JP2016202612A - Lower limb training device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lower limb training device capable of calculating respective joint torque without attaching a measurement device for measuring a torque to respective joints of a user who is a measurement object during a leg extension operation which is a multi-joint motion.SOLUTION: A lower limb training device 1 comprises: a slide part 2 for sliding and moving in linkage with a leg extension operation in which a user A extends his/her legs from a flexed state; load generation means 3 for applying a load to the user A; movement amount measurement means 4 for measuring a movement amount of the slide part 2 following to the leg extension operation; floor reaction force measurement means 5 for measuring floor reaction force during the leg extension operation; and calculation means for, using the movement amount of the slide part, the floor reaction force, respective joint angles, and a human body model in which, rigid body segments of a trunk part, thigh parts, lower leg parts, and foot parts are coupled with a hip joint, knee joints and foot joints and expressed, for calculating the joint torque of respective joint by reverse kinetics calculation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lower limb training apparatus that performs an operation of extending a leg from a bent state.

  As a strength training apparatus that has been widely used, there are, for example, a barbell type and a weight stack type. In these muscle strength training apparatuses, the load is adjusted by adjusting the amount of the weight or the like in advance. In addition, for example, a device such as Biodex is used for measurement for evaluating the joint exertion force of the user (see, for example, Non-Patent Document 1).

  On the other hand, the present inventors have developed a device that can operate a load during a training operation by computer control in a lower limb training apparatus that performs an operation of extending a leg from a state where the user has bent the leg (for example, (See Non-Patent Document 2.) In this Non-Patent Document 2, an electromyograph measures how the muscle activity changes when the load is changed by computer control halfway.

http://www.biodex.com/physical-medicine/products/dynamometers T. Honjo, N. Shiozawa, T. Isaka “Development of new training machine using variable load control”, Proceedings of Life Engineering Symposium 2013, pp.375-377, Sep. 12, 2013

  However, the apparatus as described in Non-Patent Document 1 has a problem that the joint exerting force during single joint motion can be evaluated, but each joint exerting force during multi-joint motion cannot be evaluated. In Non-Patent Document 2, it is necessary to wear an electromyograph on the user during a training operation in order to measure muscle activity.

  The present invention has been made in view of the various problems as described above, and includes a measuring device for measuring torque at each joint of a user to be measured during a leg extension operation that is a multi-joint movement. An object is to provide a lower limb training apparatus that can calculate each joint torque without wearing. Another object of the present invention is to provide a lower limb training apparatus capable of estimating muscle tension during leg extension operation without wearing a myoelectric meter that measures muscle activity during leg extension operation of the user. And

  In order to achieve the above object, a lower limb training apparatus according to the present invention is a lower limb training apparatus that performs an operation of extending a user from a state in which a leg is bent, in conjunction with the leg extension operation of the user. A slide unit that slides, a load generating unit that applies a load to the user via the slide unit, a movement amount measuring unit that measures a movement amount of the slide unit accompanying a leg extension operation of the user, Floor reaction force measuring means for measuring the floor reaction force during the leg extension operation of the user, joint angle measuring means for measuring the joint angles of the hip joint, knee joint and ankle joint of the user, and the movement amount measuring means The amount of movement of the slide part measured by the above, the floor reaction force measured by the floor reaction force measuring means, the respective joint angles measured by the joint angle measuring means, the trunk, and the thigh The joint torque of each joint is calculated by inverse dynamics calculation using a human body model in which the four rigid body segments of the lower leg and foot are connected by the hip joint, knee joint, and ankle joint. And a calculating means for calculating.

  The lower limb training apparatus according to the present invention is a musculoskeletal model in which the human body model includes a plurality of main muscles of the lower limbs, and the computing means includes the musculoskeletal model and the inverse dynamics calculation. The muscle tension of each of the plurality of muscles is estimated by optimization calculation using the calculated joint torques.

  Further, the lower limb training apparatus according to the present invention is characterized in that the load generating means generates a load due to a braking force through the slide portion during the user's leg extension operation.

  In addition, the training device according to the present invention is characterized by comprising control means for controlling the braking force of the load generating means based on the joint angle of the knee joint measured by the joint angle measuring means.

  In the training apparatus according to the present invention, the slide unit includes a back support member with which the back of the user is in contact, and the user with the back of the user in contact with the back of the user. And a restraining member that restrains the upper half of the body.

  According to the lower limb training apparatus according to the present invention, the movement amount of the slide portion that slides in conjunction with the leg extension operation of the user is measured by the movement amount measuring means, and the floor reaction force during the leg extension operation of the user is measured. It is measured by the floor reaction force measuring means, and the joint angles of the user's hip joint, knee joint and ankle joint are measured by the joint angle measuring means. In the calculation means, the measured movement amount of the slide portion, the floor reaction force, and the respective joint angles, and the four rigid body segments of the torso, the thigh, the crus, and the foot are connected to the hip joint, the knee, and the knee. The joint torque of each joint is calculated by inverse dynamics calculation using a human body model that is represented by being connected by three joints, a joint and an ankle joint. Thus, in the lower limb training apparatus according to the present invention, each joint is mounted without a measuring device such as a torque meter for measuring torque on each joint to be measured at the time of the user's leg extension operation. Torque can be calculated. Further, since the user does not need to wear a measuring device such as a torque meter, the range of motion of the lower limb can be prevented from being restrained by such a measuring device during the leg extension operation.

  Further, according to the lower limb training apparatus according to the present invention, the calculation means performs optimization calculation using a musculoskeletal model in which a plurality of main muscles of the lower limbs are arranged, and each joint torque calculated by inverse dynamics calculation. Thus, the muscle tension of each of the plurality of muscles is estimated. Therefore, in the lower limb training apparatus according to the present invention, the muscle tension during the leg extension operation can be estimated without wearing the electromyograph that measures the muscle activity during the user's leg extension operation.

  Further, according to the lower limb training apparatus according to the present invention, the load generating means generates a load by a braking force (brake) through the slide portion during the user's leg extension operation, and thus the drag force that the user receives from the slide portion. Because it does not exceed the force that the user is exerting, and even if the user's exertion power is reduced due to fatigue, etc., the user will not be overloaded, so the leg extension operation can be performed safely. Training can be done.

  Further, according to the lower limb training apparatus according to the present invention, the braking force of the load generating unit is controlled based on the joint angle of the knee joint measured by the joint angle measuring unit, so that the knee joint angle during the leg extension operation is adjusted. A corresponding load can be given.

  Further, according to the lower limb training apparatus according to the present invention, the slide unit includes the back support member with which the user's back is in contact, and the upper body of the user in a state in which the user's back is in contact with the back support unit. Therefore, it is possible to prevent the user from losing balance or the like during the leg extending operation and maintain an appropriate posture.

It is a schematic diagram showing an example of a lower limb training apparatus according to an embodiment of the present invention. It is a schematic plan view which shows an example of the leg training apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows an example of a structure of the leg training apparatus which concerns on embodiment of this invention. It is a flowchart which shows an example of the flow of an estimation process of the muscular tension using the leg training apparatus which concerns on embodiment of this invention. It is a figure which shows an example of a human body model.

  Hereinafter, an embodiment of a lower limb training apparatus according to the present invention will be described with reference to the drawings. A lower limb training apparatus 1 according to the present invention is for performing a leg extension operation in which a user A extends a leg from a bent state. As shown in FIGS. The slide portion 2 that slides in conjunction with the extension operation, the electromagnetic brake (load generating means) 3 that applies a load to the user A via the slide portion 2, and the slide portion 2 that accompanies the leg extension operation of the user A A rotary encoder (movement amount measuring means) 4 for measuring the amount of movement, a force plate (floor reaction force measuring means) 5 for measuring the floor reaction force during the leg extension operation of the user A, the user's hip joint, A goniometer (joint angle measuring means) 6 that is attached to each of the knee joint and ankle joint and measures each joint angle, and a calculation unit (calculation means) 14 for performing various calculation processes and controls each part. Control unit for And a computer 7 having a control means) 15 and the like. In FIGS. 1 and 2, the goniometer 6 attached to the user A is not shown.

  Further, as shown in FIGS. 1 and 2, the lower limb training apparatus 1 is provided on a base unit 8 serving as a base and the base unit 8 and is used for guiding the slide 2 to be slidable in an inclined direction. And an inclined unit 9. The base unit portion 8 includes a base portion 81 installed on the floor, two strut portions 82 erected in parallel from the end portion side of the base portion 81 where the user A's head is located, In order to ensure the strength of the portion 82, one end is fixed to the base portion 81, and the other end has a support portion 83 that is fixed with a predetermined inclination angle so as to support the column portion 82.

  The tilting unit portion 9 has one end side (upper end side) on which the user A's head is positioned on the column 82 so that the head of the user A is positioned above the foot during the leg extension operation. A substantially rectangular inclined portion 91 that is inclined by a predetermined angle by being fixed through a fixing tool 10 such as a nut, and a force plate 5 on which the foot of the user A is placed during the leg extension operation are fixed. The bottom end 92 provided so as to protrude from the other end (lower end) of the inclined portion 91 in a substantially vertical direction, and the upper end and the lower end are respectively the upper end of the inclined portion 91 so as to have the same inclination angle as the inclined portion 91. Two rails 93 provided in parallel by being fixed to the upper and lower ends, and an upper pulley 94a, a lower pulley 94b, and an upper pulley provided on the upper and lower back surfaces of the inclined portion 91, respectively. 94a and below And a timing belt 95 wound around the side pulleys 94b. In addition, a plurality of bolt holes 82a for attaching the inclined portion 91 detachably by the fixture 10 are formed at different heights on the support column portion 82 of the base unit portion 8, and the inclined unit portion 9 The inclination angle can be changed by changing the attachment position of 91 to the support 82.

  As shown in FIGS. 1 and 2, the slide unit 2 slides in the direction of the arrow along the rail 93 in conjunction with the leg extension operation of the user A, and rolls along the rail 93. A plurality of wheels 21, a slide plate 22 that is a substantially rectangular plate material that is mounted on the rail 93, and is fixed on the slide plate 22 and turned upside down when performing a leg extension operation. A back support member 23 against which the back of the user A in a state is in contact, and two belt members for restraining the upper body of the user A in a state in which the back of the user A is in contact with the back support member 23 ( And a connecting member 25 that connects the slide plate 22 and the timing belt 95 so as to rotate the timing belt 95 in conjunction with the movement of the slide plate 22. As the back support member 23, for example, a material having a slight cushioning property such as urethane is preferably used. However, the back support member 23 is not limited to this, and in a state where the back of the user A is in contact with the leg extension operation. Any device that can support the body is acceptable.

  The electromagnetic brake 3 is for generating a load due to a braking force via the slide portion 2 during the user A's leg extending operation, and is connected to the lower pulley 94b via the rotary shaft 11. The braking force by the electromagnetic brake 3 is generated as a drag force when the slide unit 2 slides on the rail 93 in conjunction with the leg extension operation of the user A. Therefore, the load due to the braking force of the electromagnetic brake 3 is applied to the slide portion 2 having the lower pulley 94b, the timing belt 95, and the connecting member 25 connected to the timing belt 95 when the user A performs the leg extension operation. It acts as a drag (toning load) on the user A whose upper body is restrained while the back is in contact with the backrest member 23. Thus, in the lower limb training apparatus 1, since the load is generated by the braking force of the electromagnetic brake 3, the drag that the user A receives from the slide portion 2 does not exceed the force that the user A exhibits, Even when the user A's demonstrative power decreases due to fatigue or the like, an excessive load is not given to the user, and thus the leg extension operation can be performed safely. The electromagnetic brake 3 is connected to the computer 7 by a cable (not shown). As shown in FIG. 3, the electromagnetic brake 3 is adjusted by adjusting the input from the DC power source 20 by a control signal from the control unit 15 of the computer 7. The braking force can be controlled. Further, the control unit 15 may control the braking force of the electromagnetic brake 3 in accordance with the knee joint angle of the user A during the knee extension operation measured by the goniometer 6. In the lower limb training apparatus 1 according to the present embodiment, the electromagnetic brake 3 is applied as a load generating means in consideration of safety and the like. However, the present invention is not limited to this, and a conventionally known load is used. Anyway.

  The rotary encoder 4 is for measuring the amount of movement of the slide part 2 accompanying the leg extension operation of the user A, and is provided at the end of the rotating shaft of the upper pulley 94a. In the lower limb training apparatus 1, the rotation information detection signal of the upper pulley 94 a detected by the rotary encoder 4 is input to the computer 7, and the calculation unit 14 determines the amount of movement of the slide unit 2 based on the rotation information. Calculated. In the lower limb training apparatus 1, the slide unit 2 slides in conjunction with the leg extension operation of the user A. Therefore, the movement amount of the slide unit 2 can be regarded as the movement amount (displacement) of the user A's body. it can.

  The force plate 5 is for measuring the floor reaction force and the floor reaction force action point (COP) when the user A performs the leg extension operation from the state where the leg is bent. Attached to the bottom 92. The user A performs the leg extension operation with the foot placed on the force plate 5. In the lower limb training apparatus 1, the floor reaction force detection signal detected by the force plate 5 is input to the computer 7.

  The goniometer 6 is for measuring the joint angles of the hip joint, the knee joint, and the ankle joint in the sagittal plane during the leg extension operation of the user A, and the hip joint, the knee joint, and the ankle joint of the user A Are attached to each. In the lower limb training apparatus 1, detection signals of the joint angles of the hip joint, the knee joint, and the ankle joint detected by the goniometer 6 are input to the computer 7.

  Based on the information detected by the rotary encoder 4, the force plate 5, and the goniometer 6, the computer 7 calculates the joint torque of the user A, which is the torque generated by each joint against the external force, and estimates the muscle tension. As shown in FIG. 3, for example, a CPU (Central Processing Unit) 12, a hard disk 13, a computing unit 14, a control unit 15, and a RAM (Random Access) are performed. A memory 16, a display unit 17, and an operation unit 18. These units are connected to the system bus 19, and various data and the like are input / output via the system bus 19, and various processes are executed under the control of the CPU 12.

  The hard disk 13 stores a processing program for calculating the joint torque of the user A, estimating the muscle tension, and the like based on information detected by the rotary encoder 4, the force plate 5, and the goniometer 6. . In this embodiment, an example in which the processing program is stored in the hard disk 13 is shown. Instead, the processing program is stored in a computer-readable storage medium (not shown) and processed from this recording medium. It is also possible to configure to read the program.

  The calculation unit 14 performs various calculation processes and the like under the control of the CPU 12 based on a processing program stored in the hard disk 13. Further, the control unit 15 controls the braking force of the electromagnetic brake 3 under the control of the CPU 12 based on the processing program stored in the hard disk 13.

The RAM 16 temporarily stores a processing program read from the hard disk 13 and is used as a work area for the CPU 12. In addition, the RAM 16 stores in advance data relating to a human body model used for joint torque calculation and muscle tension estimation performed by the calculation unit 14. As this human body model, for example, as shown in FIG. 5, four rigid segments including a torso (including a head, left and right arms, and a pelvis), a thigh, a crus, and a foot are a hip joint and a knee joint. A musculoskeletal model in which a plurality of main muscles of the lower limbs are arranged in a rigid body link model expressed by being connected by three joints of the ankle joint can be used. In FIG. 5, l _i , (i = 0, 1, 2, 3) is the length of the rigid body segment, and a _i , (i = 0, 1, 2, 3) is from the joint to the center of mass of each rigid body segment. , M _i , (i = 0, 1, 2, 3) represents the mass of the rigid segment, and I _i , (i = 1, 2, 3) represents the moment of inertia of the rigid segment. Since the body is fixed by the belt member 24 and does not rotate, the moment of inertia of the body does not affect the equation of motion of the human body model expressed by the following equation (2). Further, examples of major lower limb flexion / extension muscles to be implemented include the psoas major muscle, the greater ankle muscle, the biceps femoris muscle, the rectus femoris muscle, the broad muscle group, the anterior tibial muscle, the soleus muscle, the gastrocnemius muscle, and the like. Regarding the physical physical parameters and muscle arrangement necessary for such muscle tension estimation, see, for example, Michiyoshi Ae, Kaoru Yuumi, Takashi Yokoi: Society of Biomechanisms Japan, 11, pp. 23-33 (1992), P. Allard et al: Three-Dimensional Analysis of Human Movement, human Kinetics, pp. 224-225 (1995) and other documents related to the start / stop positions of other muscles.

  The display unit 17 is composed of, for example, a liquid crystal display, and displays the calculation result of the calculation unit 14 and the like. The operation unit 18 includes a mouse, a keyboard, and the like, and is used by the user A, an assistant, and the like to input various data and operation commands. The display unit 17 and the operation unit 18 may be integrally configured as a touch panel.

  Hereinafter, the flow of calculation processing of each joint torque and muscle tension estimation by the lower limb training apparatus 1 will be described with reference to the drawings. The calculation processing by the lower limb training apparatus 1 is executed offline by the calculation unit 14 under the control of the CPU 12 in accordance with a processing program stored in the hard disk 13.

  First, when performing arithmetic processing by the lower limb training apparatus 1, as shown in FIG. 1, the user A places his feet on the force plate 5 with his legs bent and his back on the backrest member 23. The upper body is fixed by the belt member 24 in a state where it is rolled up on the back to fit. In addition, goniometers 6 are attached to the hip joint, knee joint, and ankle joint of the user A, respectively. And user A performs leg extension operation from this state.

  When the leg extension operation of the user A is started, the lower limb training apparatus 1 sequentially detects the respective detection signals detected by the rotary encoder 4, the force plate 5, and the goniometer 6 during the leg extension operation of the user A. 7 is input. In the computer 7, as shown in FIG. 4, based on the respective detection signals, the calculation unit 14 moves the slide unit 2 during the leg extension operation of the user A, the floor reaction force, and the floor reaction force action point (COP). ), Each joint angle (joint angle of hip joint, knee joint, and ankle joint) is calculated. At this time, the control unit 15 may control the braking force of the electromagnetic brake 3 by adjusting the input from the DC power supply 20 by a control signal corresponding to the measured joint angle of the knee joint. .

  Thereafter, as shown in FIG. 4, the calculation unit 14 performs noise removal by performing low-pass filter processing on each joint angle and the movement amount of the slide unit 2. Further, differential processing is performed on each joint angle and the movement amount of the slide unit 2 subjected to the low-pass filter processing, and the angular velocity and angular acceleration at the time of the leg extension operation of each joint, and the speed and acceleration of the slide unit 2 are obtained. Calculate each.

As shown in FIGS. 3 and 4, in the joint torque calculation unit 141, the following equation (1) expressed as the equation of motion of the human body model shown in FIG. The inverse dynamics calculation is performed by applying the reaction force action point (COP), each joint angle, the angular velocity and angular acceleration of each joint calculated by the differentiation process, and the speed and acceleration of the slide unit 2.

Thus calculated, the joint torque calculation unit 141, as shown in Equation (2) and Equation (3) below, the vector τ is a joint torque of each joint, and the drag F _R user A receives from the slide portion can do.

  Further, the joint torque calculation unit 141 obtains a two-dimensional start / stop position of each representative muscle of the lower limb placed in the human body model, and calculates the moment generated by each muscle with respect to the corresponding joint from the initial posture. Calculate moment arm geometrically. Next, the joint torque calculator 141 obtains a Jacobian J shown in the following mathematical formula (4) that establishes the relationship between the moment arm, muscle tension, and moment.

Then, the muscle tension estimation unit 142 calculates the muscle tension vector f by performing the optimization calculation of Expression (4) based on the joint torque vector τ calculated by the joint torque calculation unit 141 and the Jacobian J. Here, the muscle tension is calculated so that the torque generated by the muscle matches the joint torque and the total sum of the muscle tension is minimized.

  Thus, in the lower limb training apparatus 1 according to the present invention, each of the joints to be measured at the time of the leg extension operation of the user A is not equipped with a measuring device such as a torque meter for measuring torque. The joint torque can be calculated. Further, in the lower limb training apparatus 1, a plurality of muscles can be calculated by optimization calculation using the calculated joint torques without attaching to the user an electromyograph that measures muscle activity during the user's leg extension operation. The muscle tension of each can be estimated. In the lower limb training apparatus 1 according to the present embodiment, in order to reduce the number of sensors, it is assumed that the motions of both legs are the same on the left and right, and the motion is limited to the sagittal plane and the calculation is performed. When analyzing a single-leg squat or the like, it can be handled by adding a sensor and correcting a calculation model.

  The embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope of the idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Lower limb training apparatus 2 Slide part 23 Back support member 24 Belt member (restraint member)
3 Electromagnetic brake (load generation means)
4 Rotary encoder (travel distance measuring means)
5 Force plate (Floor reaction force measuring means)
6 Goniometer (joint angle measuring means)
7 Computer 14 Calculation unit (calculation means)
15 Control unit (control means)
A user

Claims (5)

A lower limb training apparatus that performs an operation of extending a leg from a bent state by a user,
A slide part that slides in conjunction with the user's leg extension operation;
Load generating means for applying a load to the user through the slide portion;
A moving amount measuring means for measuring a moving amount of the slide portion accompanying the leg extension operation of the user;
Floor reaction force measuring means for measuring the floor reaction force during the leg extension operation of the user;
A joint angle measuring means for measuring a joint angle of the user's hip joint, knee joint, and ankle joint;
The amount of movement of the slide part measured by the movement amount measuring means, the floor reaction force measured by the floor reaction force measuring means, the respective joint angles measured by the joint angle measuring means, and the body, Each of the above joints is obtained by inverse dynamics calculation using a human body model in which the four rigid segments of the thigh, the lower leg, and the foot are connected by the three joints of the hip joint, the knee joint, and the ankle joint. A lower limb training apparatus comprising: an arithmetic means for calculating the joint torque of the lower limb. The human body model is a musculoskeletal model in which a plurality of main muscles of the lower limbs are arranged,
The computing means estimates the muscle tension of each of the plurality of muscles by an optimization calculation using the musculoskeletal model and the joint torques calculated by the inverse dynamics calculation. The lower limb training apparatus according to claim 1.   The lower limb training apparatus according to claim 1, wherein the load generation unit generates a load due to a braking force through the slide portion during the leg extension operation of the user.   The lower limb training apparatus according to claim 3, further comprising a control unit that controls the braking force of the load generating unit based on a joint angle of the knee joint measured by the joint angle measuring unit.   The slide portion includes a back support member that abuts on the back of the user, and a restraining member that restrains the upper body of the user in a state where the back of the user is in contact with the back support portion. The lower limb training apparatus according to any one of claims 1 to 4.

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