JP2011188995A - Lower limb derating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lower limb derating device which has simple structure, reduces burdens on lower limbs, eliminates the need of support power, is utilized in squat exercise and walking training, reduces work burdens on people working in a rehabilitation field, and is utilized in exercises for increasing muscles and maintaining and strengthening balance capability of a care giver in a clinical field and a nursing home. <P>SOLUTION: The lower limb derating device includes: a long-length base link 100; a forward inclination type looking-up/looking-down arm 200 whose journaling part at the lower end part is mounted slidably in the rear longitudinal direction of the long-length base link; a backward inclination type looking-up/looking-down arm 300 whose upper end part is journaled by the intermediate part of the looking-up/looking-down arm 200 and lower end part is journaled by the front part of the long-length base link 100; a spring mechanism 400 mounted on the long-length base link 100 and connected to the journaling part of the looking-up/looking-down arm 200, for elastically loading the backward slide movement; and a saddle 500 mounted on the upper end part of the looking-up/looking-down arm 200. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention provides a simple and robust structure and a stable assist force for reducing the burden on the lower limbs.
The present invention relates to a lower limb burden reducing device.

When rehabilitating a person with weak legs, the current situation is that they use handrails and are supported by others in order to partially relieve the burden on the legs. Although a method using a hot water pool or pressure tank using buoyancy is effective, it requires capital investment and maintenance costs, and the method using a pressure tank is technically incomplete. There are several unloading methods by computer control, but none of them has been put into practical use at the research stage. The method using a pool is ideal, but the method of computer control is large in terms of facility maintenance and maintenance costs. Therefore, it is difficult to obtain a natural feeling of unloading like a pool. In the present invention, the manufacturing and maintenance costs are small, and a predetermined unloading force is obtained that can provide a support force that is almost constant mechanically regardless of displacement. It is not necessary to perform complicated operations such as moving the actuator by processing the signal detected by the sensor with a computer. A mechanistically constant support force can be obtained. Since the structure is very simple, it can be produced at low cost, maintenance is easy, and maintenance costs are extremely low.
Japanese Patent No. 3830486

The present invention is simple in structure, reduces the burden on the lower limbs and does not require support, can be used for squat exercises and walking training, reduces the work burden of people working at the rehabilitation site, and also at clinical sites and nursing homes. A device to reduce the burden on the lower limbs that can be used for exercises to maintain and strengthen the strength and balance ability of caregivers of the elderly.

Long foundation link 100, front tilted lifting arm 200 mounted on a slider 600 whose lower end pivot support is slidable in the longitudinal direction of the rear of the long foundation link, and upper end at the middle of the lifting arm A rear tilt-type lifting auxiliary arm 300 having a lower end connected to the front of the long foundation link 100, a saddle 500 attached to the upper end of the lifting arm, and the saddle 500 A lower limb burden reducing device having a spring mechanism 400 that applies a reaction force during downward movement.

The lower limb burden reducing device according to the present invention has a simple structure, reduces the burden on the lower limb, does not require support force, and can be used for squat exercises and walking training, and is used in rehabilitation sites. The work load can be reduced, and the caregiver's strength improvement and balance ability can be maintained and strengthened at the clinical site and nursing home.

The best mode for carrying out the invention will be described in detail together with embodiments.

FIG. 1 is an explanatory side view for explaining the mechanism principle of the lower limb burden reducing device of the present invention.
FIG. 2 is a graph showing a theoretical value and an experimental value of a relationship between an assist load Q and a downward displacement h of the seating surface H described later.
FIG. 3 shows changes in the support force Q due to the seating surface displacement h due to the difference in the initial angle α0.
FIG. 4 is a side explanatory view showing a floor-standing embodiment of the lower limb burden reducing device of the present invention.
FIG. 5 is an explanatory side view showing an embodiment of the lower limb burden reducing device of the present invention.

In FIG. 1, the origin of the link mechanism comprising the horizontal long foundation link 100, the lifting arm 200, and the lifting assist arm 300 of the lower limb burden reducing device is O, and A, B, and O are freely rotatable. A pin support portion, H is a saddle (500) position serving as a seating surface, and the pin support portion A is on a slider 600 provided to be slidable along a horizontal long basic link 100. If the length AH = L of the link 100, the pin support B is at the midpoint of L, and the distances AB, BH, BO are all the same length. Therefore, △ ABO and △ OBH are isosceles triangles. If ∠OAB = α and ∠BHO = β, it can be seen that α + β = 90 ° by simple geometrical consideration. In other words, when OA is a horizontal line, OH is always on the same vertical line. A device for reducing the burden on the lower limbs is created by applying this link mechanism. When the upper end H of the link 200 is pushed down by the body weight with the saddle (500) serving as the seating surface, the distance d between the pin support A and the pin support O increases. When the connection is established via the spring mechanism 400, a tension is generated as the distance d changes, and the seat surface H is pushed up. This is the principle of the lower limb burden reducing device.

Assuming that Q is the force that lowers H vertically (Q is the support force based on the law of action and reaction), and T is the tension by the elastic body, the relationship between them is Q = Ttanα: (1) The axial force F acting on the link BO becomes F = Q / sin α: (2). From equation (1), it can be seen that if α> 45 °, Q> T, and if α <45 °, Q <T. If the height of H is y,
tanα = y / d = Lsinα / d: Equation (3), and since the y-direction component of axial force F is balanced with Q and the x-direction component is T with equation (2), the slider with pin support A The y direction component of the force acting on the slider is 0, and only the force T in the x direction acts on the slider. Therefore, it is not necessary to increase the rigidity of the guide that restrains the movement of the slider in the horizontal direction.
When Q = 0, that is, when the AO opening distance d and H height y in the no-load state are d0, y0 and ∠OAH = α0, respectively,
tan α0 = Lsin α0 / d0: Equation (4). As d0 increases by δ as Q increases, the tension increases to T. Assuming that the amount of change in the seating surface height is h, H decreases by y0−y = h, and the link angle decreases from α0 to α.
tan α = y / d = (y0-h) / (d0 + δ): Equation (5),
Substituting equation (5) into equation (1) yields Q = Ttanα = T (δ) · (y0−h) / (d0 + δ): Equation (6).
Here, T (δ) represents that the tension T is a function of the elongation δ, and when δ = 0, T = 0. When δ is expressed as a function of h using the Pythagorean theorem, Equation 1: (7) is obtained.

となる。
(7)式を(6)式に代入すると、数２：（８）式となる。

It becomes.
Substituting equation (7) into equation (6) gives equation 2: (8).

となる。(1)式と(8)式によりＱはαの減少（hの増加）とともに小さくなるtanαと、αの減少(δの増加)とともに増加する張力Ｔとの積であるため、y0とＬを適切に選ぶことでαの変化(hの変化)に対してＱの変化を小さくできる。

It becomes. From Eqs. (1) and (8), Q is the product of tanα, which decreases with decreasing α (increasing h), and tension T, which increases with decreasing α (increasing δ). By selecting appropriately, the change of Q can be reduced with respect to the change of α (change of h).

On the other hand, when H is supported in the longitudinal direction by an elastic body, the supporting force also changes greatly with respect to the change of h. Therefore, in order to reduce the fluctuation, it is necessary to reduce the spring constant. To that end, a plurality of long coil springs must be used. Therefore, in the exercise assistance link of Japanese Patent No. 3830486 used for a commercial product, two long coil springs are used behind the user as shown in FIG. 6 (in FIG. 6, since the two overlap each other, 1 (Only the book can be seen). Compared to the present invention, the apparatus is greatly complicated. Even if rubber is used instead of the coil spring, the support force increases in proportion to the increase of h, so that the user feels supported by the spring balance.

On the other hand, although this apparatus has a simple structure, there is a great difference in that the weight of the support force Q feels lighter because the change of the support force Q is small with respect to the change of h.
FIG. 2 shows experimental results and theoretical values of the relationship between the support load Q and the downward displacement h of the prototype. It can be seen that the change is smooth in the range of Q = 100 to 110 N over a wide range of h = 40 to 230 mm. It is possible to control whether Q is kept almost constant as h increases or whether the initial angle of α is set.

FIG. 3 shows changes in the support force Q due to the seating surface displacement h due to the difference in the initial angle α0. It can be seen that an almost constant support force can be obtained when α0 = 60 °.
In order to obtain a seating surface height suitable for the user without changing the initial angle α 0, the cylinder into which the shaft for supporting the seating surface is inserted is pin-supported by H so that it is within the plane of FIG. The cylinder can be rotated. If a shaft with a seating surface attached to the tip is inserted into a cylinder pin-supported by H so that the shaft and the cylinder can be fixed at any position with a pin or the like, the seating surface does not change the inclination of the link AH. The height can be changed. Since H moves only in the vertical direction, if the shaft with the seat surface fixed to the tip is inserted into the vertical guide hole fixed to the long foundation link 100, the shaft supporting the seat surface rotates due to the guide hole. There is nothing. Therefore, it is possible to adjust the seating surface height suitable for the user without changing the initial angle α0 of the link AH. Therefore, this device can be used not only as a squat exercise support device for muscle training and rehabilitation of patients with weak legs, but can also be applied to walker, etc. with casters and safety handrails.

FIG. 4 shows a floor-standing embodiment of the lower limb burden reducing device of the present invention. In FIG. 4, the lower limb burden reducing device is a practical device that satisfies the above-described functions, and includes a long basic link 100, a forward tilt type lifting arm 200, a rear tilt type lifting assist arm 300, The slider base link 100 includes a slider 600 provided so as to be able to travel only in the longitudinal direction thereof, a saddle 500, and a spring mechanism 400. The lifting arm 200 is provided with a lower end pivot support A on the slider 600.
The lifting assist arm 300 is pivotally supported by the pivotal support B at the upper end of the lifting arm 200 and pivotally supported by the pivotal support O at the front of the long foundation link 100. The slider 600 is connected to the front portion of the long foundation link 100 by the spring mechanism 400 and slides between the stoppers S1 and S2. The distance between the stoppers S1 and S2 of the slider 600 determines the up-and-down movement range of the saddle 500, and can be arbitrarily adjusted according to the inseam length of the user. The saddle 500 has a lower front portion attached to a shaft support portion H at the upper end portion of the lifting arm 200.
The spring mechanism 400 of this example applies a predetermined downward reaction force from the slider 600 to the saddle 500 via the lifting arm 200 using an elastic spring mechanism such as a coil spring or rubber, an air spring mechanism, or the like. is there. The spring mechanism 400 can be electrically controlled using a linear actuator or the like. The spring mechanism 400 only needs to add a reaction force against a predetermined downward load to the saddle 500. The present invention is not limited to this example. As another example, the spring mechanism 400 is appropriately connected between the lifting arm 200 and the lifting assist arm 300. It can be installed at any position.

In FIG. 5, the example which applied this limb burden reduction apparatus to the walker is shown.
In FIG. 5, the long foundation link 100 is provided with a footstool (not shown) on the front, a caster 101 on the front, back, left and right, and a handrail 110 for safety.
The saddle 500 has a cylindrical shape like a rolled up cushion. The cylindrical saddle can maintain a natural contact state for the user regardless of the inclination angle of the link 200.
The cylindrical saddle 500 of this example is fixed to the upper end of the vertical shaft 501, the lower part of the vertical shaft 501 is inserted into the shaft receiving cylinder 502, and only the vertical position can be adjusted with the pin 503, and the vertical safety guide 506 is raised and lowered Insert freely. The shaft receiving cylinder 502 is pivotally supported by a pin 505 on a Y-type support portion 504 provided at the tip of the lifting arm 200 so as to be slightly swingable back and forth. With this configuration, the height of the cylindrical saddle 500 can be adjusted to a height suitable for the user without changing the initial angle α0 of the lifting arm 200. Therefore, this device can be used not only as a squat exercise support device for muscle training and rehabilitation of a patient with weak leg, but also applicable to a walker.

As described above, the lower limb burden reducing device of the present invention has a simple structure, can reduce the burden on the lower limbs, does not require support force, can be used for squat exercises and walking training, and reduces the work load of people working at the rehabilitation site. At the same time, it has the excellent effect of maintaining and strengthening the muscular strength and balance ability of caregivers in clinical settings and nursing homes. There is a great deal to contribute to the nursing care industry and the physical fitness equipment industry.

It is side surface explanatory drawing for demonstrating the principle of the lower limb burden reduction apparatus of this invention. It is a graph which shows the experimental value and theoretical value of the relationship between the support load Q and the displacement (downward displacement) h of the seat surface. It is a graph which shows the theoretical relationship between the support load Q and the displacement (downward displacement) h of the seat surface H by the difference in the initial inclination angle α0. It is side explanatory drawing which shows the floor-standing type | formula example of the leg burden reduction apparatus of this invention. This is an example in which the lower limb burden reducing device is applied to a walker. It is the figure published in the reference patent document.

100 long foundation links
200 Lifting arm with front tilt
300 Back tilting assist arm
400 Spring mechanism (support force generation mechanism)
500 saddles
600 Slider A, B, O, H Shaft support
101 casters
110 railing

Claims (1)

Long foundation link 100, front tilted lifting arm 200 mounted on a slider 600 whose lower end pivot support is slidable in the longitudinal direction of the rear of the long foundation link, and upper end at the middle of the lifting arm A rear tilt-type lifting auxiliary arm 300 having a lower end connected to the front of the long foundation link 100, a saddle 500 attached to the upper end of the lifting arm, and the saddle 500 A lower limb burden reducing device having a spring mechanism 400 that applies a reaction force during downward movement.

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