JP5923904B2 - Back pain prevention device and method of operating the same - Google Patents

Description

The present invention relates to a low back pain prevention apparatus for preventing the occurrence of low back pain of an operator who handles heavy objects and an operation method thereof .

  In recent years, it is said that the percentage of people suffering from back pain is very high with respect to heavy labor as seen in nursing care sites, transportation and construction sites. In the field work, the back pain ratio is still at a high level, although there are places where appropriate work posture education and the upper limit of the load weight are taken.

  In order to improve the above problems, it is necessary for the operator himself to recognize the risk of low back pain by quantitatively indicating the burden on the lower back due to work. For quantifying the burden caused by work, for example, as disclosed in Patent Document 1, the work posture is classified and weighted, and the work burden is entered by inputting the quantity, weight, time, and their coefficients. There is a method of scoring. The work load scoring is used to create appropriate work conditions.

  Further, Patent Document 2 introduces a worker model that simulates a welding worker on a structure drawn by a CAD system, and uses a computer analysis to analyze the main joint when the worker model performs welding work. There is a method for estimating the muscle strength of the head and displaying the burden quantitatively according to the strength fatigue and recovery characteristics by age. By quantifying the burden on the worker model, it becomes possible to grasp the burden on the actual worker in advance or to review the structure corresponding to the aging of the manufacturing department.

  Furthermore, Patent Document 3 has a problem in that the burden on the long-standing posture work is obtained by checking the waist burden point and the foot burden point based on the restraint rate by task, the duration, and the number of walks, and checking with the guidelines. There is a method to confirm the presence or absence. These burden points are utilized when creating a work form that minimizes fatigue.

JP 59-164034 A JP-A-7-73157 JP 2003-10157 A

  According to the methods described in Patent Documents 1 to 3 described above, the work burden can be grasped quantitatively. However, these conventional methods have the following problems.

  First, these conventional methods are intended to quantitatively grasp the work burden and create an appropriate work plan and structure plan. Therefore, it is impossible to urge the worker who is working hard in real time to bear the risk of work burden.

  Second, in order to quantitatively grasp the work burden, the worker or the work manager or the like inputs necessary data such as the work posture based on the work performed by the worker. Alternatively, a designer or a planer inputs necessary data such as a work posture assuming a work to be performed by the worker. This input work requires a lot of labor.

  Third, while the production lines of automobiles are routine work, there are many non-regular work in the field of nursing care, transportation and construction, and appropriate input data for each work. In order to quantify the burden caused by work, a great deal of labor is required. Moreover, it takes time and effort to record the operation in the work.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a low back pain prevention device that is simple and that allows an operator to grasp the risk of burden on the lower back due to work in real time, and an operating method thereof.

  In order to solve the above-mentioned problems, the constitutional feature of the low back pain prevention device according to claim 1 is a low back pain prevention device that detects and warns in real time the risk of low back pain from a human condition, Trunk angle detection means that is mounted and detects the angle of the trunk, plantar load detection means that detects a load that is mounted on the sole of a person and acts on the sole, the trunk angle detection means, and the foot The load value calculating means for calculating the load on the waist as a load value based on each information detected by the bottom load detecting means, and the waist that may cause a disorder in the waist based on the basic information of the person A risk value setting unit that sets a burden as a risk value; and a warning unit that issues a warning based on a comparison between the burden value and the risk value.

  The constitutional feature of the invention according to claim 2 is that in the back pain prevention device according to claim 1, an upper arm angle detection means for detecting an angle of the upper arm, which is attached to a person's upper arm, and which is attached to the forearm of the person, Forearm angle detection means for detecting the angle of the forearm, input values of human trunk length, upper arm length and forearm length, trunk angle detection means, upper arm angle detection means and forearm Hand position calculating means for calculating the position of a human hand based on each piece of information detected by the angle detecting means, and the burden value calculating means includes the trunk angle detecting means and the sole load detecting means. And calculating the burden on the lower back as a burden value based on the information detected by the above and the information calculated by the hand position calculating means.

  The constitutional feature of the invention according to claim 3 is the back pain prevention device according to claim 2, further comprising hand load detecting means for detecting a load that is worn on a human hand and acts on the hand, wherein the load value calculation is performed. The means bears a burden on the waist based on each information detected by the trunk angle detecting means, the sole load detecting means, and the hand load detecting means, and information calculated by the hand position calculating means. It is to calculate as a value.

  The constitutional feature of the invention according to claim 4 is the low back pain prevention device according to claim 2 or 3, wherein each input value of a human trunk length, upper arm length, and forearm length is determined by a person. Is determined based on the correlation between the height of each and the input values.

  The structural feature of the invention according to claim 5 is that the back pain prevention device according to any one of claims 1 to 4 includes a terminal for inputting basic information of a person.

  The structural feature of the invention according to claim 6 is the back pain prevention device according to any one of claims 1 to 5, which is detected by the trunk angle detection means and / or the sole load detection means. The information thus obtained is transmitted to the burden value calculation means by radio.

  A structural feature of the invention according to claim 7 is the low back pain prevention device according to any one of claims 1 to 6, wherein the trunk angle detection means is arranged at the height of the back thoracic vertebra. It is that you are.

  The structural feature of the invention according to claim 8 is the low back pain prevention device according to any one of claims 1 to 7, wherein the warning means is worn on a person and the warning is sound and / or Or it is vibration.

  The structural feature of the invention according to claim 9 is the low back pain prevention device according to any one of claims 1 to 8, wherein the warning means is configured such that the load value ≧ the risk value. It is to send a warning.

  The structural feature of the invention according to claim 10 is the back pain prevention device according to any one of claims 1 to 9, wherein the burden value is a compression force generated in an intervertebral disc of the lumbar vertebra, The risk value is a compression force that may cause damage to the lumbar disc.

  The constitutional feature of the invention according to claim 11 is the low back pain prevention device according to claim 10, wherein the risk value is a risk value by gender age set based on basic information of a person including at least gender and age. It is to be.

In order to solve the above-mentioned problem, the structural feature of the operation method of the low back pain prevention device according to claim 12 is the operation method of the low back pain prevention device that detects and warns in real time the risk of low back pain from a human condition. A hand position calculating step for calculating the position of the human hand based on the length of the human trunk, the length of the upper arm and the length of the forearm, and the angle of the human trunk, the angle of the upper arm and the angle of the forearm; A burden value calculating step for calculating a burden on the waist as a burden value based on the angle of the human trunk, the load acting on the sole and the position of the person's hand, and a disorder may occur in the waist A risk value setting step for setting a burden on the lower back as a risk value, and a warning step for transmitting a warning when the load value ≧ the risk value.

A structural feature of the invention according to claim 13 is the operation method of the back pain prevention device according to claim 12, wherein the burden value calculating step includes an angle of the human trunk, a load acting on the sole, The burden on the waist is calculated as a burden value based on the position of the hand and the load acting on the hand.

  According to the first aspect of the present invention, the burden value of the waist is calculated by the trunk angle detecting means and the sole load detecting means attached to the human body, and the risk value of the waist is set based on the basic information of the person. Then, a warning is sent in real time based on the comparison between the burden value and the risk value. Therefore, the worker wearing the back pain prevention device of the present invention can grasp the risk of burden on the lower back due to work in real time. Thus, the operator can immediately improve the work posture and workload, switch to collaborative work, etc. before suffering from back pain, and can prevent the occurrence of back pain.

  Further, the low back pain prevention device of the present invention provides data (each information on the posture and load of the worker) for calculating the burden value by the trunk angle detecting means and the sole load detecting means that can be worn on the human body of the worker. Can be acquired automatically in real time. Therefore, the low back pain prevention apparatus of the present invention has a simple configuration and is simple because the operator or the investigator does not need to record data related to the work. In addition, even if the work content changes, data related to the work can be automatically acquired, so that any work can be handled. The trunk is the trunk and refers to the chest and abdomen excluding the head, neck and limbs of the human body.

  According to the second aspect of the present invention, the low back pain prevention device includes hand position calculating means for calculating the position of the human hand, and is detected by the trunk angle detecting means and the sole load detecting means attached to the human body. The burden value of the lower back is calculated based on the information and the position information of the human hand. In the lower back pain prevention apparatus according to the first aspect, the maximum value of the burden value of the lower back can be calculated by providing the assumption that the total load due to the operation acts vertically on the shoulder which is the uppermost part of the trunk. However, in many cases, the load is transmitted from the hand to the shoulder, and even with the same load, the moment around the waist increases as the position of the hand is further from the waist, and the burden value on the waist increases. According to the present invention, since the burden value of the lower back is calculated in consideration of the position of the human hand, the calculation accuracy of the lower shoulder is improved, and the effect of preventing the occurrence of lower back pain is further enhanced.

  According to the third aspect of the present invention, the low back pain prevention device includes hand load detecting means for detecting a load acting on a human hand, and a trunk angle detecting means, a sole load detecting means, and a hand attached to the human body. Based on each piece of information detected by the load detection means and information on the position of the human hand, the burden value of the waist is calculated. In the lower back pain prevention device according to the second aspect, the maximum value of the burden value on the lower back can be calculated by providing an assumption that the total load due to the operation acts on the hand. However, depending on the content of the work, the load may act in a distributed manner on the hand and shoulder, and there is a possibility of overestimating the burden value on the waist on the assumption that the total load due to the work acts on the hand. According to the present invention, since the load value of the waist can be calculated by distinguishing between the load acting on the hand and the load acting on the shoulder (= total load due to work−load acting on the hand), The accuracy is further improved, and it can be appropriately prevented without excessively preventing the occurrence of back pain.

  According to the invention of claim 4, the input values of the trunk length, the upper arm length, and the forearm length necessary for calculating the position of the human hand are correlated with the height and each input value. Determine based on. Therefore, it is possible to determine each input value relating to the length of the human body necessary for calculating the position of the person's hand simply by using the height of the person as an input value, which is convenient.

  According to the invention which concerns on Claim 5, the setting change of the control conditions of a back pain prevention apparatus can be easily performed by using a terminal.

  According to the invention of claim 6, information from the trunk angle detection means attached to the trunk and / or information from the sole load detection means attached to the sole is wirelessly transmitted to the burden value calculation means. Sent. Therefore, compared with the case where information is sent by wire, the movement of the worker's body is less likely to be restrained.

  According to the invention of claim 7, the trunk angle detection means is arranged at the height of the back thoracic vertebra. When the operator lifts the load, the operator's back is irregularly curved, so that the trunk angle is not constant in the vertical direction of the back. For this reason, different trunk angles are detected depending on the position where the trunk angle detection means is mounted. However, by arranging the trunk angle detection means at the height of the back thoracic vertebra, it becomes possible to detect the representative value of the trunk angle with relatively high accuracy in the irregularly curved back, and the trunk angle Based on the above, it is possible to accurately calculate the burden value of the waist.

  According to the eighth aspect of the present invention, the warning means is worn by a person and the warning is sound and / or vibration. Therefore, when the warning is a sound, it is possible to inform the worker himself and the people around him that the worker is performing work involving the risk of burden on the waist. Further, when the warning is vibration, the worker can recognize the risk of the burden on the lower back without being known to surrounding people.

  According to the ninth aspect of the invention, a warning is issued when the burden value ≧ the risk value. That is, a warning is not sent to the worker at a stage where the possibility of a failure in the lower back is small. Therefore, the worker can continue working with peace of mind unless a warning is transmitted. The configuration of the invention according to claim 9 is to issue a warning when the burden value becomes 100% risk value or more. However, as a configuration different from this configuration, for example, the burden value is 100% risk. Before reaching the value, a warning may be sent for each stage such as 90% risk value, 95% risk value, and the like. At this time, if the type of warning is changed for each stage, the operator can easily recognize the degree of the burden.

  According to the invention of claim 10, the burden value is the compression force generated in the lumbar intervertebral disc, and the risk value is the compression force that may cause a failure in the lumbar intervertebral disc. Low back pain often occurs when the compression force increases, among other loads acting on the lumbar disc. Therefore, using the burden value and the risk value as the intervertebral disc compression force is most effective from the viewpoint of preventing back pain.

  According to the invention which concerns on Claim 11, the risk value according to sex age is set based on the basic information of the person including sex and age. Since the risk value varies depending on each worker's physique, muscular strength, skeleton, health condition, etc., it is naturally desirable to determine the risk value for each worker. However, in order to determine a strict risk value for each worker, a lot of inspections are required before work, so that it is not practical. Here, the risk value is highly correlated with gender and age in the basic information of a person. Therefore, if the gender age risk value is set based on the gender and age of the worker, a risk value with a certain degree of accuracy can be set for each worker without requiring the worker's inspection.

According to the twelfth aspect of the present invention, there is a possibility that an obstacle occurs in the lower back and the burden value of the lower back calculated by the angle of the human trunk, the load acting on the sole and the position of the human hand. A warning is issued in real time based on a comparison with the risk value of the lower back. Therefore, according to the operation method of the low back pain prevention device of the present invention, as in the invention according to claim 1, the operator can grasp the risk of the burden on the low back due to the work in real time. Thus, the operator can immediately improve the work posture and workload, switch to collaborative work, etc. before suffering from back pain, and can prevent the occurrence of back pain.

According to the twelfth aspect of the present invention, the operation method of the low back pain prevention device calculates the burden value of the lower back based on the angle of the human trunk, the load acting on the sole and the position of the human hand. Therefore, according to the operation method of the low back pain prevention device of the present invention, as in the invention according to claim 2, since the burden value of the waist is calculated in consideration of the position of the human hand, the calculation accuracy of the burden value of the waist is calculated. And the effect of preventing the occurrence of low back pain is enhanced.

According to the thirteenth aspect of the invention, the operation method of the low back pain prevention device is based on the load on the lower back based on the angle of the human trunk, the load acting on the sole, the position of the human hand and the load acting on the hand. Calculate the value. Therefore, according to the operation method of the low back pain prevention device of the present invention, the load value of the lower back can be calculated by distinguishing the load acting on the hand and the load acting on the shoulder, similarly to the invention according to claim 3. The calculation accuracy of the burden value of the lower back is further improved, and the occurrence of lower back pain can be appropriately prevented without excessively preventing it.

As described above, according to the present invention, it is possible to provide a low back pain prevention apparatus and an operation method thereof that are simple and allow an operator to grasp the risk of burden on the lower back due to work in real time.

It is explanatory drawing which illustrates typically the operator with which the low back pain prevention apparatus of 1st Embodiment was mounted | worn. The calculation model of the disc compression force in 1st Embodiment is shown. It is explanatory drawing explaining the attachment position of the angle sensor in 1st Embodiment, and the structure of the spine. It is a graph which shows the limit value and tolerance value of a male intervertebral disc compression force. It is a graph which shows the limit value and tolerance value of female intervertebral disc compression force. It is a flowchart explaining the action | operation of the low back pain prevention apparatus of 1st Embodiment. It is explanatory drawing of a standing posture. It is explanatory drawing which illustrates typically the operator with which the low back pain prevention apparatus of 2nd Embodiment was mounted | worn. The calculation model of the intervertebral disk compression force in 2nd Embodiment is shown. It is a flowchart explaining the action | operation of the low back pain prevention apparatus of 2nd Embodiment.

Hereinafter, embodiments of a low back pain prevention device and an operation method thereof according to the present invention will be described in detail with reference to the drawings.

<First Embodiment>
(1) Configuration of Back Pain Prevention Device 1 As shown in FIG. 3, the trunk B (generally referred to as the trunk) of the worker (person) M is the spine Sp (generally referred to as the spine). Is supported by. The spine Sp has a structure in which vertebrae and intervertebral discs are continuously stacked and gently curved into an S shape as a whole. Thus, the spine Sp is curved in an S shape, so that the impact from the outside and the burden of weight are reduced.

  The spine Sp descends from the large occipital hole in the occipital bone of the skull and reaches the pelvis. The spine Sp is formed from about 30 vertebrae of 7 cervical vertebrae Ce, 12 thoracic vertebrae Th, 5 lumbar vertebrae Lu, 5 sacral vertebrae Sa, and 3-6 vertebrae covertebral Co in order from the top. Has been. Here, it is said that low back pain is likely to occur between the third and fourth lumbar vertebrae of the five lumbar vertebrae Lu and between the fourth and fifth lumbar vertebrae.

  As shown in FIG. 1, a back pain prevention device 1 is a device worn on the body of an operator M, and includes an angle sensor (trunk angle detection means) 2, a load sensor (plantar load detection means) 3, The control unit 4 is provided. The control unit 4 is integrally provided with a CPU (burden value calculation means, risk value setting means, warning means) 5, a speaker (warning means) 6, and a terminal 7.

  The angle sensor 2 is fixed to the belt 2b, and is attached to the height of the thoracic vertebra Th on the back of the worker M by winding the belt 2b around the chest of the trunk B of the worker M. The angle sensor 2 includes an antenna 2 a for transmitting the detected angle information to the control unit 4 wirelessly. The angle sensor 2 is a sensor that can detect an angle with respect to a reference line such as horizontal and vertical. As the angle sensor 2, an acceleration sensor, a gyro sensor, or the like can be used.

  Here, as shown in FIG. 3, the angle sensor 2 can be mounted in a range from the position of the uppermost angle sensor 2 ′ of the thoracic vertebra Th to the position of the lowermost angle sensor 2 ″ of the thoracic vertebra Th. However, since the back of the worker M is uneven, the mounting angle of the angle sensor 2 varies depending on the mounting position in the standing posture of the worker M (shown in FIG. 7). Therefore, in the standing posture where the worker M is not working, the initial value of the angle sensor 2 is detected, and the trunk angle θ after the worker M starts working is determined from the initial value of the angle sensor 2. If the amount of change is used, the trunk angle θ can be detected regardless of the mounting position of the angle sensor 2. In the present embodiment, as shown in FIG. 2, the angle formed by the spine Sp with respect to the horizontal is the trunk angle θ.

  The load sensor 3 is disposed on the sole of the work shoe 3b, and is attached to the sole S of the worker M when the worker M wears the work shoe 3b. On the heel side of the work shoe 3b, an antenna 3a for transmitting the load information detected by the load sensor 3 to the control unit 4 wirelessly is provided. The load sensor 3 is a sensor that can detect a total load (load) Wa acting on the sole S. As the load sensor 3, a load cell, a pressure sensor, a strain gauge, or the like can be used.

  In the present embodiment, a total of six load sensors 3 are arranged on the sole of one work shoe 3b, three in the front and rear and two in the left and right. Each load sensor 3 is disposed on a spike-like convex portion provided on the sole of the work shoe 3b, and the sole is in contact with the ground only at the position of each load sensor 3. Therefore, the total value of the loads detected by the total load sensor 3 of the pair of left and right work shoes 3b is the total load Wa obtained by summing the weight W of the worker M and the load of the load P lifted by the worker M (load load α). It becomes. Note that the shape, number and material of the spike-like convex portions are appropriately set according to the type of work.

  The control unit 4 is fixed to the belt 4b, and is attached to the height of the lumbar vertebra Lu on the back of the worker M by winding the belt 4b around the waist of the trunk B of the worker M. The control unit 4 includes an antenna 4a for receiving information from the angle sensor 2 and the load sensor 3.

  The CPU 5 is disposed inside the control unit 4. The CPU (load value calculation means) 5 calculates the load on the waist as a load value R based on each information detected by the angle sensor 2 and the load sensor 3. Further, the CPU (risk value setting means) 5 sets the burden on the lower back where a failure may occur on the lower back based on the basic information of the worker M as the risk value r. Further, the CPU (warning means) 5 sends a command to send a warning sound to the speaker 6 when the burden value R ≧ the risk value r, based on the comparison between the burden value R and the risk value r.

  The speaker 6 is disposed so as to be exposed on the surface of the control unit 4. The speaker 6 can select a volume and a melody.

  The terminal 7 is disposed so as to be exposed on the surface of the control unit 4. The operator M operates the input screen of the terminal 7 to input the sampling intervals of the angle sensor 2 and the load sensor 3 and input at least gender and age of the basic information of the worker M. This input information is stored in the CPU 5.

(2) Calculation of the burden value R The burden force R is the compression force (intervertebral disk compression force) generated in the intervertebral disc of the lumbar Lu by the work performed by the worker M. As shown in FIG. 2, in the present embodiment, a simple calculation model in which the upper spine Sp from the joint part for calculating the intervertebral disc compression force R of the lumbar Lu is regarded as a rigid body is created, and a force balance equation is used. Intervertebral disc compression force R acting on the lumbar Lu is calculated (Reference 1: LAStrait, VT Inman, HJRalstone; Simple Illustrations of Physical Principles Selected from Physiology and Medicine. Am. J. Phys. 15 375-382 (1947)).

  In FIG. 2, W is the weight of the worker M, α is the load applied by the load P, W1 is the weight of the trunk B, and Ws is the total weight W2 of both arms and the head plus the load load α. , L is the length of the trunk B (the total length of the thoracic vertebra Th and lumbar vertebra Lu), Fe is the spine standing muscle strength, θ is the trunk angle (spine angle), and R is the intervertebral disc compression force.

  Here, the weight W is a value detected by the load sensor 3 in a standing posture (shown in FIG. 7) where the worker M is not working. The load load α is a value obtained by subtracting the weight W from the total load Wa detected by the load sensor 3 after the worker M starts work. The weight W1 of the trunk B is generally calculated by W1 = 0.4W, and it is considered that the weight W1 acts on a position of ½ of the length L of the trunk B. The total weight W2 of both arms and the head is generally calculated as W2 = 0.2W. Further, it is considered that the erection strength Fe of the spine acts on the position 1/3 from the length L of the trunk B at an angle of 12 ° with respect to the spine Sp regardless of the posture of the worker M.

The balance equation of force is as shown below.
Fe · sin 12 ° · (2L / 3) −0.4W · cos θ · L / 2
-(0.2W + α) · cos θ · L = 0 (Equation 1)
Ry-Fe · sin (θ-12 °) -0.4W
− (0.2W + α) = 0 (Equation 2)
Rx-Fe · cos (θ-12 °) = 0 (Equation 3)
R = √ (Rx ² + Ry ² ) (Equation 4)

  Note that the variable L in (Expression 1) is deleted by dividing both sides of (Expression 1) by the variable L. When (Expression 1), (Expression 2), and (Expression 3) are substituted into (Expression 4), the intervertebral disc compression force R becomes a function with W, α, and θ as variables. Therefore, the intervertebral disc compression force (burden value) R can be calculated from the trunk angle θ detected by the angle sensor 2 and the weight W and the load load α detected by the load sensor 3.

(3) Setting of Risk Value r The speaker 6 transmits a warning sound when the burden value R ≧ the risk value r. Therefore, considering the safety of the worker M, it is preferable to set a risk value r as small as possible. However, if the risk value r is too small, warning sounds are frequently transmitted, which causes the worker M to have excessive anxiety. In the present embodiment, based on the gender and age in the basic information of the worker M, a risk value r that may cause a disorder in the lower back is set (calculated).

  Since the risk value r is a value to be compared with the above-described burden value R, it is assumed to be an intervertebral disc compression force that may cause a disorder in the lumbar region. It goes without saying that the risk value r can be set as appropriate based on various findings. Therefore, the setting method of the risk value r described below is merely an example.

  Table 1 shows the limit value Rd and the allowable value Ra of the intervertebral disc compression force for males, and Table 2 shows the limit value Rd and the allowable value Ra of the intervertebral disc compression force for females. FIG. 4 is a graph showing the limit value Rd and the allowable value Ra of the male intervertebral disk compression force, and FIG. 5 is a graph showing the limit value Rd and the allowable value Ra of the female intervertebral disk compression force.

  Reference 2 (Genaidy, Spinal compression tolerance limits for the design of manual material handling operations in the workplace) discloses the limit value Rd of the intervertebral disc compression force for a single load (single load) for each gender and target age. ing. The load load αd at which the limit value Rd of the intervertebral disc compression force is generated was calculated by the above-described (Expression 1) to (Expression 4).

  As described in (2) above, the intervertebral disc compression force R is a function with W, α, and θ as variables. Therefore, if the intervertebral disc compression force Rd, weight W, and trunk angle θ are set, the load load αd is I want. Here, as the weight W, an average weight for each target age in Japan is input, and as the trunk angle θ, assuming that the load load αd is the smallest, the spine Sp is 90 ° before the vertical. The trunk angle θ = 0 ° when tilted was input. The load load αd thus obtained is as shown in Tables 1 and 2.

  Since the load load αd is a limit value in a single load, it is considered that it is better to obtain an allowable value in a repetitive load in consideration of the safety side. Reference Criteria 1 (ISO 11228-1: 2003 Ergonomics-Manual handling-) describes the coefficients for determining the allowable value for repeated load from the limit value for single load. This coefficient is set corresponding to the work time and work frequency. For example, assuming a care facility helper, the work time is 2 to 8 hours, and the work frequency is 4 work per hour. The coefficient is 0.85. Therefore, the load αa in the repeated load was determined as αa = 0.85αd. Then, the allowable value Ra of the intervertebral disc compression force in the repeated load was obtained from the load load αa, the average weight W for each target age described above, and the trunk angle θ = 0 °.

  As shown in FIGS. 4 and 5, the allowable value Ra of the intervertebral disc compression force is smaller than the limit value Rd of the intervertebral disc compression force. In addition, the allowable value Ra of the intervertebral disc compression force is smaller for women than for men, and tends to decrease as the target age increases. In the present embodiment, the allowable value Ra of the intervertebral disc compression force is the risk value r. Then, the allowable value Ra of the intervertebral disc compression force by sex and age shown in Tables 1 and 2 was stored in the CPU 5.

(4) Operation of Back Pain Prevention Device 1 FIG. 6 shows a flowchart for explaining the operation of the back pain prevention device 1 of this embodiment. First, the worker M wears the belt 2b equipped with the angle sensor 2 and the work shoes 3b equipped with the load sensor 3. The worker M is not wearing the belt 4b equipped with the control unit 4.

  After turning on the power switch of the low back pain prevention device 1, the worker M operates the input screen of the terminal 7 in step S <b> 1 to input the sampling intervals of the angle sensor 2 and the load sensor 3, and the worker M's Enter the gender and age of the basic information. Then, the worker M wears the belt 4b equipped with the control unit 4 and takes a standing posture.

  In step S2, as described in the above (3), the disc compression force allowable value Ra corresponding to the sex and age of the worker M is determined from the gender age allowable disc Ra stored in the CPU 5 in advance. To extract. Then, this allowable value Ra is stored in the CPU 5 as the risk value r.

  In steps S3 and S4, the worker M remains in the standing posture, and the weight W of the worker M detected by the load sensor 3 is stored in the CPU 5. Further, the angle sensor 2 is initialized (the current angle is set to zero). When step S4 is completed, a notification sound of completion of preparation is transmitted from the control unit 4, and the worker M can break the standing posture.

  In step S5, the worker M starts work, and then in step S6, the trunk angle θ and the load load α are detected by the angle sensor 2 and the load sensor 3. Here, the trunk angle θ is an amount of change from the initial value of the angle sensor 2. The load load α is a value obtained by subtracting the weight W from the total load (load) Wa detected by the load sensor 3.

  In step S7, as described in (2) above, the intervertebral disc compression force (burden value) R is calculated using the trunk angle θ, the weight W, and the load load α. In step S8, the burden value R and the risk value r are compared, and if the burden value R ≧ risk value r, the process proceeds to step S9 and a warning sound is transmitted from the speaker 6. If the burden value R <the risk value r, the process returns to step S6 and continues to detect the trunk angle θ and the load load α. Step S6 is repeated at the sampling interval set in step S1.

  In step S9, after a warning sound is transmitted from the speaker 6, in step S10, the worker M selects whether to turn off the power switch of the back pain prevention device 1, and turns off the power switch. Thus, the monitoring of the burden on the lower back by the lower back pain prevention device 1 is terminated. If the power switch is not turned off, the process returns to step S6 and the detection of the trunk angle θ and the load load α is continued.

(5) Effect of the back pain prevention device 1 According to the configuration of this embodiment, the pressure force generated on the disc of the lumbar Lu by the angle sensor 2 and the load sensor 3 attached to the human body of the worker M is a burden value. While calculating as R, based on the gender and age in the basic information of the worker M, a compression force that may cause a failure in the intervertebral disc of the lumbar Lu is set as the risk value r. The burden value R and the risk value r are compared, and a warning sound is transmitted in real time when the burden value ≧ the risk value.

  Therefore, the worker M wearing the back pain prevention device 1 of the present embodiment can grasp the risk of the burden on the waist due to the work in real time. As a result, the worker M can immediately improve the work posture and workload, switch to collaborative work, and the like before suffering from back pain, and can prevent the back pain from occurring.

  Further, the back pain prevention device 1 of the present embodiment has data for calculating the burden value R by the angle sensor 2 and the load sensor 3 that can be worn on the human body of the worker M (each information on the posture and load of the worker M). Can be acquired automatically in real time. Therefore, the low back pain prevention device 1 of the present embodiment has a simple configuration and is simple because it is not necessary for the worker M or the investigator to record data regarding the work. In addition, even if the work content changes, data related to the work can be automatically acquired, so that any work can be handled.

  In the present embodiment, a warning sound is transmitted when the burden value R ≧ the risk value r. For this reason, since it becomes the structure where a warning sound is not transmitted to the worker M at the stage where the possibility of a failure occurring in the lower back is low, the worker M can continue working with peace of mind unless a warning sound is transmitted. .

  In addition, low back pain often occurs when the compression force increases particularly among various loads acting on the intervertebral disc of the lumbar Lu. Therefore, as in the present embodiment, the burden value R is a compression force generated in the intervertebral disc of the lumbar Lu, and the risk value r is a compression force that may cause a failure in the intervertebral disc of the lumbar Lu. It is most effective from the viewpoint of back pain prevention.

  The risk value r is highly correlated with gender and age in the basic information of a person. Therefore, if the gender age risk value r is set based on the sex and age of the worker M as in the present embodiment, a certain degree of accuracy can be obtained for each worker M without requiring a detailed human body inspection of the worker M. A high risk value r can be set.

  Further, according to the configuration of the present embodiment, the setting of the control conditions of the low back pain prevention device 1 can be easily performed by using the terminal 7 for data input to the CPU 5.

  Further, according to the configuration of the present embodiment, each information from the angle sensor 2 and the load sensor 3 is sent to the CPU 5 in the control unit 4 by radio. Therefore, compared with the case where each information is sent with a wire communication, the movement of the worker's M body is hard to be restrained.

  Further, according to the configuration of the present embodiment, the angle sensor 2 is disposed at the height of the back thoracic vertebra Th that can detect the representative value of the trunk angle θ with relatively high accuracy in the irregularly curved back. . Therefore, it is possible to accurately calculate the burden value R of the lower back based on the trunk angle θ.

  Further, according to the configuration of the present embodiment, the speaker (warning means) 6 that transmits a warning sound is attached to the human body of the worker M together with the control unit 4. Therefore, it is possible to inform the worker M himself and the people around it that the worker M is performing a work involving the risk of burden on the lower back.

Second Embodiment
(1) Configuration of the Back Pain Prevention Device 10 As described above, in the back pain prevention device 1 according to the first embodiment, the load load α (hereinafter referred to as the total load load α) due to work is the shoulder at the top of the trunk B. The load value R of the lumbar region is calculated by a rigid link model. In the low back pain prevention device 10 of the present embodiment, in order to improve versatility for various work situations, the position of the hand Ha is considered and an assumption is made that the total load load α is distributed to the hand Ha and the shoulder. Thus, the waist load value R is calculated by the rigid link model (shown in FIGS. 8 and 9).

  Accordingly, in the first embodiment, it is assumed that the worker M lifts the load P by extending his arm vertically downward as shown in FIG. As shown in FIG. 8, it is assumed that the worker M extends his arms forward and lifts the load P1 with his hands Ha and shoulders. In the present embodiment, it is assumed that the worker M extends both arms forward and lifts the load P1, and in the following description, the upper arm A1 and the forearm A2 unless otherwise specified. And the hands Ha are both upper arms A1, both forearms A2 and both hands Ha of both arms.

  As shown in FIG. 8, the back pain prevention device 10 is a device that is worn on the body of the worker M, and is worn on the angle sensor (trunk angle detection means) 2 that is worn on the trunk B and on the upper arm A1. Angle sensor (upper arm angle detection means) 21, angle sensor (forearm angle detection means) 22 attached to the forearm A 2, load sensor (foot load detection means) 3 attached to the sole S, and hand A load sensor (manual load detecting means) 30 attached to Ha and a control unit 40 are provided. In the control unit 40, a CPU (burden value calculation means, risk value setting means, hand position calculation means, warning means) 50, a speaker (warning means) 6, a vibrator (warning means) 60, and a terminal 70 are integrated. It has. Since the configurations and operations of the angle sensor 2, the load sensor 3, and the speaker 6 are the same as those in the first embodiment, the description thereof is omitted.

  The angle sensor 21 is fixed to the belt 21b, and is attached to each upper arm A1 of both arms of the worker M by winding the belt 21b around the upper arm A1 of the worker M. The angle sensor 21 includes an antenna 21 a for transmitting detected angle information to the control unit 40 wirelessly. Similar to the angle sensor 2 in the first embodiment, the angle sensor 21 is a sensor that can detect an angle with respect to a reference line such as horizontal and vertical. As the angle sensor 21, an acceleration sensor, a gyro sensor, or the like is used. Can do.

  Here, in the standing posture (shown in FIG. 7) in which the worker M is not working, the initial value of the angle sensor 21 is detected, and from the initial value of the angle sensor 21 after the worker M starts working. Is the upper arm angle θ1. As shown in FIG. 9, the angle formed by the upper arm A1 with respect to the horizontal is the upper arm angle θ1.

  Similar to the angle sensor 21, the angle sensor 22 includes a belt 22b and an antenna 22a. The angle sensor 22 is attached to each forearm A2 of both arms of the worker M by winding the belt 22b around the forearm A2 of the worker M. . Also in the angle sensor 22, the amount of change from the initial value of the angle sensor 22 after the worker M starts work is set as the forearm angle θ <b> 2 in the same manner as the angle sensor 21. As shown in FIG. 9, the angle formed by the forearm A2 with respect to the horizontal is the forearm angle θ2.

  In the present embodiment, in order to calculate the position of the hand Ha, it is necessary to detect the initial values of the angle sensors 21 and 22 with a more correct standing posture than in the first embodiment. The correct standing posture shown in FIG. 7 is a state in which the back and knees are stretched, the weight is equally applied to both feet, the upper limb is drooped naturally, and the palm of the hand is stretched toward the thigh. It is.

  A plurality of load sensors 30 are arranged on the entire palm surface and fingertips of each work glove 30b attached to both hands Ha of the worker M. The wrist part of the work glove 30b is provided with an antenna 30a for transmitting the load information detected by the load sensor 30 to the control unit 40 wirelessly. The load sensor 30 is a sensor that can detect a load α2 (shown in FIG. 9) acting on the hand Ha, and as the load sensor 30, a pressure sensor, a strain gauge, or the like can be used. The total load detected by the total load sensor 30 of the pair of left and right work gloves 30b is the total load α2 acting on both hands Ha.

  The control unit 40 is fixed to the belt 4b, and is attached to the height of the lumbar vertebra Lu on the back of the worker M by winding the belt 4b around the waist of the trunk B of the worker M. The control unit 40 includes an antenna 4 a for receiving information from the angle sensor 2, the angle sensor 21, the angle sensor 22, the load sensor 3, and the load sensor 30.

  The CPU 50 is disposed inside the control unit 40. By this CPU (hand position calculation means) 50, the input value of the length L of the trunk B, the length L1 of the upper arm A1, and the length L2 of the forearm A2 of the worker M, the angle sensor 2, the angle sensor 21, and The position of the hand Ha is calculated based on each angle information detected by the angle sensor 22. Further, the CPU (burden value calculating means) 50 determines the burden on the lower back based on the information detected by the angle sensor 2, the load sensor 3, and the load sensor 30 and the calculated position information of the hand Ha. Calculate as R.

  Further, the CPU (risk value setting means) 50 sets the burden on the lower back that may cause a failure on the lower back as the risk value r based on the basic information of the worker M. Further, based on the comparison between the burden value R and the risk value r, the CPU (warning means) 50 considers when the burden value R ≧ the risk value r or the warning multiplier β (β <100%). Then, when the burden value R ≧ (β × risk value r), one or both of a command for transmitting a warning sound to the speaker 6 and a command for transmitting vibration to the vibrator 60 are transmitted.

  The vibrator 60 is arranged inside the control unit 40 and transmits vibrations to the waist of the worker M. The vibrator 60 can select the strength of vibration. As the vibrator 60, a small vibrator using a small motor or the like built in a controller of a mobile phone or a game machine can be used.

  The terminal 70 is disposed so as to be exposed on the surface of the control unit 40. The worker M operates the input screen of the terminal 70 to input at least gender, age and height H among the basic information of the worker M, selection of warning means (speaker 6 and vibrator 60), and warning multiplication. The rate β is input. This input information is stored in the CPU 50. In this embodiment, the sampling interval of each sensor (angle sensor 2, angle sensor 21, angle sensor 22, load sensor 3, load sensor 30) is set in the CPU 50 in advance, and the sampling interval of the terminal 70 is Do not enter.

(2) Calculation of burden value R As shown in FIG. 9, in the present embodiment, the spine Sp, the upper arm A1, and the upper spine Sp from the joint (position o) for calculating the intervertebral disc compression force (burden value) R of the lumbar Lu A simple calculation model in which the forearm A2 is regarded as a three-connected rigid body is created, and an intervertebral disc compression force R acting on the lumbar vertebra Lu is calculated by a force balance equation. In FIG. 9, position a is the wrist position, position b is half the distance from the wrist to the shoulder, position c is the shoulder position, and position d is the half length L of the trunk B. The position e indicates a position 1/3 from the top of the length L of the trunk B.

  In FIG. 9, W is the weight of the worker M, W1 is the weight of the trunk B, W2 is the total weight of both arms and the head, α1 is a load acting on the shoulder, α2 is a load acting on the hand Ha, L is the length of the trunk B (the total length of the thoracic vertebra Th and lumbar Lu), L1 is the length of the upper arm A1, L2 is the length of the forearm A2, Fe is the erection strength of the spine, and θ is the trunk angle (spine angle) ), Θ1 represents the upper arm angle, θ2 represents the forearm angle, and R represents the intervertebral disc compression force.

  The length L of the trunk B, the length L1 of the upper arm A1, and the length L2 of the forearm A2 are correlated with the height H of the worker M, and L = 0.35H, L1 = 0.186H, and L2 = (Reference 3: DBChaffin, GBKAndersson, BJ Martin: “Occupational Biomechanics” (Wiley, New York 1984), Reference 4: JA Roebuck, KHEKroemer, WGThomson : “Engineering Anthropometry Methods” (Wiley-Interscience, New York 1975)).

  The weight W is a value detected by the load sensor 3 in a standing posture (shown in FIG. 7) where the worker M is not working. The weight W1 of the trunk B acting on the position d is generally calculated as W1 = 0.4W. The total weight W2 of both arms and the head acting on the position b is generally calculated as W2 = 0.2 W (assuming that the weight of the head also acts on the position b). The load α2 acting on the position a is a value detected by the load sensor 30. The load α1 acting on the position c is calculated by subtracting the weight W from the total load Wa detected by the load sensor 3 after the worker M starts work (α = Wa−W). This is a value obtained by subtracting the load α2 from the load load α (α1 = α−α2). Further, the spine standing muscle force Fe acting on the position e acts on the spine Sp at an angle of 12 ° regardless of the posture of the worker M.

The moments Ma, Mb, Mc, Md and Me around the position o generated by the loads α2, W2, α1, W1, and Fe acting on the positions a, b, c, d, and e are as follows. .
Ma = (L · cos θ + L1 · cos θ1 + L2 · cos θ2) · α2
Mb = {L · cos θ + (L1 · cos θ1 + L2 · cos θ2) / 2} · W2
Mc = L · cos θ · α1
Md = L / 2 · cos θ · W1
Me = 2L / 3 · sin12 ° · Fe

The balance equation of force is as shown below.
Me = Ma + Mb + Mc + Md (Equation 10)
Ry = W1 + W2 + α1 + α2 + Fe · sin (θ−12 °) (Equation 20)
Rx = Fe · cos (θ−12 °) (Equation 30)
R = √ (Rx ² + Ry ² ) (Equation 40)

  In the balance equation of moment and force around the position o, variables L, L1, L2, θ, θ1, θ2, W1, W2, α1, and α2 are input values, detected values, or calculated values, which are known numbers. Only the variable Fe is unknown. Therefore, the vertical component Ry and the horizontal component Rx of the intervertebral disc compression force R are calculated by substituting the erected spine strength Fe calculated from (Equation 10) into (Equation 20) and (Equation 30), and the calculated Ry and Rx are ( By substituting into equation (40), the intervertebral disc compression force (burden value) R can be calculated.

(3) Setting of risk value r The risk value r in the present embodiment is the same as the risk value r in the first embodiment, and is calculated based on the gender and age in the basic information of the worker M. The allowable value Ra of the intervertebral disc compression force (shown in Table 1, Table 2, FIG. 4 and FIG. 5). Since the setting method of the risk value r in this embodiment is the same as that of the first embodiment, description thereof is omitted.

  The reason why the risk values r in the present embodiment and the first embodiment are the same is as follows. When the work situation (shown in FIG. 8) of the present embodiment in which the operator M extends the arm forward and lifts the load P1 is applied to Tables 1 and 2, the limit value Rd of the intervertebral disc compression force, which is a set value, is as shown in Tables 1 and 2. Is the same value. The load load limit value αd calculated from the limit value Rd of the intervertebral disc compression force using the force balance equations (Equation 10) to (Equation 40), and the allowable value αa, increase the moment arm around the waist. As a result, the value is smaller than those in Tables 1 and 2. However, the allowable value Ra of the intervertebral disc compression force calculated from the allowable value αa of the load load using the force balance equations (Expression 10) to (Expression 40) is the same value as in Tables 1 and 2. That is, the difference in the force balance equation between the present embodiment and the first embodiment does not affect the value of the allowable value Ra (risk value r) of the intervertebral disc compression force.

(4) Operation of Back Pain Prevention Device 10 FIG. 10 shows a flowchart for explaining the operation of the back pain prevention device 10 of the present embodiment. First, the worker M places the belt 2b equipped with the angle sensor 2 on the chest of the trunk B, the belt 21b equipped with the angle sensor 21 on the upper arm A1, and the belt 22b equipped with the angle sensor 22 on the forearm A2. The work shoes 3b equipped with the load sensor 3 and the work gloves 30b equipped with the load sensor 30 are respectively worn. The worker M is not wearing the belt 4b equipped with the control unit 40.

  After turning on the power switch of the low back pain prevention device 10, the worker M operates the input screen of the terminal 70 in step SS <b> 1 to input the age, sex, and height H of the basic information of the worker M. Do. Further, the input screen of the terminal 70 is operated to select the speaker 6 and the vibrator 60 as warning means and input the warning multiplier β for the risk value r. Then, the worker M wears the belt 4b equipped with the control unit 40 and takes a standing posture.

  In step SS2, as in step S2 in the first embodiment, the disc compression force tolerance value corresponding to the gender and age of the worker M is determined from the gender age discriminating disc tolerance value Ra stored in the CPU 50 in advance. Ra is extracted. Then, the allowable value Ra is stored in the CPU 50 as the risk value r.

  In step SS3, from the height H of the worker M, the length L of the trunk B is L = 0.35H, the length L1 of the upper arm A1 is L1 = 0.186H, and the length L2 of the forearm A2 is L2 = 0. .146H, respectively.

  In step SS4, a voice instruction (announcement) for prompting the worker M to take a standing posture is issued from the control unit 40. For example, a voice instruction is issued from the control unit 40, “Please stand upright with your spine and knees extended and your arms extended downward along your body.”

  In steps SS5 and SS6, the worker M remains in the standing posture, and the weight W of the worker M detected by the load sensor 3 is stored in the CPU 50. In addition, the angle sensor 2, the angle sensor 21, and the angle sensor 22 are initialized (the current angle is set to zero). When step SS6 is completed, a notification sound of preparation completion is transmitted from the control unit 40, and the worker M can break the standing posture. Note that if the worker M breaks the correct standing posture during the execution of steps SS5 and SS6, the individual values of the plurality of load sensors 3 mounted on the sole S become unstable. At this time, a voice instruction for prompting the control unit 40 to take a correct standing posture may be issued.

  In step SS7, the worker M starts work, and in step SS8, the angle sensor 2, the angle sensor 21, and the angle sensor 22 detect the trunk angle θ, the upper arm angle θ1, and the forearm angle θ2. Here, the trunk angle θ, the upper arm angle θ1, and the forearm angle θ2 are amounts of change from the initial values detected in step SS6. In step SS7, the load sensor 3 and the load sensor 30 detect the total load load α and the load α2 acting on the hand Ha. Further, the load α1 acting on the shoulder is calculated by the equation α1 = α−α2. Here, the total load load α is a value obtained by subtracting the weight W from the total load (load) Wa detected by the load sensor 3.

  In step SS9, as described in (2) above, weight W, trunk angle θ, upper arm angle θ1, forearm angle θ2, total load load α, load α1 acting on the shoulder, load α2 acting on hand Ha, An intervertebral disk compression force (burden value) R is calculated using the length L of the trunk B, the length L1 of the upper arm A1, and the length L2 of the forearm A2. In step SS10, the burden value R is compared with (β × risk value r), and when the burden value R ≧ (β × risk value r), the process proceeds to step SS11 and the steps of the speaker 6 and the vibrator 60 are performed. A warning is transmitted from one or both selected in SS1. When the burden value R <(β × risk value r), the process returns to step SS8. Step SS8 is repeated at a sampling interval preset in the CPU 50.

  In step SS11, after the warning is transmitted, in step SS12, the worker M selects whether or not to turn off the power switch of the low back pain prevention device 10, and by turning off the power switch, the back pain prevention is performed. The monitoring of the burden on the lower back by the device 10 is terminated. If the power switch is not turned off, the process returns to step SS8.

(5) Effect of Back Pain Prevention Device 10 According to the configuration of this embodiment, the back pain prevention device 10 includes the trunk angle θ of the trunk B of the worker M, the load Wa acting on the sole S, Based on the position of the hand Ha of the worker M and the load α2 acting on the hand Ha, the compression force generated in the intervertebral disc of the lumbar Lu is calculated as a load value R. Accordingly, since the waist burden value R is calculated in consideration of the position of the hand Ha of the worker M, the calculation accuracy of the waist burden value R is improved, and the effect of preventing the occurrence of back pain is enhanced. Further, the load value R of the waist can be calculated by distinguishing the load α2 acting on the hand Ha and the load α1 acting on the shoulder (= total load load α−load α2 acting on the hand). Compared with the assumption that the load load α acts, the calculation accuracy of the burden value R of the lower back is improved, and it is possible to appropriately prevent the occurrence of low back pain without excessively preventing the back pain.

  In addition, according to the configuration of the present embodiment, the input values of the length L of the trunk B, the length L1 of the upper arm A1, and the length L2 of the forearm A2 necessary for calculating the position of the hand Ha of the worker M. Is determined based on the correlation between the height H and each input value. Therefore, it is possible to determine each input value relating to the length of the human body necessary for calculating the position of the hand Ha of the worker M simply by using the height H of the worker M as an input value, which is convenient. Other effects in the present embodiment are the same as those in the first embodiment, and thus the description thereof is omitted.

<Other embodiments>
The back pain prevention device and the operation method thereof according to the present invention are not limited to the above-described embodiments, and various modifications and improvements that can be made by those skilled in the art without departing from the gist of the present invention. Needless to say, it can be implemented in the form.

  For example, in the first and second embodiments, one angle sensor 2 is attached to the worker M, but a plurality of angle sensors 2 may be arranged along the back of the worker M. In this case, the accuracy of the trunk angle θ is improved by averaging the angle information detected by the plurality of angle sensors 2, or based on the angle information detected by each angle sensor 2 and the interval between the angle sensors 2. Thus, the curvature state of the spine Sp can be calculated to increase the accuracy of the trunk angle θ.

  Further, in the first and second embodiments, the angle sensor 2 and the control units 4 and 40 are mounted on the trunk B of the worker M by separate belts 2b and 4b, respectively. The angle sensor 2 and the control units 4 and 40 may be mounted on the outerwear, and the angle sensor 2 and the control units 4 and 40 may be mounted by the worker M wearing this vest. As described above, when the angle sensor 2 and the control units 4 and 40 are equipped on the dedicated vest, a plurality of angle sensors 2 can be easily arranged, and the angle sensor 2 and the control units 4 and 40 are wired. It can also be connected.

  In the second embodiment, the angle sensors 21 and 22 are mounted on the separate belts 21b and 22b, respectively, and attached to the upper arm A1 and the forearm A2 of the worker M. For example, the upper arm is attached to one elbow supporter. The angle sensor 21 for the forearm A2 and the angle sensor 22 for the forearm A2 may be equipped, respectively, and the worker M may wear the elbow supporter to attach the angle sensors 21 and 22.

  In the first embodiment, the control unit 4 worn by the worker M is provided with a CPU (burden value calculation means, risk value setting means, warning means) 5, a speaker (warning means) 6, and a terminal 7. For example, the CPU 5, the speaker 6, and the terminal 7 may be provided separately. The terminal 7 may be placed in a place different from the worker M. Similarly, in the second embodiment, the CPU 50, the speaker 6, the vibrator 60, and the terminal 70 may be separated.

  In the first embodiment, a warning sound from the speaker 6 is used as a warning. In the second embodiment, one or both of a warning sound from the speaker 6 and a vibration from the vibrator 60 is used as a warning. The type of warning is not limited to this. For example, as a warning, a lamp can be turned on, displayed on an electric bulletin board, displayed on a work manager's monitoring screen, and these warnings can be used in combination as appropriate.

  Further, in the first embodiment, the intervertebral disc compression force (formula 1) to (formula 4) and in the second embodiment, the force balance formula (formula 10) to (formula 40) are used. Although the burden value R is calculated, the calculation method of the burden value R is not limited to this, and other calculation formulas may be used. For example, it is possible to use a force balance equation that takes into account the “abdominal pressure” using the Fisher and Morris equations (Reference 5: N. Badler, D. Metaxas, B. Webber and M. Steedman: “The Center for Human Modeling and Simulation ”Vol.4, No.1, 81-96 (1995)).

  In the second embodiment, the load sensor 30 detects the load α2 acting on the hand Ha assuming that the worker M extends his arm forward and lifts the load P1 with the hand Ha and the shoulder. It is configured. However, in the work situation where the worker M lifts the load P1 with the hand Ha alone without using the shoulder, the load α2 acting on the hand Ha becomes the total load load α, and therefore the load α2 acting on the hand Ha is detected. The worker M does not need to wear the work gloves 30b equipped with the load sensor 30.

  In the second embodiment, assuming that the worker M extends both arms forward and lifts the load P1, the spine Sp, the upper arm A1, and the forearm A2 are regarded as three connected rigid bodies. A simple calculation model is created to calculate the intervertebral disc compression force R. However, it is also possible to assume a work situation in which the way in which the arms of the worker M are extended differs between the left and right, or the worker M lifts the load with only one of the left and right arms. In this case, it is only necessary to create a simple calculation model divided into three connected rigid bodies connecting the spine Sp to the right arm and three connected rigid bodies connecting the spine Sp to the left arm. Then, in the moment balance equation shown in (Equation 10), the moment by the right arm and the moment by the left arm are individually considered, and the force acting on the right arm in the force balance equation shown in (Equation 20) The load acting on the left arm may be considered individually.

  In the first and second embodiments, the risk value r is set based on the gender and age of the worker M, but the method for setting the risk value r is not limited to this. For example, the risk value r reflecting the weight W of the worker M may be calculated from the sex, age, and weight W of the worker M. In this case, in the flowchart shown in FIG. 6, step S2 is performed after step S3. In the flowchart shown in FIG. 10, step SS2 is performed after step SS5. Further, the risk value r reflecting the work posture may be calculated in consideration of the trunk angle θ of the worker M. In this case, in the flowchart shown in FIG. 6, step S2 is performed after step S6. In the flowchart shown in FIG. 10, step SS2 is performed after step SS8.

  If the low back pain prevention devices 1 and 10 of the first and second embodiments are used, it is possible to leave the intervertebral disc compression force (burden value) R generated in the intervertebral disc of the lumbar Lu of the worker M as electronic data. Therefore, this electronic data can be stored as a record of the workload received by the worker M.

DESCRIPTION OF SYMBOLS 1 ... Low back pain prevention apparatus 2, 2 ', 2''... Angle sensor (trunk angle detection means)
3 ... Load sensor (plantar load detection means)
5 ... CPU (burden value calculation means, risk value setting means, warning means)
6 ... Speaker (warning means) 7 ... Terminal 10 ... Back pain prevention device 21 ... Angle sensor (upper arm angle detection means)
22 ... Angle sensor (forearm angle detection means)
30 ... Load sensor (hand load detection means)
50 ... CPU (burden value calculation means, risk value setting means, hand position calculation means, warning means)
60 ... Vibrator (warning means) 70 ... Terminal A1 ... Upper arm A2 ... Forearm B ... Trunk H ... Height Ha ... Hand L ... Trunk length L1 ... Upper arm length L2 ... Forearm length M ... Worker ( Man)
Ra: Intervertebral disc compression force tolerance (risk value)
R ... Intervertebral disc compression force (burden value) r ... Risk value S ... Plantar Sp ... Spine Th ... Thoracic spine Lu ... Lumbar spine Wa ... Full load (load) α2 ... Load acting on the hand θ ... Trunk angle θ1 ... Upper arm angle θ2 ... Forearm angle

Claims (13)

A back pain prevention device that detects and warns about the risk of back pain in real time from the state of a person,
A trunk angle detection means that is mounted on a human trunk and detects the angle of the trunk;
Plantar load detection means for detecting a load applied to the plantar of a person and acting on the plantar;
A burden value calculating means for calculating a burden on the lower back as a burden value based on each information detected by the trunk angle detecting means and the sole load detecting means;
A risk value setting means for setting a burden on the waist that may cause a disorder on the waist based on the basic information of the person as a risk value;
Warning means for issuing a warning based on a comparison between the burden value and the risk value;
A low back pain prevention device comprising: Upper arm angle detection means mounted on a person's upper arm and detecting the angle of the upper arm;
Forearm angle detection means for detecting the angle of the forearm worn on a person's forearm;
Based on human trunk length, upper arm length, and forearm length input values, and information detected by the trunk angle detection means, the upper arm angle detection means, and the forearm angle detection means Hand position calculating means for calculating the position of a person's hand
The burden value calculation means uses the burden on the lower back based on the information detected by the trunk angle detection means and the sole load detection means and the information calculated by the hand position calculation means as a burden value. The back pain prevention device according to claim 1, wherein the device is calculated. Comprising a hand load detecting means for detecting a load applied to a human hand and acting on the hand;
The burden value calculating means is provided on the waist based on each information detected by the trunk angle detecting means, the sole load detecting means, and the hand load detecting means, and information calculated by the hand position calculating means. The back pain prevention device according to claim 2, wherein the burden is calculated as a burden value.   4. The human trunk length, upper arm length, and forearm length input values are determined based on a correlation between a person's height and each input value. Back pain prevention device. The back pain prevention device according to any one of claims 1 to 4 , further comprising a terminal for inputting basic information of a person. The trunk angle detecting means and / or information detected by the sole load detecting means, to any one of claims 1 to 5, characterized in that is sent to the load value calculation means by radio The back pain prevention apparatus as described.   The back pain prevention device according to any one of claims 1 to 6, wherein the trunk angle detection means is disposed at a height of a back thoracic vertebra.   The back pain prevention device according to any one of claims 1 to 7, wherein the warning means is attached to a person and the warning is sound and / or vibration.   The back pain prevention device according to any one of claims 1 to 8, wherein the warning means transmits the warning when the burden value ≥ the risk value.   10. The load value is a compression force generated in a lumbar intervertebral disc, and the risk value is a compression force that may cause a failure in a lumbar intervertebral disc. The back pain prevention apparatus as described in any one of these.   The back pain prevention device according to claim 10, wherein the risk value is a gender age risk value set based on basic information of a person including at least gender and age. A method for operating a low back pain prevention device that detects and warns in real time the risk of low back pain from a human condition,
A hand position calculating step for calculating the position of the human hand based on the length of the human trunk, the length of the upper arm and the length of the forearm and the angle of the human trunk, the angle of the upper arm and the angle of the forearm;
A burden value calculating step for calculating a burden on the waist as a burden value based on the angle of the human trunk and the load acting on the sole and the position of the human hand;
A risk value setting step for setting a burden on the lumbar region that may cause a disorder on the lumbar region as a risk value;
A warning step for issuing a warning when the burden value ≥ the risk value;
A method for operating a low back pain prevention device, comprising: The burden value calculating step calculates the burden on the waist as a burden value based on the angle of the human trunk, the load acting on the sole, the position of the human hand, and the load acting on the hand. The operating method of the back pain prevention apparatus of Claim 12.

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