Therapeutic exercise device

The present invention relates to a therapeutic exercise device comprising at least one closed container formed from flexible, substantially inextensible sheet material, said container being shaped to permit compression of same by two portions of a human body and being filled with fluid to partially pressurize the interior of said container, the pressure within said container being less than that required to make the container rigid, said container being formed into at least two compartments, each of said compartments being in direct fluid communication with at least one other of said compartments via at least one passage to inhibit the flow of fluid between said compartments in response to an external force applied to at least one of said compartments by movement of one of said human body portions to reduce the volume of said one compartment whereby the remainder of said compartments expand in volume thereby exerting a movement inducing force on the other one of said human body portions.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an exercise device. The exercise device of 
the invention is especially suitable in the prevention of venous 
thrombosis in persons confined to a particular stance or position for 
considerable periods of time, e.g. in wheelchairs, in bed or during 
prolonged travel. The exercise device of the invention also finds use in 
the physiotherapy of patients recovering from illness or surgery. 
2. Description of the Prior Art 
R. E. C. Collins, S. Field and W. Castleden, B.M.J. 2, 1478 (1979) have 
reported that venous thrombosis and subsequent pulmonary embolism occurs 
after prolonged sedentary travel. Such thrombosis can be avoided if normal 
blood-flow is maintained. Normal blood-flow can be maintained by exercise. 
There is therefore a need for an inexpensive, simple, quiet, soft, 
pliable, light-weight, portable and hygienic exercise device which can be 
used during periods of prolonged travel. Such a device is provided by the 
present invention. 
In addition to prolonged sedentary travel, similar problems are likely to 
occur also in geriatrics and persons occupied in sedentary trades or 
professions. The exercise device of the invention finds use in these 
applications. 
In post-operative and ill patients undergoing bed rest, bed sores and 
potential thrombosis are problems. The exercise device of the invention is 
also useful in providing gentle but effective exercise for such patients 
and in avoiding and/or alleviating such problems. 
SUMMARY OF THE INVENTION 
The present invention provides a therapeutic exercise device comprising a 
closed container formed from flexible, substantially inextensible sheet 
material, said container being shaped to permit compression of same by two 
portions of a human body and being filled with fluid to partially 
pressurise the interior of said container, the pressure within said 
container being less than that required to make said container rigid, said 
container being formed into at least two compartments, each of said 
compartments being in direct fluid communication with at least one other 
of said compartments via at least one passage to inhibit the flow of fluid 
between said compartments in response to an external force applied to at 
least one of said compartments by movement of one of said human body 
portions to reduce the volume of said one compartment whereby the 
remainder of said compartments expand in volume thereby exerting a 
movement inducing force on the other one of said human body portions. 
It is preferred that the exercise device be provided with a valve whereby 
it may be partially inflated with or emptied of the preferred fluid, air. 
A first preferred embodiment of the invention, which is especially useful 
to persons engaged in prolonged sedentary travel, is manufactured from two 
sheets of material joined together to form two compartments, one of which 
is provided with a valve, and each compartment being in direct fluid 
communication with the other. It is preferred that the exercise device be 
of such size that, when deflated, it may be folded to approximately the 
size of a man's handkerchief. 
In use, this embodiment is semi-inflated, and placed under the feet of a 
seated traveller or other user. Pressure with one foot on one compartment 
transfers air to the other compartment thereby raising the foot thereon. A 
pedalling or jogging on the spot movement is thus obtainable. All joints 
from toes to ankle, and knee to hip experience movement and alteration of 
position. Thighs are raised naturally and easily from contact with the 
seat. It has been found that once movement on the device is commenced 
subconscious movement continues, which makes the device especially useful 
in the case of geriatrics. The use may readily alter the inclination of 
either foot and hence change the angle between foot and leg. 
It has been found in the case of one patient who had a tendon transplant on 
one ankle that use of the exercise device of the invention enabled the 
patient to get some hip extension and foot plantarflexion which movements 
were desirable post-operation. 
Preliminary tests into the effect of this first preferred embodiment of the 
invention on vascular circulation have been conducted using the Doppler 
ultra-sound technique. The tests have indicated that circulation increased 
7% after 5 minutes exercise by heel-toe action on the exercise device. 
This indicates that 5 minutes use of the exercise device of the invention 
approximates to a walk of 200 m. 
Whilst the first preferred embodiment is described above in relation to use 
under the feet of a seated user, its use is not restricted thereto. It may 
be used, with corresponding alteration of size if necessary, under any 
parts of the body whether the user is in a seated or lying position, e.g. 
under the calves, thighs, buttocks, lumbar region, shoulders or neck. It 
also finds use in exercising the hands and fingers where one compartment 
is held in each hand and air squeezed to and fro between the compartments. 
A second preferred embodiment of the invention, which is especially useful 
to patients recovering from illness or surgery, has four compartments 
arranged side by side in line and is preferably, for hygienic reasons, 
made of suitable size to fit in a standard pillow case. 
In use, this embodiment is partially inflated and placed under the heels, 
calves or thighs of a patient in bed. Pressure with one heel, calf or 
thigh on one compartment transfers air to the other compartments including 
that one under the other heel, calf or thigh, which is accordingly raised. 
A pedalling movement is thus obtained. 
The degree of inflation in this embodiment is preferably 75% to ensure that 
some of the air displayed by pressure on one compartment by a heel, calf 
or thigh reaches the compartment under the other heel, calf or thigh. 
Most preferably in this embodiment the divisions between the compartments 
in this embodiment are non-linear. When used under calves or thighs, the 
legs are thus prevented from slipping into the divisions. 
This embodiment has been found useful in the prevention of the onset of 
venous thrombosis in the lower legs and pressure injury, which are 
frequent complications of immobility and bed-rest. 
A further integer applicable to all embodiments of the invention comprises 
adjustment means adapted to adjust the height of the plane in which the 
compartments in direct fluid communication with each other are located. 
The adjustment means is preferably a further inflatable undercompartment 
which, as well as permitting height adjustment, provides insulation 
against transferred impact. 
A third embodiment of the invention relates to a plurality of exercise 
devices of the invention, said exercise devices being attached in linear 
spaced relationship to enable two or more parts of the body to be 
exercised at the same time. For example: two of the above described first 
preferred embodiments may be joined by non-inflatable plastics sections, 
or by straps, so that a traveller could exercise with one device under the 
feet and another under the thighs; or two of the above described second 
preferred embodiments could be joined likewise to enable both the calves 
or thighs of a bed-rest patient to be raised from the mattress and 
exercised. 
In a preferred form of the third embodiment of the invention, a triple 
exercise device is formed from three of the above described first 
preferred embodiments which are provided aligned with their transverse 
ends parallel and joined by spacers such that they may be placed under the 
thighs, lumbar region and neck of a user in the seated or prone position. 
The spacers are preferably adjustable so that the triple exerciser can be 
used by persons of various heights. Adjustment may be achieved by folding 
of the spacers are formed by non-inflatable plastics sections or by 
buttons, buckles, Velcro (Registered Trade Mark) fastening and the like, 
if the spacers are straps. Buttons, buckles, Velcro fastening and the like 
may also be used in conjunction with the non-inflatable plastics sections.

In FIG. 1, the exercise device 11, shown in its semi-inflated condition is 
fabricated from two sheets of plastics material joined by welds 12 around 
the perimeter and which continue inwards forming divisions 13 dividing the 
device 11 into a left compartment 14 and a right compartment 15 in direct 
communication with each other via passage 16. The right compartment 16 is 
provided with valve 17 by which the the device 11 is filled with or 
emptied of fluid which is preferably air. 
This embodiment is designed to be used primarily by persons in the sitting 
position for the leg exercise. The user places both feet on the device, 
one foot on each compartment, and by exerting pressure with one foot 
causes fluid to flow from the compartment under that foot into the other 
compartment thereby exerting a lifting force on the other foot. Pressure 
is applied sequentially by each foot thereby exercising the legs. 
In FIG. 2 the exercise device 21 is also shown in its semi inflated 
condition and is fabricated in like manner to the embodiment illustrated 
in FIG. 1, with welds 22 around the perimeter continuing inwards to form 
divisions or partitions 23. Internal partitions or welds 221 together with 
divisions 23 define the compartments 241, 242, 251 and 252 each of which 
is in direct communication with each of its neighbours via passages 26. 
Compartment 252 is provided with a valve 27. The interior limits of the 
compartments 241, 242, 251 and 252 formed by divisions 23 and internal 
welds 221 define non-linear boundaries in this preferred embodiment of the 
invention. 
This embodiment is designed to be used primarily be persons in the lying 
positions, especially by patients confined to bed. It may be manufactured 
conveniently in a suitable size to fit inside a standard-pillow case. The 
device is placed under the patients heels, calves or thighs with the legs 
resting on any two compartments. The non-linear boundaries prevent the 
user's legs slipping into the depressions between the compartments. The 
legs are exercised in similar manner as described hereinabove in relation 
to FIG. 1. 
FIGS. 3 and 3a depict a variation of the embodiment illustrated in FIG. 1 
where means to elevate and lower the exercise device are provided. The 
exercise device 31 is formed from three sheets of plastics material, an 
upper sheet 311, a middle sheet 312 and a lower sheet 313. Divisions 33 
are formed by welding sheets 311 and 312 together, and the device 31 
completed by joining sheets 311, 312 and 313 by perimeter welds 32. The 
exercise device 31 is thus divided into a left compartment 34, a right 
compartment 35 and a lower compartment 38, the left compartment 34 and 
right compartment being in direct communication with each other via 
passage 36. The right compartment the lower compartment 38 are provided 
with valves 371 and 372 respectively. 
This embodiment is used in exactly the same manner as the embodiment 
depected in FIG. 1 and has the additional feature that it may be adjusted 
to take into account different physical dimensions of various users. Lower 
compartment 38 can be fully inflated when the device is being used by 
shorter persons and uninflated or partially inflated for taller persons. 
The exercise device 41 of FIGS. 4 and 4a embodies features of the devices 
of FIGS. 2 and 3. It is depicted with compartments 441, 442, 451 and 452 
in semi-inflated condition and in direct communication with their direct 
neighbours via passages 46. Lower compartment 48 is shown in FIG. 4a in a 
fully inflated condition. In like manner to the embodiment of FIG. 2, 
compartments 441, 442, 451 and 452 are separated by non-linear boundaries 
defined by divisions 43 and internal welds 421 between upper sheet 411 and 
middle sheet 412 with perimeter welds 42 joining sheets 411 and 412 to a 
lower sheet 413 thereby forming lower compartment 48. Compartments 452 and 
48 are provided with valves 471 and 472 respectively. 
This embodiment may be used in like manner to the embodiment of FIG. 2, 
compartment being uninflated or inflated to a greater or lesser degree to 
raise or lower the legs of the user under which the exercise device 41 is 
placed. 
FIGS. 5 and 5a shows a composite exercise device consisting of three 
exercises 51 each shown in semi-inflated condition and separated by 
spacers 59. This embodiment is fabricated from two sheets of plastics 
material joined by welds 52 which also form divisions 531 which divide the 
composite exercise device into exercisers 51 and spacers 59, and divisions 
532 which divide exercisers 51 into left compartments 53 and right 
compartments 55 each pair of which are in direct communication with each 
other via passages 56. Each right compartment is provided with a valve 57 
by which each exerciser 51 may be filled or emptied. As shown in FIG. 5a, 
spacers 59 may be shortened by folding as illustrated at 591. 
This embodiment enables a user to exercise three parts of the body, e.g., 
the neck, the small of the back, and the thighs, at the same time, in 
either the sitting or lying position. 
The embodiment shown in FIGS. 5 and 5a may also be formed by welding three 
short lengths of plastics material to a single long length of plastics 
material at the appropriate positions to form the three exercisers. 
In FIG. 6, the composite exercise device consists of three exercisers 61 
each shown in semi-inflated condition. The exercisers are substantially 
identical to that described in FIG. 1, each comprising left compartments 
64 and right compartment 65 in direct communication with each other via 
passage 66 defined by divisions 63, the exercisers 61 being formed from 
two sheets of plastics material secured by welds 62. Each right 
compartment is illustrated with a valve 67. Instead of the foldable 
spacers 59 of the embodiment shown in FIG. 5, the exercisers 61 are 
separated by straps 69 which are adjustable by buckles 691. 
To be useful for exercise purposes, it is important that there be 
sufficient inhibition to flow of fluid between compartments of the 
exercise devices of the invention that fluid in one compartment is not 
immediately displaced by placing one body portion on that compartment with 
little or no force being applied. 
It has been found that the average force applied by the foot of a seated 
healthy human adult on one compartment of the embodiment depicted in FIG. 
1 is about 70 N.+-.30 N. A convenient size for use by travellers of the 
embodiment of FIG. 1 is such that when semi-inflated with fluid, it 
contains 2.0 L.+-.0.2 L. On such an exercise device, it has been 
determined that with the device 11 resting on a surface under the feet of 
a seated average healthy adult, left foot on left compartment 14 and right 
foot on right compartment 15, the left foot fully depressed, application 
of an average force by the right foot to effect a single stroke of 
exercise will fully depress the right foot in 0.5s to 0.7s, thereby 
displacing 0.7 L.+-.0.1 L (about 30% of the total volume of fluid) to the 
left compartment 14 when the perimeter of the cross-section of the passage 
16 is about 38 mm. 
In the embodiment of FIG. 2, two passages 26 are shown between each pair of 
adjacent compartments 241 and 242, 242 and 251, and 251 and 252. This 
embodiment is primarily intended for use by patients recovering from 
surgery or illness who are usually not able to apply as great a force to 
the exercise device as a healthy adult. Accordingly, it has been found 
that when the perimeters of the cross-sections of passages 26 are also 
about 38 mm, a single stroke of exercise can be achieved in 0.4s to 0.8s. 
It should be emphasised that this does not mean that exercise on the 
embodiments as described immediately above is restricted to a stroking 
rate of 0.4s to 0.8s, this will be, however, the average maximum rate of 
exercise achievable on those embodiments by the average users thereof. 
It is therefore preferred that, in the exercise devices according to the 
invention, the total area of cross section of the passage or passages 
between adjacent compartments is such that, on application of an average 
force on a first compartment by a first body portion, the time taken to 
displace sufficient fluid from said first compartment to achieve a stroke 
of exercise is between 0.4s and 0.8s. It should be emphasised, however, 
that the invention is not restricted to exercise devices having such an 
area of cross-section of passage or passages between adjacent 
compartments. The exercise device of the invention, may also find use in 
the training of athletes or by persons wishing to improve their fitness, 
in which cases a passage of smaller cross-sections would be desirable to 
require a greater force to be applied for more strenuous exercise.