FR3043052A1 - METHOD FOR ADJUSTING THE POSITION OF A CYCLIST ON A ROAD VELO, IN PARTICULAR LOWER MEMBERS, COMPENSATION DEVICES - Google Patents

Abstract

The object of the invention is a method of adjusting the position of a cyclist C on a road bike of a test bench, equipped with shoes and automatic pedals, including a shim carried by the sole of each shoe and secured by screws and pedals provided with means for cooperating with said wedges to bind the foot to the pedals by snapping, characterized in that it consists of the following sequence of steps: - measure the length of the tibia / fibula right and left, - compensate for any differential by means of a thick plate. - measure the angle of inclination varus or valgus of the knee, - compensate for the possible differential by means of a tilt plate, - determine the position of the ankle presenting a possible inversion or eversion, - compensate by a rotation of the wedge and its possible pads in the plane of the sole in case of inversion or eversion. The invention also covers an associated device for adjusting the angular position of the foot.

Description

METHOD FOR ADJUSTING THE POSITION OF A CYCLIST ON A ROAD VELO, IN PARTICULAR LOWER MEMBERS, COMPENSATION DEVICES

The present invention relates to a method of adjusting the position of a cyclist on a road bike. The invention also covers compensation devices for carrying out the method according to the present invention. The invention essentially relates to the position of a cyclist on a road bike to overcome the problems that can occur generally during a practice or in a professional setting.

Indeed, we know that many sports cause, during an intensive practice, problems due to the repetition of movements, especially when they are performed in bad conditions.

Cycling is a little traumatic sport in general but a bad positioning quickly causes muscle or tendon discomfort.

The practitioner is faced with a size choice of bike frame and these components. Some parameters are fixed, in particular the geometry of the frame, others are adjustable, in particular the height of the saddle and the height of the hanger.

The traditional method of determining these settings is based on the distance between the crotch and the ground to estimate the seat height and the frame. Bike components such as hanger width, stem length, saddle type and width are supplied as standard by the manufacturer or sometimes changed to suit the sensations and feelings of the practitioner. There is a less random approach: it uses coefficients to establish ribs as a function of the articular distances of the individual measured with one meter. Nevertheless, this method knows limitations:

The accuracy of the measurements,

The dissymmetries of the body, the statistical approach adapted to a "standard" template

Not taking into account the support on the pedals.

Two scenarios are presented:

Either the cyclist has his own bike and wants a setting to adopt the best possible posture,

Either the cyclist wants to change his equipment or part of his equipment and a preliminary analysis makes it easier to choose the bike or even a custom made. The method according to the present invention comprises an accurate analysis of the features of the lower limbs of said cyclist.

However, the human being is asymmetrical for the majority of individuals and imperfect in all cases.

The cyclist may have one leg shorter than the other, the joints work in one plane and not in another, at least one foot is inclined in different planes etc.

However, the bike is perfectly symmetrical and can not compensate for the asymmetry of the body.

In fact, it is the body of the cyclist that compensates for the symmetry of the bicycle, which is particularly harmful to the skeleton and, instead of being able to practice cycling in the best conditions, many cyclists have musculoskeletal disorders. skeletal.

Cycling, which is a very little traumatic sport, can become so because of bad settings or the lack of consideration of certain parameters.

When driving, the cyclist has a position with his feet on pedals.

Link mechanisms between the feet and the pedals are provided. They are in the form of a wedge secured to each shoe and means for hooking / unhooking each of the wedges integral with the shoe. These pedals are called "automatic pedals".

Each shim shoe snap on the hooking / unhooking means by a specific movement of introduction of the tip by tilting the shoe and a downward pressing to ensure locking.

Voluntary unlocking is generally achieved by angular rotation of the shoe in the horizontal plane. Unlocking can also be done by a strong vertical pull up, which occurs during falls in particular, in order to free the cyclist from the bike.

More specifically, it is expected in all cases, a few degrees of freedom between the shoe and the pedal to ensure a good pedaling movement, the foot itself having the possibility of mobility in the shoe but very limited. The goal is to maintain the foot without constraining it to leave an easy blood circulation.

The shoe for road cycling is specific and has a rigid sole so as to transmit all the effort without soliciting the muscles and tendons of the foot by a folding of the sole.

This sole also receives the wedge by screwing. For this purpose, holes are formed in each shim, screws pass through these holes and screw into inserts embedded in the sole.

These screws ensure the clamping of the hold and its immobilization on the sole that receives it. The holes are generally oblong, so as to allow, to a certain extent, an adjustment of the angular position in the plane of the sole and the front / rear position of the shim relative to this sole.

The upper part of the cyclist, that is to say the bust, more precisely the length of the bust, the length of the arms, is also taken into account but is not directly studied in the present method.

The part that is the subject of the present process concerns the lower part going from the hip to the feet, that is to say from the saddle to the pedals.

It is necessary to remember that the vertical force exerted by the right leg increases in the first quarter 12h-15h by positioning laterally on the right, facing the pedal. The maximum effort is exercised at 15h. It is the same for the left leg.

During the sector 15h-18h, the cyclist dispenses the balance of 100% of the thrust exerted.

It should be noted that in this case, in order to simplify the analysis, the traction exercised by the left leg during the support on the right foot is ignored. Indeed, the left foot is integral with the left pedal and can therefore exert a tensile force. The main part of the effort made by the left foot during the support exercised by the right foot is a pull to relieve the weight of the left leg. The weight of a leg is about ten kilograms so that, if the left leg does not support this weight, part of the effort exerted by the right leg is consumed to compensate for this unnecessary weight. The offset of 180 ° pedals allows to have the bulk of the force exerted on 180 ° and the balance on the remaining 180 °. There are two top and bottom dead points, simultaneous, during which the effort is zero but this range is very narrow and compensated by inertia.

All these considerations are established in the case of a force exerted by the leg and more particularly by the vertical tibial sector and perpendicular to the plane of the pedal.

However, there are many natural defects of the body that lead to improperly exerted efforts.

The present method proposes to correct these defects so that the cyclist has a posture of the lower limbs perfectly adapted. The invention proposes an ideal adaptation for each particular case by relying on different types of measurements:

The length and the angle of the body segments of the individual standing in particular by a scanner,

The foot support characteristics by a pressure reading, The angle of the body in motion by a video analysis.

The method is now described in detail according to a particular embodiment, not limiting, this with reference to the accompanying drawings, said drawings comprising figures which respectively represent:

Figure 1: a perspective view of a cyclist on a bench comprising a bicycle, Figures 2A and 2B: views of the difference in length of the tibia / fibula assembly and the length of the compensated tibia / fibula assembly,

FIGS. 3A and 3B: views of the vertical inclination differential in front view of the tibia / fibula assembly with respect to the vertical and the compensated differential,

Figure 4: view of the foot with the support of the foot,

Figure 5: view of a shoe and the angular transfer device according to the invention.

Beforehand, a scan of the individual is performed to approach the best adaptation of the bike 10 of a test bench 12 for a first test. A foot press pressure survey is performed to determine the engagement of the hold.

From this first analysis, the operator can deduce the first parameters so that the cyclist can exert vertical pressure on the pedals by the diaphyseal portion of the tibia during the support phase 12h-15h.

The cyclist wears his shoes 14 provided with their shims 16, shims corresponding to pedals 18 of the chosen brand, because there are several technical solutions for hooking / unhooking, nevertheless these solutions provide the same functions.

The cyclist Ç is positioned on the bicycle 10 of the test bench 12.

The method according to the invention also uses a visualization from images recorded by front and side cameras 22, so as to allow visualization of the kinematics during running.

In addition, pressure sensors 24 may be placed on the saddle 26 to complete the visual and measured findings. For this purpose, the images are processed by software so as to superimpose the images captured by the cameras with a calibrated frame that allows the different measurements.

Similarly, the pressure measurements on the saddle make it possible to determine whether the supports are symmetrical or not.

The essential parameters concerning the morphological measurements relevant to the present method consist, in a first step, of measuring the length of the articular segments, directly on the cyclist or from a scanner and more particularly the length of the tibia / fibula couple. This is symbolized in Figures 2A and 2B.

A difference (Hh) in length of the tibia / left fibula H and right h pairs leads to a differentiated pressure on the saddle and thus on the sciatic tuberosities of the iliac bone which, together with the upper part of the ischium, correspond to the support for the body in a normal sitting position on the saddle.

As a result, there is too much extension of the shortest side during the pushing phase. This generates a tension in the popliteal fossa, behind the knee and especially an unbalanced position on the saddle. This leads to unsatisfactory movements in the bust to compensate for this joint stress.

In addition, incidentally but not negligible, pedaling efficiency is decreased. Video recording quickly shows these compensation movements and confirms this difference in length.

In the case of a dissymmetry observed, the solution according to the present invention consists in arranging a wafer 28 of thickness between the shim and the sole, the height of the wafer corresponding to the length differential.

It is possible to make the modification from the inside of the shoe, with a sole, as proposed by certain practices of the prior art. Nevertheless a plate 28 of thickness between the wedge and the sole is much easier to put in place. This plate 28 is provided with the same holes as the wedge so as to follow the orientations in the horizontal plane and front / rear.

This plate is advantageously of the same external profile as the wedge so as to be superimposed perfectly and to avoid inducing difficulties for the phases of snapping / unclipping of the shoe on the pedal.

Even more advantageously, the wafer is produced by 3D printing.

The correct position of the cyclist is confirmed if necessary by a video visualization with a possible association of measurements of the body of the cyclist.

The method provides the measurement of a second parameter which is the orientation of the knees. The tendency of orientation of the knees is such that they are slightly reentrant in normal position.

On the other hand, the knees can be of the valgus type, that is to say, returning in an exaggerated way or varus, that is to say going out also in an exaggerated way.

In order to compensate for this angulation which leads to having the tibia axis / fibula offset from the vertical view from the front, the method proposes a measurement from the video images and the frame, as shown in FIG. 3A. This measurement consists in determining, cyclise seen from the front, the angle β that the tibia / fibula pair makes with the vertical.

Once the angle is measured, a tilt plate 30 is disposed between the shim and the sole. Preferably, the inclination wafer is placed between the wafer 28 of thickness and the shim, when there is a wafer of thickness present.

Preferably, the inclination plate is made by 3D printer.

Preferably also the inclination plate 30 to a profile corresponding exactly to that of the wedge, so as to avoid any disturbance of the latching / disengaging phases.

The angular wafer, like the plate 28 of thickness, comprises oblong holes identical to those of the shim.

Figure 3B shows a varus knee compensated so as to have the force exerted vertically. This avoids scattering some of the forces exerted through inefficient components. The method also provides for taking into account another parameter: the combined movement of the foot in the thrust phase: eversion or inversion. The detection of this profile is based on the observation of the contact of the heel on the ground:

If the support is lateral, the movement is an eversion. The support of the forefoot is shifted towards the axis of the big toe. In this case, the wedge is oriented at an angle ε of 4 ° with respect to the center of the heel,

If the support is medial, the movement is an inversion. The support of the forefoot is shifted towards the axis of the little toe. In this case the shim is oriented at an angle Θ of 2 ° with respect to the center of the heel.

The angular compensation ε for the eversion is greater than the angular compensation Θ for the inversion.

This compensation must be carried out by means of a setting in orientation of the wedge and any plates, in the plane of the sole.

The geometric elements are shown in FIG.

On the other hand, the difficulty is to postpone this determined angular offset on the hold. For this purpose, the present invention proposes a device comprising a template 32 comprising a plate 34 of generally rectangular shape with a nose 36 forward, as shown in Figure 5. This plate 34 is advantageously made of a transparent material and allows the adjustment angular and tightening of the wedge at the same time as one performs the visualization of said angular adjustment, the shoe being returned.

The nose 36 is integral with the front edge 38 of the plate 34 and comprises a profile cut conjugate with that of the wedge to position the edge 38 of the wedge perpendicular to the longitudinal axis of the foot and centrally.

The nose 36 is specific to each type of wedge.

The template has two lines Tl, T2 which correspond to the angles ε and Θ. Alignment is achieved with the longitudinal axis of the foot which passes through the midpoint of the heel, T, generally located on the heel of said shoe.

As needed, the operator positions the nose against the wedge, loosens the screws holding the wedge with the plate and changes the orientation of said wedge by movement of the plate and tightens the said screws.

When the shim is in place to compensate for eversion or inversion, the operator tightens the screws.

The cyclist can then put the shoes back on and ride on the bike bench for a final check.

According to the method of the present invention, platelets 28 of thickness and inclination consist of a single monolithic wedge made by 3D printing.

The method therefore consists of the following steps: measuring the length of the right and left tibia / fibula, compensating for the differential, using a thickness plate, measuring the angle of inclination varus or valgus of the knee, to compensate for the possible differential by means of an inclination plate, to determine the angular position of the foot: inversion or eversion, to compensate by a rotation of the wedge and its possible plates in the plane of the sole.

It is also possible to predict the measurement of the pressure exerted on the forefoot.

Claims (10)

1. A method of adjusting the position of a cyclist Ç on a road bike (10) of a test bench (12), provided with shoes and automatic pedals, including a shim carried by the sole of each shoe and secured by screws and pedals provided with means for cooperating with said wedges to bind the foot to the pedals by snapping, characterized in that it consists of the following steps: measuring the length of the tibia / right fibula and on the left, compensate for the differential by means of a thickness plate, measure the varus or valgus angle of inclination of the knee, compensate the differential, if possible by means of a tilt plate, determine the position of the ankle presenting a possible inversion or eversion, compensate by a rotation of the wedge and its possible pads in the plane of the sole in case of inversion or eversion. 2. A method of adjusting the position of a cyclist on a road bike according to claim 1, characterized in that the measurement of the difference in differential length of the right tibia / right fibula is performed by a direct morphological measurement. on the cyclist. 3. A method of adjusting the position of a cyclist on a road bike, according to claim 1, characterized in that the measurement of the difference in differential length possible tibia / fibula right and left is achieved by a morphological measurement on the cyclist using a scanner. 4. A method of adjusting the position of a cyclist on a road bike according to claim 1, 2 or 3, characterized in that the measurement of the angle of inclination varus or valgus of the knee is measured from video images superimposed on a frame. 5. A method of adjusting the position of a cyclist on a road bike, according to any one of the preceding claims, characterized in that the thickness and / or inclination plates are made by 3D printing. 6. A method of adjusting the position of a cyclist on a road bike, according to claim 5, characterized in that, in the case of a plate thickness and inclination, the two plates are made in printing 3D, in a single piece, monolithic. 7. Device for adjusting the angular position of the shim in the plane of the soleplate in case of eversion or inversion for the implementation of the adjustment method according to one of claims 1 to 6, characterized in that it comprises a template (32) comprising a plate (34) of generally rectangular shape with a nose (36) before, integral with the edge (38) front of the plate and having a profile cut conjugate with that of the wedge to position the edge (38) of the shim perpendicular to the longitudinal axis of the foot and centrally. 8. Device for adjusting the angular position of the shim in the plane of the soleplate in case of eversion or inversion, according to claim 7, characterized in that it comprises two lines T1 and T2, on both sides. other of the median longitudinal axis, which correspond to the angles ε and Θ of eversion and inversion compensation. 9. Device for adjusting the angular position of the shim in the plane of the sole in case of eversion or inversion, according to claim 7 or 8, characterized in that ε = 4 ° and 0 = 2 °. 10. Device for adjusting the angular position of the shim in the plane of the sole in case of eversion or inversion, according to claim 7, 8 or 9, characterized in that the nose (36) is specific to each type of hold.