JPH0817789B2 - Knee joint for endoskeletal prosthesis to prevent damage to the cover - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knee joint for a prosthesis,
More specifically, the present invention relates to a knee joint provided with members for imitating the configuration and shape of the human knee joint skeleton.

[0002]

2. Description of the Related Art Prosthetic legs are required to have two functions.
One is the function of literally acting as a foot to allow the prosthesis user to walk, and the other is the function of providing the appearance of the prosthesis user as a lost foot. At present, prostheses are roughly classified into an exoskeleton type that emphasizes a walking function and an endoskeletal type that is also considered to provide the same appearance as a human foot. This endoskeletal prosthesis is mainly composed of a pipe having the same structure as the skeleton of a human foot. Then, in order to obtain a shape similar to that of the soft tissue of the human body, a urethane foam cover of one-piece is formed in conformity with the outer shape of the normal lower limb, and this is covered (exterior) with the endoskeletal prosthesis. This provides a form that is indistinguishable from the legs of the human body in appearance. For this reason, endoskeletal prostheses are widely accepted, especially by female amputees, as skirt-peg prostheses.

[0003]

However, the above-mentioned endoskeleton prosthesis has a problem in the durability of the foam cover to be mounted on it. That is, as shown in FIG. 7, in a state in which the artificial leg user sits on a chair or the like and bends the knee 90 °,
Upper knee 75 and lower leg pipe 7 connected to the thigh pipe 71
The lower part of the knee 76 connected to 7 is 9 about the connecting shaft 81.
The lower end portion 75a of the upper knee 75 opposite to the connecting shaft 81 (hereinafter simply referred to as the lower end portion 75a of the upper knee 75) and the lower end portion of the lower knee 76 opposite to the connecting shaft 81 are rotated by 0 °. The upper end 76a (hereinafter, simply referred to as the upper end 76a of the lower knee 76) is separated. Further, as shown in FIG. 8, when the artificial leg user tries to sit straight, the knee must be bent about 180 °, and the lower end 75a of the upper knee 75 and the upper end 76a of the lower knee 76 are further separated. . Each time the knee is bent in this manner, the lower end 75a of the upper knee 75 and the lower knee 76
Since the upper end portion 76a of the foam cover is largely separated from the upper end portion 76a, the knee portion of the foam cover 83 is pulled, and the shape of the knee portion of the foam cover 83, which was made to resemble the knee of a human body, lost its shape, and the portion was broken. For this reason, foam covers usually cannot withstand use for more than one year. Furthermore, not only the foam cover but also the knee parts such as stockings and pants have been damaged. The foam cover 83 was also damaged by the prosthesis user rolling down or twisting by rotating the turntable on the knee. As a method of solving this problem, it is conceivable to divide the foam cover into two parts at the knee part in advance into the thigh part and the lower leg part, that is, to form the exterior of the two-piece cover. However, the current endoskeletal prosthesis is designed on the premise of using a one-piece urethane foam cover. However, it was difficult to obtain a shape that closely resembles the outer shape of a normal lower limb.

Furthermore, the above-mentioned endoskeletal prosthesis has an appearance that does not indicate that the user is a prosthetic leg user while walking, that is, when the knee is not flexed, but the knee is flexed. Up to now, no consideration has been given to the appearance of the knee part in. Therefore, as described above with reference to FIG. 7, the user with the artificial leg sits on a chair or the like and knees 9
The lower end 75 of the upper knee 75 in the state of being bent by 0 °
Since a and the upper end portion 76a of the lower knee portion 76 are separated from each other, the foam cover 83 of the artificial leg has an unnatural shape at the knee portion. Further, as shown in FIG. 8, when the artificial leg user tries to sit straight, the knee must be bent about 180 °, and the lower end 75a of the upper knee 75 and the upper end 76a of the lower knee 76 are further separated. , The kneecap will be depressed and have a very unnatural shape.

At present, the prosthesis has come to be used more and more by the elderly who have had amputation of the lower limbs due to blood circulation disorder at the distal end of the lower limbs mainly due to arteriosclerosis.
The purpose of these elderly people to go out wearing their prostheses is to attend ceremonial occasions, and they must sit on the floor unless they actively announce that they are using prostheses. Disappear. In such a case, in the conventional prosthesis, the shape of the knee portion becomes unnatural, and it is known to the attendees around that the prosthesis is being used. In reality, it is feared that users of artificial legs hesitate to attend ceremonial occasions and abandon the use of artificial legs. Some men have this tendency, but women are particularly strong at any age.

Further, when the prosthesis user tries to sit upright at a funeral or the like, the upper end portion 76a of the lower knee portion 76 is positioned inside the knee rather than the perpendicular A drawn from the connecting shaft 81 as shown in FIG. When the upper end portion 76a hits the tatami while it is doing, a repulsive force is applied, causing a situation in which the lower limb portion jumps up toward the thigh. Since this kind of thing cannot happen with the human foot, it surprised the attendees around him, and made him very embarrassed and embarrassed. Further, as shown in FIG. 8, a conventional artificial leg has an angular lower end 75a of the upper knee 75, and therefore, when the user attempts to sit straight, the impact is cut when the lower end 75a hits the floor. It was directly applied to the tip of the thigh and made the prosthetic user feel sharp pain.

The present invention has been made to solve the above problems, and an object thereof is to construct an endoskeletal prosthesis capable of producing a well-shaped outer cover without damaging the cover. To provide a knee joint.

[0008]

To achieve the above object, the present invention connects an upper knee connected to a thigh pipe, a lower knee connected to a lower leg pipe, and an upper knee and a lower knee. In a knee joint consisting of a connecting shaft, a Patella member,
Of a Patella inductor that is attached to the upper part of the knee or the lower part of the knee and is composed of a substantially semi-circular curved surface, and slides the Patella member on the curved surface during bending of the knee, and the knee part to which the Patella inductor is attached. A holding member that is supported on the opposite knee and holds the Patella member on the curved surface of the Patella inductor, and the Patella inductor is located at an intersection point where the Patella member extends the thigh pipe and the crus pipe. Is always located outside.

[0009]

In the knee joint for an endoskeletal prosthesis configured to prevent the cover from being damaged, the holding member holds the Patella member on the curved surface of the Patella inductor. Then, when the knee is bent, the Patella member slides on the curved surface of the Patella inductor,
It is always located outside the intersection point where the thigh pipe and the crus pipe are extended. As a result, when the knee is bent, the patterner member is located at the same position as the position of the patterner on the knee of the human body, and the knee joint has substantially the same shape as the knee of the human body.

[0010]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the overall structure of a prosthesis 10 including a knee joint 24 of this embodiment. A socket base 12 is arranged under the socket 14 for accommodating the thigh, and the socket 14 is fixed to the artificial leg side. A wire 20 of the knob 16 that unlocks the knee joint 24 is arranged along the socket 14. Then, the thigh pipe 22 is connected to the lower surface of the socket base 12, and the knee upper part 31 of the knee joint 24 is attached to the lower end of the thigh pipe 22.
Patella inductors 37 for guiding the Patella 32 are formed on both sides of the. The upper knee 31 is connected to the lower knee 33 by a connecting shaft 35. And below the knee 33
The lower leg pipe 26 is connected to the lower end of the lower leg pipe 2
At the lower end of 6 is the foot module 2 when sitting straight with an artificial leg.
Ankle 27 for making 8 substantially horizontal to the lower leg pipe 26
Is attached.

Next, the structure of the knee joint 24 of this embodiment will be described in more detail with reference to FIG. 2 which is a side view and FIG. 3 which is a plan view. A thigh pipe fixing hole 31a for fixing the thigh pipe 22 is formed in the upper knee 31, and a slit 31d for arranging the bell crank 49 is formed on the left side of FIG. 1 from the thigh pipe fixing hole 31a. Further, the spring 3 is provided below the thigh pipe fixing hole 31a.
A groove 31e for arranging 9 is formed. Also,
A pair of boss portions 31b is formed on the upper part of the knee 31 on the right side of the thigh pipe fixing hole 31a, and a through hole 31c is formed in the center of the boss portion 31b. Then, on both sides of the knee upper portion 31, there are formed Patella inductors 37 having a substantially semicircular shape for guiding the Patella 32. The substantially semi-circular shape of the Patella inductor 37 has the connecting shaft 35 centered on the connecting shaft 35.
It is formed so that the radius becomes larger as it gets away from. On the other hand, the lower knee 33 is formed with a lower leg pipe fixing hole 33a for fixing the lower leg pipe 26 at its lower end, and a slit 33c is formed on the left side of the figure from the lower leg pipe fixing hole 33a.
Has been drilled. Further, an arm portion 33b that points upward is formed on the upper surface of the lower knee 33. A through hole 33d is formed in the base portion of the arm portion 33d, and a pin 4 for locking one end portion of the spring 39 is provided in the center portion thereof.
5 is installed. Further, a through hole 33c is formed in the upper end portion of the arm portion 33b, and the connecting shaft 35 is arranged so as to pass through the through hole 33c and the through hole 31c of the boss portion of the above-mentioned knee upper portion 31. The upper knee 31 and the lower knee 33 can be rotated, that is, the knee joint 24 can be bent.

A shaft 43 is arranged at the upper end of the lower knee 33 on the side of the patella 32, and the holding member 41 of the patella 32 is
The shaft 43 is pivotally supported on a plane where the knee bends. A through hole 41b is provided at a substantially central position of the holding member 41.
And a spring 39 is attached to the through hole 41b. This spring 39 has an arm 3 at the other end.
The holding member 41 is urged toward the pin 45, that is, toward the inside of the knee joint 24 by being supported by the pin 45 provided in the through hole 33d of 3a. A shaft 42 is arranged below a through hole 41b that supports a spring, and rotatably supports the patella 32 through a carrier part 32a of the patella. An L-shaped portion 41 a is formed on the upper end of the holding member 41, and the slit 31 of the upper knee 31 is formed.
The pin 51 installed on d is always locked. A shaft 47 that pivotally supports a bell crank 49 that unlocks the knee joint 24 is disposed above the holding member 41. The unlocking by the bell crank 49 will be described later.

Next, regarding the bending of the knee by the knee joint 24 of the present embodiment, FIG. 4 showing the state in which the knee joint 24 is bent by 110 ° and bending by about 180 °, that is, the prosthesis 10 is used to perform a straight sitting. This will be described with reference to FIG.
When the knee is bent, the knee joint 24 of the present embodiment, as shown in FIG. 4, has the lower end 2 of the thigh pipe 22 centered on the connecting shaft 35.
2a and the upper end 26a of the lower leg pipe 26 are separated,
Patella guides 37 are formed in a substantially semicircular shape on both side surfaces of the upper knee 31 fixing the thigh pipe 22, and on the upper right side of the lower knee 33 fixing the lower leg pipe 26,
A hemispherical patella 32 is located. This Patera 32
As the knee flexes, it slides on the Patella inductor 37 while being urged inward by the spring 39 toward the inside of the knee, so that the knee joint is always located at a position higher than the intersection point where the thigh pipe 22 and the lower leg pipe 26 are extended. It's located outside. Therefore, the Patella inductor 3
The shape formed by 7 and the patella 32 always creates a substantially semicircular outer shape with the connecting shaft 35 as the center, and has a form similar to that of a human knee. This is because when the knee joint 24 is further bent and the knee joint 24 is bent at a maximum bending position as shown in FIG. Located, Patella inductor 3
The knee portion formed by 7 and the patella 32 always creates a semi-circular outer shape like a human knee. Therefore, even in the sitting position, it is possible to give an appearance that a third party cannot know that the prosthesis is used.

Next, locking and unlocking of the knee joint of this embodiment will be described with reference to FIG. L-shaped portion 41a formed on the upper end of the holding member 41 that supports the patella 32
Always locks the pin 51 installed in the slit 31d of the upper knee 31 to prevent (lock) the upper knee 31 from rotating clockwise about the connecting shaft 35 (bending of the knee). There is. Then, in this locked state, the holding member 4
The side portion 41c of the first L-shaped portion 41a is in contact with one end portion 49a of a bell crank 49 rotatably supported by a shaft 47. A through hole 49b is formed in the other end of the bell crank 49, and the through hole 49b is formed in the ring 53.
It is connected to the wire 20 via.

When the user of the artificial leg bends the knee, the knob 16 shown in FIG. 1 is pulled to the front side. As a result, the bell crank 49 is rotated clockwise about the shaft 47 via the wire 20 (shown by a chain line in the figure), and the end 49a of the bell crank 49 is moved to the L-shaped portion 41 of the holding member 41.
By sliding on the side portion 41c of a, the holding member 41 is rotated counterclockwise about the shaft 43, and the locking between the L-shaped portion 41a of the holding member 41 and the pin 51 is released. This allows the knee joint 2
The lock of No. 4 is released, and the knee can be flexed.

[0016] On the other hand, a user with a prosthetic leg extends the knee to extend the knee joint 2
4 is fixed, the knee upper part 31 and the knee lower part 33 are rotated around the connecting shaft 35 in the direction of erecting the knee. As a result, the L-shaped portion 41a of the holding member 41 slides on the groove 31e provided below the thigh pipe fixing hole 31a, and at the position where the knee is erected (the bending angle is 0 °), the L-shaped portion is formed. The portion 41a fits into the pin 51. As a result, the knee joint 24 is locked, and it becomes possible to walk using the artificial leg 10.

In this embodiment, the Patella 32
The front surface of the is formed in a substantially hemispherical shape to have a shape similar to that of the patella of the human body, but this is not limited to a hemispherical shape as long as the object of the present invention can be achieved, and various shapes such as a dish shape and a disk shape are possible. It is also possible to form it.

When the user tries to sit upright on the artificial leg, the upper end portion 76a of the knee lower portion 76 on the side opposite to the connecting shaft 81 as described above with reference to FIG.
When it was located inside the perpendicular A drawn from the connecting shaft 81, the repulsive force of the tatami mat was applied, and the lower limb part jumped up toward the thigh. On the other hand, in this embodiment,
The patella 32 is arranged on the extension of the lower knee 33, and the lower knee 3
Since no force is directly applied to the upper end portion of No. 1, such a situation does not occur.

Further, the conventional prosthesis, as shown in FIG.
The lower end portion 75a of the knee upper portion 75 on the side opposite to the connecting shaft 81 has an angular shape, and when this sitting portion 75a hits the floor, the impact is cut directly to the tip of the thigh portion. In some cases, the prosthetic leg user may feel pain. On the other hand, in the present embodiment, since the semicircular Patella inductor 37 is provided on the upper knee 31, the impact can be dispersed even when the Patella inductor 37 hits the floor.

Further, as described above with reference to FIGS. 7 and 8, the lower end 75a of the upper knee 75 is conventionally used every time the knee is bent.
And the lower end portion 76a of the lower knee 76 are largely separated from each other, and the knee portion of the foam cover 83 is pulled, and the shape of the knee portion is lost and a defect is generated from this portion. Even when the foam cover is used as an exterior, the space between the upper knee 31 and the lower knee 33 has a space of the Patella inductor 3.
7 and the patella 32 are formed into a substantially semi-circular shape, it is possible to extend the use period of the foam cover without applying a strong force to the knee portion of the foam cover. Furthermore, in the present embodiment, it is easy to perform the exterior by the upper and lower separation covers (two-piece covers) separated into the thigh and the lower leg, and in this case, the exterior is not likely to be damaged, and further, With this exterior, it is possible to obtain a shape similar to that of a normal lower limb.

[0021]

[Effects] As described above, according to the present invention, even if the knee is bent, an excessive force is not applied to the knee portion of the foam cover, so that the life of the foam cover is extended and the stocking attached to the foam cover, It is possible to prevent damage to the knees such as pants. It is also possible to separate the exterior into the thigh and the lower leg. In that case, there is no risk of damaging the exterior, and the exterior can also have a shape similar to that of the normal lower limb. Furthermore, when the knee joint is bent, the appearance similar to that of a human knee is obtained, so that a natural knee shape can be obtained even when the prosthesis user sits on his / her seat, etc. Never known that you are using a prosthesis. In addition, when the prosthetic leg user tries to sit upright, the lower limb portion, which has been generated in the prior art, does not jump up. Further, even if the end of the upper part of the knee hits the floor or the like, the prosthetic user does not feel any pain.

[Brief description of drawings]

FIG. 1 is an external view showing the overall configuration of a prosthesis including a knee joint according to an embodiment of the present invention.

FIG. 2 is a side view of the knee joint of the present embodiment.

FIG. 3 is a plan view of the knee joint of the present embodiment.

FIG. 4 is a side view showing the operation of the knee joint of the present embodiment.

FIG. 5 is a side view showing the operation of the knee joint of the present embodiment.

FIG. 6 is a sectional view showing a lock mechanism of the knee joint of the present embodiment.

FIG. 7 is an external view showing a configuration of a conventional artificial leg.

FIG. 8 is an external view showing a configuration of a conventional artificial leg.

[Explanation of symbols]

 10 Prosthetic leg 12 Socket base 22 Thigh pipe 24 Knee joint 26 Lower leg pipe 31 Upper knee 32 Patella 33 Lower knee 37 Patella inductor 39 Spring 41 Holding member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ichie Ota, Ichita Ota 1-10-5 Minatomei, Minato-ku, Nagoya, Aichi Prefectural Labor Rehabilitation Engineering Center (72) Inventor Yasushi Yamashita 1-chome, Minato-ku, Nagoya, Aichi Prefecture No. 10-5 Labor Accident Rehabilitation Engineering Center (72) Inventor Kenji Koyama 1-10-5 Minatomei Minato-ku, Nagoya-shi, Aichi Prefectural Labor Accident Rehabilitation Engineering Center (56) Bibliographic Publication Sho 51-28877 (JP, Y2)

Claims (1)

[Claims] 1. An upper knee connected to a thigh pipe, a lower knee connected to a lower leg pipe, and a connecting shaft connecting the upper knee and the lower knee, wherein a patella member and the upper knee or the lower knee are provided. And a knee portion opposite to the knee portion to which the Patella inductor is attached, and the Patella inductor has a substantially semi-circular curved surface and is configured to slide the Patella member on the curved surface during bending of the knee. And a holding member for holding the Patella member on the curved surface of the Patella inductor, wherein the Patella inductor is always located outside the intersection point position where the Patella member extends the thigh pipe and the crus pipe. A knee joint for an endoskeletal prosthesis that prevents damage to the cover.