INFLATABLE DEVICE AND METHOD FOR USING THE DEVICE

Abstract: An inflatable device can be used for physical therapy, conditioning or training. The device has a support platform (10) and a flexible member (12). The flexible member (12) is attached or affixed to, and has a bowl-shaped distension projecting from one side of, the platform. This flexible member (12) is inflatable to a pressure for supporting a person. The device is inflated in order to support at least some of the weight of a person by compressing the inflatable device at or adjacent to its center. When the person wishes to later change the characteristics of the device, the pressure in the inflatable device can be changed to change its stability.

Description: INFLATABLE DEVICE AND METHOD FOR USING THE DEVICE BACKGROUND OF THE INVENTION 1 . Field of the Invention The present invention relates to devices for physical therapy, conditioning or training, and in particular to inflatable devices. 2. Description of Related Art Many devices are known for facilitating exercises done for therapy, conditioning or physical training. Other than variable resistance training equipment, these devices have not usually offered much adjustability to allow for exercises at different degrees of difficulty. Also, many of these devices have been dedicated to very specific exercises and therefore do not justify a significant investment of space and financial resources for such a narrow purpose. Some exercise devices require a person to maintain balance and equilibrium. A large inflatable ball (for example, 65 cm), known as a Swiss ball, has been used for this purpose. While the ball is useful for certain stability training exercises, standing upon the ball or staying atop the ball requires a high degree of skill and is inappropriate for most. In U.S. Patent 4,801 , 140 a person suffering from a physical disability can stand on the flat side of a non-inflatable molded foam hemisphere to practice balancing. The practical disadvantage of this design is that a high degree of skill is required before someone can actually stand on such an unstable platform. Without assistance from a therapist or additional balancing accessories, this platform is accessible only to trained athletes. In U.S. Patent 5,81 0,703 the underside of a small board is fitted with a smaller spherical projection. The relatively small diameter of the spherical projection tends to make the board relatively unstable. The height of the spherical projection can be set to one of three discrete settings. Overall, the adjustment has little range and resolution. Also, the projection, if inverted to face upwardly, is too small to allow a person to perform an exercise while placing weight on the projection. An inflated cushion in the shape of a disk (sold under the name DuraDisk through C.H.E. K. Institute) has been described as useful for certain exercises. This cushion is described as needing no inflation, but the product is shipped with an inflation valve that the user has access to. A separate wooden platform, 20 inches in diameter, is sold for the purpose of placing the platform over the cushion to create a balance board. This cushion is relatively flat and therefore offers little challenge to a user. It is not useful for the inflatable disk to be placed on the board as this would offer no advantage over putting the inflatable disk on the floor. Also, the use of a separate platform requires careful placement and centering of the platform and also introduces the need for regularly finding and associating the separate parts. In U.S. Patent 5,643, 1 54 a relatively squat, rounded ballast is mounted under a relatively wide platform. If the user is willing to stock an inventory, the rounded ballast can be changed, but the individual ballasts are not adjustable. This device is designed for use on land or in water. For use in water, an edge bumper is inflated an adjustable amount to reach the desired buoyancy. While this edge bumper is adjustable, this adjustment is only effective in water. The stability of the platform on land will not be substantially affected by adjusting an edge bumper, which inherently provides a stable base. See also U.S. Patent 3,024,021 for a non-adjustable device employing a platform connected through a resilient member to a rounded base. U.S. Patent 5,643, 1 65 shows a frustroconical balancing device with a flattened apex. This device is stable in only one central position, and becomes highly unstable once tilted slightly. Furthermore, the stability of this device is not adjustable. See also U.S. Patent 5,549,536 for a continually tilted platform. Accordingly, there is a need for an improved device that offers a unique experience and range of possible exercises, and that can allow adjustment, preferably with an inflatable device, to accommodate persons with different levels of skills and capabilities. SUMMARY OF THE INVENTION In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a device for physical therapy, conditioning or training. The device has a support platform and a flexible member. The flexible member is attached to, and has a bowl-shaped distention projecting from one side of, the platform. This flexible member is inflatable to a pressure for supporting a person. In accordance with another aspect of the invention there is provided, a method for physical therapy, conditioning or training. The method employs an inflatable device having a flexible member distending from a platform. The method includes the step of inflating the inflatable device to form a domed surface adjacent a relatively flat surface. Another step is placing at least some of the weight of a person on said inflatable device. The method also includes the steps of removing the weight of the person and changing the pressure in the inflatable device to change its stability. Another step is again placing at least some of the weight of a person on said inflatable device. By employing devices and methods of the foregoing type, a variety of exercises can be performed by persons of varying levels of skills and capabilities. In a preferred embodiment a flexible, sheet-like member is affixed along the edge of a rigid circular platform, although other non-circular outlines are contemplated. This preferred, sheet-like member can be inflated by a valve installed, for example, in the center of the platform. When inflated, the flexible, sheet-like member forms a domed or hemispherical surface, at least before being loaded. In some embodiments the flexible member may be a closed volume bounded by a first and second surface. The first surface can be laid on a flat circular platform and clamped to the edge of the platform with an annular bead to keep the first surface flat after inflation. Since the second surface is mostly free, it forms a curved surface that is approximately hemispherical. In some embodiments a circular panel can be attached to the underside of the platform to sandwich between them an edge of the flexible, sheet-like member. The edge of the platform may have an upwardly extending lip formed by either rolling the edge of the platform, or by attaching a bead to the platform's edge. In some embodiments the edge of the flexible, sheet-like member can be sandwiched between the bead and the platform. In some cases the user may place the flexible, sheet-like member on the ground and then stand on the platform to enhance the user's balance. The stability of the platform can be altered by adjusting the pressure behind the flexible, sheet-like member. In other cases the user may place the platform on the ground and then stand on the inflated flexible, sheet-like member. This orientation may facilitate balance exercises, to enhance proprioceptive awareness and core stability. Numerous other exercises can be performed when the person uses the flexible, sheet-like member for sitting or supporting a hand, foot, extremity, etc., while performing situps, squats, lunges, etc. BRIEF DESCRIPTION OF THE DRAWINGS The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein: Figure 1 is an axonometric view of a device in accordance with principles of the present invention; Figure 2 is a side elevational view of the device of Figure 1 , showing various levels of distension; Figure 3 is a detailed, fragmentary, cross-sectional view of the device of Figure 1 , but modified to include an additional bead; Figure 4 is a detailed, fragmentary, cross-sectional view of a device that is an alternate to that of Figure 2; Figure 5 is a detailed, fragmentary, cross-sectional view of a device that is an alternate to that of Figure 2; Figure 6 is a plan view of a device that is an alternate to that of Figure 1 ; Figures 7A-7D show the device of Figure 1 being used in a variety of exercises; Figure 8 is a cross-sectional view of a device that is an alternate to that of Figure 1 ; Figure 9 is a detailed, cross-sectional view of the platform of Figure 8; Figure 1 0 is an axonometric view of the elastomeric foot in Figure 8; Figure 1 1 is an edge view of the foot of Figure 1 0; Figure 1 2 is a cross-sectional view of another device that is an alternate to that of Figure 1 ; Figure 1 3 is a detailed, cross-sectional view of the platform of Figure 1 2; Figures 14A through 1 4J are detailed, cross-sectional views of the foot of flexible, sheet-like members that may be mounted on platforms of the type shown in Figure 8, wherein Figure 1 4A corresponds to the foot shown in Figure 8; Figures 1 5A through 1 5K are cross-sectional views of beads that may be used to secure the flexible, sheet-like members of Figures 8, and 14A-1 4J; Figures 1 6A through 1 6F are cross-sectional views of beads that may be used to secure the flexible, sheet-like members of Figures 1 2, and 1 4A-1 4J; Figures 1 7A and 1 7B are cross-sectional views of beads that may be used to secure the flexible, sheet-like members of Figures 8, and 1 4A-14J; Figure 18 is a plan view of the bead of Figure 8 and 1 2; Figure 1 9 is a plan view of a bead that is an alternate to that of Figure 1 8; Figure 20 is a detailed axonometric view of the ends of the beads of Figure 1 8; Figure 21 is a detailed, axonometric view of the ends of beads that are an alternate to that of Figure 20; Figure 22 is a detailed, axonometric view of the ends of beads that are an alternate to that of Figure 20; Figure 23 is a detailed, axonometric view of the ends of beads that are an alternate to that of Figure 20; Figure 24 is an axonometric view of the device of Figure 1 modified to include handholds; Figure 25 is a detailed, fragmentary, cross-sectional view of a constructed device that is an alternate to that of Figure 3; Figure 26 is a cross-sectional view of a device that is an alternate to that of Figure 1 ; and Figure 27 is a cross-sectional view of the device of Figure 26 taken at a circumferentially displaced position and with its flexible member deflated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figures 1 and 2, the illustrated device has a support platform 10 with a circular outline, although other outlines are contemplated (elliptical, polygonal, etc.). Platform 1 0 can be made of wood, plastic, metal, or other materials. A flexible, sheet-like member in the form of an elastomeric sheet 12 is shown secured to the edge of platform 1 0. The edge of sheet-like member 1 2 is attached with an airtight seal to platform 1 0 by glueing, by clamps, or by other sealing means. Sheet-like member 1 2 can be made of any one of a variety of materials, including natural and synthetic rubbers, plastics, etc. Also, in some embodiments sheet-like member 1 2 may be a laminate having an outer surface that is more durable and skid resistant. Sheet-like member 1 2 may be formed by rotational molding or otherwise to have a natural hemispherical shape. This hemispherical shape preferably has a diameter of 1 6 to 36 inches (41 to 91 cm), although other dimensions are contemplated. It will be appreciated, however, that under normal use, and when loaded, the sheet-like member 1 2 will have a profile that is more complex than a hemisphere. In other embodiments, sheet-like member 1 2 may start as a flat circular sheet that distends when inflated into a dome (taking essentially a hemispherical shape when unloaded). A valve means 14 is mounted in a center hole in platform 10. The valve means 14 may be a rubber bushing covered on its inside with a flexible flap that acts as a check valve. Valves of this type are used to inflate basketballs, footballs, etc. If the device need only be inflated to a relatively low pressure, a tube with a stopper can permit a user to blow into the tube to inflate the device, as is done with inflatable beach balls, and the like. Various other types of valves can be used in different embodiments, depending upon the desired pressure, pumping method, etc. Also, valve 1 4 can be located on alternate positions on platform 1 0, or on various positions on sheet-like member 1 2. Referring to Figures 1 and 3, a circular deck 1 6 is shown as an element attached to the underside of platform 1 0 by means of screws 1 8, although other types of fasteners may be used instead. The edge of sheet-like member 1 2 is shown sandwiched between platform 1 0 and underlying deck 1 6. The seal at the edge of sheet-like member 1 2 can be enhanced by using an appropriate glue, caulk, gasket compound, or other sealing material. The hole holding valve means 14 is aligned with hole 20 in underlying deck 1 6, although such alignment is unnecessary, and in some embodiments a number of spaced holes may be used instead. Platform 1 0 and deck 1 6 may be made of different materials, so that the outer surface may be flexible and skid proof, while the inside deck may be rigid and able to bear heavy loads. In still other embodiments, underlying deck 1 6 may be replaced with a hoop or other annular structure to simply concentrate on its function of acting as an affixing means for sealing sheet-like member 1 2 to platform 10. The edge of platform 10 is fitted with an annular bead 22. Bead 22 may be secured by glueing or by various fasteners. Also, bead 22 may have a variety of shapes. Bead 22 can be formed of a length of extruded rubber or plastic that is closed into a loop. Alternatively, bead 22 may be initially molded as an annulus. Preferably, the top of bead 22 rises above the surface of platform 1 0 to provide a small guard. Also in preferred embodiments, bead 22 may be relatively soft material that prevents injury caused by the user accidentally kicking or otherwise colliding with the edge of platform 10. Referring to Figure 25, alternate platform 1 0A is similar to the previously described platform of Figure 3 and may be secured to the deck 1 6' with screws or other fasteners (not shown). Deck 1 6' is similar to the previously illustrated deck, but has a rectangular annular groove 1 6A to the outside of, and concentric with, an annular, V-shaped groove or furrow 1 6B. In this constructed embodiment, the edge of flexible member 1 2 was glued and stapled in the illustrated position. A bead 21 of cement is shown in furrow 1 6B along the edge of flexible member 1 2. A spline 1 9 is shown positioned between flexible member 1 2 and platform 10A, in alignment with rectangular groove 1 6A. Spline 1 9 may be similar to the plastic cords used to secure screens into rectangular grooves in frames, although other material can be used instead. Essentially, platform 10A is secured to deck 1 6' so that spline 1 9 presses flexible member 1 2 into groove 1 6A to form a relatively tight seal. As before, platform 1 0A may have a valve (not shown) for inflating flexible member 1 2. Referring to Figure 4, alternate platform 10" is similar to the previously described platform, but with a peripheral recess 24. An annular bead 26 is shown fitted in recess 24, while sandwiched between them is previously mentioned sheet-like member 1 2. As before, bead 26 may be a molded annulus or may be formed from a length of extruded material that is closed into a loop. Alternatively, the edge of sheet-like member 12 may be sealed into recess 24 before molding bead 26 in situ. Bead 26 has an outside surface that is coplanar with the outside surface of platform 10" to facilitate situations where the device is placed with platform 1 0" down, for certain exercises to be described presently. Referring to Figure 5, previously mentioned deck 1 6 is shown attached by means of screws 18 to alternate platform 10" . Also as before, sheet-like member 1 2 is sandwiched between elements 10" and 1 6. Platform 1 0" has an integral edge 28 that is rolled. Platform 1 0" maybe shaped by molding, stamping, bending, etc. Referring to Figure 6, an alternate platform 10'" is generally rectangular with rounded corners. Platform 1 0'" to be dimensioned to simulate the general size and feel of a skate board or snowboard. Here, two inflatable domes 30 are sealed to the underside of platform 1 0'" using structure and techniques similar to that previously described. The domes 30 are arranged so that the platform 1 0'" can roll (rotation about a longitudinal axis) fairly easily, but cannot pitch unless the user places significant weight at the front or back of the platform 10'". Referring to Figure 8, the previously mentioned flexible member is shown here as an axially symmetric member 32 in the form of a closed volume having a domed portion 33 integral with a floor portion 34. Domed portion 33 and floor portion 34 merge at a foot 36. Flexible member 32 may be formed by rotational molding, although other fabrication techniques are possible, such as welding together two flexible sheets at a foot area. Domed portion 32 will be approximately hemispherical while floor portion 34 will be a substantially flat, circular disk. A plastics sleeve 38 is fitted in an opening in the center of floor portion 34. A plug 40 is shown inside sleeve 38 and has a handle 41 with a pulley-like shape. Plug 40 has a bulbous inside end 42 and a bulbous portion 44 that keeps plug 40 in approximately the position illustrated. Plug 40 can be removed to deflate flexible member 32 or to inflate it by inserting inside sleeve 38 a tubular fitting connected to a pump or other pressure source. Foot 36 is also illustrated in Figure 1 4A in a relaxed, uncompressed state. Foot 36 has a toe 37A projecting radially outward and is molded with an annular valley 37B. Foot 36 also has a heel 37C projecting radially inward. An annular bead 46 with a C-shaped cross-section is attached by screws 48 to the edge of platform 50. Bead 46 is also shown in Figure 1 5A and has on one of its branches a downwardly projecting, annular nub 47A designed to engage the valley 37B of foot 36 (Figure 1 4A). Bead 46 has a sculpted annular ridge 47B to provide a smooth transition from the bead 46 to the flexible member 32. Bead 46 also has on its other branch a graded or beveled end 47C shaped to fit in a matching undercut channel 52 in platform 50, which holds bead 46 in place to provide additional attachment strength. Platform 50 (shown also in Figure 9) is preferably a thermoplastic material molded into a honeycomb structure having a plurality of cells 50A. Platform 50 has a center opening 50B for plug 40. Platform 50 also has an annular flange 50C for holding the heel of foot 36. An elastomeric pad 54 on the underside of bead 46 is installed in a cavity that is essentially cylindrical, although some embodiments may have undercut side walls for holding pad 54. Figures 1 0 and 1 1 show pad 54 having an annular, pulley-like shape. Concentric hole 56 enables pad 54 to more easily compress and fit into a cavity. In some embodiments, pad 54 will be mounted directly in platform 50 instead, as shown in phantom as alternate pad 54'. Referring to Figure 24, previously mentioned flexible member 32 is shown installed on platform 50 with bead 46. Platform 50 is shown on its underside with a pair of cavities 51 , acting as handholds. Preferably, cavities 51 are undercut so that the user can wrap his or her fingers around the undercut, in order to carry the device. Referring to Figure 1 2, previously mentioned flexible member 32 is shown installed on alternate platform 58. Platform 58 is fitted with a number of pads 54, in a manner described previously in connection with Figure 8. Platform 58 has an annular flange 58C shaped the same as previously described flange 50C of Figure 8. Platform 58 is designed to support a hook-shaped (in this view, inverted J-shaped), annular bead 60 in place of the previously described C-shaped bead. Bead 60 has an annular groove designed to fit over and form a tongue and groove joint with the annular ridge 62, which projects upwardly along the perimeter of platform 58. Bead 60 has a number of countersunk holes 64 to allow bead 60 to be attached to platform 58 by means of a number of screws 66. The illustrated, alternate plug 68 is the same as previously mentioned plug 40 (Figure 8), except for having an annular handle 70. Referring to Figures 1 2, 14A and 1 6A, previously described bead 60 is shown with previously mentioned annular groove 60C. Bead 60 has a downwardly projecting, annular nub 60A designed to engage the valley 37B of foot 36 (Figure 14A). Bead 60 has a sculpted annular ridge 60B to provide a smooth transition from the bead 60 to the flexible member 32. Figure 1 4B shows a foot 36B that is an alternate to that of Figure 1 4A. These two feet are essentially the same except that foot 36B does not have the valley 37B shown in Figure 1 4A. Therefore, a matching platform will not need a nub designed to fit in a valley. The feet 36G and 36H are functionally equivalent to the foot 36B of Figure 14B but are proportioned somewhat differently. Foot 36C of Figure 14C is the same as foot 36 of Figure 1 4A, except that heel 37C is eliminated. Foot 36D is the same as foot 36B of Figure 1 4B, except that the heel is eliminated. Therefore, in both cases, a matching platform will not need a flange to entrap a heel. Referring to Figures 14E and 14F, the feet 36E and 36F are simple annular ridges without the previously described toes and heels of, for example, foot 36 of Figure 14A. These feet may be simply wrapped around the edge of a platform and clamped in place using techniques such as those shown in Figures 3, 4, and 5. Referring to Figure 141, a foot 361 does not project downwardly, but operates more like a simple flange. Foot 361 would be attached to a platform having a flat surface, that is, a platform without the peripheral notches shown in the embodiments of Figures 9 and 1 3. Foot 36I would be clamped to a platform by a C-shaped bead if such as those shown in Figures 1 5A-K. These beads would embrace foot 36I and the platform. Referring to Figure 1 4J, foot 36J is similar to that previously described in Figure 1 41, except that foot 36J has an upwardly and downwardly directed ridge. The upwardly directed ridge can be contained in a groove in a C-shaped bead, while the downwardly directed ridge can be contained in a groove in the bead or the platform. Referring to Figure 1 5C, bead 46C has its lower end squared and eliminates the beveling of end 47C of Figure 1 5A. Therefore a matching platform will not need the previously mentioned undercut and will simply have a butt joint. Bead 46B of Figure 1 5B is the same as bead 46C, except that the transition feature 47B of Figure 1 5A was eliminated. Bead 46 D of Figure 1 5D is the same as bead 46 of Figure 1 5A except that annular nub 47A was eliminated, so that the bead does not need a foot with a valley. Bead 46E of Figure 1 5E is the same as bead 46D of Figure 1 5D, except that the lower beveled end is replaced with a stepped profile, which will mate with a platform having a matching profile. Bead 46H of Figure 1 5H is similar to bead 46 of Figure 1 5A except that feature 47B has been elongated. Bead 46G of Figure 1 5G is the same as that of Figure 1 5H except that the lower beveled end is replaced with the squared end as shown in Figure 1 5C. Referring to Figures 1 51, 1 5J, and 1 5K, beads 46I, 46J, 46K correspond to previously mentioned beads 46F, 46B, and 46, respectively, except that their outside edges are rounded. Referring to Figure 1 6B, bead 72 is essentially the same as that of Figure 1 6A, except that sculpted feature 60B was eliminated. Referring to Figures 1 6C and 1 6D, beads 74 and 76 correspond to beads 60 and 72, respectively, of Figures 1 6A and 1 6B, except that they do not have the annular groove (for example, annular groove 60C of Figure 1 6A). These beads will fit in the notch 84 of platform 82 of Figure 1 3. Platform 82 is shown with an annular flange 86 designed to entrap feet having radially inward heels. Referring to Figure 1 6E, bead 78 is the same as that of Figure 1 6D, except for snap fitting 79, which has an arrowhead-like cross-section designed to fit in an annular groove (not shown) on a platform. This groove preferably has undercut walls. Referring to Figure 1 6F, bead 80 is the same as that of Figure 1 6E, except that bead 80 has a beveled wall 82 that allows bead 80 to fit into a matching groove (not shown) on a platform. The shape will allow bead 80 to snap into place. Referring to Figure 1 7A, bead 85 has an F-shaped cross-section which provides a corner 87. Corner 87 may fit over a shelf, such shelf 84 of platform 58 of Figure 1 3. Referring to Figure 1 7B, bead 88 is similar to bead 85 of Figure 1 7A, except for lower branch 90 which forms a groove 92 that can fit over the edge of a platform, such as platform 58 of Figure 1 3. Referring to Figure 1 8, previously mentioned bead 46F (Figure 1 5F) is shown formed from two semi circular halves. In other embodiments the bead may be a split ring, such as that shown in Figure 1 9 as bead 46F'. In any event, the ends of the bead's must be joined together. In Figure 20, beads 46 are shown with beveled cuts 94 and 96 designed to form a circumferential lap joint. Once overlapped, the two ends can be joined together by threading screw 98 through hole 1 00 and hole 1 02 into the edge of a platform. Referring to Figure 21 , the ends of previously mentioned beads 46 are squared off to form a circumferential butt joint. The beads can be aligned with pin 1 04 fitted in holes 1 06 in the ends of beads 46. Beads 46 can also be secured to a platform using screw holes 107. Referring to Figure 22, previously mentioned beads 46 are again squared to form a butt joint. Here each of the ends of the beads 46 has a slot 108. A barb 1 1 0 having an arrowhead-like shape on either end locks into slots 1 08 to align beads 46 and lock them together. Beads 46 can also be secured to a platform using screw holes 1 1 2. Referring to Figure 23, beads 46 are relieved to form a telescopic joint. In particular, an internally relieved section 1 1 4 is designed to fit over externally relieved section 1 1 6. As before, beads 46 can be screwed into the edge of a platform. Referring to Figure 26, a circular platform 1 20 may have in lower region 1 41 a number of bosses 141 A and indentations 1 41 B to form an interior, corrugated structure that prevent slipping of the flexible member 1 34, which may be formed with a mating surface having indentations 1 35A and bosses 1 35B to enhance this non-slip feature. The edge of platform 1 20 is formed by rotational molding or other means into a wall 1 24 that curls back to form a lip 1 25. The outside of peripheral curled wall 1 24 is essentially a section of a toroid. The inside of curled wall 1 24 is more complex and has an outwardly projecting, bulbous, annular cavity 1 26, and an axially projecting, bulbous, annular cavity 1 28. Wall 1 24 has annular hollow regions 1 24A and 1 24B. Cavities 1 26 and 1 28 are shaped to mate with annular bulbous projections 1 30 and 1 32 of flexible member 1 34. Flexible member 1 34 has a domed portion 1 36 and a floor portion 1 35 that are integral with each other and meet along the periphery that includes projections 1 30 and 1 32. Flexible member 1 34 may also be formed by rotational molding. Referring to Figure 27, flexible member 1 34 is shown deflated with its projections 1 30 and 1 32 released from cavities 1 26 and 1 28. Without the inflationary pressure, lower platform section 141 can return to its unstressed state, where it bows inward slightly. Platform section 1 41 also has a number of dimples 142 for receiving the shank of tack-like rubber feet 1 39. Figure 27 is taken at a different circumferential position where the previously mentioned hollows (hollows 1 24A and 1 24B) are open, thereby effectively providing handholds 1 40. In the preferred embodiment, four equiangularly spaced handholds are provided, although a different number may be employed in other embodiments. Also in the preferred embodiment, projection 1 30 may be notched to fit around inward projections (not shown) on the inside wall of cavity 1 26 in order to prevent flexible member 1 34 from rotating inside wall 1 24. When flexible member 1 34 is inflated, projections 1 30 and 1 32 swell and fit into cavities 1 26 and 1 28. This effectively locks the edge of inflatable member 1 34 into the position shown in Figure 26. Also, the inward bias of platform section 1 41 is overcome by the inflationary pressure, which pushes platform 141 from the position shown in full lines in Figure 27 to the position shown in phantom (which latter position is also the position shown in full lines in Figure 26). To facilitate an understanding of the principles associated with the foregoing apparatus, the use of the device of Figure 1 will be briefly described. The user will initially inflate the device by inserting a pump needle through valve means 1 4. The sheet-like member 1 2 will be inflated and will distend accordingly. With a modest level of inflation, sheet-like member 1 2 will take the hemispherical shape 1 2A shown in Figure 2 when unloaded (that is, when suspended so that the sheet-like member 1 2 does not touch the ground). The foregoing device may be used with the platform 1 0 resting on the ground as shown in Figure 7A. Here, a person P stands on sheet-like member 1 2, working to maintain balance. For an especially challenging session, a person can stand on one foot. The difficulty can be further increased if the person P rolls or tilts the head, with or without the eyes closed. Another, surprisingly challenging session can consist of simply kneeling on the sheet-like member 1 2. This effort can be reduced for a novice by getting down on all fours and then working to maintain balance. The person P may mount sheet-like member 1 2 in order to receive various benefits. The user may perform an exercise in order to improve the user's sense of balance. In some cases, the user may suffer from a disability that affects coordination and balance. Therefore, the device can be used to improve motor skills and balance as a form of therapy, rehabilitation and prehab. In other cases, an athlete may wish to improve balance for any one of a number of sports requiring a refined sense of balance. Alternatively, the user may stand on member 1 2 simply to exercise his or her muscles. Of course, some users will stand on member 1 2 simply for enjoyment. The amount of exercise sustained by mounting the device can be substantial. The person maintaining balance will normally be required to make many rapid and urgent posture adjustments by exerting a wide range of muscles. Moreover, this effort takes place with a sense of stimulation and excitement that makes the effort challenging and interesting. Thus, the user can quickly reach a high level of exertion without the usual sense of tedium or labor. As the user's balance, coordination, and endurance improve, the user may wish to increase the level of difficulty. Accordingly, the pressure within the device can be decreased by venting valve means 14. This reduced pressure leads to less sure footing and increased effort to maintain balance. Alternatively, the pressure can be increased to accommodate an especially difficult routine, or to accommodate a user that is tired or less experienced. This increased pressure corresponds to more stability, since the sheet-like member 1 2 is less able to shift, distend, and distort underneath the user. An advantage with the foregoing pressure adjustment is that the user can continuously and finely adjust the pressure and the level of difficulty to suit his or her personal needs. Because the device can be adjusted to become relatively stable, the user can readily perform ordinary exercises. For example, the user can squat, or stretch and stand on his or her toes as an exercise. Such exercises provide the dual benefit of conditioning muscles, while simultaneously training a person to maintain balance. Other exercises are contemplated, such as leg kicks, knee lifts, etc. A person P can also sit on sheet-like member 1 2 as shown in Figure 7B to perform abdominal exercises. Here, the user can decrease the level of difficulty by shifting forward to reduce the amount of upper body weight that is cantilevered out past the device. An additional advantage is that sheet-like member 1 2 can conform to the user's body and support the lower back as the user leans back. Decreasing the pressure within sheet-like member 1 2 can increase the amount of lower back support under such circumstances. Various other exercises can be performed on the device, oriented platform down. As shown in Figure 7C, person P can perform lunges. In fact, many of the exercises that are performed in step aerobics classes can be performed with the presently disclosed device. One advantage with this mode of use is that the exercise is very low impact, since sheet-like member 1 2 acts like a cushion. Again, the pressure behind sheet-like member 1 2 can be adjusted to change the level of difficulty. Also, the cushioning effect of sheet-like member 1 2 can make the exercises low impact, which is very important in step aerobics in order to avoid the joint injury that commonly occur with long-term use. The foregoing device need not be used with the platform down, but may be oriented platform up, as shown in Figure 7D. Because the device is inherently less stable when inverted as in Figure 7D, the user will receive a more vigorous experience, which may be appropriate for athletic training. When placed on the ground (level G 1 of Figure 2) in order to support a person as shown in Figure 7D, sheet-like member 1 2 will become more squat and take the outline 1 2A shown in phantom in Figure 2. This is a relatively more stable condition and the user can maintain balance while standing on platform 1 0 without too much difficulty. Pressure can then be increased by reattaching a pump to valve means 14. Sheet-like member 1 2 may then be pressurized to distend further and take the outline 1 2B shown in phantom in Figure 2, when placed on the ground at level G2. Outline 1 2B is closer to hemispherical and will make the platform 10 less stable. If the device is built sufficiently strong to sustain a very high pressure, sheet-like member 1 2 can distend to the almost precisely hemispherical shape shown in full line in Figure 2. This represents the highest level of difficulty, requiring a high level of skill and endurance. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims: CLAIMS: 1 . A device for physical therapy, conditioning or training, comprising: a support platform; and a flexible member affixed to, and having a bowl-shaped distention projecting from one side of, said platform, said flexible member being inflatable to a pressure for supporting a person. 2. A device according to claim 1 wherein said flexible member is dome- shaped and elastomeric. 3. A device according to claim 1 wherein said platform has a substantially circular border. 4. A device according to claim 3 wherein said platform has at least one cavity sized to provide a handhold. 5. A device according to claim 3 wherein said border of said platform is rolled in a direction away from the flexible member. 6. A device according to claim 3 wherein said flexible member is substantially hemispherical before bearing a load. 7. A device according to claim 1 comprising: valve means adapted to communicate a source of pressure for changing pressure within said flexible member, in order to adjust said device and change its support stability. 8. A device according to claim 7 wherein said valve means is located on said flexible member. 9. A device according to claim 7 wherein said valve means is located on said platform. 1 0. A device according to claim 7 wherein said valve means is centrally located on said platform. 1 1 . A device according to claim 1 wherein said platform has an outer support surface adapted for standing upon. 1 2. A device according to claim 1 wherein said flexible member has an outside surface adapted for standing upon. 1 3. A device according to claim 1 wherein said flexible member comprises a sheet-like member. 14. A device according to claim 1 3 comprising: affixing means for affixing said flexible member to said platform. 1 5. A device according to claim 1 wherein said flexible member comprises: a domed portion and a substantially flat portion encompassing a closed volume. 1 6. A device according to claim 1 5 comprising: affixing means for affixing said flexible member to said platform. 1 7. A device according to claim 1 6 wherein said affixing means comprises: an element secured to said platform, said flexible member being sandwiched between said element and said platform. 1 8. A device according to claim 1 7 wherein said platform has an outside and an inside face, said element being secured to the inside face of said platform. 1 9. A device according to claim 1 comprising: an element secured to said platform, said flexible member being sandwiched between said element and said platform. 20. A device according to claim 1 9 wherein said element has an annular groove, the device comprising: a cord positioned between said platform and said flexible member in alignment with said annular groove, so that said cord tends to press said flexible member into said annular groove. 21 . A device according to claim 20 wherein said element has an annular furrow, the flexible member having an edge secured in said furrow. 22. A device according to claim 1 comprising: an annular bead peripherally secured to said platform. 23. A device according to claim 22 wherein said flexible member is sandwiched between said bead and said platform. 24. A device according to claim 23 wherein said platform has an inside and an outside face, said bead being attached upon said outside face of said platform. 25. A device according to claim 22 wherein said flexible member comprises: a domed portion and a substantially flat portion encompassing a closed volume. 26. A device according to claim 25 wherein said flexible member comprises: an annular foot peripherally connected to said domed portion and said substantially flat portion, said annular bead being attached to said platform to engage and hold said foot. 27. A device according to claim 26 wherein said foot has a heel directed radially inward, said platform having a flange adapted to engage and hold said heel. 28. A device according to claim 26 wherein said foot has a toe directed radially outward, said annular bead being adapted to engage and hold said toe. 29. A device according to claim 28 wherein said toe has a valley, said annular bead having an annular ridge adapted to fit into said valley. 30. A device according to claim 28 wherein said annular bead has a C- shaped cross-section with a pair of branches adapted to straddle said platform. 31 . A device according to claim 30 wherein said platform has a peripheral undercut channel, one of said branches of said bead being graded to fit under said undercut channel of said platform. 32. A device according to claim 22 wherein said annular bead is joined to said platform with a tongue and groove joint. 33. A device according to claim 22 wherein said annular bead is joined to said platform with a snap joint. 34. A device according to claim 22 wherein said annular bead is closed into a loop at at least one circumferential joint. 35. A device according to claim 28 wherein said annular bead has a J- shaped cross-section attached to said platform and shaped to hook onto said toe of said foot. 36. A device according to claim 1 wherein said flexible member comprises: a plurality of domes attached to one side of said platform. 37. A device according to claim 1 wherein said platform has a peripheral curled wall arranged to peripherally engage said flexible member. 38. A device according to claim 37 wherein said flexible member comprises: a domed portion and a substantially flat portion encompassing a closed volume. 39. A device according to claim 38 wherein said curled wall has at least one annular cavity for peripherally receiving and engaging said flexible member. 40. A device according to claim 38 wherein said curled wall has a plurality of concave handholds. 41 . A device according to claim 38 wherein said platform tends to bow inwardly but deform into a flat configuration when said flexible member is inflated. 42. A method for physical therapy, conditioning or training, employing an inflatable device having a flexible member distending from a platform, the method comprising the steps of: inflating said inflatable device to form a domed surface adjacent a relatively flat surface; supporting at least some of the weight of a person by compressing said inflatable device at or adjacent to the center of said inflatable device; removing the weight of the person; changing the pressure in said inflatable device to change its stability; and replacing at least some of the weight of a person on said inflatable device. 43. A method according to claim 42 comprising the step of: laying said inflatable device down with the flexible member up before placing at least some of the weight of a person on said inflatable device. 44. A method according to claim 42 comprising the step of: laying said inflatable device down with the platform up before placing at least some of the weight of a person on said inflatable device. 45. A method according to claim 42 wherein the step of changing the pressure is performed in a manner to change stability of said inflatable device. 46. A device for physical therapy, conditioning or training, comprising: a support platform; and a flexible member attached to, and having a bowl-shaped distention projecting from one side of, said platform, said flexible member being inflatable to a pressure for supporting a person. revd. May 31, 2000

Inventors: COTTER JAMES E, WECK DAVID S, COTTER, JAMES, E., WECK, DAVID, S.
Applicants: COTTER JAMES E, WECK DAVID S, COTTER, JAMES, E., WECK, DAVID, S.
Application year: 2000
Main classification: A63B23
IPC codes: A63B22