FR2641183A1 - Apparatus for examination and reeducation of the ankle - Google Patents

Abstract

The apparatus consists of a plate 1 mounted pivotably on a ball joint 2 supported by a bracket 3 integral with a base 4 which supports vertical limit stops 11, 12, which are adjustable in length and whose tops are situated under the plate 1. The limit stops 11, 12 form two pairs of limit stops, the limit stops of the first pair being diametrically opposite relative to the bracket 3 under the longitudinal line of the plate 1 which is parallel to the longitudinal axis of the foot, and the limit stops of the second pair being likewise diametrically opposite relative to the small column 3 under the transverse line of the plate, which is parallel to the transverse axis of the foot. A third pair of limit stops is arranged diametrically opposite in a direction perpendicular to Henke's axis of the ankle.

Description

 The present invention relates to an ankle study and rehabilitation device.

 Several ankle rehabilitation devices are already known. By way of example, mention may be made of the devices which are described in French patents 2,214,463, 2,502,492 and 2,535,909.

 In patent 2 214 463, an apparatus consisting of a footrest has been described which is connected to a motor by a connecting rod-mani veil system which gives the footrest a reciprocating passive movement whose amplitude and frequency are adjustable. . The only movements allowed are those of flexion-extension, or even prono-supination for the wrist.

 The apparatus described in patent 2,502,492 consists of a plate mounted on a half-ball allowing, in a manner not controlled by the patient, both the three movements: flexion-extension, pronosupination and rotation. The amplitude of the movements is adjustable by choosing a half-ball of an adequate diameter. This device does not make it possible to separately choose an amplitude of a movement, for example the amplitude of a flexion. Its purpose is exclusively propioceptive.

 The apparatus described in patent 2,535,209 consists of a board, vertical at rest, which is connected to a horizontal axis, which can itself rotate around a vertical axis. This device allows a floxionextension movement, a varus and valgus movement, and the combination of these two movements, the leg being placed in a horizontal position. It does not allow rotational movements or loaded exercises, the body weight being totally or partially applied to the foot.

 An object of the present invention is to provide an apparatus which allows not only to freely perform the three movements of flexion-extension, varus-valgus and eversion-inversion, and rotation, independently or simultaneously, which none allows. of the above mentioned devices. It also makes it possible to determine the limits of each movement of the foot, for example before pain is felt by the patient. The apparatus of the invention also aims to have movements carried out under load, in a passive, active or active assisted manner. In practice, the apparatus of the invention is well suited to the biomechanics of the ankle and to its joint, muscular and propiocep tive rehabilitation. It also makes it possible to make assessments and treatments of the ankle.

 According to a characteristic of the invention, there is provided an apparatus consisting of a plate pivotally mounted on a ball joint carried by a post secured to a base which carries vertical stops, adjustable in length, the tops of which are located under the tray.

 According to another characteristic, the stops form two pairs of stops, the stops of the first pair of which are diametrically opposite with respect to the post under the longitudinal line of the plate which is parallel to the longitudinal axis of the foot and whose stops of the second pair are also diametrically opposite with respect to the post under the transverse line of the plate which is parallel to the transverse axis of the foot.

 According to another characteristic, there is provided a third pair of stops arranged diametrically opposite in a direction perpendicular to the axis of Henke-de la ankle.

 According to another characteristic of the invention, the plate comprises first attachment means respectively arranged diametrically opposite on the longitudinal line and the transverse line of the disc, and the #base comprises second attachment means corresponding to the first, means adjustable elastics, such as dynamometers, working in tension which can be respectively mounted removable, each between a first attachment means and the corresponding second attachment means.

 According to another characteristic, between a point on the plate situated on the longitudinal line and a second corresponding point on the base, a first double-acting cylinder can be mounted, the means for connecting the cylinder to the plate and to the base having two degrees of freedom in rotation, and between a point on the plate located on the transverse line of the plate and a second corresponding point on the base can be mounted a second double-acting cylinder, the means for connecting the cylinder to the plate and to the base having two degrees of freedom in rotation.

 According to another characteristic, the two double-acting cylinders are hydraulic cylinders.

 According to another characteristic, the base is pivotally mounted around a vertical axis passing through the intersection of the longitudinal line and the transverse line of the plate, on a fixed frame.

 According to another characteristic, said base can be rotated around said vertical axis, by means of a motor.

 According to another characteristic, each actuator is provided with a device for measuring the position of the end of the actuator rod relative to the body of the actuator.

 According to another characteristic, each cylinder is provided with a device for measuring the pressure of the fluid in the chamber of the double-acting cylinder which is under pressure.

The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of exemplary embodiments, said description being made in relation to the accompanying drawings, among which:
Fig. 1 is a schematic elevation view of an apparatus according to the invention,
Fig. 2 is another schematic view in elevation of the apparatus of FIG. 1, of which some accessories have been exchanged,
Fig. 3 is a plan view of the apparatus of FIG. 1,
Fig. 4 is a schematic view in elevation of a variant of the apparatus of FIG. 1, and
Fig. 5 is a diagram illustrating the use of the apparatus according to the invention.

 The apparatus, shown in FIG. 1, comprises a circular support plate 1 provided in its central part with a ball 2 serving as a ball joint and able to rotate freely in a bowl hollowed out at the end of a vertical post 3. The post 3 is mounted on a circular base 4 which can rotate, by means of a ball bearing 5, on a horizontal circular ring 6.

 The plate 1 is intended to serve as a support for the sole of a foot 7 which can be immobilized on the plate by means of a strap 8. As shown in FIG. 3, the foot is, on the plate, oriented so that its longitudinal axis coincides with the axis XX 'of the plate.

On the other hand, it is expected that the midpoint of the foot coincides with the center 0 of the platform, which makes it possible to define the transverse axis.
YY 'perpendicular to the X-X axis'. Finally, we have, in FIG. 3, indicated the axis of Shame H-H '.

In Fig. 1, where the plate 1 is shown in a horizontal position, two double-acting cylinders 9 and 10 have also been shown in the vertical rest position. The free end of the rod of the cylinder 9 is hooked under point a, FIG . 3, of the plate 1 by a pivoting hooking means. Similarly, the base of the cylinder body 9 is hooked to the base 4 by a pivoting hooking means. The free end of the rod of the jack 10 is hooked under a point b of the plate 1 by a pivoting hooking means. Similarly, the base of the cylinder body 10 is hooked to the base 4 by a pivoting hooking means. As shown in Fig, 3, point a is located on the axis
YY 'at a certain distance from the center 0. Likewise, point b is located on the axis XX' at a certain distance from the center 0.We understand that by actuating the jack 9, we can print a movement on the plate 1 roll in both directions because it is a double-acting cylinder. The jack 10 prints pitching movements in both directions to the plate 1. The rolling movement corresponds, for the foot, to a varus-valgus movement; the pitch movement to a flexion-extension movement; and a predetermined combination of the two to an eversion-inversion movement.

In Fig. 1, there has also been shown, resting on the base 4, two stops 11 and 12 of adjustable height, of which FIG. 3 gives the vertical positions at d and e, these points being on the axis Y-Y ', symmetrical with respect to the center 0. Two other stops, not visible in FIG. 1, are planned, their vertical traces appearing at the
Fig. 3 in f and g. The stops ll and 12 limit the rolling movement of the plate 1 while the other two stops limit its pitching movements. Finally, a third pair of stops has also been provided, the vertical traces h and i of which appear in FIG. 3. We will see below how the cylinders are used, on the one hand, and the stops, on the other hand.

 In Fig. 2, it has been shown, in place of the cylinders 9 and 10, dynamometers 13 and 14 which are assumed, in the example described, attached to the same respective points of the plate 1 and of the base 4, as the cylinders. Two other dynamometers, not visible in FIG. 2, can also be respectively hooked under points a 'and b', symmetrical between points a and b with respect to the center 0. These dynamometers are intended to create restoring forces against which the foot can fight.

 In Fig. 1, we have also shown how an electric motor 15 could drive the base 4 by means of a roller 16. We have also shown a key 17 carried by a bracket 18 and which is slid into a corresponding hole in the base 4 when wishes to immobilize it in the initial position.

 The apparatus of FIG. 4 is similar to that of FIG. 1, but the ball 2 has been replaced by a cap 2 ′ of large diameter, the center of which coincides with the real center of rotation Q of the ankle. The cap 2 'turns on itself in a spherical cup 19 which has the same center as the cap 2' and which is mounted at the top of a post 3 '. For the rest, the plate 1 can be associated with the same means, jacks, dynamometers, stops, as in the apparatus of FIG. 1.

 In the block diagram of FIG. 5, the blocks 20 and 21 symbolically represent the jacks 9 and 10. The jack 9 comprises two fluid supply pipes 22 and 23 which are selectively pressurized by a control circuit 24. It also includes a measuring device 25 used to measure the displacement of the cylinder rod and two manometers 26 and 27 respectively mounted on the pipes 22 and 23. The measuring device 25 and the manometers 26 and 27 are connected by wires to corresponding inputs of an interface 28 which digitizes the received signals. In block 21, there is also shown the jack 10 with supply lines 29 and 30, a control circuit 31, a position measuring device 32 and two manometers 33 and 34, the latter being connected to the interface 28.

 The interface 28 is connected to a microprocessor 35 by a bidirectional data bus 36. The interface 28 still has three signal outputs 37, 38 and 39 which are respectively connected to the inputs of the control circuits 24 and 31, and to the motor 15. The assembly is preferably completed by an input-output device (keyboard + display or printer) 40 which is connected to the bus 36.

 You can use the device to obtain joint amplitude gains in active mode, with muscle contraction; in passive mode with relaxed muscles; in contracted / released mode; and we have myotensive mode. One can also use it to obtain a muscular reinforcement in static mode with improvement of the stability of the joint; and in eccentric or concentric dynamic mode. It allows a progressive work of propioception in charge or in discharge. Finally, it allows you to obtain comparative assessments by also studying the patient's healthy foot, by comparing joint amplitudes, muscular forces and propioceptions.

 We understand the usefulness of the stops to limit the amplitudes of movements, jacks either free to measure the amplitudes, or loaded to provide forces or measure them. The dynamometers allow the device to be used independently.

 The microprocessor having acquired basic data from initial measurements on the sick ankle and the healthy ankle can be programmed to act on the jacks or the electric motor. There are obviously several possible movement mode programs that the therapist wants to use. We understand all the interest of the microprocessor system which allows to keep in memory the data acquired from one reeducation session to the next, therefore to follow the progress of the patient in a reliable way.

Claims (12)

 1) Apparatus for studying and rehabilitating the ankle, characterized in that it consists of a plate (1) pivotally mounted on a ball joint (2, - 2 ') carried by a post (3, 3') integral with a base (4) which carries vertical stops (11, 12), adjustable in length, the vertices of which are located under the plate (1).  2) Apparatus according to claim 1, characterized in that the stops (11, 12) form two pairs of stops, whose stops of the first pair are diametrically opposite with respect to the post (3) under the longitudinal line of the plate (1 ) which is parallel to the longitudinal axis (X-X ') of the foot and whose stops of the second pair are also diametrically opposite with respect to the post (3) under the transverse line (Y-Y') of the plate which is parallel to the transverse axis of the foot.  3) Apparatus according to claim 2, characterized in that there is provided a third pair of stops arranged diametrically opposite in a direction perpendicular to the axis of Henke (H-H ') of the ankle.  4) Apparatus according to one of claims 1 to 3, characterized in that the plate (1) comprises first attachment means respectively arranged diametrically opposite on the longitudinal line (X-X ') and the transverse line (Y- Y ') of the plate, and the base (4) comprises second attachment means corresponding to the first, adjustable elastic means (13, 14), such as dynamometers, working in tension which can be respectively mounted removable each between a first attachment means and the corresponding second attachment means.  5) Apparatus according to one of claims 18 4, characterized in that, between a point of the plate (1) located on the longitudinal line (X-X ') and a second corresponding point on the base (4) can be mounted a first double-acting cylinder (10), the means for connecting the cylinder to the plate and to the base having two degrees of freedom in rotation, and, between a point on the plate (1) located on the transverse line (Y-Y ' ) of the plate and a second corresponding point on the base (4) can be mounted a second double-acting cylinder (9), the means for connecting the cylinder to the plate and to the base having two degrees of freedom in rotation.  6) Apparatus according to claim 5, characterized in that the two double-acting cylinders (9, 10) are hydraulic cylinders.  7) Apparatus according to one of claims 1 to 6, characterized in that the base (4) is pivotally mounted about a vertical axis passing through the intersection of the longitudinal line and the transverse line of the plate, on a fixed frame.  8) Apparatus according to claim 7, characterized in that said base (4) can be rotated about said vertical axis, by means of a motor (15).  9) Apparatus according to one of claims 5 to 8, characterized in that each cylinder (9, 10) is provided with a measuring device (25, 32) of the position of the end of the cylinder rod relative to the cylinder body.  10) Apparatus according to one of claims 1 to 9, characterized  in that each cylinder (9, 10) is provided with a device (26, 27, 33, 34) for measuring the pressure of the fluid in the chamber of the double-acting cylinder which is under pressure.  11) Apparatus according to one of claims 1 to 10, characterized in that the ball joint (2 ') has for center the real point of rotation (Q) of the pin.  12) Apparatus according to one of claims 8 to 11, characterized in that said measuring devices are connected by an interface (28) and a bus to a microprocessor (35) which controls the operation of the jacks and the motor.