JP6615441B2 - Lower limb muscle strength measuring device - Google Patents

Description

The present invention relates to a system for measuring muscle strength of the lower limbs as an output distribution map and further calculating muscle strength of each muscle group.

The lower limb consists of a number of muscles, but a 3 to 6 muscle group model for two joints created by classifying muscles by function was proposed, and the relationship between each muscle group force and the output of the lower limb tip was clarified. The output that can be exhibited at the tip of the lower limb by adding the six outputs at the tip of the lower limb is defined as a hexagonal output distribution map. Furthermore, each muscle group force can be calculated by applying some assumptions to the obtained output distribution map. Therefore, the muscular strength evaluation by the above method can be performed by subdividing the muscular strength of the lower limbs as compared with the conventional muscular strength evaluation for each joint.

Patent Document 1 discloses an invention for measuring an output distribution chart and an invention for obtaining muscle strength of each muscle group from the output distribution chart. In this case, as shown in FIG. 9 of Patent Document 1, output is made from measurements in a total of four directions in the vertical direction perpendicular to the vertices of the extension direction and the bending direction of the hexagonal output distribution and the line segment connecting them. A technique for drawing a distribution chart is shown. This is based on the measurement result when a predetermined condition is satisfied by the electromyogram biofeedback method in the measurement of the vertex of the output distribution map.

JP 2000-210272 “Muscle Strength Evaluation Method and System”

D.Nozaki, et al: Muscle activity determined by cosine tuning with a nontrivial preferred direction during isometric force exertion by lower limb, J. Neurophysiol, Vol.93; pp2614-2624, 2005

In Patent Document 1, an electromyogram biofeedback method is used in apex measurement as data for drawing a hexagonal output distribution map. In this method, it is necessary to put on and take off the clothes because the electrodes need to be applied to the body surface, and the electromyogram of the subject needs to be adjusted to satisfy the predetermined conditions, so that the measurement takes a long time. Cost. Therefore, it is not suitable for measurement in a short time for a general person. Furthermore, since the output distribution chart is drawn after the measurement is completed, even if there is a mistake in the middle of the measurement, it is not possible to repeat only the work at that time.

In addition, since the output at the tip of the lower limb that is actually exhibited by a person does not have a hexagon, the output distribution map approximated by the hexagon has an error from the actually measured value. Furthermore, it is expected that each muscle group force obtained from the output distribution map having an error also has an error. In addition, in the muscle group force derivation method in Patent Document 1, an assumption is made that there is as little difference as possible between people, but a deviation from the assumption of the subject becomes an error in muscle group force.

According to the first aspect of the present invention, a back bed, a belt that is fixed to the bed and into which an ankle can be inserted, and a triaxial force that is disposed inside the belt and abuts on the ankle and exerts on the foot are sensed. A sensor, a controller that guides the measurement procedure while collecting and processing output data of the sensor, a monitor that displays the processing result of the output data and the measurement procedure,
A program for expressing the force exerted at the tip of the lower limb on the monitor as a hexagonal output distribution map, obtaining five sides of the hexagon consisting of six sides by actual measurement, and creating the hexagon When the maximum force of each force exerted in the direction orthogonal to each side of the hexagon is actually measured on the monitor and the output distribution map of the hexagon is created, the algorithm of the program is the 6 Each side of the square is determined so as to pass through the actual measurement point having the maximum distance from the center, the hexagon is created, and the vertex coordinate value of the hexagon and the maximum actual measurement point on each side are maximized. The force coordinate values are determined, and each vertex coordinate and the two maximum force coordinate values adjacent to each vertex are used to obtain six Bezier curves inscribed in the hexagon, and the six Bezier curves are combined. Create an Oval output distribution map A lower limb muscle strength measuring device according to claim Rukoto.

On the bed of the device, the subject stretches his leg against the backrest and inserts his ankle into the belt. Next, according to the guide displayed on the monitor, a force in the direction displayed on the monitor is applied to the thigh, the lower leg, and the ankle. This force is measured by a triaxial sensor installed inside the belt, and the measurement data is collected by an apparatus controller.

The collected data is judged to be valid as data by the controller. If it is not valid, the same operation is displayed on the monitor and the data is collected again. However, if the data is valid, the next task is displayed on the monitor. Therefore, the subject can complete the measurement by faithfully executing the operation of the next process displayed on the monitor according to the guide.

On the bed of the device, the subject stretches his leg against the backrest and inserts his ankle into the belt. Next, according to the guide displayed on the monitor, a force in the direction displayed on the monitor is applied to the thigh, the lower leg, and the ankle. This force is measured by a biaxial sensor installed inside the belt, and the measurement data is collected by the apparatus controller.

The invention according to claim 2 is characterized in that the program calculates effective muscle strength of 3 to 6 muscles based on the cosine rhythm using the Oval output distribution map as basic data. It is a muscular strength measuring device.

The collected data is judged to be valid as data by the controller. If it is not valid, the same operation is displayed on the monitor and the data is collected again. However, if the data is valid, the next task is displayed on the monitor. Therefore, the subject can complete the measurement by faithfully executing the operation of the next process displayed on the monitor according to the guide.

Since the hexagonal output distribution chart can be drawn only from the side measurement, it is no longer necessary to attach the electrode, which is necessary for vertex measurement, and to make a determination using it, thereby reducing the measurement effort. Moreover, since the output distribution chart was drawn after the measurement, the measurement progress can be displayed in real time during the measurement, so that the subject can be instructed on the spot while checking the measurement progress.
In addition, the introduction of the guide system allows the subject to visually grasp in which direction the force should be exerted, thereby facilitating the measurement work.

Since the method of approximating the shape of the output distribution map from a hexagon with a smooth curve is used, an error from the measured value is reduced. In the derivation of the muscle group force of each muscle group, the present invention does not use the assumption as in Patent Document 1, and is obtained from only the measurement data, so that it is expected that the muscle group force is hardly influenced by individual differences.

It is a 3 to 6 muscle model diagram of the two-joint link mechanism of the lower limbs. It is a figure of the maximum output which can be exhibited at the front-end | tip of the 3-6 muscle model figure of a 2 joint link mechanism. It is an illustration figure of the 5-point measuring method which is a measuring method of an output distribution map. It is a flowchart of the algorithm of the 5-point measuring method used with this system. It is the first step figure of a guide system. It is a 2nd step figure of a guide system. It is the last step figure of a guide system. It is a figure of a measurement environment. It is a figure of a measurement posture. It is a flowchart showing the flow of a measurement. It is a 3 to 6 muscle model diagram of the two-joint link mechanism of the lower limbs. It is a figure of the maximum output which can be exhibited at the front-end | tip of the 3-6 muscle model figure of a 2 joint link mechanism. It is an illustration figure of the six side measuring method which is a measuring method of an output distribution map. It is an illustration figure of a Bezier curve. It is an illustration figure of an oval type output distribution map. It is a flowchart of the oval type output distribution plotting algorithm of the six side measurement method used in this system. It is an illustration figure of the muscle activity in a torque plane. It is a flowchart of the effective muscular strength calculation algorithm classified by function. It is the first step figure of a guide system. It is a 2nd step figure of a guide system. It is the last step figure of a guide system. It is a figure of a measurement environment. It is a figure of a measurement posture. It is a flowchart showing the flow of a measurement.

The theory behind the invention for creating a hexagon from the actual measurement of the maximum force of the five sides will be described with reference to FIG. The human lower limb contributes to one joint muscle group that contributes to the first joint 4 and to the second joint 5 in order to control the force exerted on the two-dimensional plane at the tip 6 of the two-joint linkage mechanism and to control the direction thereof. One joint muscle group and two joint muscle groups contributing to both the first joint 4 and the second joint 5 act cooperatively.

The arrow at the tip 6 of the lower limb in FIG. 1 represents the magnitude and direction of the force exerted by each functionally classified muscle group at the tip, and the hexagon in FIG. 2 represents the tip of the lower limb when each muscle acts cooperatively. It represents the size and direction of the maximum output that can be achieved. This maximum output is defined as an output distribution diagram. This output distribution map has the following characteristics.
“Characteristic 1”: The length and inclination of the opposite sides of the hexagon in FIG. 2 are equal.
“Characteristic 2”: The inclination of the side FA12 and the side CD9 is equal to the inclination of the straight line connecting the knee joint 5 and the tip 6. The inclination of the side AB7 and the side DE10 is equal to the inclination of the straight line connecting the hip joint 4 and the tip 6. The inclination of the side BC8 and the side EF11 is equal to the inclination of the line segment connecting the hip joint 4 and the tip 6.

The five-point measurement method is a method of drawing an output distribution chart by measuring the lower extremity tip exertion force on the five sides of the subject's output distribution chart and using the characteristics of the output distribution chart. In this method, as shown in FIG. 3, when measuring a certain side 15, a straight line having the same inclination as the side 15 with respect to the force measurement point 13 is drawn, and a distance 14 from the center of the straight line is calculated.

When the distance from the center is the largest, it means that the measurement point is on that side of the output distribution, so this measurement point and a straight line are stored. Then, by implementing this on five sides and finally satisfying the characteristics of the output distribution chart, the output distribution chart can be drawn.

Furthermore, this system has an output distribution plotting program based on a five-point measurement method that enables measurement while drawing an output distribution map in real time. The algorithm of the program is as shown in FIG. 4, and first, the value of a two-dimensional plane force exerted at the lower extremity tip is measured (step S1).

A straight line having three types of inclinations of hexagons is drawn from the feature of the output distribution of “feature 2” through the measurement point. (Step S2) Here, the distance from the center is calculated in order to compare the three straight lines with the sides of the output distribution chart having the same inclination. (Step S3) The distances from the origins are compared (Step S4), and if the distance is large, a straight line is stored for use as a new side (Step S5). Otherwise, keep it as before. However, since there are two sides with the same inclination for each straight line, only the side on the same side with respect to the origin is used.

At this time, a side not to be measured is determined in advance, and a straight line for the side is not stored. You can freely choose which side to remove, but for example, it is expected that it will take longer to measure the side in the direction that many subjects are not used to exerting, so that measurement of that side is excluded. It is also possible.

An output distribution map excluding one side is obtained from the five stored straight lines. Here, since the length of one side that has not been obtained is equal to that of the opposite side, the output distribution chart can be uniquely determined by satisfying the conditions of “feature 1” and “feature 2”. (Step S6)

The obtained output distribution map is displayed on the monitor screen (step S7), and by repeating this, the output distribution map can be drawn in real time. In this program, if the subject again exerts the maximum force and becomes larger than the side of the output distribution, a new side is constituted by the value of the force, so that measurement can always be performed while the program is operating.

In this program, the maximum force is exerted in the direction of the side, and the measurement can be ended when the maximum force is exhibited on the five sides. However, if the direction in which the maximum force is exerted is the same side, the measurement is repeated. As a result, the burden on the subject increases and the measurement time also increases.

Therefore, by introducing the guide system, the output distribution can be drawn with the minimum number of times of maximum power. Displays a guide on the monitor that instructs the next task.
(1) First, as shown in FIG. 5, within the specified range 16, 17, 18 in a total of three directions, ie, the direction connecting the crotch joint 4 and the tip 6 (front direction) and the direction orthogonal to this (two directions). The maximum force F1 to F3 is exerted on each and the next step is advanced.
(2) Next, as shown in FIG. 6, the intersection point obtained by extending each of the sides BC8 and FA12 is α, and the maximum force F4 is exhibited within a predetermined range 19 around the straight line connecting α and the tip 6. .
(3) When the side AB7 is not updated in the above step (2), an intersection obtained by extending the side AB7 and the side EF11 is set as β, and a straight line connecting β and the tip 6 is set within a predetermined range. The maximum force F4 is demonstrated.
(4) Finally, F5 is exhibited as the measurement range 21 between the extension line connecting the vertex A and the center 6 and the extension line connecting the vertex B and the center 6 in FIG.

The theory behind the invention of creating an oval output distribution diagram will be described with reference to FIG. The human lower limb contributes to one joint muscle group contributing to the first joint 104 and to the second joint 105 in order to control the force exerted on the two-dimensional plane at the tip 106 of the two-joint linkage mechanism and to control the direction thereof. One joint muscle group and two joint muscle groups contributing to both the first joint 104 and the second joint 105 act cooperatively.

The arrow at the lower limb tip 106 in FIG. 11 indicates the magnitude and direction of the force exerted by each functionally classified muscle group at the tip, and the hexagon in FIG. 12 indicates the lower limb tip when each muscle acts cooperatively. It represents the size and direction of the maximum output that can be achieved. This maximum output is defined as an output distribution diagram. This output distribution map has the following characteristics.
“Characteristic 1”: The length and inclination of the opposite sides of the hexagon in FIG. 12 are equal.
“Characteristic 2”: The inclination of the side FA 112 and the side CD 109 is equal to the inclination of the straight line connecting the knee joint 105 and the distal end 106. The inclination of the side AB 107 and the side DE 110 is equal to the inclination of the straight line connecting the hip joint 104 and the tip 106. The inclination of the side BC108 and the side EF111 is equal to the inclination of the line segment connecting the hip joint 104 and the distal end 106.

The six-sided measurement method is a method for drawing an output distribution chart by measuring the lower extremity tip exertion force of the six sides of the subject's output distribution chart and using the characteristics related to the inclination of the output distribution chart. In this method, as shown in FIG. 13, when measuring a certain side 115, a straight line having the same inclination as the side 115 with respect to the force measurement point 113 is drawn, and a distance 114 from the center of the straight line is calculated.

When the distance from the center is the largest, it means that the maximum measurement point is on that side of the output distribution map, so the maximum measurement point 116 and the straight line 115 are stored. Then, this is implemented with six sides, and a hexagonal output distribution map can be drawn by using the intersection of each straight line as a vertex.

Next, in order to draw an oval output distribution map, as shown in FIG. 14, a total of 3 pieces of position information 126 and 127 of the maximum measurement points of the vertex coordinate point 123 having a hexagon and the two sides 124 and 125 adjacent to the vertex. A Bezier curve 128 is drawn using the point position information. By implementing the Bezier curve drawing method at each vertex of the hexagon and two maximum measurement points adjacent to the vertex, an oval output distribution diagram 129 as shown in FIG. 15 can be drawn.

Furthermore, in this system, an oval output distribution plotting program that can perform measurements while drawing an oval output distribution map in real time is set up. The algorithm of the program is as shown in FIG. 16. First, the value of the force on the two-dimensional plane exhibited at the tip of the lower limb is measured (step S101), and a hexagon is calculated by six-side measurement. Then, an oval output distribution map is drawn from the vertex information and the maximum measurement point and displayed on the monitor.

The algorithm will be described.
First, the hexagonal output distribution is calculated from the information obtained from the force sensor. A straight line having three kinds of inclinations of hexagons is drawn from the feature of the output distribution of “feature 2” through the measurement point. (Step S102) Here, the distance from the center is calculated in order to compare the three straight lines with the sides of the output distribution chart having the same inclination. (Step S103) The distances from the respective origins are compared (Step S104). If the distance is large, a straight line and a maximum measurement point for forming the straight line are stored for use as a new side (Step S105). Otherwise, keep it as before. However, since there are two sides with the same inclination for each straight line, only the side on the same side with respect to the origin is used.

An output distribution map can be calculated from the six stored straight lines. Then, an Oval output distribution map is drawn by drawing a Bezier curve from each vertex of the obtained output distribution map and two maximum measurement points adjacent to the vertex (step S107). Then, the oval output distribution map is displayed on the monitor screen (step S108), and by repeating this, the oval output distribution map can be drawn in real time. In this program, if the subject exerts the maximum force again and becomes larger than the side of the hexagonal output distribution map, a new side is constructed with the value of the force, so measurement is always possible while the program is running become.

A method for calculating each effective muscular strength from the Oval output distribution diagram drawn from the following will be described. The force exerted at the tip 106 can be converted into a hip joint torque acting on the first joint 104 and a knee joint torque acting on the second joint 105. Since these joint torque values can be expressed by the effective muscle strength by function and the degree of muscle activity, the effective muscle strength by function can be calculated from the Oval output distribution map by obtaining the muscle activity of each effective muscle.

Each muscle activity level is a torque space created from the hip joint torque and the knee joint torque as shown in FIG. 17 (x axis: knee joint torque value 130, y axis: hip joint torque value 131, z axis: each muscle activity level 132). In FIG. This one-plane direction 133 can be represented by an optimum direction PD135. If the optimum direction PD135 is known, the muscle activity can be calculated when torque in the space is given. Therefore, when the torque is virtually applied in the torque space, the optimum direction is given in combination to calculate the muscle activity, and then the effective muscle strength by function is substituted in combination to estimate the joint torque. Optimal direction PD135 is obtained by performing optimization calculation that minimizes the error between the applied torque and the estimated torque.

Next, the obtained oval output distribution is converted into the torque space of the hip joint torque and the knee joint torque, and the muscle activity is calculated from the torque values. Then, the effective torque is combined and substituted based on the value of the muscle activity to calculate the estimated torque. The effective muscular strength for each function is calculated by performing optimization calculation so that an error between the oval output distribution map converted into the joint torque and the estimated torque is minimized.

In this system, an effective muscular strength calculation program for displaying the results of calculating each effective muscular strength according to [0038] [0039] [0040] at the time when the oval output distribution plotting program of FIG.

As shown in FIG. 18, first, the obtained oval output distribution is converted into knee joint torque / hip joint torque values (step S109). Next, it distributes to each effective muscular strength based on the muscle activity obtained from [0031] from the values of the hip joint torque and the knee joint torque (step S110). Then, each maximum effective muscle strength is calculated from each distributed effective muscle strength (step S111). Finally, the maximum value of each effective muscular strength is displayed on the monitor (step S112).

In these programs, the maximum force is exerted in the direction of the side, and the measurement can be terminated when the maximum force is exhibited on the six sides. However, if the direction in which the maximum force is exerted is the same side, the measurement is repeated. As a result, the burden on the subject increases and the measurement time also increases.

Therefore, by introducing the guide system, the output distribution can be drawn with the minimum number of times of maximum power. Displays a guide on the monitor that instructs the next task.
(1) First, as shown in FIG. 19, the instructed ranges 136, 137, and 138 in a total of three directions, ie, a direction connecting the crotch joint 104 and the tip 106 (forward direction) and a direction orthogonal to the direction (two directions). To the next step.
(2) Next, as shown in FIG. 20, α is the intersection obtained by extending the sides AB 107 and EF 111, and the maximum force is exerted within a predetermined range 140 around the straight line connecting α and the tip 106.
(3) If the side FA112 is not updated in the above step (2), the intersection obtained by extending each of the side BC108 and the side FA112 is β, and a straight line connecting β and the tip 106 is within a predetermined range. 139 exerts its maximum power.
(4) Finally, the maximum force in a predetermined range 142 with an axis extending on the extension line connecting α and the center 106 and with a predetermined range 141 with the axis extending on the extension line connecting β and the center 106 in FIG. To finish the output distribution measurement.

A device that draws a hexagonal output distribution map from five-sided measurement is a device that can measure the tip exertion force by fixing the tip of the lower limb in an arbitrary posture as shown in FIG. It consists of a computer that performs processing such as an output distribution drawing program by a five-point measurement method from the value of 22, and a monitor 23 that displays the measurement results. A method of displaying the processing result of the computer on the monitor screen is performed using a graphic program interface OpenGL.

Although it is necessary to measure the force at the tip of the lower limb with the subject fixed in one posture, the subject performs measurement in the target posture (the hip joint angle θ1 and the knee joint angle θ2 in FIG. 9). A device that can fix the tip of the lower limb having the force sensor 22 to any position in the two-dimensional plane is used.

The apparatus having two degrees of freedom as shown in FIG. 8 fixes the position of the lower limb connection portion at a predetermined position, thereby causing the subject to take a target posture.

In order to facilitate measurement, the subject displays the magnitude and direction of the force at the tip of the lower limb as an arrow in real time as shown in the monitor screen 23 of FIG. 8 so that the force value can be visually recognized. The current output distribution map obtained so far is also displayed.

This displays the output distribution map measured so far along with the magnitude and direction of the force at the tip of the lower limb that the subject is currently demonstrating. It becomes possible to demonstrate.

The measurement flow is as shown in the flowchart of FIG. First, the subject is fixed in a target posture (step S8), and the force applied to the force sensor is read by making the subject in a weak state. Since it is desired to measure only the force exerted at the tip of the lower limb of the subject, the value of the force sensor in the weak state is read to compensate for gravity in order to remove the weight of the lower limb. (Step S9)

When this process is finished, output distribution measurement by the subject's five-point measurement method is started. (Step S10) Then, it is confirmed whether or not the subject exerts the maximum force in the direction of the five sides, and (Step S11) the measurement is finished. (Step S12)

For the guide system, in order to proceed to the next step, it is necessary to confirm whether or not the subject exerts the maximum force at each step. As a means for that, it is possible for the subject himself to make the next step at the subject's intention by button input or voice recognition, etc., and setting a time limit for each step, It is also possible to use an automatic guide to show the power and go to the next step when the time limit is exceeded.

In addition, when measuring six sides, a hexagon that does not satisfy the characteristics of the opposite sides of the hexagon can be formed, but it is also possible to draw a hexagon with the opposite sides using optimization calculation.

Furthermore, in this system, an oval output distribution plotting program that can perform measurements while drawing an oval output distribution map in real time is set up. The algorithm of the program is as shown in FIG. 16. First, the value of the force on the two-dimensional plane exhibited at the lower extremity tip is measured (step S101), and a hexagon is calculated by six-side measurement. Then, an oval output distribution map is drawn from the vertex information and the maximum measurement point and displayed on the monitor.

The algorithm will be described.
First, the hexagonal output distribution is calculated from the information obtained from the force sensor. A straight line having three kinds of inclinations of hexagons is drawn from the feature of the output distribution of “feature 2” through the measurement point. (Step S102) Here, the distance from the center is calculated in order to compare the three straight lines with the sides of the output distribution chart having the same inclination. (Step S103) The distances from the respective origins are compared (Step S104), and if they are larger, a straight line and the maximum measurement point that creates the straight line are stored for use as a new side (Step S105). Otherwise, keep it as before. However, since there are two sides with the same inclination for each straight line, only the side on the same side with respect to the origin is used.

An output distribution map can be calculated from the six stored straight lines. Then, an Oval output distribution map is drawn by drawing a Bezier curve from each vertex of the obtained output distribution map and two maximum measurement points adjacent to the vertex (step S107). Then, the oval output distribution map is displayed on the monitor screen (step S108), and by repeating this, the oval output distribution map can be drawn in real time. In this program, if the subject exerts the maximum force again and becomes larger than the side of the hexagonal output distribution map, a new side is constructed with the value of the force, so measurement is always possible while the program is running become.

In this system, an effective muscular strength calculation program for displaying the results of calculating each effective muscular strength according to [0038] [0039] [0040] at the time when the oval output distribution plotting program of FIG.

As shown in FIG. 18, first, the obtained oval output distribution is converted into knee joint torque / hip joint torque values (step S109). Next, it distributes to each effective muscular strength based on the muscle activity obtained from [0031] from the values of the hip joint torque and the knee joint torque (step S110). Then, each maximum effective muscle strength is calculated from each distributed effective muscle strength (step S111). Finally, the maximum value of each effective muscular strength is displayed on the monitor (step S112).

Moreover, the method of distributing the effective muscular strength for each function from the obtained oval output distribution is also possible in the method of estimating other muscle activity.

In these programs, the maximum force is exerted in the direction of the side, and the measurement can be terminated when the maximum force is exhibited on the six sides. However, if the direction in which the maximum force is exerted is the same side, the measurement is repeated. As a result, the burden on the subject increases and the measurement time also increases.

Therefore, by introducing the guide system, the output distribution can be drawn with the minimum number of times of maximum power. Displays a guide on the monitor that instructs the next task.
(1) First, as shown in FIG. 19, the instructed ranges 136, 137, and 138 in a total of three directions, ie, a direction connecting the crotch joint 104 and the tip 106 (forward direction) and a direction orthogonal to the direction (two directions). To the next step.
(2) Next, as shown in FIG. 20, α is the intersection obtained by extending the sides AB 107 and EF 111, and the maximum force is exerted within a predetermined range 140 around the straight line connecting α and the tip 106.
(3) If the side FA112 is not updated in the above step (2), the intersection obtained by extending each of the side BC108 and the side FA112 is β, and a straight line connecting β and the tip 106 is within a predetermined range. 139 exerts its maximum power.
(4) Finally, the maximum force in a predetermined range 142 with an axis extending on the extension line connecting α and the center 106 and with a predetermined range 141 with the axis extending on the extension line connecting β and the center 106 in FIG. To finish the output distribution measurement.

Since this device can be measured in a shorter time and with less burden on the subject than conventional measuring devices, it can be applied to epidemiological studies that require a large number of measurements. It can be used for surveys to clarify the relationship between For example, problems can be solved quantitatively by performing evaluation and diagnosis based on the results of epidemiological surveys, and effective use can be expected when considering measures such as fall prevention.

DESCRIPTION OF SYMBOLS 1 Lower leg thigh 2 Lower leg lower leg 3 Foot 21 Trunk 24 Slider 25 for moving footrest Slider rotation axis 26 Measuring device backrest 27 Trunk fixing belt 28 Lower abdominal fixing belt 29 Measuring device seat 30 Handrail 101 Lower limb Thigh 102 Lower leg Lower leg 103 Foot 112 Maximum force measurement point 113 of side FA Maximum force measurement point 114 of side AB Maximum force measurement point 115 of side BC Maximum force measurement point 116 of side CD Maximum force measurement point of side DE 117 Maximum force measurement point 134 of side EF Angle 135 when viewed from knee joint torque in optimal direction PD Direction of optimal direction PD 143 Trunk 146 Slider for footrest movement 147 Slider rotation axis 148 Measuring device backrest 149 Trunk fixation belt 150 Lower abdominal fixation belt 151 Measuring device seat 152 Handrail

Claims (2)

A back bed, a belt that is fixed to the bed and into which an ankle can be inserted, a sensor that is arranged inside the belt and that abuts against the ankle and senses a force in three axes exerted by the foot;
A controller that guides the measurement procedure while collecting and processing the output data of the sensor; a monitor that displays the processing result of the output data and the measurement procedure;
A program for creating the hexagon by expressing the force exerted at the tip of the lower limb on the monitor as a hexagonal output distribution map, obtaining five sides of the hexagon consisting of six sides by actual measurement, and creating the hexagon Have
When actually measuring the maximum force of each force exerted in the direction orthogonal to each side of the hexagon on the monitor and creating the output distribution map of the hexagon,
The algorithm of the program determines each side of the hexagon so as to pass through the actual measurement point having the maximum distance from the center, and creates the hexagon.
The hexagonal vertex coordinate value and the maximum actual measurement point on each side are determined as the maximum force coordinate value, and each hexagonal coordinate and two maximum force coordinate values adjacent to each vertex are used. A device for measuring muscle strength of a lower limb , which obtains six Bezier curves that are inscribed in and creates an oval output distribution map created by combining the six Bezier curves . The lower limb strength measurement apparatus according to claim 1 , wherein the program calculates effective muscle strength of 3 to 6 muscles based on the cosine rhythm using the Oval output distribution map as basic data.