 99 1" ~ ....11; '.1 Iocations radially spaced about pivot mechanism 276. Detents 300 are similar to the detents 272 shown m Figure 20, but detents 300 are generally rectangular in shape to receive the flat end of cylindrical locking pin 302, in contrast to the sprocket shape of detents 27~ which is adapted to receive the cylindrical cross-section of locking pin 284.
S Locking pin 302 is held against strut 278 by locking pin sleeve 298. Locking pin 302 may be spring loaded in the inward direction and provided with a means for selectively mP-~ ir~lly holding it m an outward position. For example, a tab can be provided on the knob portion of locking pin 302 to engage the edge of strut 278 when locking pin 302 is pulled out and rotated to engage the tab with the strut. In this way, the tab will ,. . l, : l~y hold the locking pin 302 in an outward position. By rotating locking pin 302, the tab ca l be disengaged from the strut and the spring force will urge the pin 302 into with detents 300. When locking pin 302 moves inward, it engages one of the detents 30~ and locks struts 274 and 278 together. When locking pin 302 is held in an outward position to clear detents 300, relative movement of struts 274 and 278 is possible.
15 Figure 22A illustrates a preferred .. ,l.o~l~."~ ' of a dynamic splint according to the present in~ention. As shown in Figure 22A, dynamic splint side 304 comprises distal strut 306, proximal strut 308, tension unit 310, proximal strut extension 311, distal strut extension 320, pivot brackets 318 and 3æ, and pivot assemblies 324 installed on each of the pivot blrackets 318 and 322. In the preferred ~ "l.o.l~ r ~1 there are two pivot brackets 318 on the proximal end of the splint and three pivot brackets on the distal end. To provide a more cle~r illustration of the pivot brackets 318 and 322 and the mounting of the proximal and distal strut extensions, only one pivot assembly 324 is shown in the Figure, but it will be understood that pivot assemblies 324 are provided on each of the pivot brackets 318 and 322.
Te]lsion unit 310 is preferably a force-adjustable tension unit constructed with a circular leaf spring, as described in detail elsewhere in the disclosure. Tension unit 310 may also ~ave bi-directional force capability as disclosed below with reference to Figure 23.
Tension unit 310 connects pro~imal strut 308 and distal strut 306 about a pivot pin and applies a force opposing pivotal relative movement of the struts in one direction and aiding pivotal relative movement of the struts in another dnrection. The splint side 304 shown in Figure 22A will be described in terms of use as a knee joint splint, so in this exemplary ~ .,.I,,~l,."r..l the proximal strut will be located along the thigh and the distal strut will be located on the leg below the knee. Elowever, it will be understood that the invention is not W095/25489 1~111 '~3199 limited to use with the knee joint, and splints for other body joints such as the elbow, ankle, and wrist can be similarly constructed using the principles described herein.
Pivot brackets 318 are mounted, for example by riYets, to the proximal strut 308, the proximal strut extension 311, and the distal strut 3061CD~
In the preferred ~ ' ' t, the pivot brackets 318 and 322 are formed of sheet steel with a flat base 328. Two rounded pivot ears 330 extend at right amgles, in parallel, from the flat base 328. Pivot holes 332 are provided in pivot ears 330 to receive a pin defining a pivot axis transverse to the length of the struts. Pins through holes 332 engage pivot assemblies 324 so that pivot assemblies 324 are attached to pivot brackets 318 and 322 and can be pivoted relative thereto about the pin axis. The extension of the pivot ears 330 may be varied depending on the position of the particular bracket along the splint, and also depending on which side of the limb the splint side 304 will support. The length of the pivot ears can be varied to adjust the position of the attached contour plates 334 with respect to the patient's limb. The pivot ear ~' which inherently establish the distances of the contour plates from the struts, may be established according to a typical anatomy, and fine ;~ ".~ in fit can be made by bending the struts or by varying the pad thickness.
Proximal strut extension 311 is attached to proximal strut 308. Proximal strut 308 has threaded holes 312 and proximal strut extension 311 has an elongated slot 314 which aligns with threaded holes 312. Fastening bolts 316 are installed through elongated slot 314 and into the threaded holes 312 to fix proximal strut extension 311 with respect to proximal strut 308. ~iv r ly~ the elongated slot 314 allows proximal strut extension 311 to take an infinite number of positions along the slot length relative to proximal strut 308. Thus, proximal strut extension 311 can be extended to any desired position within the length of elongated slot 314 prior to tightening of the fastening bolts 316.
Similarly, distal strut extension 320 is attached to distal strut 306. Because distal strut 306 has two pivot brackets mounted thereon, including one in the area of the distal strut extcnsion 320 mounting point, it is convenient to integrate the comnection of distal strut extension 320 amd the connection of pivot bracket 3æ. Thus, pivot bracket 322 ispreferably provided with threaded holes 326 in a bottom portion thereof, and distal strut 306 is provided with UU~ J ' v umthreaded holes aligned with holes 326. Fastening bolts 316 can then be installed through elongated slot 329 in distal strut extension 320, and then through the holes in the distal strut 306 and into tbreaded holes 326. Fastenmg bolts 316 are then tightened to hold together all three of the distal strut extension 320, distal strut 306, :,, _ . _ . .. ., _ . _ .. . , . . .. _ . _ . . ... . . . .. = .. . .. . . . . . ... .

wo ss/2~4~9~ , 2 ~ 8 6 2 2 7 r.~ 5 and p~vot bracket 322. Elongated slot 329 allows distal strut extension 320 to take an infinite number of positions along the slot length relative to distal strut 306. Thus, distal strut extension 320 can be extended to any desired position within the length of elongated slot 329 prior tt) tightening of fastening bolts 316.
The positioning of the pivot brackets 318 and 322 is critical to ~ y correct fitting of thl~ splint. The pivot bracket 318 on the proximal strut 308 adjacent to the tension unit 310 is positioned close to the knee joint so that &e pivot assemblies 324 attached thereto will rest firmly against the femoral condyle (bony 1~ in the knee area). By virtue of thl infinitely adjusti~ble extension struts, the two pivot brackets 318 and attached pivot assemblies 324 that are located on the proximal strut extension 311 and the distal strut extension 320 ~ ly can be adjusted with reference to the physical dimensions of a particular patient so that the pivot assembly on the proximi31 strut extension 311 rests ~:uIllru. ~bl~ on the thigh and the pivot assembly on distal strut extension 320 locates above and against the malleoli (ankle bones). In this way, the splint is provided with superior bracing stability. The tendency of most splints of tbis type to migrate downward during movement is avoided by the positioning of the pivot assemblies on bony ~ of the limb.
Pivot assembly 324 comprises a metal contour plate 334, a pad 336, and strap retaining loops 338 on each side of the metal contour plate 334. Contour plates 334 are shaped to c~Dnform to the anatomical features in the area where the contour plates 334 will be installet. In the ~ " shown, contour plates 334 are generally shaped as a portion of il cylinder, with a linear cross section parallel to the length of Ihe struts and an arcuate cross section along a given ~ .u~u to the length of the struts. Strap retaining loops 338 ale steel loops with a linear portion around which straps (e.g. of the type shown in Figure 2~) can be insti~lled. The pad 336 may be a piece of foam rubber or neoprene amd preferably has unbroken loop material integraUy affixed to the side facing the contour plate 334. Pads 336 may be selectively installed and removed from the contour plate 334 using a hook-and-loop fasterling system. Preferably, different thicknesses of pads 336 may be provided a~ld selectively installed on the various contour plates to provide a custom fit based on the anatomical features of a specific patient.
Figure 22B shows the pivot assembly 324 m more detail. Preferably, strap retaining loops 338 are pivotally mounted about an axis parallel to the length of the struts. A pivot bracket 34~ is mounted on the underside of contour plate 334. The structure of pivot W095125489 2 1 8 6227 ~ ~ --bracket 340 is similar to the structure of pivot brackets 318 and 3æ. Ears 344 fit bet~veen ears 330 of pivot brackets 318 and 322, so that upon installation of a pm or pins 342 through the holes 332 in pivot bracket 318 and ~ holes in ears 344 aligned therewith, the pivot assembly 324 is pivotably connected to pivot bracket 318 or 322.
Instead of a separate pivot bracket 340, the contour plate 334 can be provided with integral ears 344, for example cut and bent from the surface of contour plate 334, for engaging ears 330 of pivot bracket 318.
Preferably, a base portion of pivot bracket 340 is fastened to the contour plate 334, by rivets or other suitable fastening methods. ~ook fastener material 346 for mating with the loop material on pad 336 is attached to the top surface of contour plate 334 by an acrylic adhesive. It has been found that the hook fastener material 346 tends to creep along the smooth surface of the contour plate 334, l~uti~,ulcul~ in warm weather and if rubber-based adhesives are used. To further eliminate this problem, it has also been found desirable to rivet pivot bracket 340 to the contour plate 334 after installation of hook fastener material 346 so that the rivets pass through hook fastener material 346, holding it in place.
Figure 23A shows a bi-directional dynamic tension unit according to the present invention. Dynamic tension unit 348 comprises a housing 350 enclosing a circular ~eaf spring 64 which is connected at its center to pivot post 34. There is also provided an adjustment mechanism 352 of a type described above, e.g. with reference to Figure 3, comprising an adjusting gear that can be rotated to turn the pivot pin and thereby change the tension in circular leaf spring 64. Housing 350 is held together by a plurality of connecting pins 354. A hole 353 in the housing 350 provides a fixed mounting position whereby one of the splint struts can be selectively locked to the dynamic tension unit 348.
The outside end of the circular leaf spring 64 terminates in a loop 356 disposed for arcuate movement in an arcuate slot 358 in the housing. For knee use, the arcuate slot 358 preferably extends through 150 degrees of arc. Specifically, ~ zero degrees as the jntPr~ti~n of the line conmecting the centers of hole 353 and pivot post 34 with the arcuate slot 358, and looking down at the top of housing 350, the arcuate slot 358 extends for 150 degrees of arc, between + 15 degrees of arc at end 359 and -135 degrees of arc at end 357.
Loop 356 can be pulled away from end 359 of slot 358 and a stop 361 installed inslot 358 of dynamic tension unit 348, to confine the extension range to the area of slot 358 between -135' and 0. The full range extending to +15 is only used after sufficient . . . ... .. . . ... . . .. .. .. .. .. .. . . . . . . . .. . ... . .. . . ..

wossl2s~89~ 2 ~ 8 622 7 r-J

heali~g has taken place. Then, ma~imum e~tension is achievable by permitting this 15 of lly~ ' ' S;s.l;rl~ily, the radial distance D from the central axis of pivot post 34 to the - center of hole 353 is made eclual to the radial distance D from the center of pivot post 34 S to the center of loop 356. Typically, D may be eclual to about 1.25 inches, but D can be larger or smaller depending on the size of the dynamic tension unit 348 ar.d the application (e.g. wrist, elbow, leg, etc.). As will be seen, malcing these distances eclual facilitates g the dynanuc tension unit 348 from the struts and reverSing its connection to the struts, thereby reversing the force application to the limb.
Loop 356 at the end of spring 64 is a floating mounting point to which the strut other than the strllt connected to hole 353 is fixed, in a manner which will be explained in more detail below.
The internal c- ~ of the bi-directional tension unit of Figure 23A is shown in greater detail in the cross-sectional view of Figure 23B, which is taken along the line lS extending between the centers of hole 353 amd pivot post 34. As can be seen, struts 360 and 362 are rotatably commected about pivot post 34.
Strult 360 is attached to housing 350 in the following manner. As shown in Figure 23B, the housing walls about hole 353 of housing 350 are structurally reinforced by a tubular member 368. Strut 360 has a hole 366, and a machine screw 364 is installed through a washer, into hole 353 of housing 350 amd into the hole 366. Hole 366 may be provided with a threaded insert or nut 369 to receive machine screw 364 as shown, so that when machine screw 364 is installed it c~m be tightened to rigidly fix strut 360 relative to housirlg 35~. Of course, the machine screw: ~ shown is only one way of preventing l elative movement of strut 360 relative to housing 350. Various other fastening means could also be used, for example locking pins, cotter pins, clamps, or various nut-and-bolt ~".~
The floating mounting point of spring 64, that is loop 356, is used to attach strut 362 to the spring 64. With this t, strut 362 is rotatable relative to housing 350 amd strut 360 about pivot post 34. Spring 64 will apply a force aiding rotation of strut 362 in one directian and opposing rotation in the opposite direction. The force applied by spring 64 will always tend to move the rotating strut in the direction of end 359 of slot 358. As shown in Figure 23B, a sleeve 370 is provided in the loop 356 of spring 64 and is rotatable relative to loop 356. A shoulder bolt 372 is installed through a teflon or nylon washer 374, WO 95/25489 2 1 g 6 22 7 through sleeve 370, and into a threaded insert 376 installed in strut 362, thus fixing strut 362 to loop 356 of spring 64. As with strut 360 aboYe, the bolt 372 may thread into an insert in strut 362 so as to fix loop 356 to strut 362.
In the preferred ~,,.I.C,.l;,... - ~ circular leaf spring 64 is attached to pivot post 34, and 5 a tension adjustment of the type described above with reference to Figure 3 is provided to linearly vary the tension in circular leaf spring 64. However, those skilled in the art will appreciate that various other types of springs could also be used to implement the reversible tension unit of the present invention. For example, a long coil-type spring or even an elastomeric band (not shown) could be connected to loop 356, disposed clockwise around the inside periphery of housing 350, and at~ached to the housing 350 at an attachment point (not shown) adjacent to end 357 of slot 358. As can be a,u~ ' 1, while it is convenient and desirable to attach circular leaf spring 64 to tbe pivot post 34 to facilitate a linear force adjustment feature, spring 64 or a spring of a different ~ , could also be attached to other points in or about housing 350. What is important is tbat one end of the spring or other fo}ce application means be attached to the loop 356, and the other to a point that can be fixed relative to the housing 350. As noted above, the actual point of attachment may desirably be movable with respect to the housing 350 for adjustment of tension, but the point of attachment may be held immobile with respect to housing 350 during use of the splint.
As will be seen, with properly configured struts it is possible to attach housing 350 to either of the struts through hole 353, and attach loop 356 to the other strut. Depending on which strut is attached to which part of the dynamic tension unit 348, the dynamic tension unit 348 will operate in either a flexion or contraction mode. That is, the dynamic tension unit 348 can apply force in either direction depending on the attachment to the struts.
The effective bi-directional operation and easy reversibility of dynarnic tension unit 348 provided by the present invention requires that the struts be specially adapted to facilitate reversible operation. Figures 24 and 25 illustrate the UUII~IlUl,liUll of proximal and distal struts, ~ ly, which facilitate reversible operation of dynanuc tension unit 348 in a leg splint.
Referring now to Figure 24, there is shown a proximal strut 308 used with the i,;.l;,~l;~",~l dynamic splint of the present invention. Proximal strut 308 comprises an elongated strut portion 382 and a pivot portion 384. Pivot portion 384 has a centrally WO 95/25489 2 t ~ 6 2 2 7 . ~ " ~ 99 located holls 386 which engages pivot post 34 (shown in Figure 23B). A mounting hole 380 is spaced at a distaoce D from hole 386 (equal to the distance D indicated in Figure 23A) in a direction along the length of proximal strut 308. Mounting hole 380 has a threaded insert 383 for receiving a threaded fastener. Preferably, pivot portion 384 may also be S provided with detents for use with locking of the type illustrated in either Figure 20 or 21.
Ref.~rring now to Figure 25, a distal strut 388 designed to facilitate reversible splint operation ~as an elongated strut portion 390 and a pivot portion 392. Pivot portion 392 has a centrally located hole 394 for receivrng pivot post 34. Pivot portion 392 also has two holes 396 ~md 398, each spaced at distance D from the center of hole 394. Hole 398 is located distance D along a line generally parallel to the length of elongated strut portion 390. Hole 396 is located a distance D along a line at about a 45 angle to the length of elongated strut portion 390. Note that the centerline of elongated strut portion 390 is offset from the pivot which is in line with the proximal strut 382. Typical human anatomy dictates a 518~ offs-t. However, the design shown can be readily adapted to provide amy desired offset.
Holes 394 and 396 are each provided with a threaded insert 400 and 402 ~ .ly for receivillg a threaded fastener. As will be seen, hole 396 is attached to the floating mount of sl~ring loop 356 when flexion mode operation is desired, and hole 396 is not used in extensioll mode operation. Hole 398 is fixed to hole 353 when extension mode operation is desired, but is not used in flexion mode. Thus, in the case of distal strut 388, different mouotiog holes are selectively used to achieve different operational modes. As will be seen, the use of ~ifferent mounting holes facilitates reversible operation usiog the same dynamic tension unit 348. The use of different moumtiog holes repositions the distal strut so that the desired range of motion of the strut under tension c~ .r~ to the range of motionprovided by the slot 358 of dynamic tension unit 348, in either the flexion or extension modes ~ ly.
Figure 26A shows the bi-directional power unit connected for flexion operation.
Proximal strut 308 and distal strut 388 are connected to rotate about pivot post 34 of reverslble dynanuc tension unit 348. Preferably, as described above with reference to Figure 21, struts 308 and 388 are joined by a hollow pivot affixing them rotatably, relative to each ot~er. Pivot post 34 of dynamic tension unit 348 extends into this hollow pivot to fixedly locate the pivot axis relative to dynamic tension unit 348. As will be seen, screws woss/2s4ss 2 1 86227 P~l/vv ,., ~

attacbing different parts of struts 308 and 388 to the dynamic tension unit 348 will effectively hold the hollow pivot in place without further attachment of the hollow pivot at pivot post 34. By providing a slip fit between pivot post 34 and the hollow pivot connecting tbe struts, the dynamic tension unit 348 can be easily removed from and installed on the S strut assembly of the type shown in Figure 21. In this way, the strut assembly and associated contour plates and cuff/strap parts can be used as a nu.. ~1151U~Cv brace. The dynamic tension unit 348 or apower unita can then be installed, if desired, to convert the brace into a dynamic tension flexion/extension splint.
However, a snap ring, cotter pin, or other mechanism which locks the struts in place for 10 rotation about pivot post 34, yet permits di~.l-lvly of the mechanism using ~,u.u~~,~
tools, could also be provided if desired.
To make the ' for flexion operation, a machine screw placed in hole 353 or other pin v of dynannic tension unit 348 is attached to threaded insert 383 of hole 380 of proximal strut 308. Similarly, a machine screw placed through spring loop 356 is attached to threaded insert 400 of hole 396 in distal strut 388. Thus, the body of dynamic tension unit 348 is fixed to proximal strut 308 and the end of the spring 64 is connected to the distal strut. With these ~ the force of spring 64 urges the connection of the distal strut at hole 396 toward end 359 of the slot 358. Thus, the distal strut will tend to rotate clockwise in the view shown with respect to the proximal strut.
Figure 26B shows the bi-directional dynamic tension unit 348 locked in position for extension operation. To change the mode of ûperation of the unit from the flexion mode of Figure 26A to the extension mode of Figure 26B, the ~ of the struts to the body of dynamic extension unit 348 and the spring 64, as specified above with reference to Figure 26A, are removed. The dynamic tension unit 348 is then rotated, with respect to the struts, about pivot post 34, and the distal strut is rvtated as necessary, to create a new alignment of attachment points appropriate for the extension mode. Referring now to Figure 26B, for the extension mode, the fixed mounting hole 353 is comnected to the distal strut by installing a machine bolt or other ~,UI~, fastener through hole 353 into threaded insert 402 in hole 39g of the distal strut 388. The floating point mounting, at spring loop 356, is corlnected to the proximal strut by installing a machine bolt or other ~fastener through spring loop 356 into threaded insert 383 of hole 380 of the proximal strut.
In tbis way, the direction of the force applied by dynanuc tension unit 348 is reversed.

~ Wo 95/25489 2 1 8 6 22 7 In P~ach of the two modes, one of the two attachment points (356, 353) on the dynamic tension unit 348 is always connected to hole 380 of the proximal strut. ln contrast, a different hole on the distal strut is used in each mode. The use of different mounting boles on the distal strut repositions the distal strut so that the desired range of motion of the 5 strut under tension ~ ' to the range of motion provided by the slot 358 of dynarluc tension unit 348. Thus, the positioning of the holes in the distal strut is relatively critical in assuring that the desired range of motion (and limits on the range of motion) will be obtained ir~ each mode.
It wiU be understood that in the description above of the bi-directional reversible 10 dynamic tension unit 348, only one set of struts and the wll. r ' lg dynamic tension unit has been described. Those skiUed in the art wiU appreciate that a complete splint according to the presPnt invention is formed using the structure shown and described on one side of an affected limb, and also using a mirror-image structure on the opposite side of the limb.
The two sides of the splint are attached using strap means to hold each side in place against 15 the limb.
A preferred method of assembling and attaching the completed splint wiU be described ~vith reference to Figure 27. Figure 27A shows an improved single soft cufflstrap assembly according to the present invention. Cuff/strap assembly 404 comprises neoprene foam strip 406, typicaUy about 2.5 inches wide and 15 to 25 inches long. Cuff/strap 20 assembly 404 is covered entirely by different fabric layers on its two sides: on one side by a low sffltch nylon cover 408 and on the other side by an unbroken loop material 410. A
1.5 inch b~l three inch length of ~ lP~ hook material 412 for engaging the unbroken loop matelial 410 is sewn onto the assembly by a double row of heavy stitching, and extends from the end of cufflstrap assembly 404 as shown. The hook material 412 may be 25 of the typ~ known as Velcro Cl-M) and has hook fasteners on both sides for engaging unbroken loop material 410. The hook material can be provided with hooks on both sides or single-sided hook material can be glued together to provide a structure with hooks covering both sides.
Figure 27B shows the assembly of Figure 27A instaUed on the adjustable dynamic 30 splint of Figure 22. The hook end of cufflstrap assembly 404 is passed through retaining loop 338 alld doubled back with the unbroken loop side facing the retaining loop. The hook material is pressed into . ~ ~ with the unbroken loops to seal the cuff/strap assembly 404 about the retaining loop 338. The other end of cuff/strap assembly 404 is passed W0 9S125489 2 1 8 6 2 2 7 r~

through retaining loop 338 of the strut on the opposite side of the limb. The limb is omitted from the drawing for clarity but is located in limb area 411, between the struts and also between the front and back cuff/strap assemblies 404. Cuff/strap assembly is then pulled to the desired tightness and the surface of unbroken loop material 410 is engaged with the surface of e~posed hook material 412. In tbis way, cuff/strap assembly 404 is locked together to hold the struts in position against the limb. This strap: ~ providesuniversal length adjustment and can be trimmed easily for a custom fit. The installation of the cuff/strap assembly with a double thickness at any given point adjacent to the limb provides increased comfort and resistance to lengthwise stretching.
The use of neoprene foam in cufflstrap assembly 404 maintains a desirable cusbioning effect to increase patient comfort, and the layer of low stretch nylon reduces stretching of the cuff/strap assembly which could result in instability of the splint inc~ otilm The doubling over of cuff/strap assembly 404 when installed as shown in Figure 28B also tends to reduce stretching of the cuff/strap assembly 404. A designed balance is necessary in the amoumt of stretch of cuff/strap assembly 404. It is desirable to permit some stretching to compensate for muscle bulge when the underlying muscles are tensed during use. However, the amoumt of stretching should at the same time be design-limited so that the splint does not loosen during use and thus fail to provide the desired support.
The number and location of cuff/strap assemblies 404 will vaty depending on the structure of the splint and the joint to which the device will be applied (e.g. elbow, wrist, knee, ankle, etc.). In general, for a knee splint of the type shown in Figure æA, ten cuff/strap assemblies 404 will be provided: that is, both a front and a back cuff/strap assembly 404 will be provided at each of the five pivot assemblies 324.
In~illc~ hility The dynamic splint of the present invention is used for the treatment of joint occurring secondary to trauma, casting, or other i " " ~ l It is also used to restore strength and flexibility to a body joint, by creating resistance requiring the wearer to flex the joint, thereby building strength and fluidity. The bias adjustment feature ill~ ~/l l ' within the dynamic e~tension splint permits the spring bias of the splint to be varied throughout a recovery process as treatment of the joint progresses.
.:, . .... . .. ... . . . . . .. . . . .. ~ . . . . . .

WO 9~/25489 F~ l99 _33_ 21 ~62~7 The dynamic splints disclosed permit " ~ of a defined tolerable force level with ma~imum linearity over a wide range of motion of a body joint. The dynamic splints are ~ u~ usefill for ~ k~tiC ~ of range-of-motion and mobility, particular in po$-operative cases.
.

Claims

WE CLAIM:

1. An adjustable splint device for applying force across a body joint comprising:
a first strut member, a second strut member, a joint assembly including a support separate from said first and second strut members, pivot means mounted on said support for mounting said first and second strut members, said pivot means mounting at least one of said strut members for relative pivotal movement to the remaining strut member about a pivot axis, and a bias unit connected to said joint assembly and connectable to one of said strut members for applying a bias force opposing relative pivotal movement between said first and second strut members in a first of two opposite directions and aiding such pivotal movement in a second of said opposite directions, said support being rotatable separately from said first and second strut members relative to said pivot axis between a first flexion mode position and a second extension mode position, and mode reversing connection means to cause said bias unit to apply said bias force to said first or second strut members in either a flexion mode or an extension mode, said mode reversing connection means operating in said flexion mode to connect said support to said first strut member and to connect said bias unit to said second strut member so that said bias unit biases pivotal movement of said second strut member relative to said first strut member in a first direction and operating in an extension mode to connect said support to said second strut member and to connect said bias unit to said first strut member so that said bias unit biases pivotal movement of said first strut member relative to said second strut member in a second direction opposite to said first direction.

2. The adjustable splint device of claim 1 wherein both said first and second strut members are mounted for pivotal movement on said pivot means, said mode reversing connection means operating to prevent pivotal movement of said first strut member about said pivot means relative to said support in said flexion mode and to prevent pivotal movement of said second strut member about said pivot means relative to said support in the extension mode.

3. The adjustable splint device of claim 2, wherein said mode reversing connection means leaves said second strut member free for pivotal movement about said pivot means in said flexion mode and leaves said first strut member free for pivotal movement about said pivot means in said extension mode.

4. The adjustable splint device of claim 3, which includes bias adjustment means mounted on said support and connected to said bias unit for adjusting a magnitude of bias force applied by said bias unit.

5. The adjustable splint device of claim 3, wherein said bias unit includes a spring having a first end connected to said support and a second end connectable to said second strut member in the flexion mode and to said first strut member in the extension mode, said support including an arcuate guide equally spaced from said pivot means along its length, the second end of said spring being retained for movement in said arcuate guide.

6. The adjustable splint device of claim 5 which includes bias adjustment means mounted on said support and connected to the first end of said spring for adjusting the magnitude of bias force applied by said bias unit.

7. The adjustable splint device of claim 5 wherein said arcuate guide includes a first end and a second end, said support being positioned relative to said first and second strut members in said flexion mode by said mode reversing connection means to position said second end of said spring for connection to bias said second strut member toward the first end of said arcuate guide and in the extension mode to position the second end of said spring for connection to bias said first strut member toward the second end of said arcuate guide.

8. The adjustable splint device of claim 7 wherein said first and second strut members each include a first end, a pivot connection formed in the first ends of said first and second strut members to mount said first and second strut members on said pivot means, said mode reversing connection means including a spring connector formed at the second end of said spring and first fastening means spaced from the pivot connection at the first ends of said first and second strut members, said first fastening means on said first strut member operating to connect said first strut member to said support in the flexion mode and to connect said first strut member to said spring connector in the extension mode, said first fastening means on said second strut member operating to connect said second strut member to said spring connector in the flexion mode.

9. The adjustable splint device of claim 8 herein said second strut member includes second fastening means spaced from the first fastening means and the pivot connection on said second strut member, said second fastening means operating to connect said second strut member to said support in the extension mode.

10. The adjustable splint device of claim 9 wherein the first fastening means on the first and second strut members and the second fastening means on the second strut member are spaced from said pivot connection by a distance equal to the distance said pivot means is spaced from said arcuate guide.

11. The adjustable splint device of claim 10 wherein said second strut member includes a central longitudinal axis, said pivot connection and first fastening means of said second strut member being aligned along a line parallel with the central longitudinal axis of said second strut member and said second fastening means being radially positioned relative to said second strut member pivot connection along a radial line at an angle to said central longitudinal axis.

12. The adjustable splint device of claim 11 wherein said second strut member second fastening means is positioned along a radial line extending at an angle of 45 degrees to said central longitudinal axis.

13. The device of claim 2 further comprising cam locking means for selectively engaging an element connected to said first strut and an element connected to said second strut by cam action to prevent relative movement of said first and second struts.

14. The adjustable splint device of claim 1 wherein said bias unit includes a spring having a first end connected to said support and a second end connectable to said second strut member in the flexion mode and to said first strut member in the extension mode, said support including an arcuate guide equally spaced from said pivot means along its length, the second end of said spring being retained for movement in said arcuate guide.

15. The adjustable splint device of claim 14 wherein said arcuate guide includes a first end and a second end, said support being positioned relative to said first and second strut members in said flexion mode by said mode reversing means to position said second end of said spring for connection to bias said second strut member toward the first end of said arcuate guide and in the extension mode to position the second end of said spring for connection to bias said first strut member toward the second end of said arcuate guide.

16. The adjustable splint device of claim 15 which includes bias adjustment means mounted on said support and connected to the first end of said spring for adjusting the magnitude of bias force applied by said bias unit.

17. The adjustable splint of claim 1 which includes locking means for selectively locking said first and second strut members against relative pivotal movement, said locking means including detents formed on one of said strut members and a detent engaging lock mounted on the remaining strut member to engage said detents.

18. An adjustable splint device for applying force across a body joint comprising:
a first strut member, a second strut member, said first and second strut members being mounted for relative pivotal movement, a joint assembly including a support housing, separate from said first and second strut members, a pivot connected to said support housing for mounting said support housing for rotation relative to said first and second strut members, and a bias unit connected to said joint assembly and to one of said strut members for applying a bias force opposing relative pivotal movement between said first and second strut members in a first of two opposite directions and aiding such pivotal movement in a second of said opposite directions, said bias unit including a spring mounted in said support housing, the support housing being rotatable relative to said first and second strut members between a flexion position and an extension position to cause said bias unit to apply said bias force to said first or second strut members in either a flexion mode or an extension mode, and connection means operating in said flexion mode to connect said support housing to said first strut member and said bias means to said second strut member so that said bias means biases pivotal movement of said second strut member relative to said first strut member in a first direction and operating in an extension mode to connect said support housing to said second strut member and said bias means to said first strut member so that said bias means biases pivotal movement of said first strut member relative to said second strut member in a second direction opposite to said first direction.

19. The adjustable splint device of claim 18 wherein both said first and second strut members are mounted for pivotal movement about said pivot.

20. The adjustable splint device of claim 19 wherein said bias unit includes a spring having a first end connected to said adjustment means and a second end connectable by said connection means to said second strut member in the flexion mode and to said first strut member in the extension mode, said support housing including an arcuate guide equally spaced from said pivot along its length, the second end of said spring being retained for movement in said arcuate guide.

21. The adjustable splint device of claim 20 wherein said arcuate guide includes a first end and a second end, said support housing being positioned relative to said first and second strut members in said flexion position to position said second end of said spring for connection to bias said second strut member toward the first end of said arcuate guide and in the extension position to position the second end of said spring for connection to bias said first strut member toward the second end of said arcuate guide.

22. The adjustable splint device of claim 18 which includes bias adjustment means mounted on said support housing and connected to said bias unit for adjusting a magnitude of bias force applied by said bias unit, said adjustment means rotating with said support housing between the flexion and extension positions to maintain the adjusted magnitude of bias force in both the flexion and extension modes.

23. The adjustable splint of claim 1 wherein at least one of said first and second strut members includes a pivoted limb engaging cuff assembly mounted thereon, said cuff assembly including an arcuate contour plate and a plate mount assembly secured to said strut member and to said contour plate, said plate mount assembly including a plate pivot transverse to the longitudinal axis of said strut member for mounting said contour plate for pivotal movement about said plate pivot and strap retaining means formed on said contour plate and pivotal therewith.

24. The adjustable splint device of claim 23 wherein said contour plate includes a concave surface facing outwardly away from the surface of the strut member upon which said limb engaging cuff assembly is mounted, said strap retaining means including strap retaining loops secured to said arcuate contour plate and extending along opposite sides thereof substantially parallel to the longitudinal axis of said strut member.