Patent Publication Number: US-2004054305-A1

Title: Method and a device for preventing and treating ligament injuries in the lower extremities

Description:
TECHNICAL FIELD  
       [0001] The present invention relates to a device and method for treating or preventing joint and ligament injuries in the lower extremities, such as a sprained ankle or different types of serious knee injuries, by standing on a medical foot plate. The objects of the invention are to provide methods and devices for efficiently preventing or treating injuries of the indicated types.  
       [0002] These objects, as well as further objects and advantages mentioned in this specification, are partly or fully attained by the device as defined in the appended independent device claims, when used as described herein and by the method as defined in the appended independent method claim. Embodiments of the invention are defined in the appended dependent claims. Basically, the invention refers to a medical foot plate, which is sufficiently unstable to stimulate back and forth movement of a bare foot in a sideways direction, when a person tries to stand on one leg only, and mainly supports himself by the foot standing on the plate.  
       [0003] In preferred embodiments the foot plate is sufficiently narrow to provide this stimulation.  
       [0004] The stimulation can also be provided by making the plate sufficiently resilient to stimulate said back and forth movement of the bare foot in a sideways direction.  
       [0005] In preferred embodiments, the plate is made of a rubber like material which is deformed by the weight of the person using it, and the plate has a relatively high friction against the person&#39;s naked foot in order to prevent slipping.  
       [0006] The inventive method basically resides in that a person tries to stand on one leg only while trying to support his weight on the foot of that leg, when standing on the medical foot plate, that the person tries to maintain his balance when standing on the plate, whereby the foot will be stimulated to perform a back and forth movement in a sideways direction. This movement pattern is advantageous either for preventing and reducing incidents of ligament injuries, or to decrease the rehabilitation time after injury.  
       [0007] Embodiments of the invention will now be described with reference to the appended drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0008]FIG. 1 is a perspective view of the medical foot plate of the present invention;  
     [0009]FIG. 2 is a top view of the medical foot plate shown in FIG. 1;  
     [0010]FIG. 3 is an elevational left side view of the medical foot plate shown in FIG. 1;  
     [0011]FIG. 4 is a bottom view of the medical foot plate shown in FIG. 1;  
     [0012]FIG. 5 is an elevational right side view of the medical foot plate shown in FIG. 1;  
     [0013]FIG. 6 is an elevational front view of the medical foot plate shown in FIG. 1;  
     [0014]FIG. 7 is an elevational rear view of the medical foot plate shown in FIG. 1;  
     [0015]FIG. 8 is a front view of the medical foot plate shown in FIG. 1 with a person standing with his left foot thereon;  
     [0016]FIG. 9 is a front view of the medical foot plate shown in FIG. 1 with a person standing with his right foot thereon:  
     [0017]FIG. 10 is an elevational side view with one foot placed thereon:  
     [0018]FIG. 11 is a front view of the medical foot plate with a foot placed thereon along line  11 - 11  of FIG. 10; and  
     [0019]FIG. 12 is a front view of the medical foot plate with a foot placed thereon along line  11 - 11  of FIG. 10. 
    
    
     DETAILED DESCRIPTION  
     [0020] With reference to FIGS.  1 - 12 , the present invention is a medical foot plate or a “balance board”  10  that has a front side  12  and a back side  14  with a soft upper side  16  that is shaped according to a human foot (anatomical shape). The plate  10  is particularly useful for putting stress on the proprioceptive system, i.e. facilitate and stimulate the sense for positions. Lots of studies have observed a decrease in the ability to maintain single leg stance in the sprained ankle as compared to the contralateral uninjured ankle. Injuries to capsuloligamentous structures in the knee joint have resulted in alterations in kinaesthesia the sense for the position of the joint. These findings show that the injuries may not only cause damage to supporting ligamentous joint capsule and muscle structures, but also to different types of neural endings. The loss of neural input from ligament and joint mechanoreceptors may lead to a longer rehabilitation period and a higher risk for reinjuries.  
     [0021] To summarize many studies in this field, it seems reasonable to practice balance training, both for preventing and reducing the incidence of ligament injuries in the lower extremities and to decrease the rehabilitation time after the injury.  
     [0022] The plate  10  has opposite vertical sides  11 ,  13  that extend between the front side  12  and the back side  14 . The front side  12  has a triangular shaped opening  18  defined therein. Of course, the opening may have any suitable shape such as round or oval shaped. The opening  18  extends through the plate  10  so that the back side  14  also has the opening  18  defined therein.  
     [0023] The upper side  16  has a back portion  20 , a raised middle portion  22  and a front portion  24 . The back portion  20  is formed to receive a heel  26  of a foot  28  (see FIG. 10) and the middle portion  22  supports an arch  30  of the foot  28 , while the front portion  24  supports a front segment  32  of the foot  28 , s 0  that the plate  10  is ergonomically adapted to the shape of the foot  28 . A top segment  34  of the upper side  16  has a high friction surface  36 , so that the foot  28  does not slip on the plate  10  when a person is standing with one foot balancing on the plate  10 . The surface  36  should be sufficiently narrow to stimulate back and forth movement of the foot in a sideways direction when a person stands on the surface  36 . The surface  36  has a relatively wide back segment  38  and narrow middle segment  40  and a wide front segment  42 , as best shown in FIG. 2.  
     [0024] In operation, a person  44  stands bare feet, so that bare foot  28  is placed on the plate  10  and then lifts up the other foot and stretches out one of his arms  46 , so that the foot  28  will move back and forth sideways, as shown by double arrows  48 ,  49 ,  50  and  51  in FIGS.  8 - 9 , as the person tries to gain the balance while standing on the relatively narrow plate  10 . The foot  29  that is not treated may first be very close to the floor, so that the person  44  may gain some balance as the foot  28  is supported by the plate  10 . The person  44  may then be lifted up the other foot and the arm  46  is stretched out to shift the point of gravity of the body  44 . The high friction area  36  of the plate  10  reduces the risk that the foot  28  is going to slide off the plate. Because the plate  10  is made of a rubber-like material, such as polyurethane, the foot  28  may deform the plate  10  and the plate  10  is not absolutely stable so that the foot will move back and forth in a sideways direction. The opening  18  further weakens the stability of the upper part of the plate  10  to encourage the foot to wiggle back and forth on the plate  10 .  
     [0025] In the embodiment according to FIGS.  1 - 7 , the back portion  20  supports the heel  26  over a width of about 4 cm. Also the front portion  24  supports the foot over an effective width of about 4 cm.  
     [0026] The plate  10  supports the foot about 4 cm above the surface on which the plate rests.  
     [0027] In a tested embodiment, the plate consists of a material PU 80, that is a polyurethane having the hardness 80. In practice, this material is compressed about 0.5 cm by a person having a weight of 80 kg when the plate has a thickness of about 40 mm, and a through-going bole  18  as per FIGS.  6 - 7 .  
     [0028] The cross section of the hole  18  is generally a like sided triangle, having a top pointing toward the bottom surface of the plate, and a side parallel to the bottom surface, and located centrally in the plate. The side length of the triangular cross section is about 3 cm. The hole reduces the stability of the plate part above the hole, to stimulate sideways movement of the foot. When the plate has a hole  18 , the material of the plate could be chosen not to exhibit any significant elastical compression under the influence of the weight of the user. But if the plate lacks the hole  18 , significant elastical compressibility of the plate could improve the stimulation of sideways movement of the foot.  
     [0029] The middle portion  22  has narrow support surfaces against the arch of the foot so as not to prevent sideways rolling motion of the foot while supporting the arch. The medial and lateral surfaces flanking the effective foot supporting areas of the plate slope downwards from the foot support areas.