Balance training apparatus

An apparatus for the balance training of athletes, such as downhill skiers, is disclosed, and which comprises a base adapted to rest upon the floor, and a foot plate mounted in spaced relation above the base. The foot plate and base are interconnected by a plurality of springs disposed in a circular arrangement around the center of the foot plate so as to permit tilting of the foot plate relative to the base in all directions. Drive means is also provided for imparting a continuous irregular tilting movement to the foot plate, and which includes an electric motor, a vertical centerpost connected to the output of the motor, an undulating cam plate fixed to the underside of the foot plate, and a follower fixed to the centerpost. Thus upon operation of the motor, the centerpost is rotated and a continuous irregular tilting movement is imparted to the foot plate.

The present invention relates to an apparatus for the balance training of 
athletes, and which is particularly adapted for use in the training of 
downhill skiers. In such instance, the apparatus permits training for 
balance and coordination, at various levels of difficulty, by providing 
for the support upon which the athlete stands to continuously change its 
inclination or slope in an irregular manner. The level of difficulty may 
be changed by adjusting the speed of operation, and/or the magnitude of 
the irregular tilting movements. 
Balance and coordination are important skills in mastering downhill skiing, 
and together with technique, muscular strength, condition, and quickness, 
they determine the overall ability and skill of the skier. Training to 
achieve balance and coordination is difficult without actually skiing. 
While balance plates and rolling boards have heretofore been proposed for 
such training, these prior devices have the disadvantage that the skier 
himself manipulates the positioning of the plate or board. In actual 
skiing, it happens in the opposite way, i.e., when moving downhill it is 
the ground which irregularly moves against the skier, and the skier must 
adjust to such irregular movement with coordinated movement of the arms, 
legs, body, and weight. A limiting factor in the skill of a downhill skier 
is the ability of the skier to quickly meet the irregularities of the 
ground surface in a well coordinated and controlled manner. 
The proprioceptive sense, which refers to the ability to feel the position 
of a joint, may be improved by imparting movements to the joints, 
ligaments, and tendons. By changing the position of the ground, the ankle, 
knee, and hip joint will all change their position. The ability of a 
person to rapidly change the position of different parts of the body in 
order to accommodate the changes in the inclination of the ground may be 
improved by proprioceptive training. With an increasing speed in the 
changes in the orientation of the ground, as well as the magnitude of the 
changes, the proprioceptive sense, and thus also the balance and 
coordination, may be markedly improved. 
It is accordingly an object of the present invention to provide a training 
apparatus for downhill skiers and other athletes, which is adpated to 
improve balance and coordination. 
It is also an object of the present invention to provide a balance training 
apparatus useful in physical medicine and rehabilitation, in the treatment 
of neurological diseases with balance problems, and in the rehabilitation 
of patients with ankle, knee, and hip injuries. 
These and other objects and advantages of the present invention are 
achieved in the embodiment illustrated herein by the provision of a 
balance training apparatus which comprises a base adapted to rest upon a 
horizontal supporting surface such as the ground, and a foot plate upon 
which an athlete is adapted to stand, with the foot plate being supported 
in spaced relation above the base. The means for supporting the foot plate 
includes resilient means interconnecting the base and foot plate along at 
least a plurality of locations disposed in a generally circular 
arrangement around the central portion of the foot plate. The apparatus 
also includes drive means for imparting continuous irregular tilting 
movement to the foot plate relative to the base, whereby an athlete 
standing upon the foot plate is required to continuously adjust to the 
continuously changing inclination of the foot plate. 
In the preferred embodiment, the drive means includes an electric motor, 
and means whereby the athlete may change the speed of the motor and thus 
the speed of the continuously changing tilting movements. Means are also 
provided whereby the magnitude of the tilting movements may be readily 
changed.

Referring more particularly to the drawings, there is illustrated a 
preferred embodiment of a balance training apparatus at 10. The apparatus 
includes a base 12 in the form of a circular plate having a diameter of 
about one-half meter, and which is adapted to rest upon a horizontal 
supporting surface such as the floor of a room or the ground. A circular 
foot plate 14 is interconnected to the base, with the foot plate being 
disposed in spaced relation above the base in the manner best seen in FIG. 
2. 
A variable speed electric motor 15 is mounted centrally on the base 12, and 
the motor is controllable by a switch 16 which is accessible to the 
athlete standing upon the foot plate 14. The motor is oriented so that its 
output shaft extends vertically upward from the base to define a vertical 
centerpost 18 having an axis which perpendicularly intersects the center 
of the foot plate. The upper end of the centerpost is joined to the foot 
plate by means of a bearing 19 which permits the centerpost to rotate with 
respect to the foot plate. In addition, there is provided a ball and 
socket joint 20 between the centerpost and the foot plate for permitting 
the foot plate to tilt in any orientation with respect to the base. 
The means supporting the foot plate 14 above the base 12 includes a 
plurality of coil springs 22 disposed in an equally spaced apart, circular 
arrangement adjacent the periphery of the base and foot plate, and with 
the centerpost 18 being disposed at the center of the circle defined by 
the springs. The upper surface 24 of the foot plate 14 may be smooth and 
relatively slippery as indicated in FIG. 2, with a raised circular border 
25 of a rubber-like material disposed about its periphery. Alternatively, 
the upper surface of the foot plate may include a non-slippery rubber pad 
26 or the like, note FIG. 2A. 
In order to impart the desired continuous irregular tilting movement of the 
foot plate relative to the base, there is provided a circular depending 
cam plate 28 fixed to the underside of the foot plate. The lower edge of 
the cam plate defines a cam surface 29 which undulates in an irregular 
manner as best seen in FIG. 5. A lever arm 30 is fixed to the centerpost 
18 and extends outwardly in a radial direction, and a cam follower 32 is 
mounted adjacent the end of the lever arm 30. The cam follower 32 includes 
a bracket 34 releasably mounted on the lever arm by a set screw 35 or the 
like, and the bracket includes a pair of arms 37, 38 disposed on 
respective opposite sides of the cam plate 28. Also, a conical roller 40 
is mounted between the arms as best seen in FIGS. 6 and 7, and the cam 
surface 29 is inclined so as to conform to the tapered surface of the 
roller 40. The cam follower 32 is removably mounted adjacent the end of 
the lever arm by releasing the set screw 35 to permit an alternative cam 
follower 32a of greater height to be substituted for the cam follower 32. 
As will be apparent, the use of the cam follower 32a will cause the 
magnitude of the tilting movement of the foot plate 14 to be increased. 
To provide reinforcement for the lever arm 30, there may be provided a 
depending support 42 which is mounted to the lever arm generally beneath 
the cam follower 32. The support 42 includes a roller 43 at the lower end, 
which is designed to roll upon the surface of the base 12, to transmit the 
vertical forces exerted on the follower 32 directly to the base 12. 
In operation, the athlete stands upon the foot plate 14 as illustrated in 
FIG. 2, and actuates the switch 16 to commence operation of the motor 15. 
This causes the centerpost 18 to rotate relative to the foot plate 14, and 
the cam follower 32 to move along the cam surface 29, causing the foot 
plate 14 to tilt in a continuous, irregular manner. The peripheral springs 
22 act to stabilize the tilting movement, and maintain contact between the 
cam surface 29 and roller 40 of the follower 32. 
If desired, the switch 16 may incorporate a speed control, by which the 
rotational speed of the motor may be selectively increased or decreased. 
Further, it will be apparent that substitution of the taller cam follower 
32a will increase the magnitude of the tilting movements. In the event the 
upper surface 24 of the foot plate 14 is smooth, and the athlete is 
wearing socks, the feet will tend to slide on the surface during the 
tilting movement, thereby rendering it more difficult for the athlete to 
maintain balance. If a rubber pad 26 is placed on the surface 24, such 
sliding movement would not normally occur, and balancing would be somewhat 
less difficult. 
In the drawings and specification, there has been set forth a preferred 
embodiment of the invention, and although specific terms are employed, 
they are used in a generic and descriptive sense only and not for purposes 
of limitation.