WO2003057127A1

WO2003057127A1 - Device for exercising the foot

Info

Publication number: WO2003057127A1
Application number: PCT/SE2002/002341
Authority: WO
Inventors: Frida Söderblom
Original assignee: Soederblom Frida
Priority date: 2001-12-18
Filing date: 2002-12-17
Publication date: 2003-07-17
Also published as: AU2002362180A1; EP1455726A1; SE520671C2; SE0104266L; SE0104266D0

Abstract

The present invention relates to a device for exercising the foot, said device comprising means (1) for clamping a foot and transmission unit (7) that is connected to said clamping means (1), said transmission unit (7) at its opposite end being connected to driving unit (5) included in the device, the transmission unit (7) being displaceable by means of said driving unit (5) both in direction towards the clamping means (1) as well as in direction away from the clamping means (1). It is significant for the device according to the present invention that the transmission unit (7) comprises spring means (27) to detect the resistance to motion in the ankle joint of the foot that is exercised, that for reversion of the direction of displacement of the transmission unit (7) the transmission unit (7) comprises activating means (28), and that the activating means (28) are transferred to an active position at a predetermined affection of the spring means (27

Description

DEVICE FOR EXERCISING THE FOOT

Technical Field of the Invention

The present invention relates to a device for exercising the foot, said device comprising means for clamping a foot, a support unit for a lower part of the leg and a transmission unit that is connected to said clamping means, said transmission unit at its opposite end being connected to a driving unit included in the device, the transmission unit being displaceable by means of said driving unit both in direction towards the clamping means as well as in direction away from the clamping means .

Prior Art From SE-C-9903147-8 a device for exercising the foot is previously known, said device comprising means for clamping a foot and a rod shaped element that is connected to said clamping means via a hinge, said rod shaped element being displaceable in its longitudinal direction both in direction towards the clamping means as well as in direction away from the clamping means. The device comprises means for adjusting the magnitude of displacement that is performed by the rod shaped element in its longitudinal direction, the adjusting means constituting an end position stop that is displaceable along the rod shaped element. A disadvantage of this known device is that if the treated foot changes position the location of the end position stop is no longer correct.

Objects and Features of the Invention A primary object of the present invention is to present a device of the type defined above where the reversing positions of the means that clamps the foot automatically adjusts to the mobility in the ankle joint.

Still an object of the present invention is to design the device as compact as possible, this facilitating the handling of the device.

A further object of the present invention is to adapt to a possible move of the foot . At least the primary object of the present invention is realised by means of a device that has been given the features of the appending independent claim 1. Preferred embodiments of the device are defined in the independent claims.

Brief Description of the Drawings

Below a preferred embodiment of the invention will the described, reference being made to the accompanying drawings, where : Figure 1 shows a schematic side view of a device according to the present invention, said device being in a rear end position; Figure 2 shows a schematic side view of a device according to the present invention, said device being in a front end position;

Figure 3 shows a schematic side view of an adjustment unit included in the device, said adjustment unit being in a neutral position; Figure 4 shows a schematic side view of the adjustment unit when it is in a rear end position;

Figure 5 shows a schematic side view of the adjustment unit when it is in a front end position; Figure 6 shows a schematic side view of an alternative embodiment of the device according to the present invention, said device being in an initial position; and Figure 7 shows the device according to figure 6 in an end position.

Detailed Description of Preferred Embodiments of the Invention

The device for exercising the foot that is shown in figures 1 and 2 comprises a foot plate 1, a support unit 3 for a leg, a driving unit 5 and an adjustment unit 7 that extends between the foot plate 1 and the driving unit 5. Straps 2 are attached to the foot plate 1 and the foot of the patient may be clamped against the foot plate 1 by means of said straps 2. A link arrangement 9 is also attached to the foot plate 1, said link arrangement 9 comprising a lug 10 that is connected to a first link 11 via the end that faces away from the foot plate 1. The lug 10 and the link 11 are fixed relative to each other. The link arrangement 9 also comprises a bar 12 that extends between a first hinge 13 of the lug 10 and the support unit 3 and consequently the distance between the support unit 3 and the first hinge 13 remains constant. As is evident when studying figures 1 and 2 the first hinge 13 constitutes centre of rotation of the foot plate 1 when said foot plate 1 moves between its reversing positions. At the end of the first link 11 that faces away from the first hinge 13, said first link 11 being pivotally connected to a first rod element 8 of the adjustment unit 7.

The support unit 3 is equipped with means to support the lower part of the leg B, see figures 1 and 2, of the patient that is to be treated by means of the device according to the present invention.

The driving unit 5 comprises a reversible electric motor 14 and a second link 16 is attached to the driving shaft 15 of the motor 14. The second link 16 is pivotally connected to a second rod element 17 of the adjustment unit 7, said connection being at the end of the second link 16 that faces away from the driving shaft 15.

Reference is made to figures 3-5 for a more detailed description of the adjustment unit 7. The adjustment unit 7 comprises a first rod element 8 that in its turn comprises a first primary rod 18 and a yoke 19 that comprises a longitudinal element 20 and two transverse guiding elements 21 that are provided at respective ends of the longitudinal element 20. The first primary rod 18 is fixedly connected to the yoke 19. On the longitudinal element 20 two switches 22 are provided at a certain mutual distance in the longitudinal direction of the element 20.

The second rod element 17 comprises a second primary rod 23 and two secondary rods 24 that are parallel to each other. The secondary rods 24 are fixedly connected to the first primary rod 23 via a connecting element 25 that extends transverse to the rods 23 and 24. The secondary rods 24 are equipped with stops 26 at their free ends. Two pressure springs 27 are provided on each secondary rod 24. On one secondary rod 24 two activating means 28 are provided at a certain mutual distance in the longitudinal direction of the secondary rod 24. The mutual distance between the activating means 28 may be varied by having the activating means 28 detachably fixed, e.g. by means of locking screws (not shown), relative to the appending secondary rod 24.

The yoke 19 is slidingly attached to the secondary rods 24 by having the guiding elements 21 penetrated by the secondary rods 24. Between the connecting element 25 and the adjacent guiding element 21 a pressure spring 27 is located on the respective secondary rod 24 and between each stop 26 and the adjacent guiding element 21 a pressure spring 27 is located. The adjustment unit 7 assumes the neutral position shown in figure 3 when the foot plate 1 is displaced between its reversing positions, i.e. the rod elements 8 and 17 are balanced relative to each other by means of the springs 27. When the foot plate 1 assumes the rear reversing position, see figure 1, the adjustment unit 7 assumes the position shown in figure 4, i.e. when the foot has reached the rear reversing position a resistance occurs against further turning of the foot plate 1 around the first hinge 13.

Further displacement of the second primary rod 23 brings about that the secondary rods 24 are displaced relative to the yoke 19 while the right springs 27 in figure 4 are compressed. In connection therewith the activating means 28 will be displaced relative to the switches 22 and the right activating means 28 in figure 4 will affect the right switch 22. This means that the direction of rotation of the electric motor 14 is reversed and the second primary rod 23 commences a motion in direction towards the foot plate 1. The compression of the right springs 27 will then cease and the adjustment unit 7 again assumes the balanced neutral position in figure 3.

When the electric motor 14 has displaced the adjustment unit 7 so far in direction towards the foot plate 1 that the front reversing position according to figure 2 has been reached the adjustment unit 7 assumes the position shown in figure 5. When the foot has reached the front reversing position a resistance occurs against further turning of the foot plate 1 around the first hinge 13. This means that further displacement of the adjustment unit 7 in direction towards the foot plate 1 brings about that the second rod element 17 is displaced relative to the first rod element 8 and the left pressure springs 27 in figure 5 are compressed. In connection therewith the secondary rods 24 will be displaced relative to the yoke 19, i.e. the activating means 28 are displaced relative to the switches 22 and the left activating means 28 affect the left switch 22. This means that the direction of rotation of the electric motor 14 will be reversed and the first primary rod 18 commences a motion in direction from the foot plate 1. The compression of the left springs 27 then ceases and the adjustment unit 7 again assumes the balanced position shown in figure 3.

The foot plate 1 of the device according to the present invention is thus displaced to-and-fro between the reversing positions described above and the adjustment unit 7 between the foot plate 1 and the electric motor 14 will register when a reversing position is reached and then the direction of rotation of the electric motor 14 will be reversed.

An advantage of the device according to the present invention is that the compression of the pressure springs 27 that occur at the reversing positions does not need to be equal large in the rear and the front reversing positions. Normally, a higher counteracting muscle strength is performed in the rear reversing position than in the front reversing position. For this reason it might be suitable to locate the activating means 28 in such a way that a larger compression of the pressure springs 27 is allowed in the rear reversing position than in the front reversing position.

The alternative embodiment of a device according to the present invention that is schematically shown in figures 6 and 7 comprises a driving unit 105 that is assembled with an adjustment unit 107. A rod 108 projects from the driving unit 105, said rod 108 being equipped with a rack 116 at the end facing towards the driving unit 105. A driving shaft 115 of the driving unit 105 carries a gear wheel 130 that cooperates with the rack 116. The driving shaft 115 extends from a reversible electric motor 114 included in the driving unit 105. As is evident from figures 6 and 7 the electric motor 114 is pivotally supported via a hinge 131 that is stationary relative to a base 132 of the device.

The adjustment unit 107 comprises two pressure springs 133 that are located between the base 132 and the electric motor 114, in the area of the ends of the electric motor 114. The pressure springs 133 perform a balancing action as well as a resilient counteracting of the pivoting of the electric motor 114 around the hinge 131. In the area of the upper ends of the pressure springs 133 the activating means 134 are provided, said activating means 134 constituting laterally projecting fingers. In connection with each pressure spring 133/activating means 134 a switch 122 is provided, said switches 122 controlling the direction of rotation of the electric motor 114 and cooperate with the activating means 134 in a way that will be described below.

In figures 6 and 7 the foot plate and the support unit for the leg are not shown since said units in principle may be designed in a corresponding way as for the embodiment according to figures 1 and 2. The device shown in figures 6 and 7 functions in the following way. Figure 6 illustrates the initial position, i.e. before the electric motor 114 has been started. By activation of the reversible electric motor 114 the driving shaft 115 and the gear wheel 130 are brought to rotate in a certain direction that is shown by the arrow R in figure 7. In connection therewith the gear wheel 130 will displace the rack 116 and hence also the rod 108 to the right in figure 7, this being illustrated by the arrow D in figure 7. It should be noticed that a certain position of equilibrium is assumed by the electric motor 114 and this position of equilibrium means that the left spring 133 is compressed and the left end of the electric motor 114 in figure 7 is at a lower level than the right end of the electric motor 114. When the rod 108 has been displaced so far to the right in figure 7 that a certain resistance against further displacement occurs in the ankle joint of the patient the cooperation between the rack 116 and the gear wheel 130 will result in further pivoting of the electric motor 114 around the hinge 131 compared to the position that is shown in figure 7. In connection therewith the left spring 133 will be compressed further and this means that the activating means 134 affects the left switch 122 in figure 7 and the direction of rotation of the electric motor 114 is reversed, i.e. the displacement of the rod 108 to the right in figure 7 will be interrupted and the rod will commence a displacement to the left in figure 7 while a certain compression of the right spring 133 takes place. When resistance against further displacement of the rod again occurs in the ankle joint of the patient the right spring 133 will be further compressed in the way that has been described above and the direction of rotation of the electric motor 114 will be reversed.

The switches 122 are adjustably mounted by means of set screws 135, by which the distance of the switches 122 from the base may be varied. Thereby, individual adjustment of the reversing positions of the rod 108 is possible and regard may be paid to the mobility in the ankle joint of different patients .

Feasible Modifications of the Invention

In the description above of the embodiment according to figures 1-5 it is stated that the activating means 28 may be detachably fixed relative to its adherent secondary rod 24 by means of locking screws. However, it is feasible to have alternative and more user-friendly locking means for the activating means 28. Eccentric locks may be mentioned in exemplifying and non-restricting purpose, said eccentric locks may be easily handled by the operator of the device according to the present invention. In the embodiments of the device according to the present invention that is described above a reversible electric motor 14; 114 is used as power source. However, within the scope of the invention other alternative power sources are also feasible. Motors driven by pressure medium, e.g. a pneumatic motor or a hydraulic motor, may be mentioned in exemplifying and non-restricting purpose.

In the embodiments described above mechanical pressure springs 27; 133 are used in the adjustment unit 7; 107. However, within the scope of the present invention it is also feasible to use alternative spring means. Hydraulic springs or gas springs may be mentioned in exemplifying and non- restricting purpose.

Claims

1. Device for exercising the foot, said device comprising means (1) for clamping a foot, a support unit (3) for a lower part of the leg and a transmission unit (7; 108) that is connected to said clamping means (1) , said transmission unit (7; 108) at its opposite end being connected to a driving unit (5; 105) included in the device, the transmission unit (7; 108) being displaceable by means of said driving unit (5; 105) both in direction towards the clamping means (1) as well as in direction away from the clamping means (1) , c h a r a c t e r i z e d in that the transmission unit (7) or the driving unit (105) comprises spring means (27; 133) to detect the resistance to motion in the ankle joint of the foot that is exercised, that for reversion of the direction of displacement of the transmission unit (7; 108) the transmission unit (7) or the driving unit (105) comprises activating means (28; 134), and that the activating means (28; 134) are transferred to an active position at a predetermined affection of the spring means (27; 133) .

2. Device according to claim 1, c h a r a c t e r i z e d in that the transmission unit (7) also constitutes adjustment unit that determines the reversing positions of the clamping means (1) , that the adjustment unit (7) comprises two rod units (8, 17) that are displaceable relative to each other in the longitudinal direction of the adjustment unit (7) , and that the adjustment unit (7) comprises spring means (27) in order to balance the mutual displacement of the rod units (8, 17) and means (22, 28) to reverse the direction of displacement of the unit (7) for power transmission and adjustment .

3. Device according to claim 1, c h a r a c t e r i z e d in that the driving unit (105) also constitutes adjustment unit to determine the reversing positions of the clamping means (1) , said driving unit (105) comprising spring means (133) to balance the cooperation between the driving source (114) and the transmission unit (108) and means (122, 134) to reverse the direction of displacement of the transmission unit (108) when the spring means (133) are affected.

4. Device according to any of the previous claims, c h a r a c t e r i z e d in that the transmission unit (7; 108) is pivotally connected to the clamping means (1) and the driving unit (5; 105) .

5. Device according to claim 2, c h a r a c t e r i z e d in that the first rod unit (8) comprises a first primary rod (18) and a yoke (19) that is fixedly connected to the primary rod (18) , that a second rod unit (17) comprises a second primary rod (23) and secondary rods (24) that are fixedly connected to the primary rod (23), that the rod units (8, 17) are arranged to cooperate with each other in such a way that the yoke (19) is slidingly received on the secondary rods (24) .

6. Device according to any of the previous claims, c h a r a c t e r i z e d in that the adjustment unit (7; 105) comprises switches (22; 122) and activating means (28; 134) that affects the switches (22; 122) .

7. Device according to claim 5, c h a r a c t e r i z e d in that switches (22) are provided on the yoke (19) , that activating means (28) are provided on the secondary rods (24) , and that the activating means (28) are displaceable between operative positions along the secondary rods (24) or that the switches (22) are displaceable between operative positions along the yoke (19) .

8. Device according to any of claims 2-7, c h a r a c t e r i z e d in that the spring means constitutes pressure springs (27; 133) .

9. Device according to any of claims 2-8, c h a r a c t e r i z e d in that the driving unit (5; 105) comprises a reversible electric motor (14; 114).