Dynamics measurement device

Abstract

A dynamics measurement device 1 includes a layer 10 and a layer 20 that are rotatably engaged at a first engagement portion. The layer 10 includes: a base part 11; a link 12 that engages with the base part 11 on one end side and concentrically with the first engagement portion; and a link 13 that is engaged at a second engagement portion separated from the first engagement portion by a prescribed dimension on the other end side of the link 12. The layer 20 includes a link 21 that engages with the link 12 on one end side and concentrically with the first engagement portion, and a link 22 that is engaged concentrically with the second engagement portion on the other end side of the link 21. The layer 20 includes electrodes 31 and has an angle sensor 211 between the links 21 and 22 to measure a relative rotation angle. The link 13 includes an external force acting part 131 and has a force sensor 132 between the external force acting part 131 and a holding member 133 for holding the hand. This makes it possible to provide a simple, compact, and versatile dynamics measurement device.

Description

Dynamics Measurement Equipment

[0001] The present invention relates to a dynamics measurement device for measuring neuromusculoskeletal system characteristics for creating a personalized model that can be applied to, for example, the effective recovery of muscle movement through electrical stimulation.

[0002] In recent years, research has been actively conducted on the purpose of providing exercise support and functional compensation for patients with paralysis. For example, Patent Document 1 proposes an electrical stimulation device and stimulation method that effectively and selectively enables interactive functional electrical stimulation and exercise based on electromyograms using a model of the individual's muscle characteristics. More specifically, the device described in Patent Document 1 includes a first control model having parameters for converting electromyograms detected from an individual's antagonistic muscles into corresponding exercise information, and a second control model having parameters for converting the exercise information of the individual's antagonistic muscles into stimulation signals, and is configured to interactively apply the first and second control models to effectively perform rehabilitation using electrical stimulation.

[0003] The first and second control models are a model of the neuromuscular system consisting of a transfer function describing the input / output characteristics of the nervous system, and a model of the musculoskeletal system consisting of a transfer function describing the input / output characteristics of the musculoskeletal system, which are connected in series and function in both forward and backward directions (see Fig. 3 of Patent Document 1). That is, the first control model, which functions in the forward direction, uses a muscle antagonistic ratio r corresponding to the detected voltage in the electromyogram EMG. E The first control model converts the instructed angle θ around the joint via force f into the corresponding angle θ around the joint and outputs it. The second control model is opposite to the forward model and converts the instructed angle θ around the joint via force f into the muscle antagonist ratio r E The stimulation current value is converted into a corresponding stimulation current value and output to the electrode.

[0004] Furthermore, a second-order transfer function is applied to both the neuromuscular model and the musculoskeletal model. Therefore, Patent Document 1 shows a schematic plan view of a measurement unit for acquiring muscle characteristics that serve as basic information for setting coefficients (parameters) in the functions describing both models, the schematic plan view of a measurement unit for measuring neuromuscular muscle characteristics (see FIG. 4A) and the schematic plan view of a measurement unit for measuring musculoskeletal muscle characteristics (see FIG. 4B).

[0005] WO2022 / 190738A1

[0006] However, the plan view schematic diagram of the measurement unit shown in Figure 4 of Patent Document 1 only describes the configuration of the measurement unit functionally, and does not disclose the mechanical structure. In particular, it is not clear whether the component that measures neuromuscular muscle characteristics and the component that measures musculoskeletal muscle characteristics are configured as separate and independent structures, or whether they are configured as mechanically related structures with some shared parts.

[0007] The present invention has been made in consideration of the above, and aims to provide a simple and compact dynamics measurement device that has a minimum two-layer structure by sharing a structure for measuring neuromuscular muscle characteristics and a structure for measuring musculoskeletal muscle characteristics.

[0008] The dynamics measurement device according to the present invention comprises a first layer and a second layer for measuring neuromusculoskeletal characteristics, each of which has one end serving as a first engagement site and which are engaged with each other in a stacked state so as to be relatively rotatable, the first layer comprising a base and a first link at one end which engages with the base concentrically with the first engagement site, and a second link at the other end of the first link which engages with the first layer in a stacked state at a second engagement site spaced a predetermined distance from the first engagement site, the second layer comprising one end which engages with the base concentrically with the first engagement site and a fourth link at the other end of the third link that engages with the first link in a direction parallel to the engagement direction of the first link and the third link; the second layer further comprises an electrode portion, and an angle sensor is provided between the third link and the fourth link for measuring the relative rotation angle between the two links; the second link comprises an external force application portion to which an external force is applied, and a force sensor is provided between the external force application portion and a gripping member that grips the endpoint of the object to be measured for the neuromusculoskeletal characteristics.

[0009] According to the present invention, the dynamics measurement device has a two-layer structure, the first layer having a mechanism serving as a manipulandum layer equipped with a force sensor that measures the antagonistic force between the grasping member of the endpoint and the external force application unit, and the second layer having a mechanism serving as a contact layer equipped with an electrode unit that applies electrical stimulation and an angle sensor that measures the rotation angle of the joint part of the measurement target. Therefore, it is possible to provide a simple, compact, and versatile device that integrally assembles mechanisms for measuring the muscle characteristics of the musculoskeletal system and the muscle characteristics of the neuromuscular system.

[0010] According to the present invention, it is possible to provide a dynamics measurement device that is simple, small, and versatile.

[0011] Fig. 1 is an exploded overall perspective view of a dynamics measurement device according to one embodiment of the present invention; Fig. 2 is a perspective view of the dynamics measurement device in an assembled state for measuring muscle characteristics of a musculoskeletal system; Fig. 3 is a perspective view of the dynamics measurement device in an assembled state for measuring muscle characteristics of a neuromuscular system; Fig. 4 is a diagram modeling the input / output relationship in which a model of a neuromuscular system and a model of a musculoskeletal system are coupled;

[0012] Fig. 1 is an exploded perspective view of a dynamics measurement device according to one embodiment of the present invention. The embodiment shown in Fig. 1 is a configuration example corresponding to two joints that rotate on a horizontal plane, and when the shoulder joint J1 of a human body P is the center of the measurement system, the muscle characteristics of the upper arm P1, elbow joint J2, forearm P2, and wrist J3 are measured around the elbow joint J2 when the measurement target is the upper arm P1 (see Figs. 2 and 3). Note that hereinafter, when there is no particular distinction between musculoskeletal muscle characteristics and neuromuscular muscle characteristics, they will simply be referred to as muscle characteristics.

[0013] In FIG. 1 , the dynamics measurement device 1 has a two-layer structure stacked vertically. The two-layer structure is composed of a lower manipulandum layer 10 and an upper contact layer 20. The manipulandum layer 10 includes a horizontally disposed base 11. The base 11 functions as a fixed part to, for example, a desk or an exoskeleton. The base 11 is made of a robust material and is, for example, plate-shaped. The base end (right side of FIG. 1 ) includes a bearing (not visible in FIG. 1 ), on which, for example, a cylindrical rotating member 111 is rotatably supported. Note that the base 11 is not limited to a long shape. During measurement, the human body P to be measured is positioned so that the shoulder joint J1 coincides with the rotation center of the rotating member 111, as described below. A cylindrical fixing member 112 is concentrically connected to the upper side of the rotating member 111 so as to be rotatable therewith.

[0014] The link 12 has a long plate shape, and a fixed member 121 is supported concentrically with the rotating member 111 on the upper surface of the right end side, and a rotating member 122 is rotatably supported on the lower surface of the other end side (left side in FIG. 1 ). In addition, the rotating member 122 is supported rotatably in a horizontal plane on the lower surface of the left end side of the link 12 via a bearing (not shown).

[0015] The link 13 has a long plate material, and the lower surface of the rotating member 122 is fixed to the upper surface on the right end side. The rotating member 122 is fixed on either the upper or lower side, allowing relative rotation between the links 12 and 13. The rotating member 122 is, for example, cylindrical, and a coaxial rotation sensor 123 that measures the rotation angle is disposed inside, measuring the relative rotation angle between the links 12 and 13 as needed. Note that the elbow joint J2 of the human body P is positioned so that it coincides with the axis of the rotating member 122 during measurement.

[0016] A fixed member 131 having a predetermined shape, for example, a cylindrical shape, is erected on the left end of the link 13. An external force application member 131a is attached or formed at an appropriate location on the peripheral surface of the fixed member 131. The external force application member 131a can have various shapes, but in this embodiment, it is configured as a vertically disposed tubular member, allowing an external force to be applied via the tubular portion. For example, an arm 411 is provided at the tip of the robot 41, and this arm 411 is inserted into the tubular portion of the external force application member 131a, allowing an external force from the robot 41 to be applied to the fixed member 131. Alternatively, a rod-shaped portion at the tip of a portable handle member 42 may be engaged with the external force application member 131a and manually operated to apply an external force. If necessary, the rotating member 111 or the fixed member 112 may be an active element, such as a motor, to function as an external force application member. In this case, it simply functions as a passive element when no external force is being applied. When used as a passive element, a passive resistance element such as a spring or a damper may be added. In this case, the robot 41 and the handle member 42 are not required. In an embodiment in which the rotating member 122 is not used as an active element, it may simply be a fixed member.

[0017] The force sensor 132 has a predetermined shape, for example, a cylindrical shape, and is detachably fixed to the upper surface of the fixing member 131. A gripping member 133 is provided on the upper surface of the force sensor 132 to maintain the relative position between the finger portion, which is the endpoint (finger) of the human body P, and the force sensor 132. The force sensor 132 may be, for example, a capacitance-type six-axis force sensor, and measures strain resulting from the relative strength between an external force applied from the outside and the muscle strength of the flexor and extensor muscles of the upper arm P1, which will be described later. Note that, although the link 13 is disposed below the link 12 in this embodiment, the link 13 may be disposed immediately above the link 12, and the pivoting member 122 may be disposed between the links 12 and 13.

[0018] Next, the link 21 constituting the contact layer 20 has a long, plate-like shape with its left end extending beyond at least the elbow joint J2, and a fixed member 121 is fixed to the underside of the base end of the right end (concentric with the rotating member 111). An arm rest 212 for gravity compensation is located approximately in the center of the top surface of the link 21, and a cylindrical angle sensor 211, for example, is attached to the left end via a bearing (not shown), concentric with the rotating member 122 in this embodiment. The angle sensor 211 may be a goniometer or any other sensor capable of measuring rotation. A long, plate-like link 22 is fixed to the top of the angle sensor 211, rotating integrally with it. During measurement, the human body P to be measured is positioned so that the elbow joint J2 coincides with the rotation center of the angle sensor 211, as described below.

[0019] The arm rest member 212 may be preferably made of a material having a predetermined strength, or may be made of an elastic material. By placing the upper arm P1 on the arm rest member 212 and fastening the upper arm P1 to the arm rest member 212 with, for example, a belt-like fixing belt 213, it is possible to restrict inadvertent movement of the upper arm P1. In this embodiment, two pairs of electrodes 31, one positive and one negative, are arranged, and when the upper arm P1 is the measurement target, each electrode is attached to an antagonistic muscle of the upper arm P1.

[0020] Additionally, an arm rest member 221 is disposed on the upper surface of the link 22 to the left of the axis of the angle sensor 211. The arm rest member 221 may be made of the same material as the arm rest member 212. Resting the upper arm P1 and forearm P2 on the arm rest members 212, 221 enables gravity compensation, and fastening them with the fixing belts 213, 222 can prevent inadvertent movements or micro-movements of the upper arm P1 and forearm P2. In this embodiment, two pairs of electrodes 32, one positive and one negative, are disposed. When the forearm P2 is the measurement target or when measurements are performed across two joints, each electrode is attached to the upper arm P1 and the antagonistic muscles of the forearm P2. While the link 22 is disposed above the link 21 in this embodiment, the link 22 and angle sensor 211 may be disposed directly below the link 21.

[0021] Figure 2 is a perspective view of the dynamics measurement device 1 assembled for measuring muscle characteristics of the musculoskeletal system. In the dynamics measurement device 1 shown in Figure 2, the height dimensions of each component are set in advance so that the heights of the upper surfaces of the arm rest members 212 and 221 are the same. In addition, the force sensor 132 is connected to the upper surface of the fixing member 131 so that an external force can be transmitted to the force sensor 132, and the end point of the human body P placed on the arm rest members 212 and 221 is set at a height that coincides with the height of the grasping member 133.

[0022] The upper arm P1, forearm P2, and wrist J3 are held in a fixed state on the upper surfaces of the arm rest members 212 and 221 by fixing belts 213, 222, and 231 for joint restraint. By fastening the wrist J3 with the fixing belt 231 and integrating it with the upper arm, all forces acting on the endpoint can be measured by the force sensor 132, and all rotation amounts can be measured by the angle sensor 211, allowing the muscle characteristics of the upper arm P1 to be acquired with high accuracy. Furthermore, electrodes 31 (the back of the arm is not visible) are affixed to the antagonistic muscles, the biceps brachii (voluntary flexor) and the triceps brachii (voluntary extensor), allowing electrical stimulation signals for measuring muscle characteristics to be applied. The angle at which the forearm P2 rotates in response to this electrical stimulation can be measured by the angle sensor 211. Meanwhile, for example, the arm 411 of the robot 41 is fitted to the external force application member 131a, allowing an external force to be applied to the force sensor 132. When measuring muscle characteristics of the musculoskeletal system, the stimulation signal input to the electrode 31, the angle signal from the angle sensor 211 in an antagonistic state between electrical stimulation and external force, and the force signal from the force sensor 132 are acquired synchronously and continuously.

[0023] The dynamics measurement device 1 is electrically connected to a measurement processing device (not shown), outputs electrical stimulation signals to the electrodes 31 , and receives output signals from the angle sensor 211 and the force sensor 132 .

[0024] FIG. 3 is a perspective view of the dynamics measurement device 1 assembled for measuring neuromuscular characteristics. The dynamics measurement device 1 shown in FIG. 3 is substantially identical to the configuration shown in FIGS. 1 and 2 , except that it does not use external force from a robot 41 or the like, that the rotating member 122 is replaced with a fixed member 125, and that it does not use an angle signal from the angle sensor 211. Measurement is performed by the force sensor 132 by applying an electrical stimulation signal (described later) to the electrodes 31 for measuring muscle characteristics. More specifically, electrical stimulation is performed via the electrodes 31 on the biceps brachii and triceps brachii, which are antagonistic muscles of the upper arm P1 to be measured, as described later. At this time, the endpoint is constrained, and the elbow joint J2 is freely rotatable, but its rotation is restricted by the fixed member 125, creating an isometric environment. The force sensor 132 measures the force (hand force) generated during electrical stimulation via the gripping member 133 gripped by the endpoint as a force in an isometric environment.

[0025] In measuring neuromuscular properties, the electrical stimulation signal output to the electrode 31 and the force signal from the force sensor 132 are acquired in synchronization and continuously.

[0026] 4 is a diagram showing a control model. It is a diagram showing a model of the relationship in which a neuromuscular system model and a musculoskeletal system model are combined. In this embodiment, the control model is a muscle antagonistic ratio r E The inverse control model is an inverse system of the control model, and in this embodiment, it converts the instructed angle θ around the elbow joint into a force f, and then converts the force f into the muscle antagonistic ratio r E and outputs the result as a stimulation current value for each electrode of the electrode 31.

[0027] In this embodiment, second-order transfer functions such as those shown in Equation (1) and Equation (2) are used as models of input / output relationships. Equation (1) is a transfer function that describes the input / output characteristics related to the nervous system, and Equation (2) is a transfer function that describes the input / output characteristics related to the musculoskeletal system. By combining Equation (1) and Equation (2), an overall control model system is constructed.

[0028]

[0029] The constant (gain) K and natural angular frequency ω shown in equation (1) n The parameters ζ, damping ratio ζ, and dead time τ differ from person to person. The differences are thought to be due to a complex relationship between factors such as the individual's level of muscle development and the ratio of slow-twitch and fast-twitch muscle fibers. However, the modeling method is simple and easy to use, and it is possible to easily find optimal parameters for each individual with these differences. The dead time τ models the phase delay that cannot be expressed by a second-order lag system.

[0030]

[0031] As shown in equation (2), the dead time τ in the musculoskeletal system is 0, which closely matches the actual measurements, so the dead time τ was estimated to be 0. The acquired parameters of each model are stored in the measurement processing device and applied to muscle stimulation therapy, etc.

[0032] Next, we will explain the electrical stimulation signal (stimulation current) used to acquire muscle characteristics. Several measurement methods can be used to acquire muscle characteristics, and two measurement methods (1) and (2) will be exemplified here. Hereinafter, the stimulation current is defined as the electrical muscle antagonism ratio r E , the sum of electrical muscle antagonism is s E It is expressed and explained as follows.

[0033] (1) A pattern in which sweep waveforms (chirp waves) are input to the neuromuscular system and the musculoskeletal system separately to acquire muscle characteristics. (a) In acquiring the characteristics of the neuromuscular system, E constant, r E is input as a sweep waveform, and the output is obtained as a force waveform. E This will be done.

[0034] (b) In characterizing the musculoskeletal system, s E While applying constant electrical stimulation, an external force is input as a sweep wave using a robot 41 or the like, and the output is acquired as an angle signal. E This will be done.

[0035] (2) A pattern in which perturbations (short-duration rectangular waves) are input to the neuromuscular system and the musculoskeletal system separately to acquire muscle characteristics. (a) In acquiring the characteristics of the neuromuscular system, s E constant, r E The input is a perturbation and the output is a force waveform. E This will be done.

[0036] (b) In characterizing the musculoskeletal system, s E While applying constant electrical stimulation, an external force is input as a perturbation using a robot 41 or the like, and the output is acquired as an angle signal. E This will be done.

[0037] The present invention can employ the following embodiments: The present invention can employ an aspect in which neuromusculoskeletal characteristics are measured for one to three joints for each muscle.

[0038] The lengths of the links 12, 13, 21, and 22 need to be adjusted to fit the human body P to be measured as necessary. In this case, for example, each link can be made into a two-part structure that can slide in the length direction, and fastened with a fastener at the adjustment position.

[0039] Neuromusculoskeletal characteristics are measured by fixing the target muscle with a fixation belt and freeing the joint immediately downstream (endpoint side) to measure the rotation angle and force at the endpoint. When measuring muscle characteristics at two joints, the endpoint's degrees of freedom (two degrees of freedom in the x-y plane) coincide with the two degrees of freedom of the joint, so once the endpoint is determined, the joint position is uniquely determined. Therefore, for one-joint and two-joint systems, the gravity compensation and joint fixation components can be shared not only by the contact layer 20 but also by the manipulandum layer. On the other hand, for three-joint systems, the three degrees of freedom of the joint are greater than the endpoint's degrees of freedom (two degrees of freedom in the x-y plane). Therefore, even if the endpoint is determined, the joint angle cannot be uniquely determined due to the countless options. Therefore, even if an external disturbance is applied only to the endpoint or the force at the endpoint is obtained, there may be cases where the joints (position and orientation) on the human body side and the manipulandum layer 10 do not coincide depending on the human body's movements. Therefore, if the manipulandum layer is replaced with two joints (for example, by fixing the wrist with a fixing belt), the joint angles of the manipulandum layer and the human body will be the same, so the application of external forces to the endpoints and the fixing of sensors can be left to the manipulandum layer. In this case, an angle sensor must be provided to at least obtain information on angle changes on the human body side. As an angle sensor, the fixed member 112 shown in FIG. 1 may be replaced with a rotating member 122 and a rotation sensor 123. Furthermore, in the case of three joints, the manipulandum layer has a greater degree of freedom, so the engagement position with the link of the contact layer does not necessarily need to be concentric; as long as the axes are parallel, they may be eccentric by an appropriate distance.

[0040] Furthermore, for up to two joints, the functions of the contact layer (gravity compensation, joint fixation, angle acquisition, and electrodes) except for angle acquisition and electrodes may be shared with the manipulandum layer. Furthermore, for up to two joints, the arm rest members 212, 221 on the contact layer 20 side may be made of a soft material that is easily deformed as long as they can be set to the same height.

[0041] Furthermore, while the above embodiment measures neuromusculoskeletal characteristics on a horizontal plane, the present invention can also be applied to measuring neuromusculoskeletal characteristics on a vertical plane or in an oblique position with approximately the same configuration. When measuring on a vertical plane or in an oblique position, gravity compensation for the human body P is not required, so the arm rest members 212, 221 do not need to be rigid. Furthermore, the measurement target is not limited to the upper limbs, and the present invention can be similarly applied to the lower limbs.

[0042] Furthermore, the dynamics measurement device of this embodiment is simple and compact, and can be placed on a desk for use. In addition, by being portable, the base 11 can be configured in a shape that makes it easy to carry on the back, for example, so that muscle characteristics can be measured even while the device is being carried on the back.

[0043] Furthermore, the fixed member 121 may be configured as an angle sensor in consideration of the case where the rotation angle of the link 21 is to be detected.

[0044] Furthermore, although the present embodiment has been described with reference to measurements on a human body, it is also applicable to devices for inspecting the characteristics of artificial arms and legs, for example.

[0045] As described above, the dynamics measurement device according to the present invention comprises a first layer and a second layer for measuring neuromusculoskeletal characteristics, each of which has one end serving as a first engagement site and which are engaged with each other in a stacked state so as to be relatively rotatable, the first layer comprising a base and a first link at one end which is concentric with the first engagement site and engages with the base, and a second link at the other end of the first link which is engaged with the first layer in a stacked state at a second engagement site spaced a predetermined distance from the first engagement site, and the second layer comprising a first layer at one end which is concentric with the first engagement site and engages with the base, the second layer comprising a second link at one end which is concentric with the first engagement site and engages with the base, the second link comprising a second link at the other end which is concentric with the first engagement site and It is preferable that the neuromusculoskeletal system comprises a third link that engages with the first link at the center, and a fourth link at the other end of the third link that engages parallel to the engagement direction of the first link and the third link, and further, the second layer comprises an electrode portion, and an angle sensor is provided between the third link and the fourth link for measuring the relative rotation angle between the two links, and the second link comprises an external force application portion to which an external force is applied, and a force sensor is provided between the external force application portion and a grasping member that grasps the endpoint of the object of measurement of the neuromusculoskeletal system characteristics.

[0046] According to the present invention, the dynamics measurement device has a two-layer structure, the first layer having a mechanism serving as a manipulandum layer equipped with a force sensor that measures the antagonistic force between the grasping member of the endpoint and the external force application unit, and the second layer having a mechanism serving as a contact layer equipped with an electrode unit that applies electrical stimulation and an angle sensor that measures the rotation angle of the joint part of the measurement target. Therefore, it is possible to provide a simple, compact, and versatile device that integrally assembles mechanisms for measuring the muscle characteristics of the musculoskeletal system and the muscle characteristics of the neuromuscular system.

[0047] Furthermore, since the fourth link is engaged parallel to the engagement direction of the first link and the third link, i.e., it can be concentric or eccentric, it is possible to provide a device that can perform measurements depending on the usage situation even when the first layer has three degrees of freedom.

[0048] Furthermore, it is preferable that the fourth link is engaged with the second engagement portion concentrically. With this configuration, it is possible to measure the neuromusculoskeletal characteristics of at least two joints.

[0049] In addition, the present invention preferably includes a fixing device in one of the first and second layers that restricts movement of the muscle region to be measured. With this configuration, when measuring muscle characteristics of up to two joints where the first and second layers are uniquely positioned, the muscle region to be measured can be fixed on one side of the first and second layers.

[0050] Furthermore, the present invention preferably includes a mounting member for mounting the target muscle region on one of the first and second layers. With this configuration, when measuring muscle characteristics of up to two joints where the first and second layers are uniquely positioned, the target muscle region can be mounted on one side of the first or second layer.

[0051] Preferably, the mounting member includes a mounting member for mounting the muscle portion to be measured on the surfaces of the third link and the fourth link, so that the muscle portion to be measured can be mounted on the third and fourth links of the second layer.

[0052] Preferably, the gripping members are a pair of upright members arranged opposite each other with a gap therebetween that sandwiches the endpoint. With this configuration, the endpoint can be inserted between the pair of upright members to grip it, thereby ensuring reliable positioning.

[0053] Furthermore, the present invention preferably includes an external force application member that is an active element that engages the first link and the second link so as to be capable of rotating relative to each other. With this configuration, the external force application member can be provided within the measuring device, eliminating the need for an external member.

[0054] REFERENCE SIGNS LIST 1 Dynamics measurement device 10 Manipulandum layer (first layer) 11 Base 12 Link (first link) 13 Link (second link) 21 Link (third link) 22 Link (fourth link) 111 Rotating member 122 Rotating member (external force application member) 112, 121, 125, 131 Fixing member 132 Force sensor 20 Contact layer (second layer) 211 Angle sensor 212, 221 Arm rest member (rest member) 213, 222, 231 Fixing belt (fixing device) 31, 32 Electrode 41 Robot (external force application member)

Claims

1. A device for measuring neuromusculoskeletal characteristics comprising a first layer and a second layer, each having one end thereof engaged with each other in a stacked state so as to be rotatable relative to one another as a first engagement site, the first layer comprising: a base, a first link at one end thereof concentric with the first engagement site and engaging with the base, and a second link at the other end thereof which is engaged in a stacked state at a second engagement site spaced a predetermined dimension from the first engagement site, the second layer comprising: a third link at one end thereof concentric with the first engagement site and engaging with the first link, and a fourth link at the other end thereof which is engaged in a stacked state at a second engagement site spaced from the first engagement site by a predetermined dimension, the second layer further comprising an electrode portion, and an angle sensor between the third link and the fourth link for measuring the relative rotation angle between the two links, the second link comprising an external force acting portion to which an external force is applied, A dynamics measuring device comprising a force sensor between the external force application unit and a gripping member that grips the endpoint of the object to be measured for neuromusculoskeletal characteristics.

2. A dynamics measurement device as described in claim 1, characterized in that the fourth link is engaged concentrically with the second engagement portion.

3. A dynamics measuring device as described in claim 1, characterized in that one of the first layer and the second layer is provided with a fixing device for restricting the movement of the part of the muscle to be measured.

4. A dynamics measuring device as described in claim 1, further comprising a mounting member on one of said first layer and said second layer for mounting the muscle portion to be measured.

5. A dynamics measuring device as described in claim 4, characterized in that the mounting member includes a mounting member for placing the muscle portion to be measured on the surface of the third link and the fourth link.

6. A dynamics measurement device according to claim 1, wherein said gripping member is a pair of upright members arranged opposite each other with a gap therebetween that sandwiches said endpoint.

7. A dynamics measurement device according to claim 1, further comprising an external force application member comprising an active element that engages said first link and said second link so as to be capable of relative rotation.

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