Abstract:
An orthotic device for a joint of the human body, at which a body part pivots, includes first, second and third members. A first connection joins the first member and the second member and defines a first axis about which the first member and the second member pivot through an adjustable range of angular motion. A second connection joins the second member and the third member, defines a second axis substantially parallel to the first axis about which the second member and the third member pivot through a second range of angular motion, and includes a limit to plantar flexion about the second axis.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an orthotic device, and particularly to an orthotic that provides adjustable control of a range of angular motion at a joint of the human body where pivoting normally occurs. 
     2. Description of the Prior Art 
     An orthotic is a device, such as a brace or splint, for supporting, immobilizing, or treating muscles, joints, or skeletal parts, which are weak, ineffective, deformed, or injured. To assist in restoring a joint of the human body to normal, effective function, the joint may be restricted for a period by an orthotic, which imposes a fixed pivoted position. Or an orthotic may permit adjustable angular displacement of the joint, which is retained for a period by the orthotic and gradually increased at intervals to improve the pivotal range of use. 
     An orthotic that can be adjusted at multiple, mutually spaced locations to enhance the range of flexibility and use of the joint provides an added advantage. 
     A need exists for an orthotic device that enhances ambulation and heel suspension, and allows multiple ranges of pivotal movement about respective spaced axes during various stages of therapy. Preferably, a range of movement about a first axis is adjusted reliably and easily by releasing an attachment, changing the angular displacement of the orthotic about the first axis to a new, desired orientation, and securing the orthotic in the desired angular disposition by reengaging the attachment. The range of movement about a second axis may be limited reliably by mutual contact between stop surfaces located on opposite sides of a second axis. 
     SUMMARY OF THE INVENTION 
     An orthotic device for a joint of the human body, at which a body part pivots, includes first, second and third members. A first connection joins the first member and the second member and defines a first axis about which the first member and the second member pivot through an adjustable range of angular motion. A second connection joins the second member and the third member, defines a second axis substantially parallel to the first axis about which the second member and the third member pivot through a second range of angular motion, and includes a limit to the second range of angular motion to limit plantar flexion or angular movement about the second axis. 
     The orthotic is manufactured from lightweight materials, e.g., aluminum and plastic, which are formed by conventional techniques and at low cost. The aluminum may be roll formed or forged; the plastic may be molded. 
     The orthotic device provides multiple ranges of pivotal movement about respective spaced axes. The range of movement about a first axis is adjusted reliably and easily by releasing a threaded attachment, changing the angular displacement of the orthotic about the first axis to a new, desired orientation, and securing the orthotic in the desired angular disposition by reengaging the attachment. The range of movement about the second axis is limited by mutual contact between stop surfaces located on opposite sides of the second axis. 
     The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Having generally described the nature of the invention, reference will now be made to the accompanying drawings used to illustrate and describe the preferred embodiments thereof. Further, these and other advantages will become apparent to those skilled in the art from the following detailed description of the embodiments when considered in the light of these drawings in which: 
         FIG. 1  is a rear view of a device of an orthotic; 
         FIG. 2  is a side view of  FIG. 1 ; 
         FIG. 3  is a cross sectional side view to a larger scale of the lower connection shown in  FIG. 1 ; 
         FIG. 4  is a side view of an alternate embodiment of the lower connection; 
         FIG. 5  is a rear view of a leg support, into which the orthotic device of  FIG. 1  can be inserted and retained; 
         FIG. 6  is a perspective view of the leg support of  FIG. 5 ; 
         FIG. 7  is a side view of yet another embodiment of the lower connection; and 
         FIG. 8  is a rear view of the lower connection of  FIG. 7 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 1 through 3 , an orthotic device  10  includes an upper member  12 , intermediate member  14  and lower member  16 , each member preferably being of aluminum or another structural material having density, strength and endurance comparable to those of aluminum. 
     The lower end of the upper member  12  is formed with a circular arc  18  having a center  20 . The upper end of intermediate member  14  is formed with a circular arc  22 , which is centered at  20  and whose outer surface nests within the inner surface of arc  18 . Members  12  and  14  are connected mutually at an adjustable connection  23 . An outer block  24  is formed with a flat outer surface  26 , engaged by the head of threaded attachment  28 , e.g., a screw or bolt  28 , and a circular cylindrical inner surface  30  centered at  20 . An inner block  32  is formed with a circular cylindrical outer surface  34  centered at  20 , and a flat inner surface  36  contacted by self-locking nuts  38 , each nut engaging a respective attachment  28 . The upper member  12  is formed with two parallel slotted holes  40 . The intermediate member  14  is formed with two slotted holes  42 , each hole  42  being aligned with a respective hole  40 . Each attachment  28  extends through a hole in the outer block  24 , a pair of holes  40 ,  42  in members  12  and  14 , and a hole in the inner block  32 . 
     The lower portion of intermediate member  14  and the upper portion of lower member  16  are formed with arcuate surfaces, which together form an arc that is continuous across a lower connection  44 . A first hinge plate  46  is secured to member  14  by rivets  48 , and a second hinge plate  50  is secured to member  16  by rivets  52 . The lugs  54  of hinge plate  46  straddle the center lug of hinge plate  50 . Those lugs and the hinge pin  56  that connects them are located between the ends of members  14  and  16 . Therefore, lower member  16  must pivot counterclockwise about the axis  57  of the hinge pin  56  from the fully extended position shown in  FIGS. 2 and 3 , but it can pivot in either direction other than from the fully extended position. 
     In operation, the angular disposition of the first or upper connection  23  is adjusted by loosing the engagement of nuts  38  with screws  28  sufficiently to permit the arcuate surfaces  18 ,  22  of members  12 ,  14  to rotate about center  20  as the slotted holes  40 ,  42  slide relative the attachments. When the desired angular position is established, the nuts  38  and screws  28  are tightened, which draws blocks  24 ,  32  and the arcuate surfaces  18 ,  22  of members  12 ,  14  into friction contact and secures the desired angular setting of the upper connection  23 . 
     One leg  58  of an angle bracket  60  is secured by rivets  52  to the lower member  16 . Another leg  62  of bracket  60  is located near and facing a bracket  64 , which is secured to the intermediate member  14  by rivets  48  having a head counterbored in bracket  64 . The inner surface  66  of bracket  64  conforms to the contour of intermediate member  14 . Preferably, angle bracket  60  and bracket  64  are formed of plastic material. 
     Bracket  64  supports an adjustment screw  68  having screw threads  70  that extend along the screw shank and are aligned with axis  78 . The threads  70  of screw  68  engage internal screw threads, which are tapped along a length  72  of bracket  64 . A compression helical spring  74  is located in a bore  76 , aligned with axis  78  and formed in bracket  64 . Spring  74  is secured in its position in the bore  76  by a set screw  80 , which is threaded into bracket  64  and engages consecutive loops of the spring  74 . 
     Bracket  60  pivots about axis  57  when screw  68  is inserted in bracket  64  with its head at the upper end of bracket  64  and its screw threads engaged with the internal screw threads in bracket  64 , as shown in  FIGS. 2 and 3 . In this configuration, screw  68  is held in place by the engaged screw threads, and its shank acts as a guide to maintain the spring aligned with bore  76  when spring  74  extends past the end face  82  of bracket  64 , and the spring elastically opposes and prevents contact between bracket  60  and bracket  64 . The diameter of bore  79  in bracket  62  is larger than the diameter of the shank of screw  68 , so that the screw has no contact with the bore  79  or bracket  60  when the device  10  is assembled to permit bracket  60  to pivot. Notably, bracket  60  can pivot freely (without resistance) about axis  57 , except to the point of contact with spring  74 , and ultimately comes to a stop when bracket  60  finally contacts the end face  82  of bracket  64 . 
     Pivoting of bracket  60  about axis  57  is locked out or prevented when the device  10  is assembled such that the head of screw  68  is seated in a counterbore  81  in the leg  62  of bracket  60 . Specifically, the screw shank extends through bore  79  in bracket  60  and bore  76  in bracket  64 , and its screw threads engaged the internal screw threads in bracket  64  along length  72 . When assembled in this way, bracket  60  contacts the end face  82  of bracket  64  and screw  68  holds bracket  60  closed and unable to pivot. 
       FIG. 4  illustrates an alternative lower connection  90  of an orthotic, which is included with the upper member  12 , intermediate member  14 , lower member  16 , and upper connection  23 , substantially as described with reference to  FIGS. 1 through 3 . 
     The lower portion of intermediate member  14  and the upper portion of lower member  16  are formed with arcuate surfaces, which together form an arc that is continuous across the lower connection  90 . A first hinge plate  96  is secured to intermediate member  14  by rivets  98 , and a second hinge plate  100  is secured to lower member  16  by rivets  102 . Two lugs  104  of hinge plate  100  straddle the center lug of hinge plate  96 . Those lugs and the hinge pin  106  that connects them are located eccentric of the ends of members  14  and  16  and concentric with an axis  107 , about which the lower connection  90  pivots. 
     A bracket  110  is secured to the lower member  16  by rivets  102 , each rivet having a head  112  that is counterbored from the outer surface in bracket  110 . Bracket  110  is located near and facing a bracket  114 , which is secured to the intermediate member  14  by rivets  98 , each rivet having a head  116  that is counterbored from the outer surface in bracket  114 . The inner surface  118  of bracket  114  conforms to the contour of intermediate member  14 . Preferably, bracket  110  and bracket  114  are formed of plastic material. 
     When the lower member  16  pivots clockwise about axis  107  to the fully extended position, the adjacent end faces  120 ,  122  of brackets  110  and  114 , respectively, become engaged by mutually contact, such that the contact provides a resistance stop to prevent further clockwise pivoting of the lower member  16  about axis  107 , thereby limiting plantar flexion, i.e. movement that increases the angle between the foot and the leg, for treatment of drop foot especially in a stroke patient. The lower member  16  must pivot about the axis  107  of hinge pin  106  counterclockwise from the fully extended position, but it can pivot in either direction other than from the fully extended position. 
     In a third embodiment, brackets  110  and  114  can be deleted from the lower connection  90  illustrated in  FIG. 4 . The first hinge plate  96  is secured to lower member  14  by the rivets  98  and the second hinge plate  100  is directly secured to intermediate member  16  by the rivets  102 . Two lugs  104  of hinge plate  100  straddle the center lug of hinge plate  96 , and those lugs and the hinge pin  106  that connects them are located eccentric with the ends of members  14  and  16 . Therefore, in this third embodiment, when the lower member  16  pivots clockwise to the fully extended position, the adjacent end faces  124 ,  126  of members  16  and  14 , respectively, become engaged by mutually contact, which provides a resistance stop to prevent further clockwise pivoting of the lower member  16  about axis  107 . The lower member  16  must pivot about the axis  107  of hinge pin  106  counterclockwise from the fully extended position shown in  FIG. 4 , but it can pivot in either direction other than from the fully extended position. 
       FIGS. 5 and 6  show a brace or support  150 , which includes a front or inner surface that conforms to the contour of the calf of the human leg, and an outer surface  152 , which is substantially parallel to its inner surface. The outer surface  152  is formed with a hollow pocket  154  enclosed by a wall  156  and having an opening  158 , into which the upper end  160  of the upper member  12  is inserted. The outer surface  162  of the pocket  154  has a series of holes  164 , which extend through the pocket and the inner and outer surfaces of the support  150 . Threaded attachments  166 ,  168 , inserted through at least some of the holes  164  and through a slotted hole  170  in the upper member  12 , secure the support  150  and upper member  12  in a desired position. 
     A rotating bar  172 , in the form of a thin elongated plate, is secured at one end by an attachment  174  to a boss  176  formed on the outer surface  162  of pocket  154 . The opposite end  180  of the rotating bar  172  bears against the outer surface  152  when the rotating bar is not in use. The rotating bar  172  can be rotated in either direction about attachment  174  from the position shown in  FIG. 5 , such that the area of the rotating bar near its end  180  contacts a surface, e.g., the surface of a bed in which the user is lying, to prop the foot against rotation from a desired position, usually in the vertical plane. 
     In a fourth embodiment of the lower connection  130  illustrated in  FIGS. 7 and 8 , a first hinge plate  132 , secured by rivets  98  to intermediate member  14  and bracket  134 , terminates in a lug  136 , which surrounds a hinge pin  138  centered at a pivot axis  140 . A second hinge plate  142 , secured by rivets  102  to lower member  16  and bracket  144 , terminates at mutually spaced lugs, which straddle lug  136  and surround hinge pin  138 . 
     As best seen in  FIG. 8 , bracket  134  terminates in a central lug  146 , located between two lugs  148 ,  190 , which are formed on bracket  144  and straddle lug  146 . A lateral hole in lug  148  is formed with screw threads  192 , which extend across the width of lug  148 . A lateral hole in lug  190  is formed with screw threads  194 , which are aligned with threads  192  and extend across the width of lug  190 . When the lower member  16  pivots clockwise to the fully extended position, a set screw  196  engaged with screw threads  192  can be threaded from one lateral direction into lug  148  such that the set screw enters a hole  198  in lug  146 , and a set screw  200  engaged with screw threads  194  can be threaded in the opposite lateral direction into lug  190  such that the set screw enters a hole  202  in lug  146 , which is preferably aligned with the hole in lug  148 . Engagement of the set screws  196 ,  200  with lugs  146 ,  148 ,  190  secures members  16 ,  14  mutually and provides a resistance stop that locks out any pivoting of the lower member  16  about axis  140 . Otherwise, the lower member  16  pivots about the axis  140  counterclockwise from the fully extended position shown in  FIGS. 7 and 8 , and can pivot in either direction other than from the fully extended position. 
     Notably, by locking out the free motion of the ankle at axis  57  or  140 , as the case may be, the brace will transfers a floor reaction moment to the knee, which will cause the knee to go into extension, i.e. movement that increases the angle across the knee between the upper leg and lower leg. This will naturally occur during gait, i.e., while the person using the brace is walking. Notably, the lock out mechanism of the free motion hinge gives the brace additional versatility in therapy. By contrast, when the lock out mechanism is not engaged, the patient has more natural walking freedom at the ankle. As a result, this invention assists the ankle to progress through different stages of therapy as the mobility of the ankle increases. 
     It should be noted that the present invention can be practiced otherwise than as specifically illustrated and described, without departing from its spirit or scope. It is intended that all such modifications and alterations be included insofar as they are consistent with the objectives and spirit of the invention.