Bicentric hinge for use in a brace

Bicentric hinges for use in braces and methods for operating knee braces and other types of braces are disclosed herein. In one embodiment, a hinge includes a plate, first and second members pivotally coupled to the plate, and a rocker coupled to the plate. The first member is pivotable about a first axis of rotation, and the second member is pivotable about a second axis of rotation spaced apart from the first axis of rotation. The second member is not directly engaged with the first member, and the first member may not be connected to a return mechanism that urges the first member to pivot about the first axis of rotation. The first member has a first recess, and the second member has a second recess. The rocker includes a head at least partially receivable in the first recess and/or the second recess to restrict rotation of one of the first and second members until the other has rotated.

TECHNICAL FIELD

The present invention relates to bicentric hinges for use in braces.

BACKGROUND

Knee braces are widely used to stabilize and protect the knee joint. For example, knee braces are often used to prevent damage to the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, lateral collateral ligament and/or meniscus in a knee joint. Knee braces are particularly useful to protect the knee joint during vigorous athletic activities such as running, basketball, football and skiing, and they are also used to stabilize the knee joint during recovery or rehabilitation from surgery or an injury.

A knee brace typically includes an upper frame, a lower frame, and a hinge connecting the upper frame to the lower frame. The upper frame often has straps that wrap around the quadriceps or hamstring, and the lower frame often has straps that wrap around the calf. Each portion of the frame is configured to fit the shape of the corresponding portion of the leg. The hinge allows the lower frame to pivot relative to the upper frame as the knee bends. Many braces have a hinge on each side of the knee joint to give the brace additional strength.

Conventional hinges for knee braces include a single axis pivot, two gears and a four-bar linkage. The conventional geared hinge mechanisms typically have two rotating gears with interlocking teeth. The single axis pivot and geared hinge mechanisms have several disadvantages. First, the single axis pivot and geared hinge mechanisms limit the range of flexion of the leg. Second, the single axis pivot and geared hinges do not simulate the natural movement of the knee joint when the leg bends or extends. The motion of the human knee joint is quite complex and does not rotate uniformly from extension to flexion. Because the single axis pivot and geared hinge mechanisms cannot simulate the natural movement of the knee joint, the knee brace may force the knee into an unnatural position at extension or flexion if the straps on the knee brace are tight. This coupled with forces induced during activity may injure the knee joint. Moreover, a user may loosen the straps to avoid the discomfort resulting from the unnatural movement of the knee joint. If the straps on the knee brace are loose, however, the knee brace will slide down the leg during an activity. Such movement of the knee brace during an activity is uncomfortable and annoying. Additionally, as the knee brace slides down the leg, the straps might not be tight enough to provide the necessary support to the knee.

A four-bar linkage hinge mechanism better simulates the motion of the knee during flexion and extension than geared hinges. Four-bar linkage hinges, however, have several disadvantages. First, the motion of a four-bar linkage hinge is complex, making it difficult to set and adjust stops that limit the range of motion of the knee brace. As a result, patients may not accurately limit the range of motion with four-bar linkage hinge mechanisms. Second, four-bar linkage hinges are bigger than many other types of hinges. A big knee brace hinge can make it more difficult to pull clothes over the brace, and large hinges may interfere with the other knee joint during activities. Therefore, four-bar linkage hinges are not widely used in knee braces.

DETAILED DESCRIPTION

The following disclosure describes several embodiments of bicentric hinges and methods for operating anatomical braces with such hinges. Many specific details of certain embodiments of the invention are set forth in the following description and inFIGS. 1-8Dto provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the invention may have additional embodiments or that the invention may be practiced without several of the details described in the following description. For example, even though many embodiments of the bicentric hinge are described with reference to a knee brace, they can also be used in elbow braces or other braces.

The present invention is directed toward bicentric hinges for use in braces and methods for operating such bicentric hinges. In one embodiment of the invention, a hinge includes a plate, first and second members pivotally coupled to the plate, and a rocker coupled to the plate. The first member is pivotable about a first axis of rotation, and the second member is pivotable about a second axis of rotation spaced apart from the first axis of rotation. The second member is not directly engaged with the first member, and the first member may not be connected to a return mechanism that urges the first member to pivot about the first axis of rotation. The first member has a first recess, and the second member has a second recess. The rocker includes a head at least partially receivable in the first recess and/or the second recess to restrict rotation of one of the first and second members until the other has rotated.

In one aspect of this embodiment, the rocker is pivotally coupled to the plate and pivots between a first position in which the head is received at least partially in the second recess to inhibit rotation of the second member and a second position in which the head is received at least partially in the first recess to inhibit rotation of the first member. In another aspect of this embodiment, the first member includes a tooth that contacts the rocker and pivots the rocker from the first position to the second position when the first member pivots from the first position to the second position.

Another aspect of the invention is directed to methods of operating knee brace hinges. In one embodiment, a method includes pivoting a first member about a first axis of rotation from a first position to a second position, and rotating a second member about a second axis of rotation from a first position to a second position after the first member has substantially reached the second position. The second axis of rotation is spaced away from the first axis of rotation. The first member may not be connected to a return mechanism that urges the first member to pivot about the first axis of rotation. The method further includes returning the first member to the first position and the second member to the first position.

B. Embodiments of Hinges for Use in Braces

FIG. 1is an isometric view of a knee brace60including an upper frame30, a lower frame32, and hinges10connecting the upper frame30to the lower frame32. The upper frame30can include at least one strap20to wrap around the quadriceps or hamstring, and the lower frame32can also include one or more straps. In other embodiments, the upper and lower frames30and32can have different configurations and include different configurations of straps. For example, the knee brace60can also include a flexible, elastic sleeve62coupled either directly or indirectly to the upper and lower frames30and32.

FIG. 2is an exploded view andFIG. 3Ais a top plan view of one embodiment of the hinge10. In this embodiment, the hinge10includes a back plate200, a first hinge member260, and a second hinge member261. The first hinge member260rotatably mounts to the back plate200and is configured to attach to the upper frame30(FIG. 1) to permit the upper frame30to pivot about the back plate200. The second hinge member261also rotatably mounts to the back plate200and is configured to attach to the lower frame32(FIG. 1) to permit the lower frame32to pivot about the back plate200independently of the upper frame30. Accordingly, the upper and lower frames30and32pivot independently about two different axes of rotation.

Referring toFIG. 2, the first hinge member260is a generally flat plate with a front surface266, a back surface (not shown) opposite the front surface266, a top edge276, a bottom edge274, and a side edge272. The first hinge member260is configured for attachment to a portion of the upper frame30and can include two apertures262and264proximate to the side edge272for receiving fasteners (not shown) to connect the upper frame30to the first hinge member260. The second hinge member261, similarly, has a front surface267, a back surface (not shown) opposite the front surface267, a top edge277, a bottom edge275, and a side edge273. The second hinge member261is configured for attachment to a portion of the lower frame32and can include two apertures263and265proximate to the side edge273for receiving fasteners (not shown) to connect the lower frame32to the second hinge member261. In additional embodiments, the first hinge member260can be an integral portion of the upper frame30and the second hinge member261can be an integral portion of the lower frame32. The first and second hinge members260and261can have different configurations in other embodiments.

Referring toFIGS. 2 and 3together, the first hinge member260is pivotally connected to the back plate200by a fastener320and rotates relative to the back plate200about a first axis of rotation A1(FIG. 3A). The first hinge member260has a pin252that projects from the front surface266and the back surface. The portion of the pin252projecting from the back surface is received within an annular slot220in the back plate200. The annular slot220is accordingly centered about the first axis of rotation A1with a centerline at a radius R1corresponding to the distance from the first axis of rotation A1to the pin252. Accordingly, as the first hinge member260rotates relative to the back plate200about the first axis of rotation A1, the pin252slides in the annular slot220. A first endpoint224and a second endpoint226of the slot220define the maximum range of motion for the first hinge member260. As such, the length of the slot220determines the pivoting range of the first hinge member260relative to the back plate200. In other embodiments, the pin252can have a different configuration or shape. For example, the pin252can extend or project from either the front surface266or the back surface. In additional embodiments, the slot220can have different lengths to change the pivoting range of the first hinge member260. In other embodiments, the position of the slot220and the pin252can be different, such as the slot220can be in the first hinge member260and the pin252can be attached to the back plate200.

The second hinge member261is pivotally connected to the back plate200by a fastener322and rotates relative to the back plate200about a second axis of rotation A2(FIG. 3A). The second hinge member261has a pin253that projects from the front surface267and the back surface. The portion of the pin253projecting from the back surface is received within an annular slot222in the back plate200. The annular slot222is accordingly centered about the second axis of rotation A2with a centerline at a radius R2corresponding to the distance from the second axis of rotation A2to the pin253. As the second hinge member261rotates relative to the back plate200about the second axis of rotation A2, the pin253slides in the annular slot222. A first endpoint225and a second endpoint227of the slot222define the maximum range of motion for the second hinge member261. The length of the slot222determines the pivoting range of the second hinge member261relative to the back plate200. In other embodiments, the pin253can have a different configuration or shape. For example, the pin253can extend or project from either the front surface267or the back surface, or there can be two separate pins extending from each surface. In additional embodiments, the slot222can have a different length to change the pivoting range of the second hinge member261. In other embodiments, the position of the slot222and the pin253can be different, such as the slot222can be in the second hinge member261and the pin253can be attached to the back plate200.

Referring toFIG. 3A, the curved edge270on the first hinge member260is spaced away from the curved edge271on the second hinge member by a gap G so that the first hinge member260and the second hinge member261pivot independently about the two different axes of rotation A1and A2. Because the hinge has two different and independent axes of rotation, it better simulates the natural motion of the knee joint. This is expected to mitigate the sliding of the knee brace down the leg and reduce exerting unnatural forces against the knee joint.

In the illustrated embodiment, the back plate200has a cutout portion250. The cutout portion250allows the first and second hinge members260and261to rotate through the full pivoting range without the upper and lower frames30and32(FIG. 1) striking the back plate200.

In the illustrated embodiment, the first hinge member260and the second hinge member261are operatively coupled by a resilient member300. The resilient member300has a first end302attached to the first hinge member260and a second end304attached to the second hinge member261. The first end302is received within an aperture282in the first hinge member260. A channel284connects the aperture282to an edge268and is sized to receive a portion of the resilient member300. Similarly, the second end304of the resilient member is received within an aperture283of the second hinge member261. A channel285connects the aperture283to the edge277and is sized to receive a portion of the resilient member300. The first end302and the second end304of the resilient member300are enlarged so that they are not pulled through the smaller channels284and285. In one embodiment, the first end302and the second end304of the resilient member300have a donut shape with a pin in the center. In other embodiments, the first end302and second end304of the resilient member300can be clamped or bonded. In additional embodiments, such as those described below with reference to FIGS.3B and8A-8D, the hinge may not include a resilient member.

The resilient member300is elastic and provides resistance to the hinge members260and261during flexion. In one embodiment, urethane can be used; in other embodiments, other materials may be used. The resilient member300stretches as the first hinge member260rotates in a direction D1and/or the second hinge member261rotates in a direction D2. The resilient member300urges the first hinge member260to rotate in a direction D3and the second hinge member261to rotate in a direction D4. Accordingly, when no external force is placed on the first and second hinge members260and261, the pins252and253are drawn toward the first endpoints224and225of the slots220and222. When an external force is applied to the first hinge member260causing rotation in the direction D1, the resilient member300stretches elastically and rides along a curved edge270of the first hinge member260. In the illustrated embodiment, the curved edge270has a radius R3; however, in other embodiments, the curved edge270may not have a constant radius. Similarly, when an external force is applied to the second hinge member261causing rotation in the direction D2, the resilient member300stretches elastically and rides along a curved edge271of the second hinge member261. In the illustrated embodiment, the curved edge270has a radius R4that is greater than the radius R3. In additional embodiments, the radius R3can be equal to or greater than the radius R4.

The resilient member300and the radii of the hinge members260and261operate together to control the rotation of the hinge members260and261. For example, when R3is less than R4, the first hinge member260rotates in direction D1for an arc length before the second hinge member261rotates for an arc length in direction D2. This is because greater external force must be applied to rotate a member with a greater radius in light of the counter force applied by the resilient member300. Accordingly, in the illustrated embodiment, when an external force is applied to the hinge310, the first hinge member260rotates first because its radius R3is less than the radius R4of the second hinge member261. The second hinge member261will begin to rotate after the pin252of the first hinge member260has rotated through at least a portion of its range of motion. The rotation of one hinge member before the rotation of the other hinge member simulates the natural anatomical motion of the knee joint during extension and flexion. A better simulation of the natural motion of the knee joint reduces the movement of the brace down the leg of the user and the tendency of the knee brace to force the knee into unnatural positions.

FIG. 3Bis a top plan view of an assembly including a first torsion spring398attached to a first hinge member360and a second torsion spring399attached to a second hinge member361in accordance with another embodiment of the invention. Each torsion spring398and399is also attached to the back plate200. The first torsion spring398urges the first hinge member360to rotate in the direction D3and the second torsion spring399urges the second hinge member to rotate in the direction D4. Accordingly, when no external force is placed on the first and second hinge members360and361, the pins252and253are drawn toward the first endpoints224and225of the slots220and222. In one embodiment, the torsion springs can have different spring coefficients causing one hinge member to rotate before the other.

FIG. 4is a top plan view of the hinge310ofFIG. 3Awith first and second adjustable range restrictors402and404.FIG. 5Ais a top plan view of an adjustable range restrictor system406in accordance with one embodiment of the invention.FIG. 5Bis an isometric view of the adjustable range restrictor system406ofFIG. 5Awith the first and second adjustable range restrictors402and404removed from a housing540. As explained in more detail below, the adjustable range restrictor system406allows a user to adjust the pivoting range of the first hinge member260and/or the second hinge member261.

Referring to the illustrated embodiment inFIG. 4, the fastener320is received in an aperture432of the first adjustable range restrictor402so that the first adjustable range restrictor402is positionable about the first axis of rotation A1. The first adjustable range restrictor402has an annular slot422extending about the first axis of rotation A1with a centerline at the radius R1. The slot422is positioned and sized to receive the pin252of the first hinge member260. Accordingly, when the first hinge member260pivots, the pin252moves within the slot422. Similarly, the fastener322is received in an aperture430of the second adjustable range restrictor404so that the second adjustable range restrictor404is positionable about the second axis of rotation A2. The second adjustable range restrictor404has an annular slot420extending about the second axis of rotation A2with a centerline at the radius R2. The slot420is positioned and sized to receive the pin253of the second hinge member261. Accordingly, when the second hinge member261pivots, the pin253can move within the slot420. In the illustrated embodiment, the length of the slot420is approximately equal to the length of the slot222, and the length of the slot422is approximately equal to the length of the slot220. In other embodiments, the slots420and422can have different lengths.

The first and second adjustable range restrictors402and404can be rotated so that their slots422and420limit the rotation of the first and second hinge members260and261. For example, referring to the embodiment inFIG. 4, the first adjustable range restrictor402is positioned so that the slot422is offset from the slot220of the first hinge member260. Consequently, a first endpoint424of the slot422and the second endpoint226of the slot220define stops for the pin252to limit the rotation of the first hinge member260about the first axis of rotation A1. The first adjustable range restrictor402can be rotated further in the direction D1to further limit the rotation of the first hinge member260. Conversely, the first adjustable range restrictor402can be rotated in the direction D3to increase the range of rotation. The second adjustable range restrictor404can similarly be positioned about the second axis of rotation A2so that the slot420is offset from the slot222of the second hinge member261to define stops for the pin253that limit the rotation of the second hinge member261about the second axis of rotation A2.

The adjustable range restrictors402and404are held in place by the housing540. Referring toFIGS. 5A and 5B, at least a portion of the outer edge442of the first adjustable range restrictor402has teeth412, and the outer edge440of the second adjustable range restrictor404also has teeth414. The housing540has a recess570with teeth550that engage the teeth412and414of the first and second adjustable range restrictors402and404. When the housing540is attached to a front plate400(FIG. 4), the teeth550preclude the first and second adjustable range restrictors402and404from rotating about the first and second axes of rotation A1and A2. The housing540, for example, can have a lip560that snap-fits onto the front plate400to lock the first and second range restrictors402and404in desired positions for limiting the range of motion. The first and second adjustable range restrictors402and404are rotatably adjusted by removing the housing540, rotating the first and second adjustable range restrictors402and404, and replacing the housing540. The configuration of the teeth412,414and550in the illustrated embodiment permits the first and second adjustable range restrictors402and404to be adjusted in 10-degree increments. In additional embodiments, the teeth412,414and550can be sized and spaced differently.

One advantage of the embodiment of the range restrictor system406shown inFIGS. 4-5Bis the ease with which a user can adjust the pivoting range of the first and second hinge members260and261. It will be appreciated that the range restrictor system406can have other configurations. For example, in additional embodiments, other types of devices can be used to restrict the first and second adjustable range restrictors402and404from rotating about the first and second axes of rotation A1and A2. For example, the front plate400could have a projection with teeth that engage the teeth of one or both of the adjustable range restrictors402and404, thus eliminating the need for the housing540. In the illustrated embodiment, the front plate400is similar to the back plate200, but is positioned on the other side of the hinge members260and261. In still other embodiments, the front plate400can have a different configuration, or the hinge may not have the front plate400. In further embodiments, the first and second adjustable range restrictors402and404can be placed proximate to the first and second hinge members260and261, or the adjustable range restrictor system406can be placed adjacent to the back surface of the back plate200. In additional embodiments, the hinge may not have the adjustable range restrictor system406.

FIG. 6is an exploded view of the hinge10ofFIG. 1. In the illustrated embodiment, the first and second hinge members260and261are held between the back plate200and the front plate400by the fasteners320and322. The hinge10may have spacers600,620,630and632to assist the first and second hinge members260and261to rotate more easily between the plates400and200. The spacers600and630each have an aperture604through which the fastener320is placed, and an aperture602through which the first pin252is placed. Similarly, the spacers620and632each have an aperture624through which the fastener322is placed, and an aperture622through which the second pin253is placed. In additional embodiments, the spacers600,620,630and632can have different configurations, or the hinge10may not have one or more of the spacers600,620,630and632. The range restrictor system406attaches to the front plate400as explained above.

FIG. 6also illustrates the compactness of the hinge10and the range restrictor system406. The hinge10and the range restrictor system406together can have a thickness of between 0.125 inch and 1 inch. In one embodiment, the hinge10and the range restrictor system406together have a thickness of approximately 0.31 inch. The compact size of the hinge10and the range restrictor system406makes it easier to wear clothes over the knee brace and reduces the potential of having the hinge interfere with the other knee joint during activities.

C. Additional Embodiments of Hinges for Use in Braces

FIGS. 7A-7Care top plan views illustrating a hinge710in accordance with another embodiment of the invention. The hinge710is similar to the hinge10described above, and like reference numbers refer to like components inFIGS. 1-7C. In the illustrated embodiment, the hinge710includes a first hinge member660with a first recess662and a second hinge member661with a second recess663. The first and second hinge members660and661are pivotally coupled to the back plate200. Referring toFIG. 7A, the pin252of the first hinge member660is positioned at the first endpoint224of the slot220in the back plate200, and the pin253of the second hinge member661is positioned at the first endpoint225of the slot222in the back plate200. The hinge710also includes a rocker650attached to the back plate200. The rocker650has a flexible arm698and a head697positioned between the first hinge member660and the second hinge member661.

When the hinge710is in the full-extension position shown inFIG. 7A, the head697is proximate to a curved edge670of the first hinge member660and at least partially within the second recess663of the second hinge member661. Because the head697of the rocker650is at least partially within the second recess663of the second hinge member661, the second hinge member661is effectively jammed and restricted from movement. Accordingly, a force applied to either hinge member660or661will cause the first hinge member660to pivot in a direction S1about the first axis of rotation A1.

Referring toFIG. 7B, the first hinge member660has pivoted about the first axis of rotation A1to a position where the pin252is at the second endpoint226of the slot220in the back plate200. The first hinge member660accordingly cannot pivot further about the first axis of rotation A1in the direction S1. In this position, the head697of the rocker650is received at least partially within the first recess662of the first hinge member660, releasing the bending force on the arm698. In this position the head697is free to move between the two recesses662and663. As the second hinge member261begins to rotate about the second axis of rotation A2, the cam shape of the surface671forces the head697of the rocker650into the recess662of the first hinge member660, effectively jamming and precluding rotation of the first hinge member660about the first axis of rotation A1.

Referring toFIG. 7C, the second hinge member661has pivoted about the second axis of rotation A2to a position where the pin253is at the second endpoint227of the slot222in the back plate200. The second hinge member661accordingly cannot pivot further about the second axis of rotation A2in the direction S2. Throughout the rotation of the second hinge member661from the position inFIG. 7Bto the position inFIG. 7C, the head697of the rocker650remains in the first recess662of the first hinge member660precluding the first hinge member660from pivoting about the first axis of rotation A1. Because the head697of the rocker650is at least partially within the first recess662of the first hinge member660, the first hinge member660requires a greater force to rotate in a direction S3than the force required for the second hinge member661to rotate in a direction S4. Accordingly, the rocker650encourages the second hinge member661to pivot in the direction S4about the second axis of rotation A2before the first hinge member660pivots in the direction S3about the first axis of rotation A1. In additional embodiments, the hinge710can have a rocker with a different configuration, or the hinge may not have a rocker. Furthermore,FIGS. 7A-7Cillustrate the full range of extension (FIGS. 7A-B) and flexion (FIGS. 7B-C) of the illustrated embodiment. Other embodiments can also have this range of extension and flexion without the rocker650or other components.

FIGS. 8A-8Dare top plan views of a hinge810in accordance with another embodiment of the invention. The hinge810is similar to the hinge710described above with reference toFIGS. 7A-7C. For example, the hinge810includes a back plate200, first and second hinge members860and861rotatably coupled to the back plate200, and a rocker880pivotally coupled to the back plate200to selectively inhibit the first or second hinge member860or861from pivoting, as described in detail below. The illustrated hinge810, however, does not include a resilient member, a torsion spring, or any other return mechanism to urge the first and second hinge members860and861to rotate about the first and second axes of rotation A1and A2, respectively. As such, an external force is required to pivot the first and second hinge members860and861.

FIG. 8Aillustrates the hinge810in the full-extension position. The illustrated first hinge member860includes a curved surface870having a first recess862, and the illustrated second hinge member861includes a curved surface871having a second recess863. The first and second recesses862and863are sized and shaped to receive a portion of the rocker880, which when received in one of the recesses862or863, locks the corresponding hinge member860or861relative to the back plate200. The first and second hinge members860and861may also include pins252and253received in corresponding annular slots220and222in the back plate200to restrict the pivoting range of the members860and861.

The rocker880can be a rigid member to inhibit the first or second hinge member860or861from pivoting until the other member860or861has rotated. The illustrated rocker880includes a base882pivotally attached to the back plate200, a head888for engaging the first or second hinge member860or861, and an arm894extending between the base882and the head888. The rocker880pivots about a third axis of rotation A3between a first position (shown inFIG. 8A) in which the head888is partially received in the second recess863to inhibit rotation of the second hinge member861and a second position (shown inFIGS. 8C and 8D) in which the head888is partially received in the first recess862to inhibit rotation of the first hinge member860. More specifically, when the rocker880is in the first position, a round portion895of the head888is positioned partially within the second recess863and against or proximate to the curved surface870of the first hinge member860. Accordingly, a force applied to either hinge member860or861will cause the first hinge member860to pivot in a direction S5about the first axis of rotation A1.

FIG. 8Bis a top plan view of the hinge810as the first hinge member860pivots about the first axis of rotation A1. The illustrated rocker880further includes a cammed surface884extending from the arm894to the base882, and the first hinge member860further includes a tooth872projecting from the curved surface870that slides over the cammed surface884as the first hinge member860rotates about the first axis of rotation A1. When the first hinge member860approaches the end of its pivoting range, the tooth872exerts a force against the cammed surface884to cause the rocker to pivot in a direction S6about the third axis of rotation A3. As the rocker880pivots from the first position toward the second position, the head888moves out of the second recess863.

In one aspect of this embodiment, the base882of the rocker880includes a surface883having a first radius R5proximate to the cammed surface884and a second radius R6proximate to a curved surface890, which extends from the head888to the base882. The rocker880can be attached to the back plate200in an eccentric arrangement such that the first radius R5is greater than or less than the second radius R6. In other embodiments, the rocker880may not be eccentric.

FIG. 8Cis a top plan view of the hinge810with the second hinge member861pivoting in a direction S7about the second axis of rotation A2. Once the rocker880has pivoted from the first position to the second position and the head888is partially received in the first recess862, the first hinge member860is inhibited from rotating and the second hinge member861is free to rotate about the second axis of rotation A2. Accordingly, the rocker880inhibits the second hinge member861from pivoting until the first hinge member860has reached the end of its pivoting range. The curved surface871of the second hinge member861and the curved surface890of the rocker880have complementary configurations such that the second hinge member861can slide by the rocker880as the member861rotates.

FIG. 8Dis a top plan view of the hinge810after the second hinge member861has reached the end of its pivoting range. Throughout the rotation of the second hinge member861, the head888of the rocker880remains in the first recess862of the first hinge member860and precludes the member860from pivoting about the first axis of rotation A1. Because the head888is received partially within the first recess862, the rocker880inhibits the first hinge member860from rotating in a direction S8before the second hinge member861rotates in a direction S9back to the position shown inFIG. 8B. In additional embodiments, the hinge810can further include the range restrictor system406(FIGS. 5A-5B).

One feature of the hinge810illustrated inFIGS. 8A-8Dis that the rocker880inhibits one hinge member from rotating before the other member has rotated. An advantage of this feature is that the rotation of one hinge member before the other simulates the natural anatomical motion of the knee joint during extension and flexion. The improved simulation of the natural motion of the knee joint reduces the movement of the knee brace up and down the leg and the tendency of the brace to force the knee into unnatural positions. Moreover, the illustrated rigid rocker880is expected to reduce the play in the hinge810.