JP6775802B2 - Lower leg orthosis - Google Patents

Description

The present invention relates to a walking assist device, and more specifically, to a device worn on the lower leg for the purpose of improving gait.

Currently, it is estimated that there are more than 30 million patients with osteoarthritis of the knee (hereinafter referred to as knee OA (Osteoarthritis of the knee)) in Japan. Knee OA is a degenerative disease that occurs due to age-related muscle weakness, obesity, genetic factors, relaxation of ligaments, etc., and the bones and cartilage of the knee joint are worn away and the knee joint is deformed. As a symptom of knee OA, the knee joint is deformed due to wear of the knee joint and cartilage, and pain is caused by the flexion and extension movement of the knee joint.

When knee OA occurs, the exercise that was appropriate until now puts a great load on the knee joint, and the gait changes due to knee pain and changes in the position of the knee joint, and the range of action decreases. I don't walk much. As a result, muscle strength is weakened and pain is further increased, resulting in a vicious cycle, and ADL (Activities of Daily Living) and QOL (Quality of Life) are lowered. In particular, knee OA patients are more likely to develop abnormal gait that deviates from normal gait.

The knee joint has two degrees of freedom of flexion, extension, and rotational movement in the knee joint axis. This rotational movement is a torsional movement observed in the range of the final extension of the knee joint of 30 degrees, and is called a terminal extension rotation movement. The terminal extension rotation movement is useful for shock absorption when the heel touches the ground during walking, walking with a well-balanced whole body, and kicking with the thumb, and the rotation movement is one of the essential movements in walking.

Regarding the rotational movement that occurs during walking, the lower leg rotates internally during ankle plantar flexion, specifically between heel contact and sole contact, and during ankle dorsiflexion, specifically from sole contact. The lower leg rotates externally during the late stage of stance. However, many knee OA patients have this knee dyskinesia.

Therapy for knee OA patients includes surgical therapy and conservative therapy. Conservative therapies include the use of braces, exercise therapy, and drug therapy. Conservative therapies for knee OA patients who use orthoses include three-point fixed type knee orthoses and knee orthoses that utilize rotational movement.

The three-point fixed type knee brace includes one that supports three points of the thigh, knee, and lower leg, and one that supports three points of the thigh, lower leg, and foot. For example, there are an orthosis (Patent Document 1) that corrects the deformation of the knee joint to a normal alignment, and an orthosis (Patent Document 2) that assists muscle strength by the power of an actuator. A knee brace that utilizes a rotational movement is such that the brace operates to assist the rotational movement of the thigh when the knee is extended. For example, an orthosis (Non-Patent Document 1) that induces a correct terminal extension / rotational movement by deforming a flexible member that supports the thigh due to different movement directions of the shafts of the inner joint and the outer joint, is provided inside the knee. There is an orthosis (Patent Document 3) in which the rotation mechanism acts as a twisting moment for rotating the thigh inward due to the regulation of the rotation mechanism.

Japanese Unexamined Patent Publication No. 2000-5247 JP-A-2009-240488 Japanese Unexamined Patent Publication No. 2016-19603

Kazushi Takahashi, "Functions of OA Fantasy Knee Orthosis", Journal of Japanese Society of Prosthetics and Orthotics, 2008, Vol. 24, No. 1, p. 16-19

Since the knee orthosis in the above example is fixed at the thigh and the lower leg, the fixed portion is likely to shift during walking. Misalignment of the orthosis during walking not only causes discomfort and discomfort to the wearer, but also may cause unreasonable rotation correction at the misaligned position. Further, in the knee orthosis that assists the rotational movement, there is a problem that it is difficult to adjust the rotational movement in the lower leg rotation disorder, although the degree of the disorder varies depending on the patient. Furthermore, since it is difficult to adjust the mechanism, there is a problem that it cannot be applied to patients with abnormal femoral tibial angle (FTA) in the first place.

Therefore, the present invention provides an orthosis that is worn from the lower leg to the foot and can induce lower leg rotation by different tilts of the columns attached inside and outside in conjunction with the ankle joint movement during walking motion. The purpose is.

That is, the present invention is intended to achieve the above-mentioned object, and the means of claim 1 is that the lower leg rotation fitting is formed on a sole plate in which a pair of support side plates are provided upward from the left and right edges and a tip of the support side plate. A lower leg fitting including a lower leg support supported by a joint portion and a lower leg cuff fixed to the lower leg support, and a joint shaft fixed to a connecting member provided at the lower end of the lower leg support is attached to the joint. It is rotatably supported by a rotary bearing provided in the portion, so that the front limit position and the rear limit position of the rotation range of the rotary bearing can be adjusted differently on the left and right, and the inner and outer legs are supported. The rotation range on the side is configured to be variable , and a ball joint mechanism is provided between one of the rotary bearings and the lower leg strut, and the ball joint mechanism is the rotation limit of the rotary bearing. also characterized that you allow free rotation of the lower leg strut in.

Further, the means of claim 2 is characterized in that the lower leg cuff is provided with a curved portion for enabling bending, and allows different rotation ranges on the left and right sides of the rotary bearing.

The means of claim 3 is characterized in that the front limit position has a difference of more than 0 degrees and 30 degrees or less on the left and right.

The means of claim 4 is characterized in that the sole plate is provided with an upper around the heel contact portion and is formed up to the metatarsal bone contact portion.

According to the configuration of claim 1, the lower leg orthosis of the present invention can assist the plantar flexion and dorsiflexion of the ankle joint, and conservative therapy for limiting the flexion and extension movements of the knee joint becomes possible. In addition, since it can be fixed by the foot as compared with the knee orthosis, the occurrence of displacement of the orthosis is small, and the knee OA patient has a severe O-leg, and the severe FTA patient who has difficulty in wearing the knee orthosis. It can also be applied to. In addition, since the joint portion is equipped with a ball joint mechanism, the lower leg support can be freely rotated, and the impact when the lower leg support is tilted to the rotation limit of the rotary bearing in the internal rotation motion and the external rotation motion is absorbed. , The burden on the knee OA patient can be reduced. Further, the free rotation of the ball joint mechanism assists the movement of the lower leg strut due to the internal rotation motion and the external rotation motion of the knee OA patient even at the rotation limit of the rotary bearing. The adjustment of the rear limit position can be widened.

According to the configuration of claim 2, the lower leg orthosis of the present invention increases the rotation range on the outer foot side from the inner foot side in the case of a patient having an abnormal lower leg internal rotation, and also for a patient having an abnormal lower leg external rotation. In this case, the rotation range on the inner foot side can be set to be larger than that on the outer foot side.

According to the configuration of claim 3, the lower leg orthosis of the present invention easily adjusts the amount of rotation of the left and right lower legs according to the individual symptoms of the knee OA patient, and rotates the lower leg according to the plantar dorsiflexion angle of the ankle joint. It is possible to make it possible, and there is no need to worry about unreasonable correction due to misalignment of the device. In addition, by combining the configurations of claims 1 to 3, the knee OA patient is guided to the correct rotational movement of the lower leg, and is in contact with the ground contact surface at the center of the heel, and then in the first and second middle stages of stance. The center of gravity moves in the order of the center of the ankle head and the center of the outer foot side, kicking with the thumb in the late stage of stance, and the heel is separated from the ground contact surface.

Further, according to the configuration of claim 4, the lower leg orthosis of the present invention can sufficiently secure the lower leg rotation amount of the knee OA patient.

Further, according to the configuration of claim 5, the lower leg orthosis of the present invention can support the heel portion, promote the heel contact and assist the kicking with the toes, and can enhance the effect of improving the gait. ..

It is the whole perspective view of the lower leg orthosis of this invention. It is a side view of the sole plate of the lower leg orthosis of this invention. It is an enlarged front view of the joint part of the lower leg orthosis of this invention. It is an enlarged perspective view of the joint part of the lower leg orthosis of this invention. It is a schematic diagram explaining the operation of the lower leg strut of the lower leg rotation orthosis of this invention.

Hereinafter, embodiments of the present invention for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is an overall perspective view of the lower leg orthosis 100. The lower leg orthosis 100 is fixed to a sole plate 120 in which a pair of support side plates 110 are provided upward from the left and right edges, a lower leg support 140 supported by a joint portion 130 formed at the tip of the support side plate 110, and a lower leg support 140. A crus orthosis comprising a crus cuff 150. The lower leg orthosis 100 is preferably fixed to the lower leg by the shin fastener 160 and the instep fastener 170, but is not limited thereto. Examples of fixing means include slip-on type, hook-and-loop fastener, buckle, and lace. It is preferable to use a soft material for the shin fastener 160 near the meniscus of the knee OA patient.

The support side plates 110 are provided in pairs so that when the knee OA patient wears the lower leg orthosis 100, the support side plates 110 generally face the ankles of the knee OA patient from the left and right edges of the sole plate 120.

FIG. 2 is a side view of the sole plate 120. The sole plate 120 is a member with which the sole of the knee OA patient comes into contact, and an upper 122 is provided around the heel contact portion 121 to reach the metatarsal bone contact portion 123, specifically, the metatarsal foot of the knee OA patient. It is preferable to form up to the part corresponding to the metatarsal joint connecting the bone and the proximal phalanx.

Providing the upper 122 around the heel contact portion 121 is important for improving the gait of the knee OA patient. By providing the upper 122, it is possible to control the calcaneus of a knee OA patient. In general, calcaneal stability is a reflection of the movement and deformation of the subtalar joint between the calcaneus and the talus. When the normal range of motion of the subtalar joint is blocked, stress is applied to the lower limbs, pelvis and lumbar spine, resulting in a pathological condition. The varus and valgus movements of the heel are linked to the varus and valgus of the foot, and affect the varus and valgus of the lower leg and the varus and valgus of the knee joint. The upper 122 also contributes to the prevention of slippage of the insole. The insole can be used to adjust the length of the left and right feet of a knee OA patient, adjust the knee joint position of an O-leg knee OA patient, and reduce the load on the knee joint as an arch support.

In addition, the sole plate 120 is limited to the metatarsal contact portion 123, and the tip of the foot of the knee OA patient comes into direct contact with the sole, the ground, etc. by freeing the tip from the metatarsal joint. Assists in kicking with the toes.

The material of the sole plate 120 is required to have strength because it is necessary to attach the support side plate 110 to support the lower leg support 140, the lower leg cuff 150, and the like. For example, it is preferable to use polypropylene, which is a resin that is easy to mold and has high hardness, as a thickness of 5 mm, but the material is not limited to polypropylene having a thickness of 5 mm as long as it is a strong material.

With the above configuration, the sole plate 120 can support the heel portion, promote the heel contact, assist the kicking with the toes, and enhance the effect of improving the gait.

The joint portion 130 is formed at the upper end of the support side plate 110 and supports the lower leg support 140. The joint portion 130 rotatably supports the coupling shaft fixed to the coupling member provided at the lower end of the lower leg support 140 by the rotary bearing provided in the joint portion 130. Plantar flexion (movement of extending the ankle) and dorsiflexion (movement of bending the ankle) of the ankle joint between the lower leg and the foot are allowed by the rotating bearing of the joint portion 130.

The joint portion 130 of this embodiment is configured so that the front limit position and the rear limit position of the rotation range of the rotary bearing can be adjusted. A mechanism having such a configuration is called a double cleansack. By adjusting the rotation range to the left and right almost uniformly, it is possible to assist the plantar flexion and dorsiflexion of the ankle joint, and conservative therapy that limits the flexion and extension movements of the knee joint becomes possible.

Further, since the lower leg orthosis 100 including the joint portion 130 having a double cleansack mechanism can be fixed by the foot as compared with the knee orthosis, the orthosis is less likely to be displaced, and the knee OA patient is severely affected. It can also be applied to severe FTA patients who have difficulty wearing knee orthoses, such as the O-legs.

The rotation range of the joint portion 130 can be made different on the left and right, and the rotation range on the inner foot side and the outer foot side can be made variable. Here, the outer foot side means the little finger side of the foot, and the inner foot side means the thumb side of the foot. In this embodiment, the joint portion 130 on the outer leg side is capable of rotating not only the double cleansack mechanism that allows the lower leg support 140 to rotate forward and backward, but also about the longitudinal direction of the lower leg support 140. It also has a ball joint mechanism. The lower leg rotation orthosis 100 provided with such a joint portion 130 can rotate the lower leg depending on the plantar dorsiflexion angle of the ankle joint. Hereinafter, the double cleansack mechanism and the ball joint mechanism will be described.

FIG. 3 is an enlarged front view of the joint portion 130, and shows a lower leg orthosis 100 to be attached to the right foot. In the joint portion 130, the base portion 131 is rotatably connected to the support side plate 110. Rod rods 132 are built in front of and behind the base 131, and the front limit position and the rear limit position of the rotation range can be adjusted steplessly by the tightening depth of the rod rod 132. Specifically, the rod rod 132 plays the role of a rotation stopper, and by deepening the tightening, the rotation range becomes narrower, and conversely, by making the tightening shallower, the rotation range becomes wider. Become. As an example, the tightening of the rod rod 132 in front of the joint portion 130 on the outer foot side is made shallower than the tightening of the rod rod 132 in front of the joint portion 130 on the inner foot side, and the front limit position of the rotation range is set to the right side. It can be set before the front limit position of the rotation range of the joint portion 130. In this case, the joint portion 130 on the outer foot side tilts forward from the joint portion 130 on the inner foot side.

The rod rod 132 is provided in front of and behind the joint portion 130, and is easy to adjust due to a simple mechanism. As an example, a spring may be applied to the front rod rod 132 to alleviate the impact during rotation. Further, the joint portion 130 may be controlled by hydraulic pressure or electricity for the purpose of alleviating the impact during rotation.

FIG. 4 is an enlarged perspective view of the joint portion 130 on the outer leg side in FIG. The ball joint mechanism in this embodiment includes a stud 133 extending from the base 131 and a socket 134 that is spherically contacted with the stud 133 and rotatably fitted and connected to the lower leg strut 140.

In the ball joint mechanism of this embodiment, the central axis of the stud 133 and the longitudinal direction of the lower leg support 140 connected to the socket 134 are coaxial, and the inner surface of the socket 134 slides on the spherical surface of the stud 133 to slide the lower leg. The support column 140 becomes rotatable. Further, the stud 133 is provided on the outside of the base 131 so that the socket 134 does not come into contact with the leg of the knee OA patient.

FIG. 5 is a schematic view illustrating the operation of the lower leg strut 140 of the lower leg orthosis 100 to be attached to the right foot. In FIG. 5, the left support side plate 210a and the right support side plate 210b are on the support side plate 110, the flatfoot bottom plate 220 is on the sole plate 120, the left joint portion 230a and the right joint portion 230b are on the joint portion 130, and the left lower leg support 240a and The right lower leg support 240b corresponds to the lower leg support 140, respectively. Since it is attached to the right foot, the left side is the inner foot side and the right side is the outer foot side when viewed from the knee OA patient. Further, the angles of the left lower leg support 240a and the right lower leg support 240b with respect to the vertical direction from the ground contact surface are set to θ and φ, respectively.

The schematic view of FIG. 5A shows the state of the left lower leg support 240a and the right lower leg support 240b when the heel touches the ground. The time when the heel touches the ground is when the transition from the swing phase where the sole is not touching to the stance phase where the sole touches the ground occurs, and the angle α of the ankle joint between the lower leg and the foot at this time Is the standard. Here, if the angle of the left lower leg strut 240a with respect to the vertical direction from the ground contact surface at this time is θ ₁ , and the angle of the right lower leg strut 240b is φ ₁ , then θ ₁ = φ ₁ .

The schematic view of FIG. 5B shows the state of the left lower leg support 240a and the right lower leg support 240b in the middle stage of stance when the entire sole of the foot touches the ground. At this time, the ankle joint is plantarly flexed, and the angle β of the ankle joint is larger than α. In a healthy person, the lower leg is rotated toward the inner foot, that is, so-called internal rotation, from the contact of the heel where the ankle plantar flexion occurs to the middle stage of stance. Here, if the angle of the left lower leg support 240a with respect to the vertical direction from the ground contact surface at the time of the middle stage of stance is θ ₂ , and the angle of the right lower leg support 240b is φ ₂ , then θ ₂ > φ ₂ .

When the knee OA patient has an abnormality in the internal rotation of the lower leg, the anterior limit position of the rotation range of the right joint portion 230b is set to the anterior limit of the rotation range of the left joint portion 230a so that the outer foot side tilts forward from the inner foot side. It may be adjusted so that it is in front of the position. When θ ₂ > φ ₂ , the internal rotation of the lower leg is induced. By adjusting in this way, the internal rotation movement during plantar flexion of the ankle joint is corrected during walking.

The schematic view of FIG. 5C shows the state of the left lower leg support 240a and the right lower leg support 240b in the late stage of stance when the heel to the toe are about to separate from the ground contact surface. At this time, the ankle joint is dorsiflexed, and the angle γ of the ankle joint is smaller than α and β. In a healthy person, the lower leg is externally rotated during the middle to late stance phase when ankle dorsiflexion occurs. Here, when the angle of the left lower leg strut 240a with respect to the vertical direction from the ground surface at the time of the stance late - [theta] _3, also the angle of the right lower leg strut 240b and phi _3, a φ _{3> -θ 3.}

When the knee OA patient has an abnormal lower leg external rotation, the anterior limit position of the rotation range of the left joint portion 230a is set to the anterior limit of the rotation range of the right joint portion 230b so that the inner foot side tilts forward from the outer foot side. It may be adjusted so that it is in front of the position. When φ ₃ > −θ ₃ , the external rotation of the lower leg is induced. By adjusting in this way, the external rotation movement is corrected during the dorsiflexion of the ankle joint after the internal rotation movement during the plantar flexion of the ankle joint during walking.

In this embodiment, the ball joint mechanism is provided only on the right joint portion 230b on the outer foot side. By providing the ball joint mechanism, the right lower leg strut 240b can be freely rotated, and the impact when the lower leg strut is tilted to the rotation limit of the rotary bearing in the internal rotation motion and the external rotation motion is absorbed, and the knee OA The burden on the patient can be reduced. Further, the free rotation of the ball joint mechanism assists the movement of the left lower leg strut 240a and the right lower leg strut 240b due to the internal rotation motion and the external rotation motion of the knee OA patient even at the rotation limit of the rotary bearing. The adjustment of the front limit position and the rear limit position of the moving range can be widened.

Here, the crus support 140 and the crus cuff 150 will be described in detail. In FIG. 1, the crus strut 140 is supported by a joint 130 and extends upward approximately along the tibia and fibula of the knee OA patient. A crus cuff 150 can be attached to the crus strut 140. The lower leg cuff 150 is fixed to the lower leg support 140 and includes a substantially semi-cylindrical (kamaboko-shaped) curved portion 151 for enabling bending. The curved portion 151 abuts on the lower leg of the knee OA patient and transmits the movement of the lower leg support 140.

In FIG. 5, the lower leg cuff 150 is attached to the left lower leg support 240a and the right lower leg support 240b. Here, since the lower leg orthosis 100 allows different rotation ranges on the left and right of the rotary bearings of the left joint portion 230a and the right joint portion 230b, it is preferable to use a flexible resin material for the curved portion 151. If the curved portion 151 is made of a rigid material without bending, it is difficult for the left lower leg strut 240a and the right lower leg strut 240b and the left joint portion 230a and the right joint portion 230b to operate differently on the left and right. On the other hand, the curved portion 151 also needs to be strong enough to support the lower leg of the knee OA patient. For example, it is preferable to use low-density polyethylene as a thickness of 3 mm, but the material is not limited to low-density polyethylene having a thickness of 3 mm as long as it is a material having both flexibility and strength.

By attaching the lower leg cuff 150, the left lower leg support 240a and the right lower leg support 240b are interlocked. Due to the ball joint mechanism provided in the left joint portion 230a and the bending of the lower leg cuff 150, the inclination difference between the left lower leg support 240a and the right lower leg support 240b is allowed. At this time, the left lower leg strut 240a and the right lower leg strut 240b have three axes of freedom of rotation of the left joint portion 230a and the right joint portion 230b by the double cleansack and the rotation of the right joint portion 230b by the ball joint. By providing, the interlocking of the left lower leg support 240a and the right lower leg support 240b is ensured without applying a load to the entire lower leg rotation fitting 100.

The ball joint mechanism may be provided not only in the left joint portion 230a but also in the right joint portion 230b, or may be provided in both the left joint portion 230a and the right joint portion 230b. The attachment of the ball joint mechanism may be appropriately determined according to the state of the lower leg rotation amount of the knee OA patient.

When the lower leg cuff 150 is attached, the front limit position of the rotation range of the rotary bearing of the joint portion 130 is preferably a difference of more than 0 degrees and 30 degrees or less on the left and right, and 5 degrees or more and 30 degrees. The following is more preferable. With such a configuration, the lower leg orthosis 100 of the present invention can sufficiently secure the amount of lower leg rotation of the knee OA patient. At this time, since the left and right joint portions 130 can adjust the front limit position and the rear limit position steplessly, the inclination difference between the left and right lower leg columns 140 can also be adjusted steplessly.

With the above configuration, the joint portion 130, the lower leg strut 140, and the lower leg cuff 150 have a larger rotation range on the outer leg side than the inner leg side in the case of a patient having an abnormal lower leg internal rotation, and the lower leg outer side. In the case of a patient with abnormal rotation, the rotation range on the inner foot side can be set to be larger than that on the outer foot side, and the amount of rotation of the left and right lower legs can be easily adjusted according to the individual symptoms of the knee OA patient. It is possible to rotate the lower leg depending on the plantar dorsiflexion angle of the ankle joint, and there is no need to worry about unreasonable correction due to the displacement of the device.

In addition, the lower leg orthosis 100 has the above configuration, and guides the knee OA patient to the correct rotational movement of the lower leg while contacting the ground contact surface at the center of the heel, and then the first and first crus until the middle stage of stance. 2 The center of gravity moves in the order of the center of the metatarsophalangeal head and the center of the outer leg side, kicking with the thumb in the late stage of stance, and the heel is separated from the ground contact surface.

100 ... Lower leg orthosis.
110 ... Support side plate.
120 ... sole plate, 121 ... heel contact portion, 122 ... upper, 123 ... metatarsal bone contact portion.
130 ... Joint, 131 ... Base, 132 ... Rod rod, 133 ... Stud, 134 ... Socket.
140 ... Lower leg support.
150 ... lower leg cuff, 151 ... curved part.
160 ... Shin fastener.
170 ... Instep fastener.
210a ... Left support side plate, 210b ... Right support side plate.
220 ... Flatfoot sole plate.
230a ... Left joint, 230b ... Right joint.
240a ... Left lower leg support, 240b ... Right lower leg support.

Claims (4)

A sole plate with a pair of support side plates facing upward from the left and right edges,
A lower leg support supported by a joint formed at the tip of the support side plate, and
A crus orthosis comprising a crus cuff fixed to the crus strut.
The coupling shaft fixed to the coupling member provided at the lower end of the lower leg strut is rotatably supported by the rotary bearing provided in the joint portion, and the front limit position and the rear of the rotation range of the rotary bearing. The limit position can be adjusted differently on the left and right, and the rotation range on the inner and outer legs is variable , and between one of the rotating bearings and the lower leg strut. lower leg rotation orthosis comprises a ball joint mechanism, the ball joint mechanism is characterized that you allow free rotation of the lower leg strut even turning limit of said pivot bearing. The lower leg orthosis according to claim 1 , wherein the lower leg cuff is provided with a curved portion for enabling bending, and allows different rotation ranges on the left and right sides of the rotary bearing. The lower leg orthosis according to claim 1 or 2 , wherein the front limit position is a difference of more than 0 degrees and 30 degrees or less on the left and right sides. The lower leg orthosis according to any one of claims 1 to 3 , wherein the sole plate is provided with an upper around the heel contact portion and is formed up to the metatarsal bone contact portion.

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