FR3001886A1 - Method for dimensioning of upper surface of orthopedic sole adapted to morphology of foot, involves defining three-dimensional form of upper surface by adaption of three-dimensional function to anatomy of foot according to positioning data - Google Patents

Abstract

The method involves collecting positioning data that is characteristic of anatomy of the foot, where the positioning data is provided with a set of positions of four points. A reference design of an upper surface (29) of a sole (27) is determined in the form of a three-dimension function. A three-dimensional form of the upper surface is defined by the adaption of the three-dimensional function to the anatomy of the foot according to the characteristic positioning data. The reference design is allowed to correspond to a desired correction. Independent claims are also included for the following: (1) a method for dimensioning of the orthopedic sole (2) a computer program product comprising instructions for performing the method for dimensioning the sole (3) a system for dimensioning of the sole.

Description

The present invention relates to a method of dimensioning an orthopedic insole adapted to the morphology of a foot. The present invention also relates to a device for implementing the method.

It is known to size an orthopedic insole adapted to the morphology of a foot. The dimensioning aims to define a shape of an upper surface of the sole so as to correct the foot support on the ground. This correction must be effective on the one hand when the foot is in static support on the ground and on the other hand when the foot is moving during walking. According to the state of the art, the upper surface of the sole comprises a plurality of corrective elements. The correcting elements are elementary forms each constituting a portion of the upper surface. The positioning and sizing of each corrective element is made according to the morphology of the foot. To do this, an impression of the foot in charge or in discharge is carried out to define anatomical sizes of the foot. When the foot is under load, it is subjected to external stresses causing deformation of the foot. When the foot is in discharge, it is not subjected to any external constraint. The anatomical magnitudes make it possible to position each corrector element on the sole and to adapt the size of each element according to the shape of the plantar surface. Thus a juxtaposition of corrective elements gives the upper surface of the sole a clean shape. The dimensioning of the orthopedic sole is satisfactory in that on the one hand the sole is adapted to the morphology of the foot and the other to the pathology to be treated. However, the juxtaposition of corrective elements may give rise to an inconsistent upper surface shape. This lack of coherence is due to the interaction between the corrective elements and results in patient discomfort and / or treatment failure. It is then necessary to modify the shape of the upper surface of the sole. In practice this modification is complex to implement so that the shape of the upper surface of the sole remains adapted to the morphology of the foot and the pathology to be treated. The present invention aims to solve all or some of the disadvantages mentioned above.

To this end, the present invention relates to a method of dimensioning an upper surface of an orthopedic insole adapted to the morphology of a foot, the method comprising the steps of: - collecting positioning data characteristic of the anatomy of the foot, the positioning data comprising at least the positions of four points; - determining a reference model of a top surface of the sole as a three-dimensional function; defining a three-dimensional shape of the upper surface by adapting said three-dimensional function to the anatomy of the foot as a function of the characteristic positioning data. It should be noted that the adaptation of the three-dimensional function is also a function of the desired or desired orthopedic correction.

The shape of the upper surface is defined by the adaptation of a three-dimensional function depending on the anatomy of the foot and the type of correction desired. Thus, the shape of the upper surface is coherent because it has a general shape defined by a reference model.

According to one aspect of the invention, the reference model corresponds to a desired type of correction. The three-dimensional shape of the upper surface modifies, on the one hand, the support of the plantar surface on the ground and, on the other hand, the articulation of the foot during walking.

The reference model of the three-dimensional shape is determined according to the type of correction desired. According to one aspect of the invention at least partially defines an outer contour of the upper surface of the sole in a transverse plane from the positioning data characteristic of the anatomy of the foot.

The outer contour of the upper surface corresponds substantially to the extent of the plantar surface. The positioning data characteristic of the anatomy of the foot make it possible to define the outer contour of the upper surface.

According to one aspect of the invention, the collection of points is performed by a selection of points on an image of the foot. The collection of positioning data is performed from a single view of the foot by recognizing the anatomy of the foot. According to one aspect of the invention, the collection of points is performed when the foot is in the discharge position. By foot in the discharge position is meant that the foot is free of external stress and the plantar surface is substantially flat. According to one aspect of the invention, a plane of the image is substantially parallel to the plantar surface. The positioning data is three-dimensional data. The image of the foot is two-dimensional. The determination of point positions requires knowing the orientation of the foot relative to the plane of the image. According to one aspect of the invention, the collection of the positioning data comprises at least one scale data. The scale data allows to deduce the actual size of the foot. According to one aspect of the invention, scale data is determined from the value of the distance separating the plane of the image from the plantar surface. According to one aspect of the invention, a scale data is a length of the foot. According to one aspect of the invention a scale data is the foot size. According to one aspect of the invention, the positioning data comprises at least the positions of two extreme points of the foot 30 belonging to an arch axis of the foot, the arch axis passing through the cuboid and the scaphoid. According to one aspect of the invention, the positioning data comprises at least the position of the apex of the heel. According to one aspect of the invention, the positioning data comprises at least the position of the apex of the longest toe.

According to one aspect of the invention, the positioning data comprise at least the positions of two extreme points of the foot belonging to a metatarsophalangeal axis. According to one aspect of the invention, the reference model of the three-dimensional function defines a first surface portion for supporting a first portion of the plantar surface, the first portion of the plantar surface extending from the plantar surface. apex of the heel to the arch axis, the first surface portion having a first depression in the opposite direction to the plantar surface.

The first depression is arranged to accommodate the heel of the foot. According to one aspect of the invention, the first surface portion is defined from at least one profile function belonging to at least one transverse plane, and preferably orthogonal to the transverse plane and substantially perpendicular to a median axis, median axis passing through the apex of the heel and the apex of the longest toe. According to one aspect of the invention, the reference model of the three-dimensional function defines a second surface portion intended to support a second portion of the plantar surface, the second portion extending between the axis of the arch and a metatarsophalangeal axis, the second surface portion having second and third depressions in the opposite direction to the plantar surface. According to one aspect of the invention, the second surface portion is defined from at least one profile function belonging to at least one transverse plane, and preferably orthogonal to the transverse plane and substantially perpendicular to a median axis. According to one aspect of the invention, the three-dimensional function is a regression function determined to pass through the cuts of the first portion and the cuts of the second portion. According to one aspect of the invention, the three-dimensional function is determined implicitly by a neural network. The present invention also relates to a method of dimensioning an orthopedic insole comprising a top surface. The method comprises the steps of: - selecting the type and size of a shoe intended to receive the sole, - defining a three-dimensional shape of the lower surface having a complementarity of shape with the bottom of the shoe, - defining a position of the lower surface with respect to the upper surface. The type of shoe depends on the width of the shoe and the presence or not of a high heel. The present invention also relates to a computer program product comprising program code portions for executing the steps of a method according to the invention. In addition, the present invention relates to a terminal comprising processing means arranged to contain and execute the computer program product according to the claim. The present invention also relates to a sizing system of an orthopedic insole comprising: locating means for positioning data characteristic of the anatomy of the foot, the positioning data comprising at least the four-point positions; terminal comprising processing means, the terminal processing means being arranged to receive positioning data from the location means, the processing means being arranged for the execution of the steps of a method according to the invention. According to one aspect of the invention, the positioning data positioning means comprise an objective. The objective is arranged to make an image of the plantar surface, the plantar surface being substantially parallel to the plane of the image. According to one aspect of the invention, a support makes it possible to keep the foot in the discharge position and the plantar surface substantially parallel to the plane of the image. According to one aspect of the invention, the terminal is arranged to receive scale data, the scale data making it possible to associate a scale of length with the image.

According to one aspect of the invention, the scale data is a size transmitted to the processing means by a user command, the user command. According to one aspect of the invention, the scale data is a graduation included on the support, the graduation being visible on the image. According to one aspect of the invention, the scale data is a distance between the plantar surface and the plane of the image, the distance being known to the processing means. In any case, the invention will be better understood with the aid of the description which follows with reference to the appended diagrammatic drawings showing, by way of non-limiting example, an embodiment of this method and a system implementing this method. process. Figure 1 is a bottom view of a foot. Figure 2 is a top view of an upper surface of the orthopedic insole. Figure 3 is a top view of an upper surface therapeutic portion of the orthopedic insole. Figure 4 to 6 are cross-sections of the upper surface of the orthopedic insole. Figure 7 is a side view of a sizing system of an orthopedic insole according to a first embodiment. Figure 8 is a side view of a sizing system of an orthopedic insole according to a second embodiment. Figure 9 is a flowchart showing the various steps of an embodiment of the method. Figure 10 is a top view of a reference model of a therapeutic portion of the upper surface of the orthopedic insole.

Figure 11 is a juxtaposition of sections of the upper surface in planes orthogonal to a reference plane and parallel to a median axis.

Figure 12 is a sectional view of the upper surface in a plane orthogonal to the reference plane. As illustrated in FIG. 1, a foot 1 in the discharge position comprises a plantar surface 3. Three main axes characterize the anatomy of the foot 1: the median axis 7 passing through the apex 9 of the heel and the apex 11 of the longest toe, - the metatarsophalangeal axis 13 passing through the first and fifth metatarsophalangeal joints, 15 - the arch axis 15 passing through the cuboid and the scaphoid. The foot 1 is also defined by characteristic points, the characteristic points being anatomical landmarks on the foot 1. The first characteristic point 17 is the end point of the foot 1 belonging to the axis of the arch 15 and opposed to the big toe 19 by relative to the median axis 7. The second characteristic point 21 is the end point of the foot 1 belonging to the axis of the arch 15 and situated on the same side as the big toe 19 with respect to the median axis 7. The third characteristic point 11 is the apex of the longest toe. The fourth feature point 9 is the apex of the heel. The fifth characteristic point 23 is the end point of the foot 1 belonging to the metatarsophalangeal axis 13 and opposite to the big toe 19 with respect to the median axis 7. The sixth characteristic point 25 is the end point of the foot 1 belonging to to the metatarsophalangeal axis 13 and located on the same side as the big toe 19 with respect to the median axis 7. During walking the foot 1 is articulated around the metatarsal axis phalangeal 13 and the axis of vault 15. As illustrated in Figure 2, an orthopedic sole 27 comprises an upper surface 29 and a lower surface 31. The lower surface 31 has a shape complementary to a bottom of a shoe. The upper surface 29 is intended to be in contact with the plantar surface 3.

In a transverse plane 32, substantially parallel to the lower surface 31 and the upper surface 29, the sole 27 has an outer contour 33. The upper surface 29 comprises a substantially flat portion 29a in front of the foot facing the toes. and metatarsal heads. The upper surface 29 further comprises a therapeutic portion 29b disposed substantially at the center and back of the foot. Therapeutic portion 29b is itself bounded by an outline 34. For therapeutic reasons, there may be corrective elements under the forefoot and toes but these elements do not relate to the present invention. As illustrated in FIG. 3, the contour 34 of the therapeutic portion 29b of the upper surface 29 is defined in the transverse plane 32 with respect to the positions of the characteristic points. A first boundary 35 of the contour 34 of the therapeutic portion 29b is a parabola defined with respect to the fourth 9th, fifth 23rd and sixth 25th points. The first boundary 35 extends from the fifth 23 to the sixth point through the fourth point 9. The rounded portion of the parabola passes through the fourth point 9. The rounded portion defines the location of the heel on the upper surface 29. The lateral portions of the parabola pass respectively through the fifth 23 and sixth 25 points. A second boundary 37 of the contour 34 of the therapeutic portion 29b extends from the fifth 23 to the sixth point. The second limit 37 has a first central advance 39 along the median axis 7 in the direction 25 opposite to the axis of the arch 15. The second limit 37 also has two lateral projections 41, 43 surrounding the central projection 39, the two lateral projections 41, 43 being directed along the median axis 7 to the fourth point 9. The first 35 and second 37 boundaries constitute the contour 34 of the therapeutic portion 29b of the upper surface 29 of the sole 27. The shape of the Therapeutic part 29 is defined with respect to the medial axes 7, metatarsophalangeal 13 and arch 15 of the foot 1. The therapeutic part 29b has a first portion 45 of surface between the apex of the heel 9 and the axis of the arch 15. The first surface portion 45 has a first depression 47 towards the lower surface 31 of the sole 27.

The therapeutic portion 29b has a second surface portion 49 between the arch axis 15 and the second boundary 37 of the contour 34. The second surface portion 49 has a second 51 and a third 53 depression in the direction of the lower surface 31 of the sole 27. The second 51 and third 53 recesses have an elongated shape along the median axis 7 and extend respectively from the second 41 and third 43 advanced towards the axis of the arch 15. As illustrated in FIGS. a first 55, a second 57 and a third 59 section of the therapeutic portion 29b highlight the depressions 47, 51, 53 of the first 45 and second 49 surface portions. The first 55, second 57 and third 59 sections are respectively included in first 61, second 63 and third 65 planes orthogonal to the transverse plane 32 and substantially orthogonal to the median axis 7. The first section 55 is a section of the first section 55. portion 45 of surface. The first depression 47 is located substantially in the middle of the first section 55, slightly to the left or right depending on the desired effect on the step. The left and right correspond to the inner and outer sides of the foot with respect to the medial axis 7, the inner side being the side of the big toe 19 and the outer side the opposite side. The second cut 57 is a section of the second portion 49 of surface. The second 51 and third 53 recesses have a similar profile and are located substantially symmetrically with respect to the middle of the second section 57. The third section 59 is a section belonging to the first 45 and the second portion. The third section 59 has an intermediate shape profile with respect to the first 55 and second 57 sections, leaving the first central depression 47 and the second 51 and third 53 recesses. After detailing the anatomy of the foot and the constitution of the orthopedic sole, we will present a sizing system of an orthopedic insole.

As illustrated in FIG. 7 and according to a first embodiment, the sizing system 67 of an orthopedic insole 27 comprises a terminal 69. The terminal 69 comprises positioning data locating means. The locating means comprise an objective 71 arranged to form an image of the foot 1 in the discharge position. The foot 1 is positioned at a distance from the objective 71, the plantar surface 3 being substantially parallel to a plane of the image 73. As illustrated in FIG. 8 and according to a second embodiment, the dimensioning system 67 comprises also a relative positioning support 75 of the foot 1 relative to the locating means. The support 75 holds the foot 1 in the discharge position, the plantar surface 3 being substantially parallel to the plane of the image 73 and at a determined distance from the locating means. The terminal 69, according to the first and second embodiments, comprises data processing means arranged to size an orthopedic insole 27 from the image made by the objective 71. The terminal 69 comprises a user interface capable of receiving commands from a user to transfer them to the processing means and display data contained in the processing means. The terminal 169 also includes external communication means arranged to transfer definition data from the orthopedic insole to an external device such as a digital bur. It should be noted that the terminal 69 may in particular be constituted by a portable communication terminal, for example by a fixed computer, laptop, tablet or ordiphone, preferably provided with a shooting device as a camera. We will now describe in detail an embodiment of the method using the system described above with reference to Figure 9. The sizing process comprises firstly a step El of collecting positioning data. The objective 71 imparts an image of the plantar surface 3 following a user command via the user interface of the terminal 69. The data processing means of the terminal 69 collect the image from the objective 71 Scale data for associating a length scale with the image is defined beforehand.

According to a first variant, the scale data is a size of the foot 1, the size being transmitted to the data processing means by the user via the user interface of the terminal. According to a second variant, the scale data is determined by the processing means from the graduation 76 of the support 75, the graduation 76 being visible on the image. The data processing means then proceed to a recording of positioning data on the image. The data processing means determines the positions of the first 17 and second 21 characteristic points by recognition of the anatomy of the foot 1 on the image. Alternatively, the position data of the points are defined or adjusted by a user by the position or the adjustment of a point on the image taken by the locating means. The data processing means deduce the location of the vault axis passing through the first 17 and second 21 feature points. The data processing means determines the positions of the third 11 and fourth 9 characteristic points by recognition of the anatomy of the foot 1 in the image. The data processing means deduce the location of the median axis 7 passing through the third 1 1 and fourth 9 characteristic points. The sizing method includes a step E2 of selecting a reference model of an orthopedic insole upper surface as a three-dimensional function. The step of selecting a reference model is independent of the step of collecting positioning data, as illustrated in FIG. 9. The step of selecting a reference model can also be carried out before the step collection of positioning data.

The reference model is included in a set of reference models. The selection of the reference model among all the reference models depends on the pathology to be treated. The selection of the reference model is carried out by the user via the user interface of the terminal. Each reference model includes at least one correction zone, belonging to the therapeutic part of the upper surface, adapted to a pathology and defining a type of correction. The corrective zone provides a static correction for distributing the supports of the foot 1 on the ground correctly when the foot 1 is stationary, and / or a dynamic correction intended to balance the movements of the foot 1 during walking. The therapeutic portion comprising the correction zone has a regular curvature to best minimize the risk of discomfort during walking. For example, a first correction zone included in the first portion (45) of surface acts on the heel by raising the heel or widening the first depression 47 by modifying the curvature of the first depression 47. A second zone corrector included in the second portion 49 of surface acts on the forefoot by stabilizing it by modifying the curvature of the second 51 and third 53 depressions. As illustrated in FIG. 10, the reference model 77 is defined by a three-dimensional function. The reference model 77 comprises a first reference axis 79 corresponding to the median axis 7 and a second reference axis 81 corresponding to the axis of the vault 15. The first 79 and the second 81 reference axis are included in a reference plane 83. Any point of the three-dimensional function is defined by a position in the reference plane 83 and a height in a first direction 85 of an axis orthogonal to the reference plane 83. A plurality of profile functions define sections 87 of the upper surface, each section 87 belonging to a plane orthogonal to the reference plane 83 and substantially perpendicular to the first reference axis 79.

The three-dimensional function is a regression function defining a surface passing through the plurality of cuts 87. The three-dimensional function is defined by a function associating a height at each point of the reference plane 83. The three-dimensional function is determined iteratively, the criterion being to ensure that the defined function passes through the cuts 7. According to one embodiment of the invention, a neural network type calculation model is used for the definition of the three-dimensional function.

According to another embodiment of the invention, Bézier curves are used for the definition of the three-dimensional function. According to another embodiment of the invention, a Newton algorithm calculation model is used for the definition of the three-dimensional function.

The three-dimensional function is determined in advance of the execution of the method. The method further comprises a step E3 of defining a three-dimensional shape of the therapeutic portion 29b by adapting the three-dimensional function of the selected reference model to the anatomy of the foot 1. The positioning data of the first 17 , second 21, third 11 and fourth 9 characteristic points as well as the scale data and the selected reference model are parameters of the three-dimensional function. The adaptation of the three-dimensional function is performed iteratively. The first 79 and second 81 reference axes are oriented in the reference plane 83 in the same way as the median axis 7 and the arch axis 15 in the transverse plane 32. A first 89, second 91 and fourth 93 point of origin are positioned identically with respect to the first 79 and second 81 reference axes in the reference plane 83 as the first 17, second 21 and fourth 9 points with respect to the median axes 7 and 15 in the plane The location of the cuts 87 is adjusted relative to the orientation of the first 79 and second 81 reference axes and the positions of the first 89, second 91 and fourth 93 points of origin.

The profile functions are modified to match the orientation of the first 79 and second 81 reference axes and the positions of the first 89, second 91 and fourth 93 origin points. The three-dimensional function is then iteratively changed to go through sections 87 defined by the modified profile functions. The method then comprises a step E4 defining the contour 34 of the therapeutic part 29b of the upper surface 29. The contour 34 of the therapeutic part 29b is defined in the reference plane 83 by a cutting function, the cutting function limiting with respect to the reference plane 83 the extent of the area defined by the three-dimensional function. A first portion 95 of the cutting function defines in the reference plane 83 the first limit 35 of the contour 34. A fifth 97 and sixth 99 origin point are positioned identically with respect to the first 79 and second 81 axes of reference in the reference plane 83 as the fifth 23 and sixth 25 points with respect to the median axes 7 and 15 in the transverse plane 32. The first portion 95 of the cutting function is determined relative to the fourth 93, fifth 97 and sixth 99 points of origin. A second cutting function portion 101 defines in the reference plane 83 the second boundary 37 of the contour 34. The first portion 95 has a parabolic shape and the second portion 101 has a wavy shape defined by a sigmoid function of type f (x The cutting function, associating the first 95 and the second 101 portion 101, is described by a Boolean function associating at any point of the reference plane 81 a zero value for the points situated outside the contour. 34 of the therapeutic part 29b defined by the cutting function and a value equal to one for the points located inside the contour 34. The method also comprises a step E5 of positioning the upper surface relative to the lower surface 29 and defining the outer contour 33.

The size and shape of the bottom of the shoe impose the shape and dimensions of the outer contour 33 of the sole 27. The processing means of the terminal 69 comprise external contour functions which are selected according to the size and type of shoe. Indeed, shoes such as pumps or loafers require a certain narrowness of the sole while sports shoes require a sole width substantially equal to that of the foot. Likewise, the shape and dimensions of the lower surface are imposed by shoe size and type. The processing means of the terminal 69 comprise lower surface definition functions which are selected according to the shoe size and type. The terminal processing means is also arranged to define a relative position of the upper surface with respect to the lower surface. Upon completion of steps E1 through E5, the orthopedic insole is fully defined by the three-dimensional function, the cutting function, and the positioning of the upper surface with respect to the lower surface. The method includes an additional step E6 of transferring definition data from the orthopedic insole to a manufacturing apparatus. According to one embodiment, the manufacturing apparatus is a digital bur. The method also comprises a step E7 for quantizing the correction. This step is performed from the data defining the orthopedic insole in space. The quantification of the correction consists in characterizing the effect of the three-dimensional shape of the upper surface of the sole on the supports of the static foot and the dynamic walking. An example of characterization is the determination of curves formed by the upper surface 29 in planes orthogonal to the reference plane 83 and substantially parallel to the median axis 7.

A first curve 103 is defined in a plane passing through the apex of the second depression 51, a second curve 105 in a plane passing through the apex of the third depression 53 and a third curve 107 passing through the plane comprising the median axis. 7. As illustrated in FIG. 11, the comparison of the curvatures of the first 103, second 105 and third 107 curves by their superposition 5 in the same plane characterize the effect on walking, in particular the pronation and supination effect of the sole. The method comprises an optional step E8 of adjusting the shape of the upper surface by the displacement or modification of the correction zones for modifying the three-dimensional function determined by the step E3. The shape of the upper surface determined by the process can be adjusted by the displacement of the depressions or by the modification of the curvature of areas of the upper surface. The adjustment consists of adding additional geometric constraints transmitted to the processing means of the terminal 69 by a user command. The terminal processing means determines a new three-dimensional function by adapting the three-dimensional function to the additional constraints.

As illustrated in FIG. 12 by a sectional view of the upper surface in a plane orthogonal to the reference plane comprising the median axis, the adjustment step is used for example following a foot pain to make more progressive curvature of the first depression 47 of the upper surface.

As is obvious, the invention is not limited to the sole embodiment of this method, described above as an example, it encompasses all the variants.

Claims (17)

REVENDICATIONS1. A method of dimensioning an upper surface (29) of an orthopedic insole (27) adapted to the morphology of a foot (1), the method comprising the steps of: collecting positioning data characteristic of the anatomy of the foot (1), the positioning data comprising at least the four-point positions; determining a reference model (77) of an upper surface (29) of the sole (27) as a three-dimensional function; defining a three-dimensional shape of the upper surface (29) by adapting said three-dimensional function to the anatomy of the foot (1) according to the characteristic positioning data. The method of claim 1, wherein the reference pattern (77) corresponds to a desired type of correction. 3. Method according to one of claims 1 or 2, wherein at least partially defines an outer contour (33) of the upper surface (29) of the sole (27) in a transverse plane from the characteristic positioning data. anatomy of the foot (1). 4. Method according to one of claims 1 to 3, wherein the collection of points is performed by a selection of points on an image of the foot (1). 5. The method of claim 4, wherein the collection of points is performed when the foot (1) is in the discharge position. 6. Method according to one of claims 1 to 5, wherein the positioning data comprise at least the positions of two end points (17, 21) of the foot belonging to a shaft axis (15) of the foot, the axis vault (15) passing through the cuboid and the scaphoid.35 7. Method according to one of claims 1 to 6, wherein the positioning data comprises at least the position of the apex of the heel (9). The method according to one of claims 1 to 7, wherein the positioning data comprises at least the position of the apex of the longest toe (11). 9. Method according to one of claims 1 to 8, wherein the positioning data comprise at least the positions of two end points (23, 25) of the foot belonging to a metatarsophalangeal axis. 10. Method according to one of claims 6 to 9, wherein the reference model (77) of the three-dimensional function defines a first portion (45) of surface intended to support a first part of the plantar surface. the first part of the plantar surface extending from the apex of the heel to the arch axis, the first surface portion (45) having a first depression (47) in the direction opposite to the plantar surface (3); ). The method of claim 10, wherein the first surface portion (45) is defined from at least one profile feature belonging to at least one transverse plane, and preferably orthogonal, to the transverse plane (32). and substantially perpendicular to a median axis (7), the median axis passing through the apex of the heel (9) and the apex of the longest toe (11). 12. Method according to one of claims 6 to 11, wherein the reference model (77) of the three-dimensional function defines a second portion (49) of surface intended to support a second portion of the plantar surface. the second portion extending between the arch axis and a metatarsophalangeal axis, the second surface portion (49) having a second (51) and a third (53) depression in the direction opposite to the plantar surface (3). ). The method according to claim 12, wherein the second surface portion (49) is defined from at least one profile function belonging to at least one transverse plane, and preferably orthogonal to the transverse plane (32) and substantially perpendicular to a median axis (7). 14. A method of dimensioning an orthopedic insole (27) comprising an upper surface (29) according to one of claims 1 to 13, the method comprising the steps of: selecting the type and size of a shoe intended for receiving the sole, - defining a three-dimensional shape of the bottom surface (31) having a form complementarity with the bottom of the shoe, defining a position of the lower surface (31) relative to the upper surface (29). A computer program product comprising portions of program code for performing the steps of a method according to any one of claims 1 to 14, when said program is executed on a computer or a terminal (69). Terminal (69) comprising processing means arranged to contain and execute the computer program product according to claim 15. 17. Sizing system (67) of an orthopedic insole (27) comprising: - positioning data locating means characteristic of the anatomy of the foot, the positioning data comprising at least the four-point positions, - a terminal (69) according to claim 16 comprising processing means, the processing means of the terminal (69) being arranged to receive positioning data from the locating means, the processing means being arranged for the execution of the steps of a process according to any one of claims 1 to 13.