Equipment for evaluating stability of ankle joint and evaluation method thereof

Abstract

The invention discloses equipment for evaluating ankle joint stability and an evaluation method thereof, and relates to the technical field of medical examination instruments. The equipment for evaluating the stability of the ankle joint comprises a mounting frame which is formed by welding a steel structure and is fixed on the edges of a sickbed, a table and a chair through a fixing structure; the driving structure is mounted on the mounting frame and used for driving the swing arm to swing back and forth around the hinge point; the two measuring structures are installed at the first metatarsophalangeal joint of the instep and the position, corresponding to the heel, of the bottom of the swing arm respectively, the shank of the patient is shaken in a reciprocating mode in an electric driving mode, swing of the first metatarsophalangeal joint of the instep of the patient is detected, and actual data are used for analysis; whether the stability of the ankle joint of the patient is abnormal or not can be accurately recognized, a mechanical driving mode is adopted, the mode is regular compared with the mode that the patient swings by himself, the abnormity can be found more objectively and standardly, the requirement for experience of doctors is relatively low, and meanwhile the cost of equipment is lower.

Description

Technical Field

[0001] The present invention relates to the technical field of medical examination instruments, and in particular to a device for evaluating ankle joint stability and an evaluation method thereof. Background Art

[0002] Ankle sprain ("sprained ankle") is one of the most common human injuries, characterized by the tearing of the ankle ligaments. If not handled properly, the ligaments will not heal well and become loose, leading to repeated sprains and joint instability. Without surgical treatment or long-term standardized rehabilitation, it is very easy to leave symptoms of ankle instability. This will cause abnormal wear and tear of the joint when it moves in a non-aligned state, and then develop into osteoarthritis. For patients who have undergone lateral ankle ligament surgery and standardized conservative treatment and rehabilitation, accurately evaluating the recovery of lateral ankle ligament function during the rehabilitation process will help guide patients' personalized rehabilitation and develop more reasonable rehabilitation plans and return to sports time points. Therefore, it is crucial to accurately assess the stability of the ankle joint.

[0003] Existing methods for assessing ankle joint stability include the doctor's manual examination of the anterior drawer test and stress position X-ray film. The former requires a high level of doctor experience and patient cooperation, has poor repeatability, and is difficult to promote and apply; the latter uses a "bracket" to apply lateral force to the ankle joint. If the patient has ankle instability, that is, ligament dysfunction, poor bone structure alignment will be seen in the X-ray film taken at this time. However, the device cannot complete the examination independently, but only serves as an auxiliary to X-rays, which is inconvenient to use, and can only indirectly reflect ligament problems through bone structure problems. It cannot effectively evaluate whether there is joint instability caused by soft tissue damage (ligaments). In addition, this examination method will cause radiation damage to patients and operators. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a device for evaluating ankle joint stability and an evaluation method thereof, which solves the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A device for evaluating ankle joint stability, comprising:

[0006] The mounting frame is welded from a steel structure and fixed to the edge of a bed, table, or chair through a fixing structure;

[0007] A swing arm, the top end of which is hinged to the mounting frame;

[0008] A driving structure, mounted on the mounting frame, for driving the swing arm to swing back and forth around a hinge point;

[0009] A positioning hoop, arranged on the top of the mounting frame, is used to roughly locate the thigh position;

[0010] A binding structure, provided on the swing arm, for binding the calf;

[0011] The measuring structure is provided with two groups, which are respectively installed at the first metatarsophalangeal joint of the dorsum of the foot and the heel position corresponding to the bottom of the swing arm. The measuring structure at the first metatarsophalangeal joint of the dorsum of the foot is used to detect the swing amplitude of the first metatarsophalangeal joint of the dorsum of the foot, and the measuring structure at the heel position is used to eliminate the detection error of the measuring structure at the first metatarsophalangeal joint of the dorsum of the foot.

[0012] Preferably, the measuring structure includes an acceleration sensor, the acceleration sensor at the first metatarsophalangeal joint of the dorsum of the foot is bound to the first metatarsophalangeal joint of the dorsum of the foot through a strap, and the acceleration sensor at the heel position is directly installed at the bottom end of the swing arm.

[0013] Preferably, the binding structure comprises an arc-shaped leg rest, and both sides of the outer surface of the arc-shaped leg rest are connected with braids, and the two braids are adhered by Velcro.

[0014] Preferably, the mounting frame comprises a U-shaped steel and a vertical frame fixed at both ends of its bottom, the U-shaped steel is arranged in a flat position on the edge of a hospital bed, a table or a chair, an oblique brace supporting a positioning hoop is connected between the U-shaped steel and one side of the vertical frame, the bottom end of the vertical frame is fixedly connected to a vertical pipe, and the internal thread of the vertical pipe is connected to a threaded pipe, and the bottom end of the threaded pipe is rotatably connected to an anti-slip foot;

[0015] The fixing structure is a plurality of sets of tightening bolts threadedly connected to the bottom of the U-shaped steel, and the top ends of the tightening bolts are rotatably connected to a pressure plate.

[0016] Preferably, the driving structure includes a mounting plate mounted on a mounting frame, a driving motor is mounted on the bottom of one end of the mounting plate, the output end of the driving motor extends to the upper part of the mounting plate and is fixedly connected to a rocker arm, the movable end of the rocker arm is rotatably connected to a connecting rod, and one end of the connecting rod is rotatably connected to a push-pull rod, one end of the push-pull rod is rotatably connected to a slider, a sliding rail slidably connected to the slider is mounted on the bottom of one side of the swing arm, and a limit seat is also mounted on the other side of the top of the mounting plate to limit the push-pull rod to only axial sliding.

[0017] Preferably, a distance measuring sensor is rotatably mounted on the side of the swing arm hinge position, and a calibration line for aligning the infrared ray of the distance measuring sensor is printed on the acceleration sensor at the position of the first metatarsophalangeal joint of the dorsum of the foot.

[0018] The present invention also discloses an evaluation method, which specifically comprises the following steps:

[0019] S1. First install the device next to a table, chair or bed, then have the patient sit down, place the thigh in the positioning hoop, tie the calf to the swing arm with the binding structure, and then bind the active acceleration sensor to the first metatarsophalangeal joint of the dorsum of the foot;

[0020] S2. In the initial state where the swing arm is naturally drooping, adjust the angle of the distance sensor so that the infrared light it emits irradiates the calibration line of the distance sensor;

[0021] S3, the distance data detected by the distance measuring sensor is transmitted to the computer, and the positions of the distance measuring sensor and the two acceleration sensors are projected onto the XZ swing plane of the swing arm. The position of the distance measuring sensor is set as the origin O, the position coordinate of the acceleration sensor on the swing arm is set as A, and the position coordinate of the acceleration sensor at the first metatarsophalangeal joint of the dorsum of the foot is set as B. The coordinate A is known, that is, the length of OA is consistent;

[0022] S4. Start the driving structure to drive the swing arm to drive the calf to swing. At this time, the two acceleration sensors transmit the detected data to the computer. According to the ratio of OA to OB, the acceleration value of the acceleration sensor at point A is proportionally amplified. The acceleration value of the acceleration sensor at point A is used as the basic value to eliminate the error value of the acceleration value of the acceleration sensor at point B. The change of the residual value of the acceleration value of the acceleration sensor at point B is established into a line graph for record, and the ankle stability is evaluated through waveform analysis.

[0023] Preferably, the acceleration value of the acceleration sensor at point A is set to a A , the acceleration value a of the acceleration sensor at point B B , suppose the acceleration value of the acceleration sensor at point B after eliminating the error is a B^ ,but:

[0024]

[0025] Preferably, the line graph records the acceleration value a at two extreme points of each cycle of reciprocating movement as time points. B^ , several acceleration values ​​a B^ Create a set (a1, a2, ..., an) and calculate n acceleration values ​​a B^ The average value a0 of the value is set, and the allowed fluctuation threshold range Δa is set. B^ The error between the value and the average value a0 is compared with the fluctuation threshold range Δa, and the analysis a B^ instability.

[0026] Preferably, the calculation formula of the average value a0 is:

[0027]

[0028] Among them, ai represents the i-th a B^ value;

[0029] The fluctuation threshold Δa is set based on the average value a0 and the percentage p, that is:

[0030] Δa=p×a0;

[0031] Calculate the error ei between each acceleration value ai and the average value a0, then:

[0032] ei=|ai-a0|;

[0033] In order to evaluate the instability of the entire data set, two indicators are defined: the ratio of points exceeding the threshold R and the ratio of the total error to the threshold S. The larger the R and S, the more unstable it is. Then:

[0034]

[0035] The present invention provides a device for evaluating ankle joint stability and an evaluation method thereof. Compared with the prior art, it has the following beneficial effects:

[0036] 1. The device for evaluating ankle joint stability uses electric drive to reciprocately shake the patient's calf and detect the swing of the first metatarsophalangeal joint of the patient's dorsum of the foot. By analyzing the actual data, it can accurately identify whether there is any abnormality in the patient's ankle joint stability. The mechanical drive is more regular than the patient's own swinging, which helps to find abnormalities more objectively and in a standardized manner. It is more convenient and faster than using X-ray examinations, and the doctor's experience requirements are relatively low. At the same time, the cost of the equipment is also lower.

[0037] 2. The device for evaluating ankle joint stability can compare the acceleration sensors installed on the first metatarsophalangeal joint of the dorsum of the foot and the swing arm. The value of the acceleration sensor on the swing arm can be used to eliminate the interference of irregular shaking of the equipment on the acceleration sensor on the first metatarsophalangeal joint of the dorsum of the foot during the detection process, thereby further improving the accuracy of the monitoring data.

[0038] 3. The device for evaluating ankle joint stability has a mounting frame as the main frame structure of the entire device, and a fixing structure is set on it, so that the device can be fixed on the edges of beds, tables and some chairs, expanding the use conditions of the device. The height-adjustable threaded tube and non-slip feet set at the bottom can provide auxiliary stable support at the bottom after being fixed at the top, thereby fixing the device more firmly and reducing shaking.

[0039] 4. This evaluation method effectively improves the accuracy and objectivity of ankle stability assessment through precise measurement and data analysis. By binding accelerometers and ranging sensors, combined with proportional amplification and error elimination technology, it can capture subtle changes in the ankle movement process in real time and accurately, which can not only reflect bone structure problems, but also effectively evaluate whether there is joint instability caused by soft tissue damage (ligaments). At the same time, through line graph recording and data analysis, such as average value calculation, fluctuation threshold setting and error comparison, quantitative indicators are provided for evaluation, making the evaluation results more scientific and reliable. This method is not only suitable for clinical diagnosis and rehabilitation evaluation, but also provides a powerful tool for research in fields such as sports science and biomechanics. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a front perspective schematic diagram of the present invention;

[0041] Figure 2 It is a rear perspective schematic diagram of the present invention;

[0042] Figure 3 It is a schematic diagram of the structure of the slider and the slide rail of the present invention;

[0043] Figure 4 It is a schematic diagram of the method steps of the present invention;

[0044] Figure 5 It is a schematic diagram of the distribution of three points O, A and B of the present invention.

[0045] In the figure: 1-mounting frame, 11-U-shaped steel, 12-vertical frame, 13-vertical pipe, 14-threaded pipe, 15-anti-slip pad, 2-fixing structure, 21-tightening bolt, 22-pressure plate, 3-swing arm, 4-positioning hoop, 5-binding structure, 51-arc leg support, 52-woven belt, 6-measuring structure, 61-acceleration sensor, 62-binding belt, 7-driving structure, 71-mounting plate, 72-driving motor, 73-swing rod, 74-connecting rod, 75-push-pull rod, 76-slider, 77-slide rail, 78-limit seat, 8-distance measuring sensor. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] See also Figure 1-Figure 3 The present invention discloses a device for evaluating ankle joint stability and provides the following three technical solutions:

[0048] The first implementation method includes:

[0049] The mounting frame 1 is welded from a steel structure and fixed to the edge of a bed, table or chair through a fixing structure 2;

[0050] The top end of the swing arm 3 is hinged to the mounting frame 1;

[0051] The driving structure 7 is mounted on the mounting frame 1 and is used to drive the swing arm 3 to swing back and forth around the hinge point; the driving structure 7 includes a mounting plate 71 mounted on the mounting frame 1, a driving motor 72 is mounted at the bottom of one end of the mounting plate 71, the output end of the driving motor 72 extends to the upper part of the mounting plate 71 and is fixedly connected to a swing rod 73, the movable end of the swing rod 73 is rotatably connected to a connecting rod 74, and one end of the connecting rod 74 is rotatably connected to a push-pull rod 75, one end of the push-pull rod 75 is rotatably connected to a slider 76, and a slider 76 is mounted at the bottom of one side of the swing arm 3. The block 76 is slidably connected to the slide rail 77, and the other side of the top of the mounting plate 71 is also equipped with a limit seat 78 that limits the push-pull rod 75 to only slide axially; the frequency of the shaking movement of the ankle joint is not less than 0.5Hz, the stroke is not less than 100mm, and the force is not less than 50N by driving the motor 72 to pull the lower part of the calf back and forth. The external force only acts on the calf, and the patient is advised to fully relax the lower limbs, and the ankle joint swings freely with the shaking of the calf. At this time, the foot shaking amplitude of those with stable ankle joints is small, and the shaking amplitude of those with unstable ankle joints is large and irregular;

[0052] A positioning hoop 4 is provided on the top of the mounting frame 1 and is used for roughly positioning the thigh position;

[0053] The binding structure 5 is arranged on the swing arm 3 and is used for binding the calf. The binding structure 5 includes an arc-shaped leg support 51, and both sides of the outer surface of the arc-shaped leg support 51 are connected with braids 52, and the two braids 52 are attached to each other by Velcro;

[0054] The measuring structure 6 is provided with two groups, which are respectively installed at the first metatarsophalangeal joint of the dorsum of the foot and the heel position corresponding to the bottom of the swing arm 3. The measuring structure 6 at the first metatarsophalangeal joint of the dorsum of the foot is used to detect the swing amplitude of the first metatarsophalangeal joint of the dorsum of the foot, and the measuring structure 6 at the heel position is used to eliminate the detection error of the measuring structure 6 at the first metatarsophalangeal joint of the dorsum of the foot; the stability of the ankle joint is mainly caused by the lateral ankle ligaments, especially the anterior talofibular ligament damage. The position of this ligament is 1 cm below the front of the bone protruding on the outside of the joint. The present invention chooses to fix it at the joint here of the big toe because the whole equipment indirectly reflects the stability of the ankle joint according to the shaking of the whole foot, and fixing the acceleration sensor at the big toe can be used as a standardized fixed point for each patient when testing, so that the test method and data analysis method can be standardized.

[0055] By using an electrically driven method to shake the patient's calf back and forth and detecting the swing of the first metatarsophalangeal joint of the patient's dorsum of the foot, and using actual data for analysis, it is possible to accurately identify whether there is an abnormality in the stability of the patient's ankle joint. Mechanically driven swinging is more regular than the patient's own swinging, which helps to detect abnormalities in a more objective and standardized manner. It is more convenient and faster than using X-ray examinations, and requires less experience from the doctor, and the cost of the equipment is also lower.

[0056] The second embodiment is mainly different from the first embodiment in that the measuring structure 6 includes an acceleration sensor 61 with a sampling frequency of 100 Hz. The acceleration sensor 61 at the first metatarsophalangeal joint of the dorsum of the foot is bound to the first metatarsophalangeal joint of the dorsum of the foot through a strap 62, and the acceleration sensor 61 at the heel position is directly installed at the bottom end of the swing arm 3.

[0057] A distance measuring sensor 8 is also rotatably mounted on the side of the hinged position of the swing arm 3, and a calibration line for aligning the infrared ray of the distance measuring sensor 8 is printed on the acceleration sensor 61 of the first metatarsophalangeal joint position of the dorsum of the foot.

[0058] By installing acceleration sensors 61 on the first metatarsophalangeal joint of the dorsum of the foot and the swing arm 3, they can be compared with each other. By using the value of the acceleration sensor 61 on the swing arm 3, the interference of irregular shaking of the equipment on the acceleration sensor 61 on the first metatarsophalangeal joint of the dorsum of the foot during the detection process can be eliminated, thereby further improving the accuracy of the monitoring data.

[0059] The third embodiment is mainly different from the first embodiment in that: the mounting frame 1 includes a U-shaped steel 11 and vertical frames 12 fixed at both ends of the bottom thereof, the U-shaped steel 11 is set on the edge of the bed, table, or chair in a flat state, and an oblique brace supporting the positioning hoop 4 is connected between the U-shaped steel 11 and one side of the vertical frame 12, a vertical pipe 13 is fixedly connected to the bottom end of the vertical frame 12, and a threaded pipe 14 is connected to the internal thread of the vertical pipe 13, and a non-slip foot 15 is rotatably connected to the bottom end of the threaded pipe 14;

[0060] The fixing structure 2 is a plurality of sets of tightening bolts 21 threadedly connected to the bottom of the U-shaped steel 11 , and a pressing plate 22 is rotatably connected to the top of the tightening bolts 21 .

[0061] The mounting frame 1 serves as the main frame structure of the entire device, and a fixing structure 2 is arranged on it, so that the device can be fixed on the edges of beds, tables and some chairs, thereby expanding the use conditions of the device. The height-adjustable threaded tube 14 and anti-slip feet 15 arranged at the bottom can provide auxiliary stable support at the bottom after being fixed at the top, thereby fixing the device more firmly and reducing shaking.

[0062] See also Figure 4-Figure 5 The present invention also discloses an evaluation method, which specifically comprises the following steps:

[0063] S1. First, install the device next to a table, chair or bed. Fix the device by clamping the U-shaped steel 11 on the edge of the table, chair or bed, and then tighten the tightening bolt 21 from the bottom to make the pressure plate 22 press the table, chair or bed. Then, turn the threaded tube 14 to lower the anti-skid foot 15 until the anti-skid foot 15 presses the ground to fix the device. Then, the patient sits down, places the thigh in the positioning hoop 4, and fastens the calf to the swing arm 3 with the binding structure 5. Then, the movable acceleration sensor 61 is bound to the first metatarsophalangeal joint of the dorsum of the foot.

[0064] S2. In the initial state where the swing arm 3 is naturally drooping, the angle of the distance measuring sensor 8 is adjusted so that the infrared light emitted by the distance measuring sensor 8 irradiates the calibration line of the distance measuring sensor 8;

[0065] S3, the distance data detected by the distance measuring sensor 8 is transmitted to the computer, and the positions of the distance measuring sensor 8 and the two acceleration sensors 61 are projected onto the XZ swing plane of the swing arm 3, the position of the distance measuring sensor 8 is set as the origin O, the position coordinate of the acceleration sensor 61 on the swing arm 3 is set as A, and the position coordinate of the acceleration sensor 61 at the first metatarsophalangeal joint of the dorsum of the foot is set as B, and the coordinate A is known, that is, the length of OA is consistent;

[0066] S4, start the driving structure to drive the swing arm 3 to drive the calf to swing, at this time, the driving motor 72 drives the swing rod 73 to rotate, and uses the connecting rod 74 to push the push-pull rod 75 and the slider 76 to reciprocate, and pushes the slide rail 77 and the swing arm 3 to swing back and forth, thereby driving the calf to swing back and forth, at this time, the two acceleration sensors 61 transmit the detected data to the computer, and the acceleration value of the acceleration sensor 61 at point A is proportionally amplified according to the ratio of OA to OB, and the acceleration value of the acceleration sensor 61 at point A is used as the basic value to eliminate the error value of the acceleration value of the acceleration sensor 61 at point B, and the change of the residual value of the acceleration value of the acceleration sensor 61 at point B is established as a line graph for record, and the ankle stability is evaluated through waveform analysis.

[0067] Assume that the acceleration value of the acceleration sensor 61 at point A is a A , the acceleration value a of the acceleration sensor 61 at point B B , assuming that the acceleration value of the acceleration sensor 61 at point B after error elimination is a B^ ,but:

[0068]

[0069] The line graph records the acceleration value a at the two extreme points of each cycle of reciprocating movement as time points. B^ , several acceleration values ​​a B^ Create a set (a1, a2, ..., an) and calculate n acceleration values ​​a B^The average value a0 of the value is set, and the allowed fluctuation threshold range Δa is set. B^ The error between the value and the average value a0 is compared with the fluctuation threshold range Δa, and the analysis a B^ instability.

[0070] The calculation formula of the average value a0 is:

[0071]

[0072] Among them, ai represents the i-th a B^ value;

[0073] The fluctuation threshold Δa is set based on the average value a0 and the percentage p, that is:

[0074] Δa=p×a0;

[0075] Calculate the error ei between each acceleration value ai and the average value a0, then:

[0076] ei=|ai-a0|;

[0077] In order to evaluate the instability of the entire data set, two indicators are defined: the ratio of points exceeding the threshold R and the ratio of the total error to the threshold S. The larger the R and S, the more unstable it is. Then:

[0078]

[0079] The above evaluation method effectively improves the accuracy and objectivity of ankle stability evaluation through precise measurement and data analysis. By binding accelerometers and ranging sensors, combined with proportional amplification and error elimination technology, it can capture subtle changes in the ankle movement process in real time and accurately, which can not only reflect bone structure problems, but also effectively evaluate whether there is joint instability caused by soft tissue damage (ligaments). At the same time, through line graph recording and data analysis, such as average value calculation, fluctuation threshold setting and error comparison, quantitative indicators are provided for evaluation, making the evaluation results more scientific and reliable. This method is not only suitable for clinical diagnosis and rehabilitation evaluation, but also provides a powerful tool for research in fields such as sports science and biomechanics.

[0080] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art, and the model parameters of each electrical appliance are not specifically limited, and conventional equipment can be used.

[0081] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0082] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for evaluating ankle joint stability and an evaluation method thereof, characterized in that: include: The mounting frame is welded from a steel structure and fixed to the edge of a bed, table, or chair through a fixing structure; A swing arm, the top end of which is hinged to the mounting frame; A driving structure, mounted on the mounting frame, for driving the swing arm to swing back and forth around a hinge point; A positioning hoop, arranged on the top of the mounting frame, is used to roughly locate the thigh position; A binding structure, provided on the swing arm, for binding the calf; The measuring structure is provided with two groups, which are respectively installed at the first metatarsophalangeal joint of the dorsum of the foot and the heel position corresponding to the bottom of the swing arm. The measuring structure at the first metatarsophalangeal joint of the dorsum of the foot is used to detect the swing amplitude of the first metatarsophalangeal joint of the dorsum of the foot, and the measuring structure at the heel position is used to eliminate the detection error of the measuring structure at the first metatarsophalangeal joint of the dorsum of the foot.

2. A device for assessing ankle joint stability according to claim 1, characterized in that: The measuring structure includes an acceleration sensor. The acceleration sensor at the first metatarsophalangeal joint of the dorsum of the foot is bound to the first metatarsophalangeal joint of the dorsum of the foot through a strap, and the acceleration sensor at the heel position is directly installed at the bottom end of the swing arm.

3. A device for assessing ankle joint stability according to claim 1, characterized in that: The binding structure comprises an arc-shaped leg rest, and both sides of the outer surface of the arc-shaped leg rest are connected with braided belts, and the two braided belts are adhered to each other by Velcro.

4. A device for assessing ankle joint stability according to claim 1, characterized in that: The mounting frame includes a U-shaped steel and a vertical frame fixed at both ends of its bottom. The U-shaped steel is placed flat on the edge of a hospital bed, a table, or a chair. An oblique brace supporting a positioning hoop is connected between the U-shaped steel and one side of the vertical frame. The bottom end of the vertical frame is fixedly connected to a vertical pipe, and the internal thread of the vertical pipe is connected to a threaded pipe. The bottom end of the threaded pipe is rotatably connected to an anti-slip foot. The fixing structure is a plurality of sets of tightening bolts threadedly connected to the bottom of the U-shaped steel, and the top ends of the tightening bolts are rotatably connected to a pressure plate.

5. A device for assessing ankle joint stability according to claim 1, characterized in that: The driving structure includes a mounting plate mounted on a mounting frame, a driving motor is mounted on the bottom of one end of the mounting plate, an output end of the driving motor extends to the upper portion of the mounting plate and is fixedly connected to a rocker arm, a movable end of the rocker arm is rotatably connected to a connecting rod, and one end of the connecting rod is rotatably connected to a push-pull rod, one end of the push-pull rod is rotatably connected to a slider, a sliding rail slidably connected to the slider is mounted on the bottom of one side of the swing arm, and a limit seat is also mounted on the other side of the top of the mounting plate to limit the push-pull rod to only axial sliding.

6. A device for assessing ankle joint stability according to claim 2, characterized in that: A distance measuring sensor is also rotatably mounted on the side of the swing arm hinge position, and a calibration line for aligning the infrared ray of the distance measuring sensor is printed on the acceleration sensor at the position of the first metatarsophalangeal joint of the dorsum of the foot.

7. An evaluation method, using the device for evaluating ankle joint stability according to claim 6 to evaluate ankle joint stability, characterized in that: The specific steps include: S1. First install the device next to a table, chair or bed, then have the patient sit down, place the thigh in the positioning hoop, tie the calf to the swing arm with the binding structure, and then bind the active acceleration sensor to the first metatarsophalangeal joint of the dorsum of the foot; S2. In the initial state where the swing arm is naturally drooping, adjust the angle of the distance sensor so that the infrared light it emits irradiates the calibration line of the distance sensor; S3, the distance data detected by the distance measuring sensor is transmitted to the computer, and the positions of the distance measuring sensor and the two acceleration sensors are projected onto the XZ swing plane of the swing arm. The position of the distance measuring sensor is set as the origin O, the position coordinate of the acceleration sensor on the swing arm is set as A, and the position coordinate of the acceleration sensor at the first metatarsophalangeal joint of the dorsum of the foot is set as B. The coordinate A is known, that is, the length of OA is consistent; S4. Start the driving structure to drive the swing arm to drive the calf to swing. At this time, the two acceleration sensors transmit the detected data to the computer. According to the ratio of OA to OB, the acceleration value of the acceleration sensor at point A is proportionally amplified. The acceleration value of the acceleration sensor at point A is used as the basic value to eliminate the error value of the acceleration value of the acceleration sensor at point B. The change of the residual value of the acceleration value of the acceleration sensor at point B is established into a line graph for record, and the ankle stability is evaluated through waveform analysis.

8. An evaluation method according to claim 7, characterized in that: Assume the acceleration value of the acceleration sensor at point A is a A , the acceleration value a of the acceleration sensor at point B B , suppose the acceleration value of the acceleration sensor at point B after eliminating the error is a B^ ,but:

9. An evaluation method according to claim 8, characterized in that: The line graph records the acceleration value a at the two extreme points of each cycle of reciprocating movement as time points. B^ , several acceleration values ​​a B^ Create a set (a1, a2, ..., an) and calculate n acceleration values ​​a B^ The average value a0 of the value is set, and the allowed fluctuation threshold range Δa is set. B^ The error between the value and the average value a0 is compared with the fluctuation threshold range Δa, and the analysis a B^ instability.

10. An evaluation method according to claim 9, characterized in that: The calculation formula of the average value a0 is: Among them, ai represents the i-th a B^ value; The fluctuation threshold Δa is set based on the average value a0 and the percentage p, that is: Δa=p×a0; Calculate the error ei between each acceleration value ai and the average value a0, then: ei=|ai-a0|; In order to evaluate the instability of the entire data set, two indicators are defined: the ratio of points exceeding the threshold R and the ratio of the total error to the threshold S. The larger the R and S, the more unstable it is. Then:

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