An apparatus for evaluating ankle joint stability and an evaluation method thereof

Abstract

The application discloses a device for evaluating ankle joint stability and an evaluation method thereof, and relates to the technical field of medical examination apparatuses. The device for evaluating ankle joint stability and the evaluation method thereof comprise: a mounting frame which is welded from a steel structure and is fixed on the edge of a sickbed, a table or a chair through a fixing structure; a driving structure which is installed on the mounting frame and is used for driving a swing arm to swing back and forth around a hinge point; and two sets of measuring structures which are installed at the first metatarsophalangeal joint of the dorsum of the foot and the heel position corresponding to the bottom of the swing arm, respectively, and are used for swinging the lower leg of a patient in a reciprocating manner through an electric driving mode, detecting the swing of the first metatarsophalangeal joint of the dorsum of the foot of the patient, and analyzing actual data, so that whether the ankle joint stability of the patient is abnormal can be accurately identified. The mechanical driving mode is more regular than the self-swinging of the patient, is helpful to more objectively and standardly find abnormalities, has a relatively low requirement on the experience of doctors, and is lower in cost.

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 sprains ("sprains") are one of the most common human injuries, characterized by a tear in the ankle ligaments. Improper treatment can lead to poor ligament healing and laxity, which can lead to recurrent sprains and joint instability. Without surgical treatment or long-term standardized rehabilitation, ankle instability symptoms are very likely to remain. This will cause abnormal wear and tear of the joint when it moves in a misaligned state, and then develop into osteoarthritis. For patients who have undergone lateral ankle ligament surgery and are recovering with standardized conservative treatment, accurately assessing the functional recovery of the lateral ankle ligament during the rehabilitation process can help guide the patient's personalized rehabilitation, develop a more reasonable rehabilitation plan, and determine the time point for returning to sports. Therefore, accurately assessing ankle stability is crucial.

[0003] Current methods for assessing ankle stability include manual examination using the anterior drawer test and stress-position X-rays. The former requires high physician experience and patient cooperation, resulting in poor reproducibility and limited widespread application. The latter, which uses a "bracket" to apply lateral force to the ankle joint, reveals malalignment of the bony structures on X-rays if the patient has ankle instability, i.e., ligament dysfunction. However, this device cannot independently perform the examination and serves only as an adjunct to X-rays, making it inconvenient to use and only indirectly reflecting ligament problems through bone structure issues. It cannot effectively assess whether soft tissue damage (ligaments) is causing joint instability. Furthermore, this examination method can expose both the patient and the operator to radiation. Summary of the Invention

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

[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 made of welded steel structure and fixed to the edge of the bed, table or chair through a fixing structure;

[0007] 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 the hinge point;

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

[0010] A binding structure is provided on the swing arm and is used to bind the calf;

[0011] There are two sets of measurement structures, which are installed respectively at the first metatarsophalangeal joint of the dorsum of the foot and the heel position corresponding to the bottom of the swing arm. The measurement 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 measurement structure at the heel position is used to eliminate the detection error of the measurement 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 includes 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 being placed flat on the edge of a bed, table or chair, an oblique brace supporting a positioning hoop being connected between the U-shaped steel and one side of the vertical frame, the bottom end of the vertical frame being fixedly connected to a vertical pipe, and the internal thread of the vertical pipe being connected to a threaded pipe, the bottom end of the threaded pipe being rotatably connected to a non-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 the pressure plates.

[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 first metatarsophalangeal joint position of the dorsum of the foot.

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

[0019] S1. Install the device next to a table, chair, or bed. Then, have the patient sit down, place their thigh in the positioning cuff, and secure their calf to the swing arm using a binding structure. Then, attach the active accelerometer to the first metatarsophalangeal joint on the dorsum of the foot.

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

[0021] S3. The distance data detected by the distance measuring sensor is transmitted to the computer. The positions of the distance measuring sensor and the two accelerometers 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 accelerometer on the swing arm is set as A, and the position coordinate of the accelerometer at the first metatarsophalangeal joint of the dorsum of the foot is set as B. Coordinate A is known, that is, the OA length is consistent.

[0022] S4. Start the drive structure to drive the swing arm to drive the calf to swing. At this time, the two acceleration sensors will 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 base 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 recording, and the ankle stability is evaluated through waveform analysis.

[0023] Preferably, 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:

[0024] a B^ =a B -a A × .

[0025] Preferably, the line graph records the acceleration value a at the two extreme points of each 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, and set the allowed fluctuation threshold range Δa, through n a 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] a0= ;

[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] ;

[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] R = ;

[0035] S = .

[0036] The present invention provides a device and method for evaluating ankle joint stability. Compared with the prior art, it has the following advantages:

[0037] 1. This device for assessing ankle joint stability uses an electrically driven method to swing the patient's calf back and forth 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 are abnormalities in the patient's ankle joint stability. The mechanically driven swinging method is more regular than the patient's own swinging, which helps to detect abnormalities more objectively and in a standardized manner. Compared with X-ray examinations, it is more convenient and quicker, requires less experience from the doctor, and the cost of the equipment is also lower.

[0038] 2. This device for assessing ankle joint stability installs acceleration sensors on both the first metatarsophalangeal joint of the dorsum of the foot and the swing arm, which can be compared with each other. The value of the acceleration sensor on the swing arm can 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, further improving the accuracy of the monitoring data.

[0039] 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, which can fix the device to the edge of a hospital bed, table, and some chairs, expanding the conditions for use of the device. The height-adjustable threaded tube and non-slip feet set at the bottom can be fixed at the top and then provide auxiliary stable support at the bottom, thereby fixing the device more firmly and reducing shaking.

[0040] 4、The evaluation method effectively improves the accuracy and objectivity of ankle stability evaluation through precise measurement and data analysis. By binding acceleration sensors and distance measuring sensors, combined with proportional amplification and error elimination technology, it can capture the subtle changes in the ankle movement process in real time and accurately. Not only can it reflect bone structure problems, but also effectively evaluate whether there is joint instability caused by soft tissue injury (ligament). At the same time, through line chart recording and data analysis, such as average value calculation, fluctuation threshold setting and error comparison, it provides quantitative indicators 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 the fields of sports science and biomechanics. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a front perspective view of the present application;

[0042] Figure 2 is a rear perspective view of the present application;

[0043] Figure 3 is a schematic view of the structure of the slider and the slide rail of the present application;

[0044] Figure 4 is a schematic view of the method steps of the present application;

[0045] Figure 5 is a schematic view of the distribution of O, A and B points of the present application.

[0046] In the figure: 1 - mounting frame, 11 - U-shaped steel, 12 - vertical frame, 13 - vertical pipe, 14 - threaded pipe, 15 - non-slip foot, 2 - fixed structure, 21 - tightening bolt, 22 - pressing plate, 3 - swing arm, 4 - positioning hoop, 5 - binding structure, 51 - arc leg support, 52 - woven belt, 6 - measurement structure, 61 - acceleration sensor, 62 - binding belt, 7 - driving structure, 71 - mounting plate, 72 - driving motor, 73 - swing lever, 74 - connecting rod, 75 - push-pull rod, 76 - slider, 77 - slide rail, 78 - limit seat, 8 - distance measuring sensor. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] Reference Figure 1-Figure 3 The present application discloses a device for evaluating ankle joint stability, and provides the following three technical solutions:

[0049] The first implementation method includes:

[0050] The mounting frame 1 is made of welded steel structure and is fixed to the edge of the bed, table or chair through the fixing structure 2;

[0051] The top end of the swing arm 3 is hinged to the mounting frame 1;

[0052] 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, and one end of the push-pull rod 75 is rotatably connected to a slider 76. A bottom portion of one side of the swing arm 3 is mounted with a The slider 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 axial sliding. The driving motor 72 reciprocates and pulls the lower part of the calf to trigger the ankle joint to oscillate at a frequency of not less than 0.5Hz, a stroke of not less than 100mm, and a force of not less than 50N. The external force acts only on the calf. The patient is advised to fully relax the lower limbs, and the ankle joint will swing freely with the swaying of the calf. At this time, the foot swaying amplitude of those with stable ankle joints is small, while the amplitude of swaying amplitude of those with unstable ankle joints is large and irregular.

[0053] A positioning hoop 4 is provided on the top of the mounting frame 1 and is used to roughly locate the thigh position;

[0054] The binding structure 5 is provided on the swing arm 3 and is used to bind 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 to a braid 52, and the two braids 52 are attached to each other by Velcro;

[0055] There are two groups of measuring structures 6, 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 due to the damage of the lateral ankle ligament, especially the anterior talofibular ligament. The position of this ligament is 1 cm below and in 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 entire equipment indirectly reflects the stability of the ankle joint based on the shaking of the entire foot, and fixing the acceleration sensor at the big toe can be used as a standardized fixed point for testing each patient, so that the testing method and data analysis method can be standardized.

[0056] By using an electrically driven method to swing 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 analyzing the actual data, it is possible to accurately identify whether there is any abnormality in the stability of the patient's ankle joint. The mechanically driven swinging is more regular than the patient's own swinging, which helps to detect abnormalities more objectively and in a standardized manner. Compared with the use of X-ray examinations, it is more convenient and faster, requires less experience from the doctor, and the cost of the equipment is also lower.

[0057] 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.

[0058] A distance 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 sensor 8 is printed on the first metatarsophalangeal joint position acceleration sensor 61 of the dorsum of the foot.

[0059] By installing acceleration sensors 61 on both 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.

[0060] The third embodiment differs from the first embodiment mainly in that: the mounting frame 1 includes a U-shaped steel 11 and vertical frames 12 fixed at both ends of its bottom. The U-shaped steel 11 is placed flat on the edge of a bed, table, or chair. A diagonal brace supporting the positioning hoop 4 is connected between the U-shaped steel 11 and one side of the vertical frame 12. The bottom end of the vertical frame 12 is fixedly connected to a vertical pipe 13, and the internal thread of the vertical pipe 13 is connected to a threaded pipe 14. The bottom end of the threaded pipe 14 is rotatably connected to an anti-slip foot 15.

[0061] 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 the top ends of the tightening bolts 21 are rotatably connected to the pressing plates 22 .

[0062] The mounting frame 1 serves as the main frame structure of the entire device, and a fixing structure 2 is set on it, which can fix the device to the edge of a hospital bed, a table, and some chairs, expanding the use conditions of the device. The height-adjustable threaded tube 14 and the anti-slip feet 15 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.

[0063] See Figure 4-Figure 5 The present invention also discloses an evaluation method, which specifically includes the following steps:

[0064] S1. First, install the device next to a table, chair, or bed. Clamp the U-shaped steel 11 to the edge of the table, chair, or bed. Then, tighten the tightening bolt 21 from the bottom to press the pressure plate 22 against the table, chair, or bed. Then, turn the threaded tube 14 to lower the anti-slip foot 15 until the anti-slip foot 15 presses against the ground to secure the device. The patient then sits down, places their thigh in the positioning hoop 4, and secures their calf against the swing arm 3 using the binding structure 5. Finally, the movable acceleration sensor 61 is bound to the first metatarsophalangeal joint of the dorsum of the foot.

[0065] S2. In the initial state where the swing arm 3 is naturally drooping, adjust the angle of the distance sensor 8 so that the infrared light it emits hits the calibration line of the distance sensor 8;

[0066] S3. The distance data detected by the distance measuring sensor 8 is transmitted to the computer. 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 coordinates of the acceleration sensor 61 on the swing arm 3 are set as A, and the position coordinates of the acceleration sensor 61 at the first metatarsophalangeal joint of the dorsum of the foot are set as B. The coordinate A is known, that is, the length of OA is consistent;

[0067] 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 move back and forth, and push 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. 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.

[0068] 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 , assume that the acceleration value of the acceleration sensor 61 at point B after error elimination is a B^ ,but:

[0069] a B^ =a B -a A × .

[0070] 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 ​​aB^ Create a set (a1, a2, ..., an) and calculate n acceleration values ​​a B^ The average value a0, and set the allowed fluctuation threshold range Δa, through n a 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.

[0071] The calculation formula for the average value a0 is:

[0072] a0= ;

[0073] Among them, ai represents the i-th a B^ value;

[0074] The fluctuation threshold Δa is set based on the average value a0 and the percentage p, that is:

[0075] Δa=p×a0;

[0076] Calculate the error ei between each acceleration value ai and the average value a0, then:

[0077] ;

[0078] 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:

[0079] R = ;

[0080] S = .

[0081] The above-mentioned assessment 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 accurately capture subtle changes in ankle movement in real time. This not only reflects bone structure problems, but also effectively evaluates 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 assessment, but also provides a powerful tool for research in fields such as sports science and biomechanics.

[0082] At the same time, the contents not described in detail in this specification belong to the existing technology 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.

[0083] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.

[0084] While the embodiments of the application have been shown and described herein, it is to be understood that the scope of the application, jointly pointed out in the appended claims, is not to be limited to the above-described embodiments but can be otherwise variously changed, modified, replaced, and altered within the principles and spirit of the present application.

Claims

1. A device for assessing ankle joint stability, characterized in that include: The mounting frame is made of welded steel structure and fixed to the edge of the bed, table or chair through a fixing structure; 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 the hinge point; A positioning hoop is provided on the top of the mounting frame and is used to roughly locate the thigh position; A binding structure is provided on the swing arm and is used to bind the calf; There are two sets of measurement structures, which are installed respectively at the first metatarsophalangeal joint of the dorsum of the foot and the heel position corresponding to the bottom of the swing arm. The measurement 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 measurement structure at the heel position is used to eliminate the detection error of the measurement structure at the first metatarsophalangeal joint of the dorsum of the foot.

2. The 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. The device for assessing ankle joint stability according to claim 1, wherein: The binding structure includes an arc-shaped leg support, and both sides of the outer surface of the arc-shaped leg support are connected with braids, and the two braids are adhered by Velcro.

4. The device for assessing ankle joint stability according to claim 1, wherein: 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 bed, table, or chair. A diagonal 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 a non-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 the pressure plates.

5. The device for assessing ankle joint stability according to claim 1, wherein: 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. The device for assessing ankle joint stability according to claim 2, wherein: 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 first metatarsophalangeal joint position of the dorsum of the foot.

7. An assessment method for assessing ankle joint stability using the device for assessing ankle joint stability according to claim 6, characterized in that: The specific steps include: S1. Install the device next to a table, chair, or bed. Then, have the patient sit down, place their thigh in the positioning cuff, and secure their calf to the swing arm using a binding structure. Then, attach the active accelerometer to the first metatarsophalangeal joint on the dorsum of the foot. S2. In the initial state of the swing arm drooping naturally, adjust the angle of the distance sensor so that the infrared light it emits hits the calibration line of the distance sensor; S3. The distance data detected by the distance measuring sensor is transmitted to the computer. The positions of the distance measuring sensor and the two accelerometers 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 accelerometer on the swing arm is set as A, and the position coordinate of the accelerometer at the first metatarsophalangeal joint of the dorsum of the foot is set as B. Coordinate A is known, that is, the OA length is consistent. S4. Start the drive structure to drive the swing arm to drive the calf to swing. At this time, the two acceleration sensors will 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 base 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 recording, and the ankle stability is evaluated through waveform analysis.

8. An evaluation method according to claim 7, characterized in that: Assume that the acceleration value of the accelerometer 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: a B^ =a B -a A × 。 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, and set the allowed fluctuation threshold range Δa, through n a 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 for the average value a0 is: a0= ； 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: ； 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: R = ； S = 。

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