Patent Publication Number: US-2021161746-A1

Title: Leg brace and garment covering leg brace

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2019-215431, filed on Nov. 28, 2019, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND 
     The present disclosure relates to a leg brace and a garment covering the leg brace. 
     Published Japanese Translation of PCT International Publication for Patent Application, No. 2018-518318 (hereinafter referred to as Patent Literature 1) discloses an artificial knee including a thigh link fixed to a thigh of a user, a shin link fixed to a shin thereof, and a passive compressive force generator that resists bending of the shin link with respect to the thigh link. The passive compressive force generator is, for example, an air spring or a compression coil spring. 
     SUMMARY 
     Patent Literature 1 does not disclose any technical matter about the reduction of a physical burden on a user that is caused when the user stands up from a sitting position. 
     One of the objects of the present disclosure is to provide a technique for reducing a physical burden on a user that is caused when the user stands up from a sitting position. 
     A first exemplary aspect is a leg brace configured to be attached to a leg of a user, including: a thigh link extending along a thigh of the user; and a lower-leg link rotatably connected to the thigh link and extending along a lower leg of the user, in which a handle is provided in the thigh link, the handle being configured to project forward when the user is in the sitting position. According to the above-described configuration, when a user stands up from a sitting position, the user grasps the handle and applies the load (i.e., the weight) of his/her upper body to the handle, so that a moment which assists the user&#39;s standing-up motion is generated in the thigh link. As a result, the physical burden of the user that is caused when the user stands up is reduced. 
     The thigh link and the lower-leg link are connected to each other near the knee joint of the user, and the thigh link and the handle are also connected to each other near the knee joint. According to the above-described configuration, it is possible to prevent the load applied to the handle from counteracting the moment which assists the user&#39;s standing-up motion. 
     The handle is disposed in the thigh link in a cantilevered manner. According to the above-described configuration, a handle having a simple structure can be realized. 
     The leg brace further includes two thigh links arranged so as to sandwich a thigh of the user therebetween in the left/right direction of the user, and the handle is disposed so as to connect the two thigh links to each other. According to the above-described configuration, the two thigh links can be connected to each other by the handle. 
     The handle is detachably disposed in the thigh link. According to the above-described configuration, when the handle is not used, the handle can be detached from the thigh link. 
     An attaching/detaching part configured to attach/detach the handle to/from the thigh link is formed in the thigh link. According to the above-described configuration, the handle can be attached to and detached from the thigh link. 
     The handle can extend and contract in a longitudinal direction. According to the above-described configuration, when the handle is not used, the handle can be contracted in the longitudinal direction. 
     The handle is configured to be switchable between a first posture in which the handle projects forward when the user is in the sitting position and a second posture in which the handle extends along the thigh link when the user is in the sitting position. According to the above-described configuration, when the handle is not used, the handle can be brought into the second posture. 
     Another aspect is a garment with an opening formed therein, the garment being configured to be put on a leg of a user, to which the above-described leg brace is attached, so as to cover the leg brace, the opening conforming to the attaching/detaching part. According to the above-described configuration, the handle can be attached to and detached from the thigh link while the user is wearing the garment. 
     The garment includes an opening cover configured to cover the opening. According to the above structure, since the opening can be covered by the opining cover when the handle is not used, the design of the garment is improved. 
     According to the present disclosure, it is possible to reduce a physical burden of a user that is caused when the user stands up from a sitting position. 
     The above and other objects, features and advantages of the present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a leg brace (first embodiment); 
         FIG. 2  is a diagram for explaining a mechanism of a motion of the leg brace that is performed when a user stands up from a sitting position (first embodiment); 
         FIG. 3  is a side view showing a connecting structure between a handle and a thigh link (second embodiment); 
         FIG. 4  shows a handle that can extend and contract in a longitudinal direction (third embodiment); and 
         FIG. 5  shows a handle that can be tilted (fourth Embodiment). 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     A first embodiment will be described hereinafter with reference to  FIGS. 1 and 2 . 
       FIG. 1  shows a leg brace  2  which is attached to a leg  1  of a user when it is used. 
     The leg  1  is composed of a thigh  3 , a lower leg  4 , and a foot  5 . A buttock  6  is positioned above the leg  1 . 
     The leg brace  2  includes two link structures  7 , a buttock support part  8 , a handle  9 , a foot attaching part  10 , a thigh fixing band  11 , and a lower-leg fixing band  12 . 
     The two link structures  7  are arranged so as to be opposed to (i.e., face) the right side and the left side, respectively, of the leg  1 . That is, the two link structures  7  are arranged so as to sandwich the leg  1  therebetween in the left/right direction of the user. Hereinafter, the left/right direction of the user is simply referred to as the left/right direction. The left/right direction can also be considered to be the width direction of the user. 
     Each of the link structures  7  is composed of a buttock link  20 , a front thigh link  21 , a rear thigh link  22 , and a lower-leg link  23 . 
     The buttock link  20  is a link that is disposed at the base of the thigh  3  and extends roughly horizontally when the user is in the standing position. 
     The front and rear thigh links  21  and  22  extend along the longitudinal direction of the thigh  3 . The front and rear thigh links  21  and  22  extend roughly vertically when the user is in the standing position. The front thigh link  21  is disposed forward of the rear thigh link  22 . 
     The lower-leg link  23  extends in the longitudinal direction of the lower leg  4 . A thigh link connection part  24  is formed at the upper end of the lower-leg link  23 . 
     Further, the upper end of the front thigh link  21  is rotatably connected to a front connection part  20   a  of the buttock link  20 . The upper end of the rear thigh link  22  is rotatably connected to a rear connection part  20   b  of the buttock link  20 . The front connection part  20   a  is positioned forward of the rear connection part  20   b.    
     The lower end of the front thigh link  21  is rotatably connected to a front connection part  24   a  of the thigh link connection part  24 . The lower end of the rear thigh link  22  is rotatably connected to a rear connection part  24   b  of the thigh link connection part  24 . The front and rear connection parts  24   a  and  24   b  are disposed away from each other (i.e., arranged with a space therebetween) in the front/rear direction and in the vertical direction. The front connection part  24   a  is positioned forward of and above the rear connection part  24   b.    
     Therefore, the buttock link  20 , the front thigh link  21 , the rear thigh link  22 , and the thigh link connection  24  constitute the so-called four-bar linkage. 
     The lower end of the lower-leg link  23  is rotatably connected to a leg connection part  10   a  of the leg attaching part  10 . 
     The foot attaching part  10  is fixed to the foot  5 . In  FIG. 1 , the foot attaching part  10  is a sandal, and is composed of a sole part  25  that is opposed to the sole of the foot  5  of the leg  1  and a foot fixing band  26  that is opposed to the instep of the foot  5  of the leg  1 . Further, the foot attaching part  10  is fixed to the foot  5  in such a manner that the foot  5  is sandwiched between the sole part  25  and the foot fixing band  26 . Alternatively, the foot attaching part  10  may be a boot, a sneaker, a leather shoe, or a slip on. 
     In this embodiment, the front thigh link  21  is a string made of a flexible material, typically made of a polyamide synthetic resin such as nylon. The front thigh link  21  includes a length adjusting mechanism  21   a  and a detaching mechanism  21   b . The length adjusting mechanism  21   a  is a mechanism for adjusting the length of the front thigh link  21  in the longitudinal direction, i.e., the distance between the front connection part  20   a  and the front connection part  24   a , and is typically formed by a belt feed. The detaching mechanism  21   b  is a mechanism for temporarily detaching the front thigh link  21 , and is typically a buckle. 
     In this embodiment, the front thigh link  21  is made of a flexible material. 
     However, the front thigh link  21  may be made of a non-flexible material. For example, the front thigh link  21  is formed of a beam made of metal or wood. Further, specific examples of the flexible material are not limited to the above-shown synthetic resins and may include metals. In such cases, the front thigh link  21  may be a metal wire. 
     The rear thigh link  22  is composed of a rear thigh link upper part  22 A and a rear thigh link lower part  22 B. The rear thigh link upper part  22 A and the rear thigh link lower part  22 B are rotatably connected to each other at a rear thigh connection part  27 . The rear thigh connection part  27  is provided with a switching snap  28  for switching between a state in which the rear thigh link upper part  22 A is relatively rotatable with respect to the rear thigh link lower part  22 B and a state in which the rear thigh link upper part  22 A is not rotatable with respect to the rear thigh link lower part  22 B. The switching snap  28  is typically a tubular member provided in the rear thigh link lower part  22 B in such a manner that the tubular member is slidable along the rear thigh link lower part  22 B in its longitudinal direction. In this case, when the switching snap  28  is slid upward and thereby covers the rear thigh link upper part  22 A, the rear thigh link upper part  22 A becomes the aforementioned non-rotatable state. Further, when the switching snap  28  is slid downward and hence is moved away from the rear thigh link upper part  22 A, the rear thigh link upper part  22 A becomes the aforementioned rotatable state. The configuration of the switching snap  28  is not limited to the above-described configuration. That is, other known configurations may be adopted for the switching snap  28 . 
     A gas spring  29  is provided in the rear thigh link upper part  22 A. The gas spring  29  is a spring using a reaction force of a compressed gas, and obtains the reaction force by filling a sealed cylinder with a nitrogen gas, which is used as the compressed gas, and compressing the gas by a piston. The rear thigh link upper part  22 A can be extended and contracted in the longitudinal direction thereof by the gas spring  29 . 
     The buttock support part  8  is a part that supports a buttock  6  of a user. The buttock support part  8  includes a buttock facing part  8   a  that is substantially opposed to (i.e., faces) the hipbone of the user when the user is in the standing position or in the sitting position. The buttock support part  8  is supported as a double fixed beam by the buttock links  20  of the two link structures  7 . That is, the buttock support  8  connects the buttock links  20  of the two link structures  7  to each other. The buttock facing part  8   a  is disposed rearward of the rear connection part  20   b  when the user is in the standing position. The buttock facing part  8  may has an open-cell structure such as urethane foam, or a closed-cell structure such as polyethylene foam in order to disperse a contact pressure exerted to the user buttock facing part  8 . 
     The thigh fixing band  11  is provided for fixing the buttock links  20  of the two link structures  7  and the buttock support part  8  to the base of the thigh  3 . Therefore, it can be expressed that the front and rear thigh links  21  and  22  are fixed to the thigh  3 . 
     The lower-leg fixing band  12  is provided for fixing the lower-leg links  23  of the two link structures  7  to the lower leg  4 . 
     The handle  9  is provided in order to reduce the physical burden of the user that is caused when the user stands up from the sitting position, and is disposed near his/her knee. Specifically, the handle  9  connects the rear thigh link upper parts  22 A of the rear thigh links  22  of the two link structures  7  to each other. Further, the handle  9  is supported as a double fixed beam by the two rear thigh link upper parts  22 A and is formed in a U-shape with its opened side facing rearward. 
     That is, the handle  9  includes two forward projecting parts  9   a  and a grasping part  9   b . The handle  9  includes at least one forward projecting part  9   a.    
     Each of the front projecting parts  9   a  projects forward from the rear thigh upper part  22 A of the rear thigh link  22  of a respective one of the link structures  7 . As shown in  FIG. 2 , when the user is in the sitting position, each of the front projecting parts  9   a  projects forward from a respective one of the rear thigh link upper parts  22 A. Specifically, when the user is in the sitting position, each of the front projecting parts  9   a  projects forward and upward in an oblique direction from a respective one of the rear thigh link upper parts  22 A. The grasping part  9   b  is a part that connects the tips of the two front projecting parts  9   a  to each other, and extends in the left/right direction. Further, the grasping part  9   b  has such a thickness that the user can easily grasp it. Note that the forward is a direction in which the front of the user&#39;s body faces. 
     The above-described leg brace  2  is particularly suitable for knee osteoarthritis. 
     The knee osteoarthritis causes a symptom in which cartilage in a knee joint deteriorates or is worn away, causing a pain in the knee during walking. 
     In the early stage of knee osteoarthritis, walking on level ground does not cause a problem, but the patient may feel a pain in his/her knee when he/she goes up and down stairs. Alternatively, the patient does not feel a pain in his/her knee during walking, but he/she cannot sit down in the Japanese “seiza” style (i.e., cannot sit on his/her heels) because of a pain in his/her knee. 
     As the knee osteoarthritis progresses, both legs become O-shaped bowlegs or X-shaped bowlegs. As a result, the burden on the joint increases due to the wear of the cartilage and hence the knee joint becomes arthritic. Further, because of the arthritis, mere bending and stretching of the knee become painful. Therefore, the patient has a difficulty in not only going up and down stairs, but also walking on level ground. 
     Further, as the knee osteoarthritis progresses even further, the cartilage disappears (i.e., is completely worn out) and the thighbone and the shinbone directly rub against each other, thus causing a severe pain. 
     For a patient with knee osteoarthritis, the most direct cause of a pain in the knee joint is that the knee joint supports the trunk, the head, and the arms of the patient. Therefore, if a part or the whole of the load (e.g., the weight) exerted on the knee joint can be relieved, the pain in the knee joint can be alleviated. 
     Therefore, the leg brace  2  functions as a knee joint weight-bearing apparatus for relieving a part or the whole of the load exerted on the knee joint. 
     Specifically, once the leg brace  2  is attached to the leg  1 , the user feels, when he/she walks, as if he/she is walking while sitting on a chair at all times. Note that the buttock support part  8  of the leg brace  2  functions as a sitting surface of the chair, and both of the link structures  7  function as legs of the chair. 
     Specific operations of the leg brace  2  are described hereinafter. 
     That is, when a user applies a load (e.g., his/her weight) to the buttock support  8 , the load is received by the rear thigh links  22  of both the link structures  7  and the lower-leg links  23 . In this state, a compressive force acts on each of the rear thigh links  22  in the longitudinal direction thereof. Meanwhile, an expansive force acts on each of the front thigh link  21  in the longitudinal direction thereof. That is, the front connection part  20   a  acts as a fulcrum, the buttock facing part  8   a  becomes a point of force. Further, the rear connection part  20   b  becomes a point of action. 
     When the user bends the knee joint of the leg  1 , the gas spring  29  moderately contracts in the longitudinal direction thereof, so that the posture of the buttock support  8  does not lean forward and hence it can continuously and stably support the buttock  6 . 
     When the user is in the sitting position, firstly, he/she separates the front thigh link  21  into two sections by using a detaching mechanism  21   b  thereof. Next, the user brings the rear thigh link upper part  22 A into a state in which it is rotatable about the rear thigh connection part  27 , i.e., rotatable with respect to the rear thigh link lower part  22 B by using the switching snap  28 . In this way, the user can change his/her position to the sitting position as shown in  FIG. 2  without being hampered by the link structure  7 . 
     When the user stands up from the sitting position, the user grasps the grasping part  9   b  of the handle  9  and applies the load (i.e., the weight) of his/her head and upper body to the grasping part  9   b . As a result, a moment for pushing the buttock support part  8  upward is generated in the rear thigh link upper part  22 A which is fixed to the base of the thigh  3 . That is, a moment that assists the user&#39;s standing-up motion is generated in the rear thigh link upper part  22 A. The standing-up motion includes, for example, a motion of lifting the buttock  6  upward. Therefore, it is possible to reduce the physical burden of the user that is caused when the user stands up from the sitting position. 
     The first embodiment has been described above, and the above-described first embodiment includes the below-described features. 
     That is, as shown in  FIG. 1 , the leg brace  2  attached to a leg  1  of a user includes a rear thigh link  22  (a thigh link) extending along a thigh  3  of the user, and a lower-leg link  23  rotatably connected to the rear thigh link  22  and extending along a lower leg  4  of the user. The rear thigh link  22  is provided with a handle  9  that projects forward when the user is in the sitting position. According to the above-described configuration, when the user stands up from the sitting position, the user grasps the handle  9  and applies the load (i.e., the weight) of his/her upper body to the handle  9 , so that a moment which assists the user&#39;s standing-up motion is generated in the rear thigh link  22 . As a result, the physical burden of the user that is caused when the user stands up is reduced. 
     Further, the rear thigh link  22  and the lower-leg link  23  are connected to each other near the knee joint of the user. Specifically, the rear thigh link  22  and the lower-leg link  23  are connected to each other at a rear connection part  24   b  disposed near the knee joint. Further, the rear thigh link  22  and the handle  9  are connected to each other near the knee joint. According to the above-described configuration, it is possible to prevent the load applied to the handle  9  from counteracting the moment which assists the user&#39;s standing-up motion. 
     Further, the leg brace  2  also includes two rear thigh links  22  arranged so as to sandwich a thigh  3  of the user therebetween in the left/right direction of the user. The handle  9  is provided in order to connect the two rear thigh links  22  to each other. According to the above-described configuration, the two rear thigh links  22  can be connected to each other by the handle  9 . Therefore, the handle  9  contributes to improving the rigidity of the leg brace  2 . 
     The above-described first embodiment can be modified as described below. 
     That is, in the rear connection part  24   b , which connects the rear thigh link  22  and the lower-leg ling  23 , a bending/stretching assisting motor that controls the angle between the rear thigh link  22  and the lower-leg facing part  23  is provided, so that the bending/stretching motion of the knee joint may be assisted. 
     Further, although the link structure  7  is the four-bar link in the above-described embodiment, it is not limited to such an example. For example, the front thigh link  21  and the gas spring  29  are not indispensable. Further, the rear thigh connection part  27  and the switching snap  28  are also not indispensable. 
     Second Embodiment 
     Next, a second embodiment will be described with reference to  FIG. 3 . This embodiment will be described hereinafter with a particular emphasis on differences from the first embodiment, and redundant descriptions will be omitted. 
     In the first embodiment, each of the front projecting parts  9   a  of the handle  9  is attached to the rear thigh link upper part  22 A of a respective one of the rear thigh links  22  in an undetachable manner as shown in  FIG. 1 . 
     In contrast, in this embodiment, each of the front projecting parts  9   a  of the handle  9  is detachably attached to the rear thigh link upper part  22 A of a respective one of the rear thigh links  22  as shown in  FIG. 3 . According to the above-described configuration, when the handle  9  is not used, the handle  9  can be detached from the rear thigh links  22 . Therefore, when the handle  9  is not used, the leg brace  2  can be made compact in size. 
     Note that the means for making each of the front projecting parts  9   a  attachable to and detachable from a respective one of the rear thigh link upper parts  22 A is not limited to any particular means. For example, they may be connected by screws or may be magnetically connected. In this embodiment, the handle  9  may further include an attachment projecting part  9   c  that projects from each of the front projecting parts  9   a  toward the rear thigh link upper part  22 A. Further, the handle  9  is configured so that it can be attached to and detached from the rear thigh link upper parts  22 A by inserting each of the attachment projecting parts  9   c  of the handle  9  into an attachment recessed parted part  30  formed in a respective one of the rear thigh link upper parts  22 A. That is, the attaching recessed parts  30  are formed in the rear thigh link upper parts  22 A as attaching/detaching parts for attaching/detaching the handle  9  to/from the rear thigh link upper parts  22 A. According to the above-described configuration, the handle  9  can be attached to and detached from the rear thigh link upper parts  22 A. 
     Further,  FIG. 3  shows trousers  31  as an example of a garment which is put on the legs of a user to which (i.e., to at least one of which) the leg brace  2  is attached. The trousers  31  are put on the legs so as to cover the leg brace  2 . The trousers  31  are a garment that the user puts on by inserting each of his/her legs into a respective one of two branched cylindrical part  32  thereof. In this embodiment, an opening  33  having a shape that conforms to the shape of the attachment recessed part  30  is formed in the cylindrical part  32 . The opening  33  conforms to the attachment recessed part  30 . The opening  33  is formed on the front side of the trousers  31 . The opening  33  has a sufficiently large size so that the user can easily pass the front projecting part  9   a  therethrough. With the above configuration, the user can attach/detach the handle  9  to/from the rear thigh link upper parts  22 A in the state where the user is wearing the trousers  31 . 
     Further, the cylindrical part  32  of the trousers  31  is provided with an opening cover  34  that covers the opening  33 . The opening cover  34  may be sewn to the cylindrical part  32  so that it provides a state in which the opening  33  is covered by the opening cover  34  and a state in which the opening  33  is exposed in a switchable manner. According to the above-described configuration, since the opening  33  can be covered by the opening cover  34  when the handle  9  is not used, the design of the trousers  31  is improved. 
     Third Embodiment 
     Next, a third embodiment will be described with reference to  FIG. 4 . This embodiment will be described hereinafter with a particular emphasis on differences from the first embodiment, and redundant descriptions will be omitted. 
     In the first embodiment, the handle  9  is a double fixed beam supported by the two rear thigh links  22  as shown in  FIG. 1 . 
     In contrast, in this embodiment, the handle  9  is not provided with the grasping part  9   b  as shown in  FIG. 4 . The handle  9  includes a cantilevered front projecting part(s)  9   a  supported by the rear thigh link upper part(s)  22 A. Further, the front projecting part  9   a  is configured so as to be able to extend and contract in its longitudinal direction thereof. According to the above-described configuration, when the handle  9  is not used, the handle  9  can be contracted in the longitudinal direction. Note that in this case, the user grasps an upper end  35  of the front projecting part  9   a  when he/she stands up from the sitting position. 
     Fourth Embodiment 
     Next, a fourth embodiment will be described with reference to  FIG. 5 . This embodiment will be described hereinafter with a particular emphasis on differences from the first embodiment, and redundant descriptions will be omitted. 
     In the first embodiment, each of the front projecting parts  9   a  of the handle  9  is attached to the rear thigh link upper part  22 A of a respective one of the rear thigh links  22  in a non-rotatable manner as shown in  FIG. 1 . 
     In contrast, in this embodiment, the front projecting part  9   a  of the handle  9  is rotatably attached to the rear thigh link upper part  22 A of a respective one of the rear thigh links  22  as shown in  FIG. 5 . Further, the rear thigh link upper part  22 A is provided with an angle regulating mechanism  36  that regulates a range of the angle between the front projecting part  9   a  and the rear thigh link upper part  22 A. The angle regulating mechanism  36  includes a first stopper  36   a  and a second stopper  36   b.    
     The first stopper  36   a  prevents the forward projecting part  9   a  from further rotating counterclockwise from a first posture in which the forward projecting part  9   a  projects forward and upward in an oblique direction when the user is in the sitting position, and maintains the first posture of the forward projecting part  9   a . A typical example of the posture-maintaining means is magnetic coupling, but it is not limited to such an example. 
     The second stopper  36   b  prevents the front projecting part  9   a  from further rotating clockwise from a second posture in which the front projecting part  9   a  extends along the rear thigh link upper part  22 A when the user is in the sitting position, and maintains the second posture of the front projecting part  9   a . A typical example of the posture-maintaining means is magnetic coupling, but it is not limited to such an example. 
     That is, the handle  9  is configured so as to be switchable between the first posture of the front projecting part  9   a  and the second posture thereof. According to the above-described configuration, when the handle  9  is not used, the handle  9  can be brought into the second posture. Therefore, when the handle  9  is not used, the leg brace  2  can be made compact in size. An example of the state where the handle  9  is not used is, for example, a state where user is walking. 
     From the disclosure thus described, it will be obvious that the embodiments of the disclosure may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims.