METHOD FOR CONTROLLING THE CONNECTION BETWEEN A GLIDING/ROLLING APPARATUS AND USER AND A DEVICE FOR IMPLEMENTING THE METHOD

Abstract

A method and a device for controlling the connection between a user and a gliding or rolling apparatus on which the user is retained by a releasable retaining system, i.e., such as between a skier and ski by means of a ski binding. According to the method, the values of at least two flexion and torsion angles between the user's upper leg and lower leg are measured and the values of these angles in relation with the angles that indicate a critical posture of the user are considered, and the release of the retaining system is caused if the angle values measured exceed the indicative values. The device includes a member for measuring at least two angles and a processing circuit in relation with a table of indicative values.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 of French Patent Application No. 06 10784, filed on Dec. 11, 2006, the disclosure of which is hereby incorporated by reference thereto in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for controlling the connection between a user and his/her gliding or rolling apparatus. The invention also relates to a device for controlling the implementation of the method.

2. Description of Background and Other Information

Particularly in the field of skis, it is known to retain each of the skier's boots on the skis by means of retaining elements, i.e., bindings. These elements are conventionally of the releasable type, that is, they are able to release the boot in case of excessive force to prevent, as much as possible, injury or fracture of a limb of the skier.

A substantial number of models of retaining elements are commercially available. These elements are essentially mechanical, that is, the boot is released after the boot retaining jaw is opened. The jaw is returned by means of a spring, and the opening of the jaw occurs when the forces that the boot exerts on the jaw override the return force applied by the spring.

These devices yield good results for simple falls, namely, mostly front and torsion falls. For so-called combined falls, for example a front torsion fall or a twisted fall, the friction between the boot and the retaining elements is difficult to control. However, there are compensating devices for the combined falls, such as described, for example, in the patent documents FR 2 523 857 and family member U.S. Pat. No. 4,538,828, FR 2 314 742 and family member U.S. Pat. No. 4,095,821; and FR 2 707 514.

There are also constructions by which the forces between the boot and the ski are received by electronic gauges and are processed by electronic circuitry, which controls the release of the boot. Such constructions are disclosed, for example, in the patent documents FR 2 459 669 and family member U.S. Pat. No. 4,395,759, FR 2 351 678 and family member U.S. Pat. No. 4,160,555; and U.S. Pat. No. 4,371,188. The electronic reception of the forces is more precise and less sensitive to friction than mechanical reception. However, it is not entirely satisfactory. Indeed, the reception of the forces in the area of the boot does not enable certain postures of the skier, any of which risks an injury to the skier, to be highlighted or identified. Moreover, commercially available boots are increasingly high-performance boots. They provide better protection for the lower portion of the leg, particularly protection against injuries, caused by a fall, which extend along the leg and which affect more particularly the knee, especially the ligaments of the knee.

Certain constructions have been proposed which receive the forces along the leg, as in the patent documents U.S. Pat. No. 3,909,028 and FR 2 767 266, for example. The solutions described in these two documents are mostly mechanical and, therefore, they are very limiting for the skier.

The patent U.S. Pat. No. 6,007,086 proposes arranging directional transmitter systems and receivers on the skis and on the user, and to control the release of the boot when a receiver transmitter transmits its signal in a direction outside the receiving area of the receiver. Such a device does not allow for the forces exerted on the skier's lower limbs to be received with sufficient precision.

Another solution, described in the patent U.S. Pat. No. 5,295,704, provides for the skier to be equipped with a type of knee pad and for the flexion angle of the lower limb to be measured on this element. However, such measurement alone is insufficient to identify the situations by which the skier risks an injury.

In view of the state of the art, there is a need for a method for controlling the connection between a user and his/her gliding or rolling apparatus, such as a board, a snowboard, or skis, that enables the critical situations in which the skier runs a risk of an injury to be determined more precisely.

SUMMARY OF THE INVENTION

A method and a device of the invention provide for critical situations of a user to be determined more precisely, as well as for the achievement of various objects and advantages, the descriptions of which follow.

The invention is directed to a method for controlling a connection between a user and his/her gliding or rolling board to which he/she is bound by a releasable type of retaining system provided with a two-state retaining member, a retention state and a release state, whereby, in the retention state of the retaining member, the measurement of at least two distinct flexion or torsion angles is taken between the skier's thigh and leg, and whereby the value of each of such angles is compared to posture indicative values, and whereby the switch of the retention state to the release state of the member is controlled if, for each of the two angles, the angle value measured is greater than its posture indicative value.

In a particular aspect of the invention, in a control method of the invention, the angle corresponding to the knee bend (AFX) and at least one of the angles among the angles corresponding to the valgus angulation (AVG), the varus angulation (AVR), the internal rotation (ARI), and the external rotation (ARE) are measured

The control device includes a member for measuring at least two distinct flexion or torsion angles between the user's thigh and leg.

In a particular aspect of the invention, in a control device according to the invention, the measuring member measures the angle corresponding to the knee bend (AFX) and at least one of the angles among the corresponding to the valgus angulation (AVG), the varus angulation (AVR), the internal rotation (ARI), and the external rotation (ARE).

According to a particular aspect of the invention, various critical postures in which the skier runs a significant risk of injury in the area of the skier's knees, particularly in the area of different ligaments, are observed and identified. These postures can be identified by taking at least two angle measurements in the area of each of the skier's lower limbs.

The control method and device according to the invention can be implemented on any type of releasable retaining system. For example, it is possible to complete a releasable retaining system that is known and broadly distributed on the market with the control device of the invention. In such case, the front stop and the rear heel piece of a boot retaining system are releasable as a function of the forces to which the user's leg is subjected while an additional release will occur in accordance with the invention as a function of the user's posture.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be better understood from the following description, with reference to the annexed drawings.

FIG. 1 shows a skier;

FIG. 2 schematically shows a flexing position of the skier;

FIGS. 3 and 4 schematically show so-called valgus/varus positions;

FIGS. 5 and 6 schematically show situations in external/internal rotation;

FIG. 7 shows a flow chart representing the determination mode of the release control;

FIG. 8 shows a diagram of the principle of the control device.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a skier 1 gliding on a gliding apparatus in the form of two skis 2 and 3. A connection system connects the skier to his gliding apparatus, the connection system including retaining elements, or bindings, namely, toe piece 4a and heel piece 4b which retain the left boot 6 on the ski 2, and toe piece 5a and heel piece (hidden by the left boot) which retain the right boot 7 on the ski 3. The retaining elements are of the releasable type, which means that they can release the boot in the case of an application of force exceeding certain threshold levels. For example, these elements are constructed in accordance with the patent documents FR 843 037 FR 2 860 729, and U.S. Pat. No. 7,073,812, the disclosure of the latter of which is hereby incorporated by reference thereto in its entirety. However, the constructions disclosed in these documents are not to be considered limiting to the present invention, and any other construction can be suitable. In a known manner, the retaining elements have two main states, a retaining state by which they retain the boots on their respective skis, and a release state by which they allow the boot to be released. In the case where the retaining system includes front and rear elements, only one of these elements needs to have a control for switching to the release state. In other types of known constructions, the boot is retained by a central retaining element.

A control device is provided to control the connection between the user/skier and each of his/her skis. In particular, this device controls the change of state of the connection between the boot and the ski to its release state.

In the release state of the retaining system, the control device receives the forces sustained by the skier, analyzes them, and transmits a release command to the connection system if the analysis of the forces identifies a critical situation necessitating the release of the connection between the skier and his/her apparatus, that is, at least one of the skis in the present case, i.e., in the case of the gliding apparatus comprising a pair of skis rather than a single gliding board or other apparatus.

The control method and device of the invention focus upon the forces sustained by the skier's knees and upon the consideration by which at least two angles are measured in the area of the knees for the purpose of detecting certain movements or postures of the skier that are susceptible to causing injury to the knees.

The movements that are monitored include the flexional movements of the upper leg on the lower leg, that is, a knee-bend angle; varus/valgus movements, that is, an inward or outward deviation of the upper leg with respect to the lower leg; and a rotational movement toward the outside or inside of the lower leg relative to the upper leg. In the following description, reference will be made to the femur and tibia, with respect to the upper leg (or thigh) and the lower leg, respectively.

These movements are observed by measuring angles in the area of each of the knees. The angles measured include the flexion angle (AFX), represented in FIG. 2 between the axes 10 and 11 of the femur 12 and the tibia 13; the valgus/varus (AVR, AVG) angle, represented in FIGS. 3 and 4; and the medial/lateral (ARI, ARE) rotation angle, represented in FIGS. 5 and 6.

These angles are measured with any appropriate means. For example, as suggested in FIG. 1, the skier can be provided with knee pads 25, 26. The knee pads are worn directly by the skier or they are incorporated to the skier's clothing. The knee pads are instrumentalized, i.e., equipped, for example, with conductive fibers that are integrated into the material of the knee pad at various locations and according to various orientations, and which work as extensometry gauges. Another possibility is to provide the knee pad with an inertial unit that has goniometers and/or inclinometers. Other measuring means are also suitable, such as potentiometers, for example.

The flowchart diagram of FIG. 7 represents an algorithm on the basis of which a command to switch to the release state of a binding is generated. In the diagram, the command to switch to the release state is designated by the reference character “C” and is located in the last box of the chart.

At each step of the chart, when the answer to the question asked in the decision box (diamond) is “YES”, a “1” appears on the arrow connecting the diamond to a subsequent diamond; a “0” appears if the answer is “NO”.

In the embodiment illustrated in FIG. 7, the algorithm includes a the real-time measurement of the angles AFX, AVR, AVG, ARI, ARE, which measurement is transmitted from the box 28, the measurement being designated by the reference character “M”.

The algorithm includes two decision-making levels 29 and 31. On a first level 29, the angles ARI, AFX, and AVG are measured, and the measured values are compared with indicative values, namely 15 degrees for ARI, 90 degrees for AFX, 5 degrees for AVG. This is shown in the three diamonds 32, 33, 34 of the chart.

If one of the three angles is greater than the associated indicative value, one then moves to the second analysis level 31.

If it is the ARI value that is greater than its indicative value, the measurement of AFX and AVR is then considered, more particularly, a consideration is them made whether AFX is less than the indicative 20-degree value or whether AVR is greater than the 5-degree indicative value as determined in the diamonds 37 and 38. If one of these conditions is fulfilled, a command to switch to the release state is transmitted to the retaining system in order to release the connection between the user and his gliding apparatus.

In the case where the indicative value of AFX has been exceeded, the value of the angle ARI is considered, which is shown schematically in the diamond 39. If ARI is greater than the 15-degree indicative value, a release command is transmitted to the retaining system.

If AVG has exceeded its indicative value, the value of the angle ARE is considered, as shown in the diamond 41. If ARE is greater than the 15-degree indicative value, a release command is transmitted to the retaining system.

Thus, a release command is triggered in each case scenario, from the measurement of two angles among the angles which include the flexion angle, the valgus/varus angle, the internal/external (i.e., medial/lateral) rotation angle, and the comparison of these angles to posture-indicative values which are associated to them, respectively.

The angle measured can be the real angle, that is, measured between the directions defined by the femur axis and the tibia axis, or it can be a measurement of the variation of this angle from an initial value. Indeed, for the valgus/varus and the medial/lateral rotation, it is known that the deviation or rotation angle at rest can vary by several degrees inwardly or outwardly, from one user to the next. In such a case, one can, in an initialization phase, measure these angles, or part of these angles, at rest so that only the variation of the angles involved is measured subsequently.

The angle measurements can be processed in any appropriate format, whether analog or digital. To this end, the measurement can be carried out continuously or sequentially.

Each association of indicative angles identifies a critical posture of the skier in which an injury in the area of the knee is at risk. The values of the indicative angles are not to be considered limiting. For example, the values can considered, within the scope of the invention, to be within a margin of more or less 30 percent. These values may not be exactly the same for all users or categories of users. For example, the indicative values can be more or less high for experienced skiers or beginners.

The algorithm of FIG. 7 includes a consideration of four critical postures. This number is non-limiting; there could be more or less, the general idea being that there needs to be at least two angle measurements between the upper leg and lower leg in order to identify a critical posture. A third level could also be added, above the level 31, that is, adding the measure of a third angle and its comparison with an associated indicative angle to analyze the posture of the skier and identify the critical character of the skier's posture.

Moreover, the invention is to prevent only certain risks of injury, meaning that it is possible to control the release command by associating the measurement and the analysis of other angles or forces, for example, of the angles or forces in the area of the ankle and/or of the user's boot.

FIG. 8 shows a schematic representation of the principle of the control device. It shows a measuring member in the form of a knee pad 42. This member is able to measure at least two flexion or rotation angles of the lower limb of the skier among the angles, which include the flexion angle, the valgus/varus angle, the medial/lateral rotation angle. Other constructions are suitable for this measuring member. The signal originating from the measuring member is transmitted to a circuit 44 for processing the signal.

The device further includes a table 46 with the posture-indicative values associated with each of the measured angles. A processing circuit 47 analyzes the angles measured and compares them to the indicative values in accordance to what has been described above.

The processing circuit 47 controls a command circuit 48, which is able to transmit a command for switching the release state to the retaining system. For example, as shown, the circuit 48 controls the opening of a front retaining element 49 in accordance to the patent documents FR 2 843 037 and U.S. Pat. No. 7,073,812, mentioned above. Other constructions of retaining systems are also suitable.

The transmission between the various components of the device is carried out by wire or wireless, as appropriate. Furthermore, the signals can be analog or digital.

The present disclosure is given only by way of example, and other embodiments of the invention are possible without leaving the scope of the invention.

In particular, the invention is not limited to the field of skiing but can be applied to any gliding or rolling activity whereby the user is retained on his/her apparatus by at least one releasable retaining mechanism/binding, such as the activities of snowboarding, telemark skiing, cross-country skiing, and other types of activities and sports. Depending upon the sport and the category of users, the indicative values can be different from those that have been described herein.

Claims

1. A method for controlling a connection of a user to a gliding or rolling apparatus to which the user is retained by a releasable retaining system equipped with a two-state retaining member, a first state of said two states being a retaining state, a second state of said two states being a release state, said method comprising:

measuring, during the retaining state of the retaining member, at least two distinct flexion or torsion angles between the user's upper leg and lower leg and determining a measured value for each of said at least two angles;

comparing the measured value of each of said at least two angles to a respective posture-indicative value;

transmitting a command to cause the two-state retaining member to be in said release state when, for each of said at least two angles, the measured value exceeds the respective posture-indicative value.

2. A method according to claim 1, wherein:

said measuring at least two angles comprises measuring a knee-bend angle (AFX) and at least one of the following angles: a valgus angle (AVG), a varus angle (AVR), a medial rotation angle (ARI), and a lateral rotation angle (ARE).

3. A method according to claim 1, wherein:

said measuring at least two angles comprises measuring at least two angles from among the following angles on two decision-making levels: flexion angle (AFX), varus angle (AVR), valgus angle (AVG), medial rotation angle (ARI), and lateral rotation angle (ARE).

4. A method according to claim 3, wherein:

on a first of said two decision-making levels, at least one angle from among the following angles is measured: medial rotation angle (ARI), flexion angle (AFX), and algus angle (AVG).

5. A method according to claim 4, wherein:

said measuring comprises measuring the medial rotation angle (ARI) and the flexion angle (AFX);

said comparing results in determining whether the medial rotation angle (ARI) is greater than the respective posture-indicative value by about 15 degrees and whether the flexion angle (AFX) is less than the respective posture-indicative value by about 20 degrees.

6. A method according to claim 4, wherein:

said measuring comprises measuring the medial rotation angle (ARI) and the and the varus angle (AVR);

said comparing results in determining whether the medial rotation angle (ARI) is greater than the respective posture-indicative value by about 15 degrees and whether the varus angle (AVR) is greater than the respective posture-indicative value by about 5 degrees.

7. A method according to claim 4, wherein:

said measuring comprises measuring the flexion angle (AFX) and the medial rotation angle (ARI);

said comparing results in determining whether the flexion angle (AFX) is greater than the respective posture-indicative value by about 90 degrees and whether the medial rotation angle (ARI) is greater than the respective posture-indicative value by about 15 degrees.

8. A method according to claim 4, wherein:

said measuring comprises measuring the valgus angle (AVG) and the lateral rotation angle (ARE);

said comparing results in determining whether the valgus angle (AVG) is greater than the respective posture-indicative value by about 5 degrees and whether the lateral rotation angle (ARE) is greater than the respective posture-indicative value by about 15 degrees.

9. A method according to claim 1, further comprising:

measuring, in an initialization phase, at least part of said at least two distinct flexion or torsion angles at rest.

10. A control device for controlling a connection of a user to a gliding or rolling apparatus while the user is retained to the apparatus by a releasable retaining system equipped with a two-state retaining member, a first state of said two states being a retaining state, and a second state of said two states being a release state, said device comprising:

a measuring member for measuring at least two distinct flexion or torsion angles between the user's upper leg and lower leg.

11. A device according to claim 10, wherein:

said at lease two distinct flexion or torsion angles comprises an angle corresponding to knee bend (AFX) and at least one angle from among the following angles: a valgus angle (AVG), a varus angle (AVR), a medial rotation angle (ARI), a lateral rotation angle (ARE).

12. A device according to claim 11, further comprising:

a table of user posture-indicative values associated with at least part of the flexion or torsion angles (AFX, AVG, AVR, ARI, ARE).

13. A device according to claim 12, further comprising:

a processing circuit for analyzing measuring signals transmitted by the measuring member and for comparing said measuring signals to the posture-indicative values of the table.