Abstract:
An orthotic device for a joint of a human body at which a body appendage pivots includes a first member able to extend along a posterior portion of the appendage on a first side of the joint and a second member able to extend along a posterior portion of the appendage on a second side of the joint opposite the first side. A connection joining the first member and the second member provides a series of defined positions spaced angularly about an axis at which positions the connection can be alternately locked and released, allows pivoting, selective ratcheting and positioning of the second member relative to the first member about the axis, and can restrict pivoting of the second member relative to the first member within a desired angular range of motion. Notably, this orthotic device uniquely combines multiple joint functions into one convenient device which allows it to be used at different stages of therapy without being replaced or requiring additional equipment.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates generally to an orthotic device, and particularly to a leg brace that provides multiple, adjustable functions for controlling the angular position and motion of a knee. 
         [0003]    2. Description of the Prior Art 
         [0004]    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, it may be preferred that the joint be restricted for a period by an orthotic, which imposes a fixed pivoted position. Or an orthotic may be needed that permits 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. 
         [0005]    An orthotic leg device, for example, can typically provide one or two of five common functions: i) free motion about the knee joint as illustrated in U.S. Pat. No. 3,779,654 to Home and U.S. Pat. No. 3,669,105 to Castiglia; ii) a ring drop lock joint to keep the knee joint extended as shown in U.S. Pat. No. 3,923,047 to Chant and U.S. Pat. No. 4,928,676 to Pansiera; iii) a step-lock ratchet joint to support the strength of the knee as it extends to various angular positions as seen in U.S. Pat. Nos. 4,502,472 and 5,776,086 to Pansiera; iv) a range of motion joint as disclosed in U.S. Pat. No. 4,337,764 to Lerman and U.S. Pat. No. 4,982,732 to Morris; or v) a variable, fixed position joint that can be locked in select positions as seen in U.S. Pat. No. 4,388,920 to Hajost et al. and U.S. Pat. No. 7,122,016 to DeToro et al. Each of these five different functioning knee braces has a specific use during therapy of a patient. In each case, a different brace is typically required. 
         [0006]    A need exists, therefore, for one orthotic device that provides these multiple functions, including: a fixed position by releasing an attachment, changing the angular displacement of the orthotic about the axis to a new, desired orientation, and securing the orthotic to that desired position; a limited range of movement about the axis that can be adjusted easily and remain limited reliably by mutual contact between stop surfaces located on opposite sides of the axis; and a free range of movement about an axis. Further, an orthotic device that can be adjusted to multiple, mutually spaced ratcheted locations to enhance the range of flexibility and use of the joint provides an added advantage. 
       SUMMARY OF THE INVENTION 
       [0007]    An orthotic device for a joint of the human body at which a body appendage pivots includes a first member able to extend along a posterior portion of the appendage on a first side of the joint and a second member able to extend along a posterior portion of the appendage on a second side of the joint opposite the first side. A connection joining the first member and the second member provides a series of defined positions spaced angularly about an axis at which positions the connection can be alternately locked and released, allows pivoting, selective ratcheting and positioning of the second member relative to the first member about the axis, and/or allows pivoting of the second member relative to the first member within a desired angular range of motion. 
         [0008]    When the leg is contracted, the ratchet will lock in angular increments and stop re-contracture until the leg reaches the straight position, whereupon the brace prevents contracture and extension (i.e. step-lock ratchet function). 
         [0009]    If the ratchet function is released, the leg can be contracted at the knee. More specifically, the ratcheting function can be locked out temporarily, such as when the person using the brace wishes to sit down. Notably, the ratchet re-engages automatically when the brace is fully extended, or it re-engages manually by applying slight upward pressure on the ratchet when in the locked out position (i.e. drop lock function). 
         [0010]    By disengaging the ratchet completely, the joint of the orthotic device can turn freely about the lateral axis upon loosening lock nuts (i.e. free motion function). 
         [0011]    Further, the brace can the adjusted to provide a range of pivoting motion about the joint by adjusting locknuts a predetermined amount corresponding to the desired flexion limit angle. The flexion limit angle is set first by adjusting the flexion limiting lock nut, and an extension angular limit is set by tightening or loosening the other lock nut (i.e. range of motion function). Further yet, the brace can be returned to the free motion function upon completely loosening both lock nuts, or the brace can be locked in any position by placing the brace in the desired angular flexion and tightening both lock nuts (i.e. variable, fixed position function). 
         [0012]    Still further, the brace accommodates contraction and expansion of the muscles and skin that accompany flexion and extension of the knee joint, by providing an upper member having a thigh cuff attachable to the thigh that slides in an upper pocket, a lower member having a calf cuff attachable to the calf that slides in a lower pocket, so that the positions of the thigh and calf cuffs remain unchanged relative to the extension and contraction of the leg. The position of the joint, therefore, remains unchanged at the back of the knee due to the tendency of the springs to keep the brace cuffs at their secured positions. 
         [0013]    The scope of applicability of the preferred embodiment will become even more apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating the 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 
         [0014]    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: 
           [0015]      FIG. 1  is a rear view of a multiple function leg orthotic device; 
           [0016]      FIG. 2  is a top view of an upper member of the orthotic device of  FIG. 1 ; 
           [0017]      FIG. 3  is a side view of the upper member of  FIG. 2 ; 
           [0018]      FIG. 4  is an end view of the upper member of  FIG. 2 ; 
           [0019]      FIG. 5  is a top view of a lower member of the orthotic device of  FIG. 1 ; 
           [0020]      FIG. 6  is a side view of the lower member of  FIG. 5 ; 
           [0021]      FIG. 7  is an end view of the lower member of  FIG. 5 ; 
           [0022]      FIG. 8  is a side view of the joint that includes the upper and lower members and a ratchet; 
           [0023]      FIG. 9  is a side view of the ratchet of  FIG. 8 ; 
           [0024]      FIG. 10  is a front view of the ratchet of  FIG. 8 ; 
           [0025]      FIG. 11  is a top view of the ratchet of  FIG. 8 ; 
           [0026]      FIG. 12  is a side view of the ratchet joint that connects the upper and lower members; 
           [0027]      FIG. 13  is a top view of the ratchet joint of  FIG. 12 ; and 
           [0028]      FIG. 14  is a cross section taken at plane  14 - 14  of  FIG. 13 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    Referring first to  FIGS. 1 through 4 , an orthotic device  10  includes an upper member  12  and a lower member  14 , which are interconnected by a ratcheting joint  15 . Each member  12 ,  14  is preferably formed of aluminum or another structural material having density, strength and endurance comparable to those of aluminum. 
         [0030]    The-upper member  12  includes two lugs  16 ,  18 , spaced mutually along a lateral axis  20 , each lug having a hole  22 ,  23 , in which screw threads are tapped. Preferably, the screw threads in holes  22 ,  23  are right-hand threads. The outer surface of each lug  16 ,  18  is counterbored at the respective hole. A plastic thigh cuff  24 , whose front surface conforms to the contour of the back of the human thigh, is formed at its back surface with a longitudinal pocket  26 . The upper member  12  is inserted into pocket  26  and retained there by threaded attachments  28 , each attachment comprising a screw which passes through a slotted hole  30  in member  12  and a nut that engage the screw and contacts the outer surface of pocket  26 . Tension springs  32 ,  33 , each have an end secured to the upper member  12  by engaging a hole  34 , and the opposite end secured to the thigh cuff  24  at attachment element  35 , thereby permitting member  12  to move elastically along an longitudinal axis  36  relative to the thigh cuff  24 . Multiple velcro straps  38 ,  40  secure the thigh cuff  24  to the leg of the person wearing the brace  10 . A threaded hole  42  is tapped in the upper member  12 , and an elongated hole  44  is formed at a lower elevation than that of the threaded hole  42 . The lower edge  46  of the upper member  12  faces the lower member  14 . 
         [0031]    Referring now to  FIGS. 1 and 5  through  8 , the lower member  14  includes: a central lug  50  located between lugs  16 ,  18  and formed with an unthreaded hole  52 , which is aligned with lateral axis  20  and threaded holes  22 ,  23 ; a series of ratchet teeth  54 , spaced mutually about axis  20 ; a stop surface  55 ; and a slot  56 . Two tapped holes  58 ,  59 , directed toward axis  20 , are formed in lug  50 . A calf cuff  60 , whose front surface conforms to the contour of the calf of the human leg, is formed at its back surface with a longitudinal lower pocket  62 . The lower member  14  is inserted into pocket  62  and retained there by threaded attachments  64 ,  65 , each attachment comprising a screw which passes through a slotted hole  66  in member  14  and a nut that engage the screw and contacts the outer surface of pocket  62 . Tension springs  68 ,  69 , each have one end secured to the lower member  14  by engaging a hole  67 , and the opposite end secured to the calf cuff  60 , permitting member  14  to move along longitudinal axis  36  relative to the calf cuff  60 . Multiple velcro straps  70 ,  72  secure calf cuff  60  to the patient&#39;s leg. A hole  74  is drilled in the lower member  14  to lock the cuff in a shortened position if necessary. 
         [0032]      FIGS. 1 and 8  show that the ratcheting joint  15  for connecting the upper member  12  and lower member  14  includes an angle stop bracket  76  secured to the upper member  12  by a screw  78  engaged in threaded hole  42 , a ratchet  80 , and a spring-loaded ratchet lockout pin  82  for securing the ratchet to the upper member  12 . 
         [0033]      FIGS. 8 through 12  illustrate details of the ratchet  80 , which includes an upper plane  84  formed with an unthreaded hole  86 ; a lower plane  88  formed with an unthreaded hole  90 , aligned with hole  86 ; and a latch  92  for engaging alternately the ratchet teeth  54 , stop surface  55 , and slot  56  on the lower member  14 . A curved arm  94 , located at the lower end of the upper plane  84 , overlaps the ratchet teeth  54  to protect against an otherwise pinching-point. An adjustment arm  96 , located at the upper end of plane  84 , provides a surface with which to manually slide ratchet  80  along axis  36  away from the ratchet teeth  54 . The ratchet includes two laterally spaced holes  98  directed parallel to axis  36  and closed at their lower ends, each hole  98  containing a compression spring  100 . The leg of angle stop bracket  76  bears against one end of springs  100 , urging latch  92  toward lug  50  and the ratchet teeth  54 . 
         [0034]    The spring-loaded ratchet lockout pin  82  is biased outward from holes  86  and  90  by a spring  101 , fitted between the head of pin  82  and the outer surface of plane  84 . A portion of the shank of pin  82  extends through spring  101  and the aligned holes  86 ,  90  in the ratchet  80 . The threaded shank of pin  82  engages a floating nut  103 , which is retained in a space between plane  84  and springs  100  such that the nut  103  cannot rotate when pin  82  is rotated. 
         [0035]    Ratchet  80  can be moved manually upward along axis  36  against the force of springs  100  to a point where holes  86  and  90  in the ratchet become aligned with hole  44  in the upper member  12 . When the ratchet  80  is in that position, it can be more permanently retained there by rotating pin  82  relative to nut  103 , thereby driving and securing its shank against the force of spring  101  into elongated hole  44 . Ratchet  80  is retained in that position due to contact between the shank of pin  82  and the surface of hole  44 . When ratchet  80  is in that position, the ratchet is locked out, i.e., preventing engagement of latch  92  with the ratchet teeth  54  and slot  56  to allow free motion. 
         [0036]    The force of springs  100  continually biases ratchet  80  downward toward engagement with the ratchet teeth  54 . Ratchet  80  can be returned to the ratcheting position from the lockout position by rotating pin  82  in the opposite direction sufficiently to disengage its shank from nut  103 , whereupon ratchet  80  is forced elastically to the ratcheting position by the force of springs  100 , i.e. step lock function. 
         [0037]    It is important to note that ratchet  80  can be placed temporarily in the lockout position by aligning holes  86 ,  90  in the ratchet with hole  44  in the upper member  12 . Then, without rotating the pin  82  relative to floating nut  103 , pin  82  and nut  103  are pushed against the force of spring  101  into hole  44 , where ratchet  80  is retained by a frictional reaction force between the shank of pin  82  and the surface of elongated hole  44  due to the force of springs  100 . 
         [0038]    In summary, therefore, with view of  FIG. 12 , the shank of ratchet lockout pin  82  is engaged with nut  103  and the holes  86 ,  90  of ratchet  80 . The ratchet is moved upward along axis  36  in opposition to the force of springs  100  to the ratchet lock out position, where pin  82  enters the elongated hole  44  in the upper member  12 . In the ratchet lock out position, latch  92  is disengaged from ratchet teeth  54  and slot  56  on the lower member  14 . Upon moving pin  82  out of hole  44 , ratchet  80  is forced downward by springs  100  such that latch  92  ratchets on or engages with the ratchet teeth  54 , or engages the stop surface  55  or enters the slot  56  on lug  50  of the lower member  14 . 
         [0039]    Further,  FIG. 12  shows a set screw  102  threaded into hole  58  and engaged with the shank of a headless bolt  104 , whose right-hand screw threads are engaged with the threaded holes  22 ,  23  in lugs  16 ,  18 , respectively, of the upper member. Bolt  104  passes through the unthreaded hole  52  in the lug  50  of the lower member  14 . A similar set screw  102  is threaded into hole  59  and engaged with bolt  104 . The set screws  102  prevent rotation of bolt  104  relative to lug  50  about axis  20 , so as to create axial rotation of bolt  104  along axis  20  in joint  15  by pivoting the lower member  14  relative to upper member  12 . 
         [0040]    Focusing now on  FIGS. 1 ,  13  and  14 , a thrust bearing  108  and washers  110 , located on opposite sides of the thrust bearing, are fitted in the counterbore formed in the outer surface of lugs  16 ,  18  to facilitate loosening and tightening lock nuts  112 ,  114  on the threads of bolt  104 . 
         [0041]    As  FIG. 13  illustrates, the surfaces of the lugs  16 ,  18  of the upper member  12  include a scale  120  of graduated angular positions or witness marks  122 . The scaled witness marks  122  correspond to the angular displacement of the joint  15  from a reference angular position, i.e., the straight-out position of the leg, in which members  12  and  14  are aligned substantially parallel to axis  36 . Latch  92  can engage the respective ratchet tooth  54  that corresponds to the selected angular position. 
         [0042]    In operation, the joint  15  is able to pivot about the lateral axis  20  and the brace  10  can provide multiple functions, as described below: 
         [0043]    1. To activate the ratchet  80 , the ratchet lockout pin  82  is turned counterclockwise relative to nut  103  several revolutions until the ratchet releases. The ratchet  80  can be locked again by retracting ratchet  80  and turning the ratchet lockout pin  82  several turns clockwise. 
         [0044]    To lock out the ratchet  80  on a temporary basis, such as when the person using the brace  10  is sitting down, ratchet  80  is retracted to the stop bracket  76  and the ratchet lockout pin  82  is pushed toward the back of the leg, which causes the shank of pin  82  to enter hole  44  where it is retained by the force of springs  100  in a friction hold position. Pin  82  is held in, thereby releasing ratchet  80 . The ratchet  80  will lock automatically when the brace  10  returns to the straight position, i.e., the drop lock function. The ratchet  80  can also be reengaged by applying slight upward pressure on the ratchet to release the friction hold position. 
         [0045]    2. When ratchet  80  is locked out on a temporary basis as described above, it will automatically release when slot  56  is contacted, slightly pushing latch  92 , causing the shank of pin  82  to briefly move away from the wall of hole  44 , whereby spring  101  forces upward the lock out pin  82  to disengage. Then, in the released position, the ratchet will automatically lock when the leg reaches the straight position, i.e. full extension. Once the ratchet is released from the temporary lockout position when the leg is contracted at the knee, the ratchet will lock and stop contracture every 10° to  200 , i.e. the distance between successive ratchet teeth, until the leg reaches the straight position, whereupon the brace  10  will not allow contracture or extension due to engagement of latch  92  in slot  56 . Preferably, the distance between successive ratchet teeth corresponds to about 15°. 
         [0046]    3. The joint  15  can rotate freely (i.e. free motion function) or be set to a particular range of motion (i.e. range of motion function), with or without ratcheting (which is described in more detail below) upon loosening or tightening lock nuts  112  and  114  about bolt  104 . By adjusting the lock nuts  112 ,  114 , the range of motion of brace  10  is changed about the lateral axis  20 . More specifically, as upper member  12  rotates about bolt  104  (which is secured to lower member  14  by set screws  102  at center lug  50 ), lugs  16 ,  18  move up and down axis  20  by their threadable engagement with bolt  104  at threaded holes  22 ,  23 , respectively, until either lug  16  contacts lock nuts  112  or lug  18  contacts lock nut  114 . At that point, the range of motion stops. 
         [0047]    By adjusting lock nuts  112  and  114  along bolt  104 , the pivotal range of motion between lower member  14  and upper member  12  can be changed or locked to best accommodate the several stages of therapy. More specifically, with ratchet  80  locked out permanent or temporarily as described above, the brace  10  can be adjusted to provide a range of motion. With brace  10  in the straight position, both lock nuts  112 ,  114  are tightened. The joint  15  is then locked and allows no rotary movement about axis  20 . If, for example, a flexion limit angle of 20° is desired, lock nut  112  is loosened, and the joint  15  can then be pivoted through an angle of approximately 20°, in the direction that reduces the magnitude of the angle between the thigh and the calf. The desired flexion limit angle can be checked with reference to the witness marks  122  located near the lock nuts  112 ,  114  on lugs  16 ,  18 . Lock nut  112  can be adjusted to precisely set the desired flexion limit angle. 
         [0048]    If a combination of flexion and extension is desired, the flexion limit angle is set first by adjusting lock nut  114 , as described above. Then, the extension angular limit is set by tightening lock nut  112 . The desired extension limit angle can be checked with reference to the witness marks  122  located near the lock nuts  112 ,  114  on lugs  16 ,  18 . Lock nut  112  can be adjusted to precisely set the desired extension limit angle. The brace  10  is returned to the free motion function upon loosening both lock nuts  112 ,  114  about one-half turn. 
         [0049]    4. The brace  10  can also be adjusted to select a desired angular position without pivoting in either direction. To accomplish this, lock nuts  112 ,  114  are loosened about one-half turn and, with ratchet  80  locked out permanent or temporarily as described above, joint  15  is pivoted about axis  20  to the desired angular position, and the lock nuts are retightened, thereby relocking joint  15  at the desired position (i.e. variable, fixed position function). 
         [0050]    Finally, it is important to note that with this orthotic device being mounted to the posterior portion of an appendage, as the joint flexes, contraction of the muscles and skin occurs. Therefore, with this knee orthotic, for example, the thigh cuff  24  and calf cuff  60  are positioned and firmly secured by velcro straps  38 ,  40  and  70 ,  72 , respectively, to the leg and back of the knee. In order to accommodate contraction and expansion of the muscles and skin that accompany flexion and extension of the knee joint, therefore, upper member  12  slides along axis  36  in upper pocket  26  and lower member  14  slides along the axis  36  in the longitudinal lower pocket  62 , while the positions of the thigh cuff  24  and calf cuff  60  relative to the leg remain unchanged. As a result, the location of joint  15  remains unchanged at the back of the knee due to the tendency of springs  32 ,  33 ,  68 ,  69  to allow the thigh cuff  24  and calf cuff  60  to dynamically reposition relative to the joint  15 . 
         [0051]    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.