Foot type data measuring method

Abstract

The foot type data measurement method comprises the following steps: placing a foot to be measured on a plane of a reference object, wherein the reference object has a color difference with the foot to be measured; obtaining a two-dimensional image, wherein the two-dimensional image comprises a complete to-be-detected foot image and a reference object image; and measuring foot type data according to the to-be-measured foot image and / or the reference object image on the two-dimensional image. According to the invention, a general mobile camera device is adopted to shoot a picture of a foot, a three-dimensional scanner is not needed, data of a collection side is relatively accurate, meanwhile, a user does not need to arrive at a site, the service cost is relatively low, the user can be better served, and the time cost of the user is relatively low.

Description

Technical Field

[0001] The invention belongs to the technical field of foot shape data collection, and in particular relates to a foot shape data measuring method. Background Art

[0002] Personalized biomechanical insoles (also called orthopedic insoles) are individually designed according to the user's individual foot biomechanical characteristics. By adjusting the force position, angle and force of the foot, the foot can return to a normal biomechanical state. This can improve poor ankle biomechanics (such as flat feet, high arches, unequal length of lower limbs, etc.), relieve ankle / plantar pain and some low back and leg pain, improve gait, and enhance walking and athletic ability.

[0003] Before customization, it is necessary to obtain the user's individual foot data. The most common method is to use a foot 3D scanner (hardware device) to collect the user's foot 3D data (such as foot length and width, foot feature point position angle, arch height, etc.). The advantage of this collection method is that the data is more accurate, but the disadvantage is that the user must go to the site, the service cost is relatively high, the coverage area radius is relatively small, and the user's time cost is also high. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for measuring foot shape data, which comprises the following steps:

[0005] S10: placing the foot to be tested on a plane of a reference object, wherein the reference object has a color difference compared to the foot to be tested;

[0006] S20: Acquire a two-dimensional image, wherein the two-dimensional image includes a complete image of the foot to be tested and an image of a reference object;

[0007] S30: measuring foot shape data according to the image of the foot to be measured and / or the image of the reference object on the two-dimensional image.

[0008] The present invention uses a general mobile camera device to take pictures of the feet, without the need for a three-dimensional scanner. The data collected by the present invention is relatively accurate. At the same time, the user does not need to go to the site, the service cost is relatively low, and the user can be better served, and the user's time cost is low.

[0009] In a further preferred embodiment, the foot shape data measurement method is a foot length data measurement method;

[0010] Before step S10, a straight line is set on the reference object along the X direction, and the length of the line is known;

[0011] In step S10, the plantar mechanical axis of the foot to be tested is placed along the marking line, and the outermost point of the heel is at the same position as the first end point of the marking line, the foot to be tested is located in a reference object, and a scale line parallel to the marking line is also provided on the reference object, and the scale line extends from the second end point of the marking line to the first end point of the marking line;

[0012] In step S20, the two-dimensional image also includes an image of the scale line;

[0013] In step S30, a perpendicular line is drawn from the front end point of the toe in the toe direction of the two-dimensional image to the marking line, the perpendicular line intersects with the scale line, and the reading from the second end point of the marking line to the scale line corresponding to the perpendicular line is obtained, and the foot length data is the difference between the length value of the marking line and the reading value of the scale line.

[0014] In a further preferred embodiment, the foot shape data measurement method is a foot width data measurement method;

[0015] Before step S10, a straight line marking line is set on the reference object along the X direction;

[0016] In step S10, the plantar mechanical axis of the foot to be tested is placed along the marking line, the foot to be tested is located within a reference object, and a scale line perpendicular to the marking line is also provided on the reference object, and the scale line is located in front of the toe;

[0017] In step S20, the two-dimensional image also includes an image of the scale line;

[0018] In step S30, a perpendicular line is drawn from the medial convex point of the first metatarsal ball in the toe direction of the two-dimensional image to the short side of the reference object and intersects with the scale line to obtain the scale value of the point. A perpendicular line is drawn from the lateral convex point of the fifth metatarsal ball to the short side of the reference object and intersects with the scale line to obtain the scale value of the point. The difference between the two scale values ​​is calculated to obtain the foot width value.

[0019] In a further preferred embodiment, in step S20: a camera is used to take a picture of the top of the foot to obtain a two-dimensional image, wherein the camera is parallel to a reference object; when taking pictures, the image of the foot to be measured and the image of the reference object are located within the display screen of the camera; and the image outside the A4 paper frame in the obtained two-dimensional image is cropped and flattened before measuring the foot shape data.

[0020] In a further preferred embodiment, the foot shape data measurement method is a foot calcaneal angle measurement method;

[0021] In step S10, the foot of the person being measured is placed on a reference object, and the foot to be measured is completely in the plane of the reference object;

[0022] In step S20, a two-dimensional image is acquired by taking a photo from directly behind the heel of the foot to be tested;

[0023] In S30: identify and obtain the medial and lateral malleolus convex points in the two-dimensional image, connect a line and obtain the midpoint of the line, and the line connecting the midpoint with the midpoint of the heel arc is the calcaneal angle line, and draw a vertical line from the continuous midpoints of the medial and lateral malleolus convex points to the horizontal plane of the reference object, and the angle between the calcaneal angle line and the vertical line is the calcaneal angle.

[0024] In a further preferred embodiment, the foot shape data measurement method is a method for measuring the instep angle of the foot under a weight-bearing state;

[0025] In step S10, the subject's foot is placed on a reference object, and the subject's plantar mechanical axis is within the reference object;

[0026] In step S20, a two-dimensional image is obtained by photographing the front side of the medial arch of the foot to be tested, and a long-side straight line is formed at the junction of the medial bottom of the foot to be tested and the reference object;

[0027] In step S30, identify and obtain the lowest point A1 of the first metatarsal head in the two-dimensional image, where A1 is located on the long side; identify and obtain B1 in the two-dimensional image, where B1 is located on the long side and corresponds to half the length of the medial arch of the foot; draw vertical lines upward from A1 and B1 on the long side respectively and intersect with the instep contour line to obtain intersection points A2 and B2, where the straight line where A2 and B2 are located and the long side is the instep inclination angle of the foot.

[0028] In a further preferred embodiment, the foot shape data measurement method is a method for measuring the instep angle of the foot in a non-weight-bearing state;

[0029] In step S10, the subject's body weight falls on the supporting foot in a sitting or standing position, the forefoot and sole of the foot are supported on a reference object, the subject's heel is raised so that the supported foot is in a dorsiflexed state, and the sole plane of the foot forms an angle of 20° to 50° with the horizontal reference object;

[0030] In step S20: using a camera device to take a photo of the medial arch of the subject's foot to obtain a two-dimensional image;

[0031] In step S30: draw a straight line from the lowest point of the calcaneus in the two-dimensional image to the lowest point of the first metatarsal head.

[0032] The lowest point C1 of the first metatarsal head in the two-dimensional image is identified and obtained. C1 is located on the straight line. D1 in the two-dimensional image is identified and obtained. D1 is located on the long side and corresponds to half the length of the medial arch of the foot. Vertical lines are drawn upward from C1 and D1 on the long side respectively and intersect with the instep contour line to obtain intersection points C2 and D2. The straight line where C2 and D2 are located and the straight line are the instep inclination angle of the foot in a non-weight-bearing state.

[0033] In a further preferred embodiment, the foot shape data measurement method includes any combination of a foot length data measurement method, a foot width data measurement method, a foot calcaneal angle measurement method, a foot instep inclination angle measurement method under a weight-bearing state, and a foot instep inclination angle measurement method under a non-weight-bearing state;

[0034] Before step S10, a rectangle with known length and width is selected as a reference object, and a marking line is set on the reference object, and the reference object is placed on a horizontal support surface, wherein the marking line is parallel to the long side of the reference object, and at least one end of the marking line is connected to the short side of the reference object, and the length of the marking line is greater than the length of the plantar mechanical axis of the foot to be measured;

[0035] In step S10, the plantar mechanical axis of the foot to be tested is placed along the marking line, and the outermost point of the heel is at the same position as the first end point of the marking line, and the foot to be tested is located within the reference object;

[0036] When obtaining a two-dimensional image of the measured foot length data, a scale parallel to the marking line is also provided on the reference object, the scale having scale lines extending from the second end point of the marking line toward the first end point of the marking line;

[0037] When obtaining a two-dimensional image of the foot width measurement data, a scale perpendicular to the marking line is also provided on the reference object, the scale has scale lines, and the scale is located in front of the toes.

[0038] In a further preferred embodiment, a two-dimensional image parallel rectangular reference object is obtained when measuring foot length data or foot width data;

[0039] When measuring the calcaneal angle of the foot, take the short side of the rectangular reference object as a parallel reference and take a photo from directly behind the heel of the target foot to obtain a two-dimensional image;

[0040] When measuring the instep inclination angle of the foot under weight-bearing state or the instep inclination angle of the foot under non-weight-bearing state, the camera device is perpendicular to the horizontal plane and parallel to the long side of the reference object, and the photo is taken from the front of the medial arch of the foot being photographed.

[0041] In a further preferred embodiment, the reference object is A4 paper, and a two-dimensional image is obtained by taking a photo with a mobile phone. When taking the photo, a built-in level gauge in the mobile phone can be enabled for guidance. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other purposes, features and advantages of the present invention will become more clear by more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts in all the accompanying drawings, and the accompanying drawings are not deliberately scaled to the actual size, and the focus is on illustrating the main purpose of the present invention.

[0043] Figure 1A two-dimensional image is obtained by taking a photo of the upper part of the foot using a mobile phone.

[0044] Figure 2 for Figure 1 The schematic diagram is formed by cutting out the image outside the A4 paper border in the acquired two-dimensional image and flattening it.

[0045] Figure 3 To pass Figure 2 Schematic diagram of foot length measurement formed by drawing a vertical line and reading the value.

[0046] Figure 4 Use a mobile phone to take a photo of the top of the foot to obtain a two-dimensional image.

[0047] Figure 5 for Figure 4 The schematic diagram is formed by cutting out the image outside the A4 paper border in the acquired two-dimensional image and flattening it.

[0048] Figure 6 To pass Figure 5 Schematic diagram of foot width measurement formed by drawing a vertical line and reading the value.

[0049] Figure 7 A two-dimensional image is obtained by taking a photo from the back of the heel of the foot to be tested using a mobile phone.

[0050] Figure 8 To pass Figure 7 Schematic diagram of the calculated calcaneal angle of the foot.

[0051] Fig. 9 This is a schematic diagram of analysis and judgment based on X-rays of the foot.

[0052] Fig.10 There are three conditions for the calcaneal angle of the foot: normal, foot valgus and foot inversion.

[0053] Fig.11 To obtain a two-dimensional image from the front of the medial arch of the foot to be tested.

[0054] Fig.12 To pass Fig.11 Schematic diagram of the calculated instep angle of the foot under weight-bearing state.

[0055] Fig.13 This is a measurement method that uses X-rays to determine the medial longitudinal arch angle.

[0056] Fig.14 Take a photo from the front of the medial arch of the foot to be tested to obtain a two-dimensional image.

[0057] Fig.15 To pass Fig.14 Schematic diagram of the calculated instep angle of the foot in a non-weight-bearing state. DETAILED DESCRIPTION

[0058] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. The terms used in the specification herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. In the description of this specification, the description of the reference terms "preferred embodiment", "another embodiment", "other embodiments" or "specific examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the different embodiments or examples described in this specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradicting each other.

[0059] Please refer to Figures 1 to 6 , steps and methods to take photos to obtain foot length and width data.

[0060] Select a rectangular reference object with known length and width, set a marking line to connect the midpoints of the short sides of the rectangular reference object, and place the rectangular reference object on a horizontal support surface;

[0061] The subject's foot is placed on the reference object, the subject's plantar mechanical axis coincides with the marking line, and the outermost point of the subject's heel is vertically aligned with the short side of the rectangular reference object. The plantar mechanical axis is the black straight line parallel to the long side of the A4 paper in the attached figure, as shown in the figure. Figure 1 or Figure 4 .

[0062] Set continuous scale lines that match the actual size on the rectangular reference object parallel to the long side and / or short side of the reference object, and use a mobile phone (or tablet) to take a photo of the foot directly above the reference object parallel to the rectangular reference object, and ensure that all four sides of the rectangular reference object are within the display screen of the mobile phone when taking the photo;

[0063] See Figure 3 , draw a perpendicular line from the front end of the toe in the direction of the toes to the long side of the reference object (the perpendicular line is Figure 3The red line parallel to the short side of the A4 paper) intersects with the scale line to get the scale value of the point, calculate the absolute value of the difference between the scale value of the front end point of the toe and the scale value of the short side of the reference object in the toe direction, and then calculate the difference between the absolute value and the total length of the long side of the reference object to get the foot length value, such as Figure 3 .

[0064] See Figure 6 , draw a perpendicular line from the medial convex point of the first metatarsal ball to the short side of the reference object and intersect it with the scale line to get the scale value of the point; draw a perpendicular line from the lateral convex point of the fifth metatarsal ball to the short side of the reference object and intersect it with the scale line to get the scale value of the point; calculate the difference between the two scale values ​​to get the foot width value.

[0065] In the field of foot and ankle biomechanics, the side close to the midline of the body is defined as the inside, and the side far from the midline of the body is defined as the outside. In actual operation, the length and width of the rectangular reference object are greater than the length and width of the foot of the subject, and an A4 paper (length 297mm, width 210mm) can be used as the reference object; the subject's plantar mechanical axis (also called the plantar meridian) is the line between the midpoint of the heel arc and the heel point of the second toe (the big toe is the first toe), and the line between the midpoint of the heel arc and the center point of the toenail area of ​​the second toe can be used as an approximation; the way to set scale lines that match the actual size on the reference object can be to place a real ruler on the A4 paper, which is simple and feasible, or to print the scale lines that match the actual size on the A4 paper at a 1:1 ratio and print them. Special settings are required before printing to avoid the impact of page margins on the scaling of the scale lines. The scale (or scale lines) should not cover the feet of the person being measured as much as possible. When setting the scale parallel to the long and / or short sides of the A4 paper, the scale can be placed at the end close to the toes for easy observation and reading of data. When taking pictures, the built-in level of the mobile phone can be used to control the parallel angle between the mobile phone and the A4 paper surface within the set deviation range, and the four sides of the A4 paper are parallel to the four sides of the mobile phone screen display screen. In order to improve the convenience of operation and improve the accuracy of data reading, the image outside the A4 paper frame in the foot photo can be cropped and flattened before marking and reading (see Figure 2 or Figure 5 ), because the phone and the A4 paper may not be absolutely parallel when taking a photo, and may be tilted at a certain small angle.

[0066] The above method of obtaining foot length and width data by taking photos with a mobile phone requires only regular A4 paper and a regular ruler in addition to the mobile phone. It does not require complex algorithms, is low in cost, and is not affected by the hardware configuration of the mobile phone. It also does not have high requirements for the shooting environment. Moreover, even if the mobile phone is slightly tilted from the horizontal plane during shooting, the measurement accuracy will not be affected because the foot, A4 paper, and ruler are all tilted and scaled synchronously.

[0067] Please refer to Figures 7 and 8, take a photo to obtain the calcaneal angle of the foot (approximate value).

[0068] Select a rectangular reference object with known length and width, set a marking line to connect the midpoints of the short sides of the rectangular reference object, and place the rectangular reference object on a horizontal support surface;

[0069] like Figure 7 , the subject's feet are placed on the reference object, and the subject's plantar mechanical axis coincides with the marking line; the subject's feet are naturally opened to the width of the shoulders, the bottom of the mobile phone is attached to the horizontal support surface, perpendicular to the horizontal plane, parallel to the short side of the reference object, and the photo is taken from the back of the heel of the target foot;

[0070] like Figure 8 , identify the medial and lateral malleolus convex points in the photo, connect the lines and obtain the midpoint of the line, and the line connecting the midpoint with the midpoint of the heel arc is the calcaneal angle line. Draw vertical lines from the consecutive midpoints of the medial and lateral malleolus convex points to the short side of the reference object. The angle between the calcaneal angle line and the vertical line of the short side of the reference object is the calcaneal angle (approximate value).

[0071] In actual operation, when shooting, the bottom of the mobile phone is attached to the horizontal support surface and is perpendicular to the horizontal plane. The short side of the reference object close to the mobile phone is parallel to the lower edge of the mobile phone screen display, and the marking line is located in the middle of the mobile phone display screen. The calcaneal angle (approximate value) is obtained in order to determine the calcaneal inversion or eversion of the subject and the specific angle value, which is an important reference data when customizing biomechanical insoles.

[0072] In foot and ankle medical assessment, the calcaneal angle is defined by the angle between the calcaneal centerline and the horizontal plane (ground) in the perspective view of the calcaneal directly behind the X-ray. However, the appearance of the foot cannot see through the bones, so the following approximate calcaneal angle is used for evaluation. Since the calcaneal angle obtained by taking a photo and the point line selected by the X-ray are actually very close, it still has positive significance.

[0073] Please refer to Figures 9 and 10 There are 26 bones in the human foot, among which the calcaneus is the largest and bears the largest body weight (proportion). When standing (barefoot), about 50% (or more) of the plantar pressure is concentrated on the heel. In most cases when walking, the heel touches the ground first. Therefore, the importance of the heel (calcaneus) is self-evident. Studying the inversion or eversion angle of the calcaneus is of great significance in foot and ankle biomechanics.

[0074] In foot and ankle biomechanics or anatomy, the method for measuring the calcaneal angle is as follows: the subject is in a standing position, and the Achilles tendon axis and the calcaneal axis are used as the two sides of the angle, and the talar tuberosity is used as the vertex of the angle, and a goniometer is used to measure the calcaneal valgus angle or varus angle. This measurement method requires analysis and judgment based on X-rays of the foot, or on-site palpation and measurement by professionals (orthopedic surgeons or foot and ankle orthotists). Therefore, in order to remotely judge the calcaneal angle by taking photos of the posterior perspective of the calcaneus, a simplified measurement method that can obtain an approximate value is needed. Figure 7 , obtain the midpoint of the line connecting the medial and lateral malleolus, and obtain the midpoint of the line connecting the medial and lateral sides of the heel, make a perpendicular line segment from the first midpoint, and the angle between the perpendicular line segment and the line connecting the two midpoints can represent the calcaneal angle of the foot. The normal value range of the calcaneal angle of the foot is 0-3°. When the calcaneal angle of the foot is not within the normal value range and turns outward, it is valgus of the foot. When the calcaneal angle of the foot is not within the normal value range and turns inward, it is inversion of the foot.

[0075] Please refer to Figure 11 to Figure 12 , take a photo to obtain the instep inclination angle of the foot under weight-bearing state.

[0076] Select a rectangular reference object with known length and width, set a marking line to connect the midpoints of the short sides of the rectangular reference object, and place the rectangular reference object on a horizontal support surface;

[0077] like Fig. 9 , the subject's foot is placed on the reference object, and the subject's plantar mechanical axis coincides with the marking line; the subject's body center of gravity falls on the photographed foot, the mobile phone is placed horizontally with the bottom attached to the horizontal support surface, perpendicular to the horizontal plane and parallel to the long side of the reference object, and the photo is taken from the front of the inner arch of the photographed foot;

[0078] like Fig.10 , two points are selected at the limited position of the instep contour line to connect a line, and the angle between the connecting line and the plantar plane in the viewing direction of the photograph is the instep inclination angle under the weight-bearing state.

[0079] In actual operation, two points of a specific proportion can be selected from the length line of the sole of the foot in the photographed view, and a perpendicular line can be drawn perpendicular to the long side of the reference object and compared to the two points of the instep contour line. The two intersection points of the instep contour line are connected, and the angle between the two points and the long side of the reference object is the instep inclination angle, which is the instep inclination angle under weight-bearing state.

[0080] In actual application, the instep inclination angle under weight-bearing state can be used to evaluate the foot shape characteristics of the subject when the foot is under weight-bearing (including standing). Specifically: the instep inclination angle within a certain range is a normal foot, the instep inclination angle less than the minimum value of the range is a flat foot, and the instep inclination angle greater than the maximum value of the range is a high arch foot.

[0081] Please refer to Fig.11In foot and ankle biomechanics or anatomy, the "medial longitudinal arch angle" is usually used to determine the foot type: normal foot, flat foot or high arch foot. The angle of the medial longitudinal arch angle in the figure is 127°. The normal value of the medial longitudinal arch angle is 113° to 130°. When the foot is flat, the medial longitudinal arch angle increases (due to the collapse of the medial arch), and the opposite is true for high arch foot. In other words, when the medial longitudinal arch angle is greater than 130°, it can be defined as flat foot, and the larger the angle, the more severe the flatness; when the medial longitudinal arch angle is less than 113°, it can be defined as high arch foot, and the smaller the angle, the more severe the high arch.

[0082] The specific method for measuring the medial longitudinal arch angle is as follows: (in the X-ray of the medial longitudinal arch of the foot in the frontal view) draw a straight line from the lowest point of the calcaneus to the lowest point of the talar head, and then draw a straight line from the lowest point of the talar head to the lowest point of the first metatarsal head, and then measure the angle formed by the two straight lines.

[0083] Using X-rays to use the medial longitudinal arch angle to determine flat feet, normal feet or high arches is a relatively accurate method, but it is relatively costly for users. However, through analysis and comparative measurement, it can be seen that in the positive view of the medial longitudinal arch, the first metatarsal axis (midline) and the first metatarsal segment of the instep can be regarded as parallel, so the inclination angle of the first metatarsal segment of the instep is closely related to the medial longitudinal arch angle, that is, the larger the medial longitudinal arch angle, the smaller the inclination angle of the first metatarsal segment of the instep, and vice versa.

[0084] The straight line AB distance between the lowest point of the calcaneus (B) and the lowest point of the talus head (A) was simplified to a fixed value, and the straight line AC between the lowest point of the talus head (A) and the lowest point of the first metatarsal head (C) was simplified to a fixed distance. Point B was defined as a fixed point, and points A and C were active points. Through measurement, it can be known that: 1. When the medial longitudinal arch angle is 127°, the angle between the AC straight line and the plantar plane is about 17°, and the angle between the first metatarsal segment of the instep and the plantar plane is about 25°, and the difference between the two is 8° (which can be regarded as a fixed value); 2. When the medial longitudinal arch angle is 130°, the angle between the AC straight line and the plantar plane is about 16°, and the angle between the first metatarsal segment of the instep and the plantar plane is about 24°; 3. When the medial longitudinal arch angle is 113°, the angle between the AC straight line and the plantar plane is about 22°, and the angle between the first metatarsal segment of the instep and the plantar plane is about 30°.

[0085] In summary, it can be deduced that the angle between the first metatarsal segment of the dorsum of the foot and the plantar plane is between 24° and 30° for a normal arch; the angle between the first metatarsal segment of the dorsum of the foot and the plantar plane is less than 24° for a flat foot, and the smaller the angle, the more severe the flatness; the angle between the first metatarsal segment of the dorsum of the foot and the plantar plane is greater than 30° for a high-arch foot, and the larger the angle, the more severe the high arch. Based on the above conclusions, the angle between the first metatarsal segment of the dorsum of the foot and the plantar plane can be calculated using the medial longitudinal arch view photograph taken at a set direction and angle, and the foot type (flat, normal or high arch) can be judged by the value of the angle. This judgment method does not require expensive X-ray equipment, is low-cost and easy to promote.

[0086] Please refer to Figure 11 to Figure 12 , take a photo to obtain the instep inclination angle of the foot in a non-weight-bearing state.

[0087] When sitting or standing, the center of gravity of the body falls on the supporting foot, the front of the foot being tapped touches the ground, the heel of the foot being tapped is lifted up so that the foot being tapped is in a dorsiflexed state, and the sole plane of the foot forms an angle of 20° to 50° with the horizontal plane (ground);

[0088] Place the phone horizontally and perpendicular to the horizontal plane, with the phone at the same height as the medial ankle bulge of the subject's foot, and take a photo directly at the medial arch of the subject's foot;

[0089] Two points are selected at the limited position of the instep contour line to connect a line, and the angle between the connecting line and the plantar plane in the viewing direction of the photograph is the instep inclination angle in the non-weight-bearing state.

[0090] The mid-plantar plane mentioned above is defined as the plane formed by the heel center of the tapped foot, the lowest point of the first metatarsal ball, and the lowest point of the fifth metatarsal ball.

[0091] In practical applications, the foot instep inclination angle in a non-weight-bearing state is combined with the foot instep inclination angle in a weight-bearing state to evaluate rigid flat feet (i.e. structural flat feet) and flexible flat feet (i.e. functional flat feet). If the foot instep inclination angle in a weight-bearing state is flat feet and the foot instep inclination angle in a non-weight-bearing state is normal, it is evaluated as flexible flat feet; if the foot instep inclination angle in both the weight-bearing and non-weight-bearing states is flat feet, it is evaluated as rigid flat feet.

[0092] The present invention uses a common mobile terminal with a camera function (such as a mobile phone or tablet computer) to take a photo or video of the foot, and obtains the user's individual foot shape data through software algorithm processing, which can greatly reduce the service cost of customized insoles and break the limitation of the service area, so that users can more conveniently obtain customized insoles (or customized shoes) services by remotely collecting foot shape data online. It can also solve the following problems:

[0093] 1. The existing technical solutions require a very complex reverse 3D reconstruction algorithm, which is difficult to develop and too costly; 2. The existing technical solutions need to first establish a foot type database for comparison, which requires a large number of foot types to be collected. On the one hand, the collection cost is high, and on the other hand, it still cannot truly reflect the actual foot type data of the specific subject; 3. The existing technical solutions have large measurement errors, and there are multiple factors that affect the measurement errors, such as hardware configuration, ambient light factors, accuracy of software algorithms, and deviations in user shooting angles; 4. The existing technical solutions only consider obtaining the external dimensions of the foot (for shoe size recommendations), but do not obtain effective foot biomechanical data that can be used for biomechanical customized insoles from the perspective of foot and ankle biomechanical correction.

[0094] Furthermore, according to the shoemaking standards of various countries, the difference in the length of the last sample between two adjacent shoe sizes (that is, the difference in adjacent sizes) is 4mm to 7mm (the length is slightly larger than the foot length), and the difference in the width of the last sample is 1.3mm to 2.0mm (the width is slightly smaller than the foot width). Because the foot length and width correspond to the shoe size, this requires that the error of the foot length and width of the collected foot shape data must be controlled within at least the deviation of one shoe size. If it is to have further practical use significance (for accurate recommendation of shoe size, making customized insoles, customized shoes, etc.), the error needs to be controlled within half a shoe size.

[0095] The existing technical solutions for collecting foot shape data often focus on the detection error of foot length and ignore the error of foot width. However, the actual situation is that under the condition of the same foot length, the difference in foot width between fatter feet and thinner feet is also quite obvious (more than one or even two width differences of shoe lasts), so accurate measurement of foot width is also very important. The present invention can evaluate foot shape data through multiple dimensions.

[0096] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for measuring foot shape data, characterized in that: The foot shape data measuring method comprises the following steps: S10: placing the foot to be tested on a plane of a reference object, wherein the reference object has a color difference compared to the foot to be tested; S20: Acquire a two-dimensional image, wherein the two-dimensional image includes a complete image of the foot to be tested and an image of a reference object; S30: measuring foot shape data according to the image of the foot to be measured and / or the image of the reference object on the two-dimensional image.

2. The foot shape data measuring method according to claim 1, characterized in that: The foot shape data measurement method is a foot length data measurement method; Before step S10, a straight line is set on the reference object along the X direction, and the length of the line is known; In step S10, the plantar mechanical axis of the foot to be tested is placed along the marking line, and the outermost point of the heel is at the same position as the first end point of the marking line, the foot to be tested is located in a reference object, and a scale line parallel to the marking line is also provided on the reference object, and the scale line extends from the second end point of the marking line to the first end point of the marking line; In step S20, the two-dimensional image also includes an image of the scale line; In step S30, a perpendicular line is drawn from the front end point of the toe in the toe direction of the two-dimensional image to the marking line, the perpendicular line intersects with the scale line, and the reading from the second end point of the marking line to the scale line corresponding to the perpendicular line is obtained, and the foot length data is the difference between the length value of the marking line and the reading value of the scale line.

3. The foot shape data measuring method according to claim 1, characterized in that: The foot shape data measurement method is a foot width data measurement method; Before step S10, a straight line marking line is set on the reference object along the X direction; In step S10, the plantar mechanical axis of the foot to be tested is placed along the marking line, the foot to be tested is located within a reference object, and a scale line perpendicular to the marking line is also provided on the reference object, and the scale line is located in front of the toe; In step S20, the two-dimensional image also includes an image of the scale line; In step S30, a perpendicular line is drawn from the medial convex point of the first metatarsal ball in the toe direction of the two-dimensional image to the short side of the reference object and intersects with the scale line to obtain the scale value of the point. A perpendicular line is drawn from the lateral convex point of the fifth metatarsal ball to the short side of the reference object and intersects with the scale line to obtain the scale value of the point. The difference between the two scale values ​​is calculated to obtain the foot width value.

4. The foot shape data measuring method according to claim 2 or 3, characterized in that: In step S20: a camera is used to take a picture of the top of the foot to obtain a two-dimensional image, wherein the camera is parallel to the reference object; when taking the picture, the image of the foot to be measured and the image of the reference object are located within the display screen of the camera; and the image outside the A4 paper frame in the obtained two-dimensional image is cropped and flattened before measuring the foot shape data.

5. The foot shape data measuring method according to claim 1, characterized in that: The foot shape data measurement method is a foot calcaneal angle measurement method; In step S10, the foot of the person being measured is placed on a reference object, and the foot to be measured is completely in the plane of the reference object; In step S20, a two-dimensional image is acquired by taking a photo from directly behind the heel of the foot to be tested; In S30: identify and obtain the medial and lateral malleolus convex points in the two-dimensional image, connect a line and obtain the midpoint of the line, and the line connecting the midpoint with the midpoint of the heel arc is the calcaneal angle line, and draw a vertical line from the continuous midpoints of the medial and lateral malleolus convex points to the horizontal plane of the reference object, and the angle between the calcaneal angle line and the vertical line is the calcaneal angle.

6. The foot shape data measuring method according to claim 1, characterized in that: The foot shape data measurement method is a method for measuring the instep angle of the foot under a weight-bearing state; In step S10, the subject's foot is placed on a reference object, and the subject's plantar mechanical axis is within the reference object; In step S20, a two-dimensional image is obtained by photographing the front side of the medial arch of the foot to be tested, and a long-side straight line is formed at the junction of the medial bottom of the foot to be tested and the reference object; In step S30, identify and obtain the lowest point A1 of the first metatarsal head in the two-dimensional image, where A1 is located on the long side; identify and obtain B1 in the two-dimensional image, where B1 is located on the long side and corresponds to half the length of the medial arch of the foot; draw vertical lines upward from A1 and B1 on the long side respectively and intersect with the instep contour line to obtain intersection points A2 and B2, where the straight line where A2 and B2 are located and the long side is the instep inclination angle of the foot.

7. The foot shape data measuring method according to claim 1, characterized in that: The foot shape data measurement method is a method for measuring the instep angle of the foot in a non-weight-bearing state; In step S10, the subject's body weight falls on the supporting foot in a sitting or standing position, the forefoot and sole of the foot are supported on a reference object, the subject's heel is raised so that the supported foot is in a dorsiflexed state, and the sole plane of the foot forms an angle of 20° to 50° with the horizontal reference object; In step S20: using a camera device to take a photo of the medial arch of the subject's foot to obtain a two-dimensional image; In step S30: draw a straight line from the lowest point of the calcaneus in the two-dimensional image to the lowest point of the first metatarsal head. The lowest point C1 of the first metatarsal head in the two-dimensional image is identified and obtained. C1 is located on the straight line. D1 in the two-dimensional image is identified and obtained. D1 is located on the long side and corresponds to half the length of the medial arch of the foot. Vertical lines are drawn upward from C1 and D1 on the long side respectively and intersect with the instep contour line to obtain intersection points C2 and D2. The straight line where C2 and D2 are located and the straight line are the instep inclination angle of the foot in a non-weight-bearing state.

8. The foot shape data measuring method according to claims 1 to 7, characterized in that: The foot shape data measurement method includes any combination of a foot length data measurement method, a foot width data measurement method, a foot calcaneal angle measurement method, a foot instep inclination angle measurement method under a weight-bearing state, and a foot instep inclination angle measurement method under a non-weight-bearing state; Before step S10, a rectangle with known length and width is selected as a reference object, and a marking line is set on the reference object, and the reference object is placed on a horizontal support surface, wherein the marking line is parallel to the long side of the reference object, and at least one end of the marking line is connected to the short side of the reference object, and the length of the marking line is greater than the length of the plantar mechanical axis of the foot to be measured; In step S10, the plantar mechanical axis of the foot to be tested is placed along the marking line, and the outermost point of the heel is at the same position as the first end point of the marking line, and the foot to be tested is located within the reference object; When obtaining a two-dimensional image of the measured foot length data, a scale parallel to the marking line is also provided on the reference object, the scale having scale lines extending from the second end point of the marking line toward the first end point of the marking line; When obtaining a two-dimensional image of the foot width measurement data, a scale perpendicular to the marking line is also provided on the reference object, the scale has scale lines, and the scale is located in front of the toes.

9. The foot shape data measuring method according to claim 8, characterized in that: A two-dimensional image parallel rectangular reference object obtained when measuring foot length data or foot width data; When measuring the calcaneal angle of the foot, take the short side of the rectangular reference object as a parallel reference and take a photo from directly behind the heel of the target foot to obtain a two-dimensional image; When measuring the instep inclination angle of the foot under weight-bearing state or the instep inclination angle of the foot under non-weight-bearing state, the camera device is perpendicular to the horizontal plane and parallel to the long side of the reference object, and the photo is taken from the front of the medial arch of the foot being photographed.

10. The foot shape data measuring method according to claim 8, characterized in that: The reference object is A4 paper, and a two-dimensional image is obtained by taking a photo with a mobile phone. When taking the photo, the built-in level of the mobile phone can be enabled for guidance.

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