Analysis system and analysis method

Abstract

To provide an analysis system capable of easily calculating the stress applied to a body part of a subject that releases exercise equipment.SOLUTION: An analysis system comprises a calculation unit for calculating the mass and the moment of inertia of a segment containing a body part of a subject that releases exercise equipment containing a sensor, on the basis of body information of the subject, an acquisition unit for acquiring exercise information of the exercise equipment that is detected by the sensor, a torque calculation unit for calculating the torque acting on the body part on the basis of the body information, the moment of inertia and mass, and the exercise information, and a stress calculation unit for calculating the stress applied to the body part when the exercise equipment is released, on the basis of the torque.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present disclosure relates to an analysis system and an analysis method.

Background Art

[0002] In recent years, a method of measuring parameters such as the movement trajectory, rotation speed, and direction of the rotation axis of a ball by using information from a sensor incorporated in the ball has been known. For example, Japanese Unexamined Patent Application Publication No. 2018-134153 (Patent Document 1) discloses a pitching analysis system.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In baseball, pitching motions are frequently performed, and elbow joint pain is cited as one of the sports injuries. For example, in Major League Baseball, the number of players leaving the game due to injuries to the inner part of the elbow joint, particularly medial collateral ligament injuries, is increasing. To calculate the stress on the elbow (e.g., the valgus torque of the elbow joint), which is an index suggesting the risk of elbow joint injury, methods using motion capture, high-speed cameras, etc. are known. However, in such methods, the subject needs to wear markers or the like on the body, which is cumbersome, and there is a problem that a sense of restraint occurs during the pitching motion. Patent Document 1 considers giving various evaluations and advice to the subject by calculating the movement trajectory of the ball, but does not teach or suggest any solution to the above problems.

[0005] An object of certain aspects of the present disclosure is to provide an analysis system and an analysis method capable of easily calculating the stress applied to a body part of a subject who releases a sports implement.

Means for Solving the Problem

[0006] An analysis system according to an embodiment includes a calculation unit that calculates the moment of inertia and mass of a segment including a body part of a subject that releases a sports equipment incorporating a sensor based on the body information of the subject, an acquisition unit that acquires the motion information of the sports equipment detected by the sensor, a torque calculation unit that calculates the torque acting on the body part based on the body information, the moment of inertia and mass, and the motion information, and a stress calculation unit that calculates the stress applied to the body part when releasing the sports equipment based on the torque.

[0007] Preferably, the motion information includes accelerations in three axial directions and angular velocities in three axial directions.

[0008] Preferably, the analysis system further includes a timing calculation unit that calculates the timing at which the sports equipment is released from the body part based on the accelerations in three axial directions. The stress calculation unit extracts the maximum value of the torque in a predetermined period before the timing and calculates the multiplication value obtained by multiplying the maximum value of the torque by a predetermined coefficient as the stress applied to the body part.

[0009] Preferably, the analysis system further includes an impulse calculation unit that calculates the impulse acting on the body part in a predetermined period based on the body information, the position of the center of mass of the segment, the mass, the resultant acceleration of the accelerations in three axial directions, and the resultant angular velocity of the angular velocities in three axial directions.

[0010] Preferably, the torque calculation unit calculates the torque based on the body information, the position of the center of mass of the segment, the moment of inertia and mass, the resultant acceleration of the accelerations in three axial directions, and the resultant angular velocity of the angular velocities in three axial directions.

[0011] Preferably, the body information includes the length of the body part and the weight of the subject.

[0012] Preferably, the sports equipment is a ball. The body part includes the subject's forearm.

[0013] Preferably, the sensor includes a three-axis acceleration sensor and at least one of a three-axis angular velocity sensor and a three-axis geomagnetic sensor.

[0014] An analysis method according to another embodiment includes: calculating a moment of inertia and a mass of a segment including a body part of a subject who releases a sports equipment with a built-in sensor based on the body information of the subject; obtaining motion information of the sports equipment detected by the sensor; calculating a torque acting on the body part based on the body information, the moment of inertia and the mass, and the motion information; and calculating a stress applied to the body part when releasing the sports equipment based on the torque.

Advantages of the Invention

[0015] According to the present disclosure, it becomes possible to easily calculate the stress applied to the body part of the subject who releases the sports equipment.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

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Figure 5

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Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0018] <Overall Configuration> FIG. 1 is a diagram for explaining the overall configuration of the analysis system 1000. Referring to FIG. 1, the analysis system 1000 is a system for analyzing the stress applied to a body part (for example, a part including the forearm) when a subject 5 releases (for example, throws) a sports equipment with a built-in sensor. In the present embodiment, it is assumed that the sports equipment is a baseball ball 2. Further, as an index suggesting the risk of medial elbow joint disorder, the peak value of the internal elbow torque that appears before and after the maximum external rotation (MER) of the shoulder joint during the pitching motion is used. Hereinafter, the internal elbow torque is defined as the stress (value) applied to the body part that releases the ball 2.

[0019] The analysis system 1000 includes a terminal device 10 and a ball 2 with a built-in sensor device 20. In the present embodiment, the sensor device 20 has a function of analyzing the above stress, and the terminal device 10 has a function of displaying the analysis result by the sensor device 20. In FIG. 1, the three mutually orthogonal axes in the sensor coordinate system are represented by the x-axis, y-axis, and z-axis, and the three mutually orthogonal axes in the absolute coordinate system are represented by the a-axis, b-axis, and c-axis.

[0020] The terminal device 10 is configured as a smartphone. However, the terminal device 10 can be realized as any device regardless of its type. For example, the terminal device 10 may be a laptop PC (personal computer), a tablet terminal, a desktop PC, etc.

[0021] The terminal device 10 communicates with the sensor device 20 by a wireless communication method. For example, as the wireless communication method, BLE (Bluetooth (registered trademark) low energy) is adopted. However, the terminal device 10 may adopt other wireless communication methods such as Bluetooth (registered trademark) and wireless LAN (local area network).

[0022] The sensor device 20 detects acceleration and angular velocity in a sensor coordinate system (i.e., a local coordinate system). Specifically, the sensor device 20 includes an acceleration sensor and an angular velocity sensor. The acceleration sensor detects accelerations in three mutually orthogonal axes (x-axis, y-axis, z-axis) directions. The angular velocity sensor detects angular velocities around the three axes (x-axis, y-axis, z-axis).

[0023] The sensor device 20 executes a predetermined analysis process based on the body information of the subject 5 and the detected sensor data (e.g., time-series acceleration and angular velocity), and calculates the stress applied to the body part that releases the ball 2. The terminal device 10 receives the calculated stress from the sensor device 20 and displays the stress on the display.

[0024] FIG. 2 is a diagram for explaining a rigid body link model according to the present embodiment. Referring to FIG. 2, in the present embodiment, a model in which the forearm is regarded as a rigid body is used. Typically, the rigid body segment 52 is defined by a line segment connecting the center of the wrist joint and the center of the elbow joint. The point 53 indicates the position of the center of mass of the rigid body segment 52 (here, the forearm). The center of mass ratio is represented by the ratio of the distance from the center of the elbow joint to the center of mass position to the length of the forearm. In the present embodiment, a known coefficient (0.4574) is used as the center of mass ratio.

[0025] <Hardware Configuration> (Terminal Device 10) FIG. 3 is a block diagram showing the hardware configuration of the terminal device 10. Referring to FIG. 3, the terminal device 10 mainly includes a CPU (Central Processing Unit) 102, a memory 104, a touch panel 106, a display 110, a wireless communication unit 112, a communication antenna 113, a memory interface (I / F) 114, a speaker 116, a microphone 118, and a communication interface (I / F) 120. Also, the recording medium 115 is an external storage medium.

[0026] The CPU 102 controls the operations of each part of the terminal device 10 by reading and executing the programs stored in the memory 104. The memory 104 is realized by a RAM (Random Access Memory), a ROM (Read-Only Memory), a flash memory, etc. The memory 104 stores programs executed by the CPU 102 or data used by the CPU 102.

[0027] The touch panel 106 is provided on the display 110 having a function as a display unit. The wireless communication unit 112 is connected to the mobile communication network via the communication antenna 113 and transmits and receives signals for wireless communication.

[0028] The memory interface (I / F) 114 reads data from the external recording medium 115. The CPU 102 reads the data stored in the external recording medium 115 via the memory interface 114 and stores the data in the memory 104. The CPU 102 reads data from the memory 104 and stores the data in the external recording medium 115 via the memory interface 114. Examples of the recording medium 115 include media that non-volatilely store programs, such as a USB (Universal Serial Bus) memory and a hard disk.

[0029] Speaker 116 outputs sound based on instructions from CPU 102. Microphone 118 receives speech directed at terminal device 10. Communication interface (I / F) 120 is, for example, a communication interface for transmitting and receiving data between terminal device 10 and sensor device 20. The communication method is, for example, wireless communication such as BLE or Wi-Fi.

[0030] (Sensor device 20) Figure 4 is a block diagram showing the hardware configuration of sensor device 20. Referring to Figure 4, sensor device 20 mainly includes CPU 202 for executing various processes, memory 204 for storing programs, data, etc. executed by CPU 202, acceleration sensor 205, angular velocity sensor 206, communication interface (I / F) 210 for communicating with terminal device 10, and battery 212 for supplying power to various components of sensor device 20.

[0031] <Operation example> Figure 5 is a flowchart for explaining an operation example of analysis system 1000. Typically, among the steps shown in Figure 5, the steps performed by terminal device 10 are realized by CPU 102, and the steps performed by sensor device 20 are realized by CPU 202.

[0032] Terminal device 10 receives an input of the physical information of subject 5 (step S10). Specifically, terminal device 10 receives an input of physical information from a user (e.g., subject 5, etc.) via touch panel 106. The physical information includes the length L of the forearm and the body weight Mbo. Note that the length L of the forearm may be estimated based on the height of subject 5 who provided the input. Note that the length L of the forearm corresponds to the length of rigid segment 52 defined in Figure 2. Terminal device 10 transmits length L and body weight Mbo to sensor device 20 (step S12).

[0033] The sensor device 20 calculates the mass Mf of the rigid segment 52 based on the weight Mbo of the subject 5 (step S14). Specifically, the sensor device 20 calculates the mass Mf using the following equation (1). In the equation, "·" indicates multiplication.

[0034] Mf = 0.0162·Mbo …(1) The right side of equation (1) represents the mass of the subject 5's forearm.

[0035] The sensor device 20 calculates the moment of inertia If of the rigid segment 52 based on the length L and the mass Mf (step S16). Specifically, the sensor device 20 calculates the moment of inertia If using the following equation (2).

[0036] If = {Mf·(L·0.265) 2} …(2) Here, it is assumed that the subject 5 starts the pitching motion of the ball 2. The timing of starting the pitching motion may be any timing as long as it is between step S10 and step S18.

[0037] The sensor device 20 calculates the resultant acceleration A of the three-axis accelerations detected by the acceleration sensor 205 and the resultant angular velocity ω of the three-axis angular velocities detected by the angular velocity sensor 206 (step S18). Typically, the resultant acceleration A is the square root of the sum of the squares of the accelerations in each axis direction, and the resultant angular velocity ω is the square root of the sum of the squares of the angular velocities in each axis direction.

[0038] The sensor device 20 calculates the time t0 when the subject 5 releases (releases) the ball 2 based on the acceleration in three axial directions (step S20). For example, the sensor device 20 calculates the time when any one of the accelerations in the three axial directions becomes equal to or greater than the threshold value Th1 as the time t0. Further, the sensor device 20 may calculate the time when the combined acceleration A becomes equal to or greater than the threshold value Th2 as the time t0. Furthermore, the sensor device 20 may calculate, for each of the accelerations in the three axial directions, the difference value between the acceleration at the previous time and the acceleration at the current time, and calculate the time when any one of the difference values becomes equal to or greater than the threshold value Th3 as the time t0.

[0039] The sensor device 20 sets an analysis section Tx of the stress applied to the body part during the pitching motion (step S22). Specifically, the sensor device 20 sets the time ts (= t0 - T1) before a predetermined time T1 (for example, 200 ms) from the time t0 as the start time of the analysis section Tx. Further, the sensor device 20 sets the time tf (= t0 - T2) before a predetermined time T2 (for example, 50 ms) from the time t0 as the end time of the analysis section Tx. The analysis section Tx is a section from the start time of the pitching motion (that is, the time ts) to the time immediately before releasing the ball 2 (that is, the time tf). It is assumed that the time tf corresponds to the time of the maximum external rotation position of the shoulder joint.

[0040] FIG. 6 is a diagram showing the time change of the combined acceleration of the ball. FIG. 7 is a diagram showing the time change of the combined angular velocity of the ball. Referring to FIGS. 6 and 7, it is understood that the combined acceleration A and the combined angular velocity ω gradually increase from the time ts to the time tf.

[0041] Again, referring to FIG. 5, the sensor device 20 filters the acceleration in the three-axis directions and the angular velocity in the three-axis directions using a low-pass filter having a predetermined cut-off frequency to remove high-frequency noise components (step S24). The sensor device 20 differentiates the combined angular velocity ω of the angular velocities in the three-axis directions to calculate a combined angular acceleration dω (step S26). In step S24, since the high-frequency noise components of the angular velocity are removed, the combined angular acceleration dω is appropriately calculated without amplifying the noise components included in the angular velocity. Note that the process of step S24 may be executed between step S16 and step S18.

[0042] The sensor device 20 calculates a torque acting on the body part (for example, a combined elbow joint torque Te) based on the length L, the mass Mf, the center of mass ratio COM, the moment of inertia If, the combined acceleration A, and the combined angular velocity ω (step S28). Specifically, the sensor device 20 calculates the translational acceleration Af of the rigid segment 52 using the following equation (3). g is the acceleration due to gravity. "×" in the equation indicates a cross product.

[0043] Af = A - dω × L - ω × (ω × L) - g …(3) Next, the sensor device 20 calculates the acceleration Acom at the center of mass position of the rigid segment 52 using the following equation (4).

[0044] Acоm = Af + dω × L × COM + ω × (ω × L × COM) …(4) Next, the sensor device 20 calculates the combined elbow joint torque Te using the following equation (5). p indicates the position vector from the center of the elbow joint to the center of mass position.

[0045] Te = If·dω + p × (Mf·Acom - Mf·g) …(5) FIG. 8 is a diagram showing the time change of the acceleration at the center of mass position of the rigid segment 52. FIG. 9 is a diagram showing the time change of the combined elbow joint torque. Referring to FIGS. 8 and 9, it is understood that the acceleration Acom and the combined elbow joint torque Te generally increase gradually from the time ts to the time tf.

[0046] Again, referring to FIG. 5, the sensor device 20 extracts the maximum value Tmax of the combined elbow joint torque Te in the analysis interval Tx (step S30). Specifically, the sensor device 20 extracts the combined elbow joint torque Te at the time tf corresponding to the maximum external rotation position of the shoulder joint as the maximum value Tmax. The sensor device 20 calculates a multiplication value obtained by multiplying the extracted maximum value Tmax by the correction coefficient k as the stress applied to the body part (i.e., the elbow joint varus torque) (step S32). The correction coefficient k is a value determined in advance based on the measured data of the combined elbow joint torque and the elbow joint varus torque, etc.

[0047] The terminal device 10 receives the stress calculated by the sensor device 20 and displays the stress on the display 110 (step S34).

[0048] FIG. 10 is a diagram showing an example of stress display. FIG. 10 shows a radar chart indicating three parameters: the ball speed and rotation speed of the ball 2, and the stress. The triangle 510 indicates the score of the parameters for the subject 5, and the triangle 520 indicates the average value of the scores of the parameters for each subject in the team to which the subject 5 belongs. Each parameter is evaluated on a 10 - point scale, and the higher the value of the parameter, the higher the score.

[0049] Comparing the triangles 510 and 520, the stress of the subject 5 is smaller than the team average value, but the ball speed and rotation speed of the subject 5 are higher than the team average value. Therefore, it is suggested that the subject 5 is a player who can perform excellent pitching with high ball speed and rotation speed while suppressing the stress on the elbow joint.

[0050] Note that the sensor device 20 calculates the ball speed and rotation speed of the ball 2 by analyzing the acceleration in the three-axis directions and the angular velocity in the three-axis directions using a known ball analysis application program. The "rotation speed" is the number of rotations per unit time of the ball 2 immediately after release. The terminal device 10 receives the ball speed and rotation speed together with the stress calculated by the sensor device 20, and displays a radar chart shown in FIG. 10 on the display 110.

[0051] In the above flowchart, the sensor device 20 may be configured to calculate the impulse Im acting on the body part in the analysis section Tx based on the length L, the mass Mf, the center of mass ratio COM, the combined acceleration A, and the combined angular velocity ω. Specifically, the sensor device 20 calculates the impulse Im using the following formula (6).

[0052]

Equation

[0053] In this case, the terminal device 10 may receive the impulse Im calculated by the sensor device 20 and display the impulse Im on the display 110.

[0054] <Functional Configuration> FIG. 11 is a block diagram showing an example of the functional configuration of the sensor device 20. Referring to FIG. 11, the sensor device 20 includes a moment of inertia calculation unit 250, a motion information acquisition unit 252, a timing calculation unit 254, a section setting unit 256, a torque calculation unit 258, a stress calculation unit 260, and an impulse calculation unit 262. These are basically realized by the CPU 202 of the sensor device 20 or the like. Note that some or all of these functional configurations may be realized by hardware other than the CPU 202.

[0055] The moment of inertia calculation unit 250 receives the body information of the subject 5 from the terminal device 10. Based on the body information of the subject 5, the moment of inertia calculation unit 250 calculates the moment of inertia If and the mass Mf of a segment (e.g., the rigid body segment 52) including the body part (e.g., the forearm) of the subject 5 that releases the sports equipment (e.g., the ball 2) incorporating sensors (e.g., the acceleration sensor 205 and the angular velocity sensor 206). The body information includes the length of the body part (e.g., the length L of the forearm) and the body weight Mbo of the subject 5.

[0056] The motion information acquisition unit 252 acquires the motion information of the sports equipment detected by the sensors. Specifically, the motion information acquisition unit 252 acquires the acceleration in three axial directions detected by the acceleration sensor 205 and the angular velocity in three axial directions detected by the angular velocity sensor 206.

[0057] The timing calculation unit 254 calculates the timing (e.g., the time t0) at which the sports equipment is released from the body part based on the acceleration in three axial directions. Specifically, the timing calculation unit 254 calculates, as the time t0, the time when any one of the accelerations in the three axial directions becomes equal to or greater than the threshold value Th1, the time when the three-axis combined acceleration becomes equal to or greater than the threshold value Th2, or the time when the difference value between the acceleration at the previous time and the acceleration at the current time becomes equal to or greater than the threshold value Th3.

[0058] The section setting unit 256 sets an analysis section Tx for the stress applied to the body part during the pitching motion. The analysis section Tx is a section before the time t0 of the release timing, and is a section from the time ts to the time tf (e.g., a section from 200 ms before to 50 ms before the release timing).

[0059] The torque calculation unit 258 calculates the torque acting on the body part (for example, the combined elbow joint torque Te) based on the body information, the moment of inertia If and the mass Mf, and the motion information. Specifically, the torque calculation unit 258 calculates the combined elbow joint torque Te based on the body information, the position of the center of mass of the rigid body segment 52, the moment of inertia If and the mass Mf, the combined acceleration A of the accelerations in the three-axis directions, and the combined angular velocity ω of the angular velocities in the three-axis directions. Specifically, the torque calculation unit 258 calculates the combined elbow joint torque Te based on equations (3) to (5), the length L, the mass Mf, the center of mass ratio COM, the moment of inertia If, the combined acceleration A, and the combined angular velocity ω.

[0060] The stress calculation unit 260 calculates the stress (for example, the internal elbow joint torque) applied to the body part when releasing the sports equipment based on the torque (for example, the combined elbow joint torque Te) calculated by the torque calculation unit 258. Specifically, the stress calculation unit 260 extracts the maximum value Tmax of the combined elbow joint torque Te in a predetermined period (for example, the analysis section Tx) before the time t0 of the release timing. The stress calculation unit 260 calculates the multiplication value obtained by multiplying the maximum value Tmax by a predetermined coefficient (for example, the correction coefficient k) as the stress.

[0061] The impulse calculation unit 262 calculates the impulse acting on the body part in the analysis section Tx based on the body information, the position of the center of mass of the rigid body segment 52, the mass Mf, the combined acceleration A of the accelerations in the three-axis directions, and the combined angular velocity ω of the angular velocities in the three-axis directions. Specifically, the impulse calculation unit 262 calculates the impulse Im using equation (6).

[0062] The terminal device 10 (for example, the display control unit) receives the stress and the impulse Im calculated by the stress calculation unit 260 from the sensor device 20 and displays the stress and the impulse Im on the display 110. The display control unit is realized by the CPU 102 etc. of the terminal device 10.

[0063] <Advantages> According to this embodiment, just by the subject 5 throwing the ball 2 with a built-in sensor, the stress on the body part of the subject 5 is calculated. Therefore, the subject 5 does not need to wear a marker or the like on the body, and there is no sense of restraint during the pitching motion.

[0064] <Other Embodiments> (1) In the above-described embodiment, the configuration in which the sports equipment with a built-in sensor is a baseball ball has been described as an example, but the configuration is not limited thereto. For example, the sports equipment may be various balls such as a softball, a handball, a rugby ball, a javelin for javelin throwing, or the like, as long as it is released from a specific body part of the subject.

[0065] (2) In the above-described embodiment, the configuration in which the sensor device 20 includes an acceleration sensor and an angular velocity sensor has been described, but the configuration is not limited thereto. For example, the sensor device 20 may include a geomagnetic sensor instead of the angular velocity sensor. The geomagnetic sensor detects geomagnetic data indicating the magnetic fields (magnetic flux densities) in three axial directions orthogonal to each other. For the geomagnetic sensor, for example, MR (Magnet resistive) elements, MI (Magnet impedance) elements, Hall elements, etc. are used. In this case, the sensor device 20 may calculate the three-axis angular velocity data by a known method based on the three-axis acceleration data detected by the acceleration sensor and the three-axis geomagnetic data detected by the geomagnetic sensor. Therefore, the sensor incorporated in the sensor device 20 may be configured to include a three-axis acceleration sensor and at least one of a three-axis angular velocity sensor and a three-axis geomagnetic sensor.

[0066] (3) In the above-described embodiments, some functions of the sensor device 20 may be configured to be included in the terminal device 10. For example, the functions of the sensor device 20 in FIG. 11 may be configured to be included in the terminal device 10. In this case, the motion information acquisition unit of the terminal device 10 receives sensor data (e.g., acceleration and angular velocity) detected by the sensors of the sensor device 20. Other functions (the inertial moment calculation unit 250, the timing calculation unit 254, the section setting unit 256, the torque calculation unit 258, the stress calculation unit 260, and the impulse calculation unit 262) are the same as the functions described in FIG. 11.

[0067] (4) In the above-described embodiments, as shown in FIG. 2, a configuration has been described in which the forearm is regarded as a rigid body and the rigid body segment 52 is defined by a line segment connecting the wrist joint center and the elbow joint center (i.e., the forearm). However, a model in which the ball 2, the hand part, and the forearm are regarded as rigid bodies may be adopted.

[0068] When the above model is adopted, the rigid body segment is defined by a line segment connecting the ball center and the elbow joint center. The mass center ratio of the rigid body segment including the forearm, the hand part, and the ball 2 is calculated based on the mass center ratios of the forearm, the hand part, and the ball 2, respectively. Also, the length of the rigid body segment is the length from the elbow joint center to the ball center. Furthermore, the mass Mf* of the rigid body segment is represented by the following formula (7).

[0069] Mf*=(0.006·Mbo)+(0.0162·Mbo)+Mb …(7) The first term on the right side of formula (7) represents the mass of the hand part, the second term on the right side represents the mass of the forearm, and the third term on the right side (i.e., Mb) represents the mass of the ball 2.

[0070] (5) It is also possible to provide a program that causes a computer to function and execute the control as described in the above embodiments. Such a program can be recorded on a non-transitory computer-readable recording medium such as a flexible disk, CD-ROM (Compact Disk Read Only Memory), ROM, RAM, and memory card attached to the computer, and provided as a program product. Alternatively, it can be recorded on a recording medium such as a hard disk built into the computer to provide the program. Also, the program can be provided by downloading via a network.

[0071] (6) The configurations exemplified as the above embodiments are merely examples of the configurations of the present invention, and it is possible to combine them with other known technologies, or to change the configurations by omitting some parts etc. without departing from the gist of the present invention.

[0072] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Explanation of Reference Numerals

[0073] 2 ball, 5 subject, 10 terminal device, 20 sensor device, 52 rigid body segment, 102, 202 CPU, 104, 204 memory, 106 touch panel, 110 display, 112 wireless communication section, 113 communication antenna, 114 memory interface, 115 recording medium, 116 speaker, 118 microphone, 205 acceleration sensor, 206 angular velocity sensor, 212 storage battery, 250 moment of inertia calculation section, 252 motion information acquisition section, 254 timing calculation section, 256 section setting section, 258 torque calculation section, 260 stress calculation section, 262 impulse calculation section, 1000 analysis system.

Claims

1. A calculation unit that calculates the moment of inertia and mass of a segment including a body part of the subject before releasing an exercise tool with a built-in sensor based on the body information of the subject; An acquisition unit that acquires the motion information of the exercise tool detected by the sensor; A torque calculation unit that calculates the torque acting on the body part based on the body information, the moment of inertia and the mass, and the motion information; An analysis system comprising a stress calculation unit that calculates the stress applied to the body part when releasing the exercise tool based on the torque.

2. The analysis system according to claim 1, wherein the motion information includes acceleration in three axial directions and angular velocity in three axial directions.

3. Further comprising a timing calculation unit that calculates the timing at which the exercise tool is released from the body part based on the acceleration in the three axial directions, The stress calculation unit extracts the maximum value of the torque in a predetermined period before the timing, and calculates, as the stress applied to the body part, a multiplication value obtained by multiplying the maximum value of the torque by a predetermined coefficient. The analysis system according to claim 2.

4. Further comprising an impulse calculation unit that calculates an impulse acting on the body part in the predetermined period based on the body information, the position of the center of mass of the segment, the mass, the resultant acceleration of the acceleration in the three axial directions, and the resultant angular velocity of the angular velocity in the three axial directions. The analysis system according to claim 3.

5. The torque calculation unit calculates the torque based on the body information, the position of the center of mass of the segment, the moment of inertia and the mass, the resultant acceleration of the acceleration in the three axial directions, and the resultant angular velocity of the angular velocity in the three axial directions. The analysis system according to any one of claims 2 to 4.

6. The analysis system according to any one of claims 1 to 5, wherein the body information includes the length of the body part and the weight of the subject.

7. The exercise tool is a ball, The body part includes the forearm of the subject. The analysis system according to any one of claims 1 to 6.

8. The sensor includes at least one of a three-axis acceleration sensor, a three-axis angular velocity sensor, and a three-axis geomagnetic sensor. The analysis system according to any one of claims 1 to 7.

9. An analysis method executed by a processor included in an analysis system, The step of the processor calculating the moment of inertia and mass of a segment including the body part of the subject that releases the sports equipment with a built-in sensor based on the body information of the subject; The step of the processor acquiring the motion information of the sports equipment detected by the sensor; The step of the processor calculating the torque acting on the body part based on the body information, the moment of inertia and the mass, and the motion information; An analysis method including the step of the processor calculating the stress applied to the body part when releasing the sports equipment based on the torque.

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