EP1377345B1

EP1377345B1 - Dynamic balance board

Info

Publication number: EP1377345B1
Application number: EP02722400A
Authority: EP
Inventors: Gillian Brydson; Daniel Rafferty
Original assignee: University of Glasgow; Glasgow Caledonian University
Current assignee: University of Glasgow; Glasgow Caledonian University
Priority date: 2001-04-04
Filing date: 2002-04-03
Publication date: 2004-09-01
Anticipated expiration: 2022-04-03
Also published as: GB0108421D0; WO2002081033A3; DE60201130D1; US20040198573A1; ES2230485T3; DE60201130T2; ATE274978T1; EP1377345A2; AU2002253282B2; CA2443033A1; WO2002081033A2

Abstract

A dynamic balance board is described that incorporates a means for providing objective measurements on a user's dynamic balance. The balance board comprises a top board, a rocker base and a plurality of force sensitive transducers strategically positioned on the rocker base. When a user stands on the top board the rocker base permits the oscillation of the top board about an equilibrium position. The force sensitive switches then provide output information regarding the angle of the top board and the rotational movement of the balance board relative to the equilibrium position. By monitoring the output information the dynamic balance board provides an objective measurement of the user's ability to balance on the top board.

Description

The present invention relates to the field of balance boards. In particular, it relates to a balance board for the automated measurement of dynamic balance.
Wobble or rocker style balance boards are commonly used by physiotherapists in the rehabilitation of patients with a variety of diagnoses and within a range of clinical specialisms. Such boards are purported to improve dynamic balance, range of movement, coordination, proprioception (joint position sense) and confidence. They comprise a non-flexing piece of plywood on a rocker base that provide approximately 10-20 degrees of tilt. If the range of motion over which this tilt is exhibited is 180 degrees then the board is referred to in the prior art as a rocker board. If such a range is 360 degrees then the board is refereed to as a wobble board, and as such, wobble boards offer a greater challenge to a patient.
For instance, document EP-A-0862930 discloses a dynamic balance board comprising a top board, a rocking means permitting the oscillation of the top board about an equilibrium position, and detection means mounted on the top board.
Wobble and rocker boards are routinely used for patients with ankle and knee ligament injuries to improve a patient's proprioceptive ability. They also help increase the available range,of movement of the ankle and foot so improving movement and a patient's perception of stiffness. A third area where such devices are commonly employed is in helping patients with balance problems arising as a result of neurological, orthopaedic problems or normal ageing.
Such devices are suitable for use across the whole spectrum of patients. For example they may be employed in the rehabilitation of children or athletes as well as to improve independent mobility in the elderly.
Wobble and rocker boards are popular because they are cheap, portable easy to use and are understood by both clinicians and patients alike. They are designed to be used independently by patients and are easily graded so as to progress difficulty. However, the devices are limited when in comes to the provision of an objective measurement on a patient's progress. There is an increasing movement for physiotherapists to formally audit the outcome of their work with patients by showing what progress has been made. Although there are some balance monitor systems available on the market they do not directly measure performance in a manner familiar to the patient. Also such devices tend not to be portable and are considerably more expensive that traditional wobble or rocker boards.
It is an object of an aspect of the present invention to provide a balance board that incorporates a means for providing objective measurements on a user's dynamic balance, thereby permitting an objective measurement of progress to be made.
A further object of an aspect of the present invention is to provide a balance board capable of producing dynamic balance measurements that is highly portable and cost effective to produce.
According to the present invention there is provided a dynamic balance board comprising a top board, a rocking means and one or more detection means, whereby the rocking means permits the oscillation of the top board about an equilibrium position and the detection means provides output information regarding the angle of the top board relative to the equilibrium position.
The output information of the detection means is binary, whereby the output is off when the top board is substantially horizontal and on when the top board rotates through a predetermined angle.
The predetermined angle is determined by the location of the detection means on the rocking means.
Preferably the detection means provides output information regarding the rotation of the dynamic balance board relative to an equilibrium position
Preferably the rocking means comprises a dome.
Preferably the dome is substantially hemispherical.
Preferably the detection means comprises one or more force sensitive switches.
Preferably the force sensitive switches comprise active transducers mounted on the dome at predetermined locations, whereby when a force, greater than a critical magnitude, is applied to the transducer a resultant output voltage from the transducer is produced.
Preferably the transducers are mounted on the dome in a substantially radial manner.
Most preferably transducers on different radii are located on the dome at predetermined latitudes, defined by the diameter of a horizontal chord of the dome, whereby when the top board tilts through the predetermined angle a force applied to the transducer is greater than the critical magnitude.
Preferably the output signals from the transducers are transmitted to a recording and processing means that provides a time dependent profile of the angle of the top board. Optionally the recording and processing means provides a time dependent profile of the rotational movement of the dynamic balance board.
Preferably the dynamic balance board comprises a biofeedback device capable of relaying information regarding the user to the recording and processing means.
Optionally the recording and processing means is a microcomputer. Alternatively the recording and processing means is a computer.
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 illustrates a side elevation of a dynamic balance board;
Figure 2 illustrates a bottom elevation of a rocker base of the dynamic balance board of Figure 1;
Figure 3 illustrates a top elevation of a force sensitive switch of the dynamic balance board of Figure 1;
Figure 4 illustrates a side elevation of the force sensitive switch of the dynamic balance board of Figure 1; and
Figure 5 illustrates an alternative embodiment of the rocker base of the dynamic balance board of Figure 1.
Referring initially to Figure 1 a dynamic balance board 1 is generally depicted and can be seen to comprise a top board 2 and a rocker base 3 in the shape of a hemisphere.
Figure 2 presents a bottom view of the rocker base 3. As can be observed the force sensitive switches 4 are mounted on the rocker base 3. Figure 3 and Figure 4 show further detail of the force sensitive switches 4. Each switch 4 can be seen to comprise an active transducer 5 and an electrical connector 6. The force sensitive switches 4 operate in a binary mode. When no external force is applied to the active transducer 5 the force sensitive switch 4 remains in an off position. However, the application of a force to the active transducer 5, greater than a critical magnitude, activates the force sensitive switch 4.
With the force sensitive switches 4 mounted on the rocker base 3 they operate in conjunction with the angle of the top board 2. When the top board 2 is substantially horizontal the force sensitive switches 4 are all off and so provide no output. However, when the top board 2 tilts more than an angle as determined by the location of the force active switches on the rocker base (for example 10 degrees relative to horizontal) a force of sufficient magnitude is applied to the active transducer 5 so activating the switch 4.
The output from each force sensitive switch 4 is connected to an electronic comparator (not shown) that produce TTL (transistor-transistor logic) pulses that form the digital input for an electronic display (not shown). The period of time that any force sensitive switch 4 is activated can then be calculated, hence the period of time that a patient spends at 10 degrees or more from the horizontal equilibrium position can be recorded. The time and direction of tilt can then be expressed as a percentage of the overall test duration, therefore producing a dynamic measurement of a patient's ability to balance the board 1.
In an alternative embodiment, shown in Figure 5, the rocker base 3 is populated with force sensitive switches 4 located at two separate diameters on the rocker base 3.
The mounting of the force sensitive switches 4 at a second diameter provides means for taking secondary angular measurements of the tilt angle of the top board, as described previously. However, in this embodiment an additional signal is produced by the force sensitive switches corresponding to what diameter the switch is located. Therefore, employment of this second embodiment provides greater information on the angle of tilt and the time spent at these angles.
Additional force sensitive switches 4 can easily be incorporated on the rocker base 3. These additional switches 4 would increases the accuracy of the dynamic balance profile obtained since the discrete directions in which the angle of tilt is measured would increase. Therefore, the dynamic balance board 1 could readily be employed to provide information regarding rotational movement as well as that relating to angular tilt.
A yet further embodiment includes the incorporation of biofeedback devices to the dynamic balance board in order to allow patients to self-monitor their own progress. Such direct feedback has been shown to improve patient recovery as motivation levels to continue with exercise are increased.
An advantage of the present invention is that it provides a balance board that incorporates a means for providing objective measurements on a user's dynamic balance.
A second advantage of the present invention is that it is small and portable, not requiring a separate computer to record data, thereby making it easy for user's to deploy and store.
Further modifications and improvements may be incorporated without departing from the scope of the invention as defined by the appended Claims.

Claims

A dynamic balance board (1) comprising a top board (2), a rocking means (3) permitting the oscillation of the top board (2) about an equilibrium position, and
one or more detection means (4) mounted on the rocking means (3) wherein a binary output of the one or more detection means provides information regarding the angle of the top board relative to the equilibrium position.
A dynamic balance board according to Claim 1 wherein the binary output of the one or more detection means provides information regarding the rotation of the top board relative to a substantially vertical axis.
A dynamic balance board according to Claim 1 or Claim 2 wherein the binary output of the one or more detection means is off when the top board is in a substantially horizontal equilibrium position and on when the top board rotates through a predetermined angle about a substantially horizontal axis.
A dynamic balance board according to any of the preceding claims wherein the rocking means comprises a dome.
A dynamic balance board according to Claim 4 wherein the dome is substantially hemispherical.
A dynamic balance board according to any of the preceding claims wherein the one or more detection means comprises a force sensitive switch.
A dynamic balance board according to Claim 6 wherein the force sensitive switch comprise a transducer whereby when a force, greater than a critical magnitude, is applied to the transducer a resultant output voltage from the transducer is produced.
A dynamic balance board according to Claim 7 wherein the transducers are mounted on the dome in a substantially radial manner.
A dynamic balance board according to Claim 8 wherein transducers mounted on different radii are located on the dome at predetermined latitudes.
A dynamic balance board according to Claims 7 to 9 wherein the output signals from the transducers are transmitted to a recording and processing means that provides a time dependent profile of the angle of the top board relative to the equilibrium position.
A dynamic balance board according to Claims 7 to 9 wherein the output signals from the transducers are transmitted to a recording and processing means that provides a time dependent profile of the rotation of the top board relative to the substantially vertical axis.
A dynamic balance board according to any of the preceding claims comprising a biofeedback device capable of relaying information regarding the user to the recording and processing means.
A dynamic balance board according to Claims 10 to 12 wherein the recording and processing means is a microcomputer.
A dynamic balance board according to Claims 10 to 12 wherein the recording and processing means is a computer.