Abstract:
A substantially hollow exercise and rehabilitation device is disclosed, and is useable by athletes and others in training and/or rehabilitation sessions to develop stronger and more precise movements. A user typically stands in a pool of water approximately chest-deep and moves the device through the water in an approximation of a proper swing for a sport, or in a motion designed to rehabilitate or strengthen one or more muscles or muscle groups. The device includes holes that tend to minimize turbulence that a solid device would generate, yet provides both resistance and good haptic feedback to the user. The holes are adjustable in size to provide variable resistance. These features develop or redevelop strength and consistency in the user&#39;s movement. Analogous training benefits are obtained for many activities, such as batting, golfing, and tennis, and for rehabilitation and strength training using devices in the shape of tools and other instruments.

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of, and claims priority to, U.S. patent application Ser. No. 12/044,964, entitled “WATER-BASED SPORT TRAINING” and filed on Mar. 8, 2008, pending. 
    
    
     FIELD 
     The present invention relates to training and physical therapy. More specifically, the present invention relates to a device for developing and strengthening consistent large motor movements, such as the swing of a bat in baseball or the swing of a racquet in tennis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a practice bat in one embodiment. 
         FIG. 2  is a cutaway view of the interior of the practice bat in  FIG. 1 . 
         FIG. 3  is an exploded view of an adjustable resistance practice bat, a variation of the embodiment in  FIG. 1 . 
         FIG. 4  is a side view of the adjustable-resistance practice bat of  FIG. 3 . 
         FIGS. 5-7  are cutaway side views of practice bats that are second, third, and fourth variations on the embodiment of  FIG. 1 . 
         FIG. 8  is a side view of a practice golf club according to a further embodiment. 
         FIGS. 9 and 11  are side views of a person using a practice bat according to  FIG. 1 . 
         FIG. 10  is a side view of a person using a practice golf club according to  FIG. 8 . 
         FIG. 12  is a side view of a practice racquet according to a still further embodiment. 
         FIG. 13  is a side view of a broom according to a yet further embodiment. 
     
    
    
     DESCRIPTION 
     For the purpose of promoting an understanding of the principles of the present invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications of the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
     Generally, one form of the present device is a substantially hollow practice bat useable by baseball players in training and rehabilitation sessions to develop or redevelop stronger and more precise upper body swinging habits. In this form, a user stands in a pool of water, approximately chest-deep. He or she holds the practice bat with both hands and swings it in a proper batting swing, so that (at least through the middle portion of the swing) it passes a few inches under the surface of the water in a level arc. As described in more detail herein, the practice bat includes structural features that tend to minimize turbulence that a standard bat would generate, yet provides both resistance and good haptic feedback to the user. These features develop (or, in some instances of rehabilitation, redevelop) strength and consistency in the user&#39;s swing. Analogous training and benefits are described for other activities, such as golf or tennis. 
     As illustrated in  FIG. 1 , bat  20  includes a handle portion  22  and a distal portion  24 . Handle portion  22  in this embodiment is adapted to approximate the grip on a baseball bat, though in some embodiments, handle portion  22  is further adapted (for example, by wrapping a substantial portion of handle portion  22  with grip tape) to avoid slippage in the user&#39;s hands, particularly in wet environments. In this illustrated embodiment, practice bat  20  is constructed of polyethylene, though in other embodiments other materials such as graphite that are sufficiently resistant to shear forces are used, and in still other embodiments a combination or composite of materials is used. 
     Distal portion  24  of bat  20  is generally a hollow cylinder through which holes  26  are made around its circumference and along its length. In some embodiments, distal portion  24  has an outer diameter of approximately three inches, and holes  26  are each one-half inch in diameter, though in other embodiments the outer diameter and/or holes are larger or smaller. In this embodiment, holes  26  are drilled in a pattern by which two holes are placed on opposite sides of the bat, and the next two holes are placed somewhat further down the bat in an axial direction, and offset rotationally from the placement of the corresponding holes in the previous set. In some embodiments, holes  26  are all of the same size, while in others, the sizes vary in a repeating pattern, and in others the holes  26  are either monotonically increasing or monotonically decreasing in size along practice bat  20 . 
       FIG. 2  illustrates a cutaway view of the inside of the distal portion  24  of bat  20 . Holes  26  pass all of the way through the walls of distal portion  24  and are staggered in their positioning from one circumference to the next. 
     In a variation on the embodiment shown in  FIG. 1 , the size of openings  26  is variable, being adjustable by the user to accommodate a variety of levels of resistance and user skill. One such embodiment is shown in  FIG. 3 , where inner cylinder  28  defines holes  30 , which are positioned in a pattern corresponding to holes  26  in distal portion  24  of practice bat  20 . In this embodiment, post  32  extends radially from inner cylinder  28  so that, when inner cylinder  28  is fully inserted into the distal portion  24  of the outer cylinder, post  32  is received into locking slot  34 . When inner cylinder  28  is fully inserted, post  32  extends to the bend in locking slot  34  and can be turned by the user (by grasping handle  22  and end cap  36 , for example) to rotate them into place. When inner cylinder  28  has been rotated so that post  32  extends into leg portion  38  of locking slot  34 , forces (such as centrifugal force during a swing) that would tend to push inner cylinder  28  out of the outer cylinder will be resisted sufficiently to prevent movement of inner cylinder  28  in that direction. 
     Rotational movement of inner cylinder  28  relative to the outer cylinder adjusts the alignment of inner holes  30  relative to outer holes  26  to increase or decrease the resistance provided to movement of practice bat  20  through water  52 . This adjustment of end cap  36  and relative alignment of holes  26  and  30  are illustrated in  FIG. 4 . 
     The embodiments illustrated in  FIGS. 1-4  use round holes  26  and  30 , but in other embodiments, the holes have different shapes. For example,  FIG. 5  illustrates an embodiment wherein holes  26   a  have an elliptical shape, while in  FIG. 6 , holes  26   b  have a pear shape. In  FIG. 7 , holes  26   c  have the shape of a rectangle with rounded corners. Other shapes of holes will occur to those skilled in the art and will provide advantages such as adjustability, shear strength, or aesthetics. 
       FIG. 8  illustrates another embodiment of a practice device  40 , wherein handle  42  resembles handle portion  22  of practice bat  20  in  FIG. 1 , and leg portion  44  resembles distal portion  24  of practice bat  20 . Holes  46  pass through the exterior surface into a hollow interior of leg portion  44  and may have any of a variety of patterns. One difference in practice device  40  as compared to practice bat  20  is attachment of corner  47  and head piece  49 , which is also drilled through with holes  48 . 
     Operationally, practice club  40  passes through water much like practice bat  20 , but with extra resistance to the motion due to head piece  49 . This resistance results in torque about the axis of handle  42  and leg portion  44  resembles the torque about the shaft of a golf club during a swing. This torque helps train the user to compensate and maintain proper alignment of practice club  40  with the swing. 
     In use, a user  50  stands in water  52  and simulates a batting swing with a motion illustrated by arrow  54 , as shown in  FIG. 9 . The swinging motion is generally just under the surface of the water  52  when water  52  is at the appropriate height—about the level of the armpits of user  50 . In some embodiments, return stroke  56  also maintains a depth just below the surface, both to strengthen muscles used in the stroke and to improve precision movement. Likewise, as shown in  FIG. 10 , user  50  moves practice club  40  through simulated swing  58  to analogous effect. In  FIG. 11 , user  50  moves training device  20  through arc  60  to simulate a tennis swing. 
       FIG. 12  illustrates a practice racquet  70  designed, for example, for players of tennis, racquetball, squash, and other one- and two-handed racquet sports. The user holds handle  72  and swings the racquet  70  in the motion illustrated in  FIG. 9  or  FIG. 11  (for two- or one-handed practice, respectively). Paddle end  74  includes holes  76  and  77  through the outer surface, the interior space between the outer layers of paddle end  74 , and through holes on the other side. Some of the holes  76  are adjustably occluded by a moveable interior panel  78  that, in this embodiment and unlike the generally cylindrical panel/inner cylinder  28  in the embodiment of  FIGS. 3-4 , is generally disc-shaped. Tab  75  can be moved through a limited portion of the circumference of paddle end  74  in the directions indicated by arrow A, and that rotates interior panel  78  in the inner space between the outer layers of paddle end  74 , thereby adjusting the portion of holes  76  that are blocked. In this embodiment, hole  77  is not adjusted during this process. 
       FIG. 13  illustrates a therapeutic tool  80 , which has the general shape of a broom. Handle  82  is suitable for holding by a user in positions spaced apart from resistance end  84 . Holes  86  in resistance end  84  are partially blocked by interior panel  88 , which is sandwiched between the outer surface portions of resistance end  84 . Tab  85  on handle  82  moves in directions indicated by arrow B, i.e., longitudinally along handle  82 , thereby moving interior panel  88  in the corresponding direction. This movement occludes or opens holes  86  so that more or less water can pass through resistance end  84 , providing more or less resistance to movement. 
     A wide variety of implementations will occur to those skilled in this area of technology. In one such example, the device illustrated in  FIGS. 1-4  is constructed with a roughly triangular cross-section instead of the round cross-section illustrated herein. In another, the cross-section is hexagonal, while in others the cross-sectional shape has a still different shape. In devices with these alternative cross-sections, the inner panel takes a corresponding shape and is adjustable in the direction of the length of the device, thereby adjusting the size of the openings and the resistance provided by the device during a swing. 
     In some embodiments, the device is (or is adapted to be) held in one hand, while in others it is (or is adapted to be) adapted to be held in two hands. In some embodiments, the part of the device that is moved through the water takes the shape of an item that is moved during play of a sport or other athletic activity (such as a tennis, squash, or racquetball racquet, golf club, baseball bat, cricket bat, hockey stick, lacrosse stick, jai alai basket, or fishing rod. In others, it takes the shape of a tool, such as a broom or shovel, while in still others it takes the shape of an item of rehabilitation equipment, such as a dumbbell-shaped bar with adjustable-resistance structures on each end. 
     All publications, prior applications, and other documents cited herein are hereby incorporated by reference in their entirety as if each had been individually incorporated by reference and fully set forth. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.