Teaching aid for spinal mobilization and manipulation therapy

A teaching aid for spinal mobilization and manipulation therapy is described which includes a first support on which is mounted a spinal model. A second support underlies the first support. A third support underlies the second support. The third support has a cavity into which the second support is telescopically received. Telescopic movement of the second support relative to the third support occurs when a force is applied to the first support. A load sensor is disposed between the first support and the second support whereby a force with which the first support is pressed toward the second support is measured. A plurality of springs are disposed between the second support and the third support to provide resistance to telescopic movement of the second support relative to the third support. A displacement sensor is secured between the second support and the third support whereby the displacement of the second support relative to the third support is measured. A microprocessor is linked to the load sensor and the displacement sensor. The microprocessor is programmed to receive signals from the load sensor and the displacement sensor, convert the signals into values, and compare the values as to the amount of displacement occurring and the amount of force being applied to a therapeutic range of values. Human readable feedback is provided as to whether the measured values for force and displacement are within the therapeutic range.

The present invention relates to a teaching aid for spinal mobilization and 
manipulation therapy. 
BACKGROUND OF THE INVENTION 
Spinal mobilization and manipulation therapy, involving a manual adjustment 
of the spine, is recognized as having beneficial effects. It is the 
foundation of the chiropractic field of medicine. 
With spinal mobilization and manipulation therapy the amount of pressure 
applied is critical. When the pressure applied is insufficient, the 
treatment lacks utility. When the pressure applied is excessive, the 
patient may suffer physical harm. 
Text book descriptions of assessment and treatment techniques use terms 
such as "firm" or "steady" to describe the forces required. These terms 
are subject to individual interpretation. 
The pressure applied must be related to the amount of spinal displacement 
that is occurring. The amount of pressure required to achieve a 
therapeutic displacement of the spine varies between patients. 
SUMMARY OF THE INVENTION 
What is required is a teaching aid for spinal mobilization and manipulation 
therapy which provides feedback to a therapist regarding the amount of 
pressure to be applied achieve a therapeutic displacement of the spine. 
According to the present invention there is provided a teaching aid for 
spinal mobilization and manipulation therapy which includes a first 
support on which is mounted a spinal model. A second support underlies the 
first support. A third support underlies the second support. The third 
support has a cavity into which the second support is telescopically 
received. Telescopic movement of the second support relative to the third 
support occurs when a force is applied to the first support. A load sensor 
is disposed between the first support and the second support whereby a 
force with which the first support is pressed toward the second support is 
measured. A plurality of springs are disposed between the second support 
and the third support to provide resistance to telescopic movement of the 
second support relative to the third support. A displacement sensor is 
secured between the second support and the third support whereby the 
displacement of the second support relative to the third support is 
measured. A microprocessor is linked to the load sensor and the 
displacement sensor. The microprocessor is programmed to receive signals 
from the load sensor and the displacement sensor, convert the signals into 
values, and compare the values as to the amount of displacement occurring 
and the amount of force being applied to a therapeutic range of values. 
Human readable feedback is provided as to whether the measured values for 
force and displacement are within the therapeutic range. 
The teaching aid, as described above, enables a mobilization and 
manipulation therapist to determine the amount of force required to 
provide displacement of the spine within the therapeutic range. 
Although beneficial results may be obtained through the use of the teaching 
aid, as described above, the relative stiffness of adjacent articular 
segments is a function of the change in applied force to a change in 
displacement. It is the applied force in combination with the resultant 
motion that occurs under specific conditions of stiffness that determines 
the consequences of the therapist's action during mobilizations. Even more 
beneficial results may, therefore, be obtained when the spring resistance 
is variable thereby simulating patients with varying spinal stiffness.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred embodiment, a teaching aid for spinal mobilization and 
manipulation therapy generally identified by reference numeral 10, will 
now be described with reference to FIGS. 1 through 3. 
Teaching aid 10 includes a first support 12, a second support 14, and a 
third support 16. First support 12 has a top surface 18 and a bottom 
surface 20. A spinal model 22 is mounted on top surface 18 of first 
support 12. Second support 14 underlies first support 12. Second support 
14 has a top surface 26 and a bottom surface 28. A load sensor 30 disposed 
between bottom surface 20 of first support 12 and top surface 26 of second 
support 12. A force exerted upon spinal model 22 to press first support 12 
toward second support 14 is measured by load sensor 30. Third support 16 
underlies second support 14. Third support 16 has a cavity 32 into which 
second support 14 is telescopically received. Telescopic movement of 
second support 14 relative to third support 16 occurs when a force is 
applied to spinal model 22 of first support 12. A plurality of springs 34 
are disposed between bottom surface 28 of second support 14 and cavity 32 
of third support 16 to provide resistance to telescopic movement of second 
support 14 relative to third support 16. A displacement sensor 36 is 
secured to second support 14 and third support 16. The displacement of 
second support 14 relative to third support 16 is recorded by displacement 
sensor 36. Displacement sensor 36 has a male member 38 which moves further 
into a female housing 40 as second support 14 is displaced further into 
cavity 32 of third support 16. Load sensor 30 and displacement sensor 36 
are linked by means of cables 42 and 44, respectively, to a microprocessor 
46. Other optional equipment illustrated in FIG. 1, include a signal 
conditioning unit 48, a power supply and amplifying unit 50, and a display 
monitor 51. Signal conditioning unit 48 places the signals received from 
load sensor 30 into a form acceptable for microprocessor 46. Power supply 
and amplifying unit 50 ensures that all the described components receive 
the necessary power requirements. The form of load sensor 30 which is used 
has two components 52 and 54 and measures the force exerted by component 
52 upon component 54. For orienting the forces vertically, guides 56 are 
provided which extend between first support 12 and second support 14. 
The use and operation of teaching aid 10 will now be described with respect 
to FIGS. 1 through 3. Referring to FIG. 2, teaching aid is illustrated in 
a first or initial resting position prior to the application of force by a 
therapist. A therapist exerts a force upon spinal model 22. This force is 
sensed by load sensor 30 and the data is transmitted via cable 42 to 
microprocessor 46. Referring to FIG. 3, the force applied serves to 
compress springs 34 resulting in a displacement of second support 14 
relative to cavity 32 of third support 16. Upon displacement occurring 
male member 38 of displacement sensor 36 extends into female housing 40. 
Referring to FIG. 1, the magnitude of the displacement is sensed by 
displacement sensor 36 and the data is transmitted via cable 44 to 
microprocessor 46. Microprocessor 46 is programmed to receive signals from 
load sensor 30 and displacement sensor 36. The signal from load sensor 30 
is converted into values of displacement and force. Microprocessor 46 then 
compares the values as to the amount of displacement occurring and the 
amount of force being applied to a therapeutics range of values. The 
results of the analysis are then provided in human readable form. In this 
case, display monitor 51 provides a graphic image that demonstrates 
whether the measured values for force and displacement are within the 
therapeutic range. It is preferred that the resistance provided by springs 
34 be variable so as to duplicate varying conditions of spinal stiffness. 
In teaching aid 10, variable resistance is provided by manually adding or 
removing springs from cavity 32 of third support 16. The resistance is in 
direct proportion to the number of springs 34 that are provided. It will 
be apparent that as the system is refined a more sophisticated manner of 
varying resistance can be substituted. 
It will be apparent to one skilled in the art that modifications may be 
made to the illustrated embodiment without departing from the spirit and 
scope of the invention as defined by the claims.