Abstract:
The present invention is a piece of exercise equipment designed to train and condition sport-specific muscle groups used during a swinging motion, as in golf. It is comprised of a mechanical linkage, with at least six degrees of freedom of motion so that it effectively simulates a wide variety of golf swings without the need for complex adjustments. It includes a resistance mechanism, such as a pulley system linked to two one-way hydraulic cylinders. This allows a user to simultaneously practice swing form and technique while also strengthening and conditioning the specific muscles needed for the sport.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    As almost anyone who has recently tried a new sport can attest, different sports often require the use of different muscles. Even if a person is generally fit (as through a regular exercise routine), they will often find that the particular movements required by different sports will work previously untested muscles or will work tested muscles in a different way, causing muscle soreness and tightness the next day. The reason for this is that different sports work different muscle groups through different ranges of motion. Consequently, for more advanced participants of a sport, it may be more desirable to train the specific muscle groups for their particular sport using the specific movements for their particular sport rather than to attempt to improve through a more general, unfocused exercise routine.  
           [0002]    The most typical way to train sport-specific muscle groups is actually practicing the sport itself. While actually practicing the sport would obviously work the appropriate muscle groups through the appropriate range of motion, it typically would not produce the same sort of results (in terms of strengthening muscles) as strength-resistance training (i.e. free weights or circuit machines). So, it may be useful, especially to more advanced participants of a sport, to have exercise equipment which is specifically designed to apply strength-resistance training to the muscle groups used to play their particular sport. And, such equipment would be even more useful if it allowed the user to work the appropriate muscle groups through the appropriate range of motion as the user also worked on technique and form, essentially developing muscle memory for their particular sport.  
           [0003]    One such sport, which could use this type of specific strength-resistance training of specialized muscle groups through a particular range of motion, is golf. While there are currently existing devices, such as that disclosed in U.S. Pat. No. 4,261,573, which simulate a golf swing (such that a user may in essence practice the sport indoors in limited space in order to improve swing technique and form), these devices do not provide the simultaneous benefit of strength-resistance training to condition the specific muscle groups. Further, the existing devices require a user to preset the device in order for it to be appropriate for the particular user (according to height, stance, arc of swing, lie angle, etc).  
           [0004]    The present invention of the Golf Swing Conditioner (“GSC”) includes a mechanical linkage, which simulates a golf swing, and resistance-type training. The GSC has sufficiently flexible degrees of freedom of motion to allow various users to simulate the full range of motion of their golf swing without the need for complex adjustments; in the preferred embodiment, the GSC&#39;s design automatically adjusts to fit each particular user. In addition to allowing various users to employ the GSC without the need to make adjustments, the degrees of freedom of motion also accommodate users who have an unusual or extraordinary swing, such that they may condition their muscles through the actual range of motion in their actual swing (as opposed to some idealized version of a swing). And, in the preferred embodiment, the GSC allows users to adjust the amount of strength-resistance training so that it is appropriate to their strength level. Thus, the GSC is a more complete exercise-raining machine for golfers to use in improving the technique, form, and strength of their swing and developing sport-specific muscle memory. Of course, the GSC is not limited to use in simulating, training, and conditioning for golf. The GSC may be configured for use in training for any sport which includes a swinging motion, such as baseball, tennis, or racketball; golf is only one such application.  
         SUMMARY OF INVENTION  
         [0005]    The Golf Swing Conditioner (“GSC”) is essentially comprised of a mechanical linkage, which simulates the swinging of a club through its entire range of motion and which adjusts automatically to the specific characteristics of a particular user, such as their height, their swing technique, and the lie, and a resistance mechanism, which applies resistance to the motion of the mechanical linkage in order to strengthen and condition the muscle groups used during the swing. Generally, the mechanical linkage is attached to a vertical frame, although the mechanical linkage could also be attached to a wall, attached to hang down from a ceiling, or attached to any other type of rigid support structure, which supports the mechanical linkage and holds it up such that it hangs down above the floor. The frame may also include a base platform on which the user would stand. The resistance mechanism is also attached to the frame, typically on the opposite side of the frame away from the mechanical linkage for safety and convenience. The resistance mechanism interacts with the mechanical linkage so that any movement of the mechanical linkage must overcome the resistance imposed by the resistance mechanism. So, when users swing the mechanical linkage to simulate their actual swing, they will receive the benefit of strength-resistance training for the specific muscle groups used during a swing while also practicing their form and technique.  
           [0006]    In order to be fully effective, such that it allows different users to move through the entire range of motion of their particular swing, the mechanical linkage must provide at least six degrees of freedom of motion. That is to say that the mechanical linkage must allow lateral movement left-to-right in relation to the user (with the arm pivoting about its connection to the frame), depthwise movement towards-and-away-from the user and the frame (with the arm pivoting about its connection to the frame), sliding movement of the handle gripped by the user along the arm of the mechanical linkage (depthwise towards-and-away-from the user, and, if such movement is not purely horizontal, this may also allow for automatic height adjustment), rotary movement of the handle in rotation about the arm, pivotal movement of the handle about a hinge, and rotary movement of the handle about its own center axis.  
           [0007]    More specifically, the mechanical linkage is comprised of at least two elements linked together in such a way as to provide the appropriate degrees of freedom of motion: an arm and a handle. The arm is typically the larger element. The top portion of the arm rotatably (both laterally and depthwise) attaches at a joint to the frame, such that the arm has two different degrees of motion: lateral rotation and depthwise pivoting. The arm hangs down from the frame, held above and not contacting the floor. Furthermore, the arm must not contact the frame or the floor (i.e. base platform) as it is swung through its full range of motion. At least some portion of the arm must angle towards the user (i.e. the entire arm cannot be vertical). This may be accomplished by having the bottom portion of the arm bend towards the user sharply, so that it is essentially horizontal and parallel to the floor, or it may be accomplished by having the bottom portion angle less sharply towards the user&#39;s feet, such that it is not parallel to the floor but presents a declining angle. If the bottom portion of the arm is essentially parallel to the floor, then the GSC will not automatically adjust to users of different height but will instead require a height setting of the arm and/or frame using, for example, a pop pin to control the height of the arm above the floor; if the bottom portion of the arm extends at a declining angle towards the feet of the user such that it is not essentially horizontal, however, then the GSC will automatically adjust for users of various heights. While it is possible to have the entire length of the arm angle away from the frame and down towards the floor near the user (i.e. a single straight rod at a decline ), it is typically more practical to have the bottom portion of the arm angled away from the frame much more sharply so that the mechanical linkage does not require as much space to operate (i.e. to make the GSC more compact).  
           [0008]    When the arm includes a bend or two elements linked together at an angle, the arm can be constructed of a single element with an essentially straight upper portion and an angled bend leading into an essentially straight lower portion so that the lower portion extended away from the upper portion at some angle. Or, in its most typical configuration, the arm of the mechanical linkage would be further comprised of two rods rigidly attached together at some angle, wherein the upper rod of the arm would be the largest portion of the arm and would hang down from the joint near the top of the frame nearly vertically, with only a slight angle away from the frame, while one end of the lower rod of the arm would be rigidly attached to the bottom end of the upper rod, and the lower rod would angle away from the frame with less slope (i.e. less vertically and more towards horizontal) than the upper rod, such that it reaches out towards the user.  
           [0009]    Attached to the bottom of the arm and most typically, when there are two rods forming the arm, to the lower rod of the arm, at a connector mechanism that is pivotal (about a hinge), rotatable about the lower rod of the arm, and slidable along the length of the lower rod of the arm, is a handle. The handle of the GSC simulates the handle of the club to be swung and provides the location for the user to grip the mechanical linkage and to swing the mechanical linkage through the appropriate range of motion in order to use the GSC. The handle is also rotatable about its own center axis. Typically, the handle is further comprised of an inner rod, which is pivotally attached at the connector to the lower rod of the arm, and a cylindrical outer sleeve casing, which is free to rotate about the center axis of the handle. So, the user would address the handle of the GSC as if it were the handle of a golf club and would use the handle to swing the mechanical linkage in simulation of an actual golf swing.  
           [0010]    Because of the six degrees of motion available, the mechanical linkage allows users to perform their actual swing through the full range of motion without undue restriction, such that the linkage accommodates the varying swings of different users so that they may practice their particular form and technique. And, when the bottom rod of the arm is angled downward rather than horizontal towards the user, the linkage automatically adjusts to varying heights of users as the handle slides up and down along the angled bottom rod of the arm. When the bottom rod is essentially horizontal and parallel to the floor as it extends towards the user, the arm must also include a means, such as a pop pin at the joint connecting the rod to the frame, for adjusting the height of the arm to accommodate different size users. Used alone, without a resistance mechanism, the mechanical linkage would allow users to simulate and practice their swing without restriction through the full range of motion, and could serve as a teaching/practice tool.  
           [0011]    For simultaneous strength-resistance training the mechanical linkage is connected to a resistance mechanism, such that lateral rotation of the arm of the mechanical linkage is resisted. Typically, the resistance mechanism is located on the opposite side of the frame from the mechanical linkage, for safety and convenience, to keep the moving parts of the resistance mechanism away from users in order to reduce the chances of injury and to reduce the required clearance between the mechanical linkage and the frame while still allowing a full range of motion, but such placement is not required. The resistance mechanism interacts with the lateral rotation of the arm to provide the resistance needed for strength training. And, although not required, typically the resistance mechanism is adjustable, so that particular users may set the resistance level to meet their particular needs.  
           [0012]    Any resistance mechanism which can be applied to a rotary input will function in the GSC. There are several different types of resistance mechanisms available, including hydraulic, mechanical (such as friction clutch, weighted pulleys, rotary actuators, hydraulic pumps, air resistance fan blades), and electromagnetic options. The most typical resistance mechanisms employ one or more hydraulic cylinders connected to the rotary input (i.e. the lateral rotation of the linkage arm) by a train of mechanical elements that converts the rotary input into linear motion of the pistons in the hydraulic cylinders. Although there are numerous possible configurations, one simple example configuration uses a pulley system with two one-way hydraulic cylinders, while other examples include a lever-connecting-rod-rocker-bar system, a sprocket-chain-rocker-bar system, and an offset-lever system. Although a person skilled in the art field will appreciate the wide array of potential choices of mechanical elements available to allow such linear hydraulic cylinder resistance to interact with the rotational motion of the arm of the mechanical linkage, several illustrative examples will be set forth in more detail below in the preferred embodiment section. Furthermore, a person skilled in the art field will appreciate the wide variety of resistance mechanisms available, and that hydraulic cylinders are only one of many possibilities. The present invention includes all such interchangeable elements, with hydraulic cylinders used only for illustrative purposes.  
           [0013]    The primary object of this invention is to allow users to simulate and practice their swing for a particular sport through a full range of motion without restriction. It is still another object of this invention to provide strength-resistance training of the specific muscle groups used during such a swing. It is yet another object of this invention to simultaneously allow users to simulate their swing and to strengthen the particular muscle groups used during such a swing using resistance to develop strength in the appropriate muscle groups throughout the entire actual range of motion of their swing. It is yet another object to develop muscle memory for the user&#39;s swing. It is yet another object for the invention to be usable by users of different heights without the need for adjustments. It is yet another object to allow users to alter the amount of resistance applied throughout the swing. It is yet another object for this invention to be durable. It is yet another object for this invention to provide a smooth, continuous swing. It is yet another object for this invention to be constructed of parts sized for shipment to consumers in standard mailing boxes. These and other objects will be apparent to persons skilled in the art field.  
           [0014]    A person skilled in the art field will also appreciate that several different varieties of resistance mechanisms would function in the present invention. While some examples will be discussed herein, these are only intended as illustrations of common resistance mechanisms; the present invention is not limited to these examples. And, a person skilled in the art field will also appreciate that the present invention is not limited to use in simulating, practicing, conditioning, and/or strengthening for golf. Although the preferred embodiment will be discussed in terms of training for golf, the present invention may also be used to train for other sports involving a swinging motion (such as baseball, racketball, and tennis). Further, the present invention may also be used for non-sports-related activities, such as for a general exercise routine or for physical therapy and rehab work.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    Reference will be made to the drawings wherein like parts are designated by like numerals and wherein:  
         [0016]    [0016]FIG. 1 is a side view of the first preferred embodiment of the GSC.  
         [0017]    [0017]FIG. 2 is a front view of the first preferred embodiment of the GSC.  
         [0018]    [0018]FIG. 3 is a side view of the second preferred embodiment of the GSC.  
         [0019]    [0019]FIG. 4 is a front view of the second preferred embodiment of the GSC.  
         [0020]    [0020]FIG. 5 is a side view of the second preferred embodiment of the GSC illustrating the preferred dimensions and angles.  
         [0021]    [0021]FIG. 6 is a perspective/isometric view of joint  30  from FIGS. 1 and 2.  
         [0022]    [0022]FIGS. 7A and 7B are cross-section views of the connector  40  about the lower rod of arm  35  pivotally attached to the rotatable handle  45 .  
         [0023]    [0023]FIG. 8 is a perspective/isometric view of joint  30  from FIGS. 3 and 4.  
         [0024]    [0024]FIG. 9 is a rear view of the lever connecting rod rocker bar resistance mechanism.  
         [0025]    [0025]FIG. 10 is a rear view of the pulley-hydraulic cylinder resistance mechanism.  
         [0026]    [0026]FIG. 11 is a perspective view, FIG. 12 is a side view, and FIG. 13 is a rear view of the offset lever resistance mechanism. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]    The GSC  10  is a device for practicing a sport swing and for exercising the specific muscle groups used throughout the range of motion of such a swing. The GSC  10  simulates a swing, as in the sport of golf, using a mechanical linkage  25 . Most often, the mechanical linkage  25  is suspended from a vertical frame  20 , with the mechanical linkage  25  rotatably attached to the frame  20  near the top of the frame  20  and hanging down towards, but not contacting, the floor (or the base platform  24 ). The bottom of the frame  20  may be attached to a platform  24  upon which a user would stand to make use of the mechanical linkage  25 . The platform  24  would provide a broader base, making the frame  20  more stable, and would employ the user&#39;s weight to more firmly brace the frame  20  to the floor. To simulate a golf swing in a way that will not restrict the range of motion of the user, the mechanical linkage  25  employs at least six independent degrees of freedom of motion. The mechanical linkage  25  is further comprised of an arm  35  and a handle  45 . While the arm  35  often includes an upper portion which is essentially vertical (i.e. hanging down vertically from its connection to the frame  20 ), the arm  35  must have at least some portion, located at the bottom of the arm  35 , which is not essentially vertical, but which instead projects forth towards the user at some angle which is typically greater than or equal to 90 degrees from the upper portion of the arm  35 . In the preferred embodiment, the six degrees of freedom are accomplished by the joint connection  30  between the mechanical linkage  25  (and more specifically, the arm  35 ) and the frame  20 , the joint connector  40  between the arm  35  and the handle  45 , and the ability of the handle  45  to rotate about its own center axis.  
         [0028]    There are three basic configurations for the arm  35  of the mechanical linkage  25 . In the first configuration, shown in FIGS. 1 and 2, the upper portion of the arm  35  is essentially vertical or angles away from the frame  20  and towards the user only slightly, while the lower portion of the arm  35  bends substantially away from the frame  20  and towards the user at an angle such that the bottom portion of the arm  35  is essentially horizontal (i.e. parallel to the floor or the platform  24 ). In the second configuration, shown in FIGS. 3, 4, and  5 , the upper portion of the arm  35  is essentially vertical, although it may also angle towards the user, while the lower portion of the arm  35  bends substantially away from the frame  20  and towards the user at an angle greater than 90 degrees from the upper portion of arm  35 , such that the lower portion of the arm  35  is angled downward towards the platform  24  (or the floor) where the user stands. In another configuration (not shown), the entire arm is angled downward from the joint  30  towards the platform  24  (or the floor) and outward away from the frame  20  and towards the user. This configuration, obviously, requires more room, since the entire arm  35  extends further away from the frame  20 .  
         [0029]    In addition to the mechanical linkage  25  used for simulating the golf swing, the GSC  10  may also include a resistance mechanism  50  so that it may be used for strength-resistance training. Any resistance mechanism  50  can be used in conjunction with the mechanical linkage  25 , so long as it is able to apply resistance to the rotation of the mechanical linkage  25  (i.e. the resistance mechanism  50  must be configured to retard rotational motion). The resistance mechanism  50  may use hydraulic, electromagnetic, friction, weight, air/fan-blade, or any other type of resistance, including a magnetic disk, a friction clutch, a rotary actuator, or an hydraulic motor. The preferred resistance mechanism  50 , however, employs hydraulic cylinders with pistons. A single two-way hydraulic cylinder may be used such that the piston encounters resistance both on the down stroke and the up stroke, or two or more one-way hydraulic cylinders may be used, such that each encounters resistance in only one stroke direction.  
         [0030]    In the preferred embodiments, two one-way hydraulic cylinders are used. The hydraulic cylinders provide resistance in a linear fashion, however, so a train of mechanical elements must be used to translate the linear resistance into rotational resistance. There are several different mechanisms, some of which will be discussed in more detail below, through which this translation from linear to rotational resistance may occur, including pulley systems, lever-connecting-rod-rocker-bar systems, sprocket-chain-rocker-bar systems, and offset-lever systems. Thus, in the preferred embodiments, the resistance mechanism  50  is comprised of two hydraulic cylinders in conjunction with some sort of train of mechanical elements. Whichever type of resistance mechanism  50  is used, it must be designed so that it does not hamper, limit, or restrict a full swinging motion of the mechanical linkage  25 .  
         [0031]    Turning now to the drawings of the preferred embodiments in more detail, the first preferred embodiment of the GSC  10  is shown in FIGS. 1 and 2. The GSC  10  is comprised of a frame  20 , a base platform  24 , a mechanical linkage  25 , and a resistance mechanism  50 . The frame  20  is rigidly attached and braced at its base to the platform  24 , which is intended to rest upon the ground (providing a broader base in order to stabilize the GSC  10 ) and to provide a place for the user to stand while swinging the mechanical linkage  25 . The frame  20  extends up vertically from the base platform  24 . In this first preferred embodiment, the frame  20  is comprised of two elements: a braced frame sleeve  20   a , that is sturdily anchored to the base platform  24 , and a pole (or column)  20   b , which slidably mates with the sleeve  20   a . In this embodiment, the height of the frame  20  is adjustable by means of a pop-pin, which also acts to secure the mating of the pole  20   b  to the sleeve  20   a . The sleeve  20   a  includes a pop-pin (i.e. a hole with a pin that fits securely through said hole), and the pole  20   b  has a vertical series of holes (sized so that the pop-pin fits securely) drilled along the bottom portion of its length. Thus, the height of the frame  20  may be adjusted by pulling out the pop-pin of frame sleeve  20   a , sliding the pole  20   b  up or down in relation to the frame sleeve  20   a , aligning the hole in the frame sleeve  20   a  with a hole in the pole  20   b  located at approximately the desired level, and reinserting the pop-pin of frame sleeve  20   a . Typically, the height of the frame  20  is adjustable between approximately 75 inches and 87 inches. At or near the top of the pole  20   b  of the frame  20  is a hole  31 . In the preferred embodiment, the hole  31  is lined with bearings, preferably pillow bearings, passes all the way through the frame  20 , and is sized to securely receive the rotational shaft of joint  30  that links the mechanical linkage  25  to the resistance mechanism  50  while supporting the weight of the mechanical linkage via the frame  20 .  
         [0032]    The mechanical linkage  25  is further comprised of an arm  35  and a handle  45 . In this embodiment, the arm is further comprised of two rods: an upper rod  35   a  and a lower rod  35   b . One end of the lower rod  35   b  is rigidly attached to the bottom end of the upper rod  35   a  of the arm  35 . The upper rod  35   a  is pivotally attached via joint  30  to the frame  20  (and on through the frame  20  to interact with the resistance mechanism  50 ), and hangs down essentially vertically (i.e. the upper rod  35   a  may hang straight down or may be slightly angled away from the frame as it descends) from joint  30 . The lower rod  35   b  extends out from the bottom of the upper rod  35   a  in the direction away from the frame  20  at an angle between 90 degrees and 170 degrees from the upper rod  35   a , preferably at an angle between 150 degrees and 170 degrees. Near the top end of the upper rod  35   a  is a vertical series of holes  36  which are used in conjunction with the pop-pin  34  of joint  30 .  
         [0033]    The joint  30  rotatably (in two directions) connects the mechanical linkage  25  to the frame  20  near the top of frame  20 , such that frame  20  supports the mechanical linkage  25 , and the arm  35  of the mechanical linkage  25  hangs down from near the top of frame  20  towards, but not contacting, the platform  24 . In resting position, the gap between the bottom of arm  35  and the platform  24  is approximately 10 inches in the preferred embodiment. More specifically, as shown in FIG. 6, joint  30  is comprised of a yoke  32  with a shaft and a T-shaped bushed housing  33  with a pop-pin  34 . The T-shaped bushed housing  33  is essentially two cylinders rigidly joined together. The vertical cylinder of the bushed housing  33  is hollow, has the pop-pin  34 , and is sized so that it acts as a sleeve to receive the top end of the upper rod  35   a . Upper rod  35   a  of arm  35  is slidably mated within the vertical hollow cylinder (with pop-pin  34 ) of the T-shaped housing  33 , with the pop-pin  34  securing the arm  35  within the T-shaped bushed housing  33 . The horizontal cylinder of the bushed housing  33  fits within the bracket of the yoke  32  to form a depthwise hinge joint, such that the arm  35  may pivot towards the vertical frame  20  or away from the vertical frame  20 . The shaft end of the yoke  32  fits securely into the pillow block bearings in hole  31  near the top of frame  20 , such that the arm  35  may rotate laterally about the shaft of the yoke  32 . Thus, joint  30  provides two separate degrees of rotation of the arm  35 .  
         [0034]    The height of the arm  35  may be adjusted by pulling out the pop-pin  34 , sliding the upper arm  35   a  up or down within the T-shaped bushed housing  33 , and releasing the pop-pin  34  into a hole  36  in the upper arm  35   a  at the appropriate height. When the arm  35  is secured within the T-shaped bushed housing  33 , then the arm  35  hangs down from the joint  30 , which is supported by frame  20 , and the upper arm  35   a  is essentially vertical (i.e. approximately parallel to the pole  20   b  of frame  20 , or angling slightly away from pole  20   b  as it descends) while the lower arm  35   b  extends out from the bottom end of the upper rod  35   a  at an angle preferably between 150 degrees and 170 degrees from the upper rod  35   a , away from the pole  20   b  of the frame  20  (towards the user). Joint  30 , which rotatably (pivotally) connects the arm  35  to the top of frame  20 , allows the arm to rotate laterally (i.e. left-to-right) with respect to the frame  20  (and the user) and to pivot depthwise (i.e. towards and away) with respect to the frame  20  (and the user). Thus, the arm  35  may rotate in a plane approximately parallel to the frame  20  and may pivot in a plane approximately perpendicular to the frame  20 .  
         [0035]    The handle  45  is rotatably, slidably, and pivotally attached to the lower rod  35   b  of the arm  35  using connector  40 . Connector  40 , shown in more detail in FIG. 7A, is comprised of a bushed housing  40   a  fitted about the lower rod  35   b  of arm  35 , with a pivot  40   b  rigidly attached to the outside of the bushed housing  40   a . The bushed housing  40   a  is a hollow cylinder with bearings, preferably self-lubricating bearings/bushings such as garlock bearings, along the inside surface. The bushed housing  40   a  fits securely around the lower rod  35   b  and, due to the bearings, may slide along the length of the lower rod  35   b  and may rotate about the lower rod  35   b  (i.e. two degrees of motion). One end of the pivot  40   b  is rigidly attached to the outer surface of the bushed housing  40   a , while the other end of the pivot  40   b  is attached to handle  45 , such that handle  45  may pivot with respect to the bushed housing  40   a . In the preferred embodiment, the pivoting hinge  40   b  is half of a universal joint.  
         [0036]    Furthermore, the handle  45 , shown in FIGS. 7A and 7B, also may rotate about its own center axis. The handle  45 , in this preferred embodiment, is further comprised of an end cap  45   a , an inner rod  45   b , an outer sleeve casing  45   c , bearings  45   d , and an end collar  45   e . The handle  45 , when assembled, resembles the handle of a golf club. The end cap  45   a  is pivotally attached to the bushed housing  40   a  of connector  40 . The end cap  45   a  has a pivot point attachment on one end and extends into a hollow cylinder. One end of the inner rod  45   b  is inserted inside the hollow cylindrical end of the end cap  45   a  along the centerline of the cylinder of the end cap  45   a  and is rigidly attached to the end cap  45   a . The inner rod  45   b  has a smaller outside diameter than the inner surface diameter of the hollow cylinder of the end cap  45   a , such that there is clearance space between the inner rod  45   b  and the end cap  45   a . The outer sleeve casing  45   c  is a hollow cylinder with an inner surface diameter which is larger than the outer diameter of the inner rod  45   b  and with an outer surface diameter that is smaller than the inner surface diameter of the hollow cylinder of the end cap  45   a . The bearings  45   d  are located in the space between the inner rod  45   b  and the inner surface of the outer sleeve casing  45   c  and securely contact both the inner rod  45   b  and the outer sleeve casing  45   c . The end collar  45   e  attaches rigidly to, for example by screwing onto, the inner rod  45   b , and has an outer surface diameter which is at least as large as the outer surface diameter of the outer sleeve casing  45   c . Thus, when assembled, the handle  45  is pivotally attached to the bushed housing  40   a  of connector  40  (and thereby to the lower rod  35   b  of arm  35 ) via the end cap  45   a . The outer sleeve casing  45   c  is the gripping surface for the user which rotates with respect to the centerline of the handle  45  about the bearings  45   d  resting upon inner rod  45   b . The outer sleeve casing  45   c  is held in place about the inner rod  45   b  with the end cap  45   a  at one end and the end collar  45   e  at the other end. The preferred embodiment uses self lubricating bearings/bushings, and the surfaces which contact the bearings are hard and smooth, ensuring smooth rotation.  
         [0037]    In this preferred embodiment, the resistance mechanism  50  (shown in FIG. 10) is located on the opposite side of the frame  20  from the mechanical linkage  25  and is comprised of a pulley system with hydraulic cylinder resistance. The shaft of joint  30  extends through the hole with pillow block bearings  31  in the frame  20  and out the other side to interact with the resistance mechanism  50 . The upper pulley wheel  51  is rigidly attached at its center to the shaft of joint  30 , such that it rotates in unison with the shaft of joint  30 . The upper pulley wheel  51  is a sprocket with teeth. The lower pulley wheel  53  is also a sprocket with teeth. The lower pulley wheel  53  is rotatably mounted to the frame  20  some distance below the upper pulley wheel  51  (i.e. an axis is rigidly attached to the frame  20  and the lower pulley wheel  53  is rotatably centered on said axis). A chain  52 , which is formed into an elliptical loop, connects the upper pulley wheel  51  to the lower pulley wheel  53 , with the teeth of the upper pulley wheel  51  and the lower pulley wheel  53  catching the links of the chain  52  so that motion is transmitted between the upper pulley wheel  51  and the lower pulley wheel  53  (and vice versa) via the chain  52 .  
         [0038]    Typically, the lower pulley wheel  53  is significantly larger in size (diameter) than the upper pulley wheel  51 , so that a large rotation of the arm  35  (and thereby the upper pulley wheel  51  via the shaft of joint  30 ) results in only a slight rotation of the lower pulley wheel  53 . This is particularly important in this type of embodiment since a full swing range should not rotate the lower pulley wheel  53  more than 180 degrees in order to effectively translate the rotational motion into linear motion of the pistons in the hydraulic cylinders  54   a  and  54   b . Typically, the ratio of size between lower pulley wheel  53  and upper pulley wheel  51  is between 1.75-2.5 to 1; in the preferred embodiment, the ratio is approximately 2 to 1. The top of the pistons of both one-way hydraulic cylinders  54   a  and  54   b  are rotatably attached to a face of lower pulley wheel  53  (equidistantly spaced from the axis of rotation, one on each side when the GSC  10  is at rest), while the exterior of the hydraulic cylinders  54   a  and  54   b  are rotatably mounted upon the frame  20  directly below the connection of the pistons to the lower pulley wheel  53  when the GSC  10  is at rest. In this initial rest position, both pistons of both hydraulic cylinders  54   a  and  54   b  extend up approximately half of their stroke length. The hydraulic cylinders are mounted a distance below the lower pulley wheel  53  relative to the length of the piston stroke, and the piston stroke must be sufficiently long to span the maximum up/down displacement caused by rotation of the lower pulley wheel  53  during a full swing (i.e. approximately based on the diameter of the lower pulley wheel  53 ). More specifically, the entire resistance mechanism  50  is mounted to the pole  20   b . These rotatable connections allow the hydraulic cylinders  54   a  and  54   b  to maintain proper linear alignment as the lower pulley wheel  53  rotates.  
         [0039]    Thus, when the lower pulley wheel  53  rotates, one of the pistons of the hydraulic cylinders  54  is pushed down in compression (experiencing resistance), while the other piston of the other hydraulic cylinder  54  is pulled up (with no resistance). If the lower pulley wheel  53  rotates the other way, the opposite effect occurs. Thus, the two hydraulic cylinder  54   a  and  54   b  provide resistance to the rotation of the lower pulley wheel  53  no matter which way it rotates, and this resistance is passed up through the chain  52  to the upper pulley wheel  51  and through the shaft of joint  30  to the arm  35 . The amount of resistance is typically adjustable by altering the opening size of a valve in the hydraulic cylinders  54   a  and  54   b  via a knob, for example, with a larger opening reducing the resistance while a smaller opening increases resistance.  
         [0040]    The frame  20  and the base platform  24  should be made of a strong and durable material so that they can effectively support the weight of the entire GSC  10 . In the preferred embodiment, the frame  20  is made of steel and base platform  24  is made of a steel frame with a plywood top coated with a rubber gripping surface. The arm  35  should be made of a strong, durable, and lightweight material, and the lower rod  35   b  of the arm  35  should also have a hard, smooth surface for the bearing contact of the bushed housing  40   a  of connector  40 , so that the bearings may slide and rotate smoothly along the surface without catching. In the preferred embodiment, the upper rod  35   a  of the arm  35  is made of steel tubing, while the lower rod  35   b  is made of steel, with a hard chrome surface finish. Similarly, the bearing surface on the inside of the outer sleeve cover  45   c  and the bearing surface on the outside of the inner rod  45   b  of the handle  45  should both be hard and smooth. Finally, the bearing surface on the shaft of joint  30  should also be hard and smooth. Preferably, there will be little or no resistance in the mechanical linkage  25  itself, such that all resistance is evenly and smoothly applied by the resistance mechanism  50 . This allows for a smooth, fluid swinging motion, without any jerking or catching that could cause injury, and reduces wear to improve durability. In the preferred embodiment all bearings/bushings are self-lubricating, hard, and tough. This ensures that they are durable enough to work effectively over the life of the GSC. In the preferred embodiment, garlock bushings are used throughout. But, even with the self-lubricating bearings/bushings, additional lubrication is often advisable.  
         [0041]    The second preferred embodiment of the GSC  10  is shown in FIGS. 3 and 4. The GSC  10  is comprised of a frame  20 , a base platform  24 , a mechanical linkage  25 , and a resistance mechanism  50 . The frame  20  is rigidly attached and braced at its base to the platform  24 , which is intended to rest upon the ground (providing a broader base in order to stabilize the GSC  10 ) and to provide a place for the user to stand while swinging the mechanical linkage  25 . The frame  20  is attached at one end of the platform  24  and extends up from the base platform  24 . In this preferred embodiment, the frame  20  is comprised of an angled pole (or column)  20   a  braced by a crossbar  20   b , which supports the pole  20   a  as it leans over the platform  24 . The pole  20   a  of the frame  20  does not project straight up; rather, the pole  20   a  angles towards the portion of the platform  24  upon which the user will stand as it rises vertically. This configuration provides additional clearance between the frame  20  and the mechanical linkage  25 . The height of the pole  20   a  is not adjustable, but is fixed. Typically, the overall height of the frame is approximately 75 inches to 87 inches. In the preferred embodiment, the frame  20  is approximately 81 inches tall. At or near the top of the pole  20   a  of the frame  20  is a hole with pillow block bearings  31  passing all the way through the frame  20  and sized to securely receive the rotational shaft of joint  30  that links the mechanical linkage  25  to the resistance mechanism  50 .  
         [0042]    The mechanical linkage  25  is further comprised of an arm  35  and a handle  45 . In this embodiment, the arm is further comprised of two rods: an upper rod  35   a  and a lower rod  35   b . One end of the lower rod  35   b  is rigidly attached to the bottom end of the upper rod  35   a  of the arm  35 . The upper rod  35   a  is pivotally attached via joint  30  to the frame  20  and on through to interact with the resistance mechanism  50 , and hangs down essentially vertically from joint  30 . Alternatively, the upper rod  35   a  could angle somewhat away from the frame  20  (towards the user) down its length rather than hanging essentially vertical. The lower rod  35   b  extends out from the bottom of the upper rod  35   a  in the direction away from the frame  20  (towards the user) typically at some angle greater than 90 degrees but less than 180 degrees from the upper rod  35   a , such that the lower rod  35   b  is not horizontal or past horizontal/angled upwards, but declines as it extends outward away from the frame  20 . In the preferred embodiment, the lower rod  35   b  extends out from the upper rod  35   a  at an angle between 155 degrees to 160 degrees, as this angle has proven most comfortable to users. The top of the upper rod  35  a is rigidly attached to a cylindrical bushed housing  33  that forms part of the joint  30 , as shown in FIG. 8.  
         [0043]    The joint  30  rotatably (in two directions) connects the mechanical linkage  25  to the frame  20  near the top of frame  20 , such that frame  20  supports the mechanical linkage  25 , and the arm  35  of the mechanical linkage  25  hangs down from near the top of frame  20  towards but not contacting the base platform  24 . More specifically, as shown in FIG. 8, joint  30  is comprised of a yoke  32  with a shaft and a cylindrical bushed housing  33 . The cylindrical bushed housing  33  fits within the bracket of the yoke  32  to form a depthwise hinge joint, such that the arm  35 , which is rigidly attached to the cylindrical bushed housing  33 , may pivot towards the frame  20  or away from the frame  20 . The shaft end of the yoke  32  fits securely into the pillow block bearings in hole  31  near the top of frame  20 , such that the arm  35  may rotate laterally (left-to-right in relation to the frame  20  and the user) about the shaft of the yoke  32 . Thus, the arm  35  may rotate in a plane approximately parallel to frame  20  and may pivot in a plane approximately perpendicular to frame  20 .  
         [0044]    When the arm  35  is secured within the yoke  32  via the cylindrical bushed housing  33 , the arm  35  hangs down from the joint  30 , which is supported by frame  20 , above but not contacting the platform  24 . In the preferred embodiment, the gap between the bottom of arm  35  and the base platform  24  (in resting mode) is approximately 10 inches. The upper arm  35   a  hangs approximately vertical while the lower arm  35   b  extends out at a declining angle away from the frame  20  (such that it points towards the platform  24 ). Joint  30 , which rotatably (pivotally) connects the arm  35  to the top of frame  20 , allows the arm to rotate laterally (i.e. left-to-right) with respect to the frame  20  (and the user) and to pivot depthwise (i.e. towards and away) with respect to the frame  20  (and the user).  
         [0045]    The handle  45  is rotatably, slidably, and pivotally attached to the lower rod  35   b  of the arm  35  using connector  40 . Connector  40 , shown in more detail in FIG. 7A, is comprised of a bushed housing  40   a , fitted about the lower rod  35   b  of arm  35 , with a pivot  40   b  rigidly attached to the outside of the bushed housing  40   a . The bushed housing  40   a  is a hollow cylinder with bearings, such as garlock bearings, along the inside surface. The bushed housing fits securely (snugly) around the lower rod  35   b  and, due to the bearings, may slide along the length of the lower rod  35   b  and may rotate about the lower rod  35   b  (i.e. two degrees of motion). One end of the pivot  40   b  is rigidly attached to the outer surface of the bushed housing  40   a , while the other end of the pivot  40   b  is attached to handle  45 , such that handle  45  may pivot with respect to the bushed housing  40   a . In the preferred embodiment, the pivoting hinge  40   b  is half of an universal joint.  
         [0046]    Furthermore, the handle  45  also may rotate about its own center axis. The handle, in this preferred embodiment, is further comprised of an end cap  45   a , an inner rod  45   b , an outer sleeve casing  45   c , bearings  45   d , and an end collar  45   e . The handle  45 , when assembled, resembles the handle of a golf club. The end cap  45   a  is pivotally attached to the bushed housing  40   a  of connector  40 . The end cap  45   a  has a pivot point attachment on one end and extends into a hollow cylinder. One end of the inner rod  45   b  is inserted inside the hollow cylindrical end of the end cap  45   a  along the centerline of the cylinder of the end cap  45   a  and is rigidly attached to the end cap  45   a . The inner rod  45   b  has a smaller outside diameter than the inner surface diameter of the hollow cylinder of the end cap  45   a , such that there is clearance space between the inner rod  45   b  and the end cap  45   a . The outer sleeve casing  45   c  is a hollow cylinder with an inner surface diameter which is larger than the outer diameter of the inner rod  45   b  and with an outer surface diameter that is smaller than the inner surface diameter of the hollow cylinder of the end cap  45   a . The bearings  45   d  are located in the space between the inner rod  45   b  and the inner surface of the outer sleeve casing  45   c  and securely contact both the inner rod  45   b  and the outer sleeve casing  45   c . The end collar  45   e  attaches rigidly to, for example by screwing onto, the inner rod  45   b , and has an outer surface diameter which is at least as large as the outer surface diameter of the outer sleeve casing  45   c . Thus, when assembled, the handle  45  is pivotally attached to the bushed housing  40   a  of connector  40  (and thereby to the lower rod  35   b  of arm  35 ) via the end cap  45   a . The outer sleeve casing  45   c  is the gripping surface for the user which rotates with respect to the centerline of the handle  45  about the bearings  45   d  resting upon inner rod  45   b . The outer sleeve casing  45   c  is held in place about the inner rod  45   b  with the end cap  45   a  at one end and the end collar  45   e  at the other end. The preferred embodiment uses self lubricating bearings/bushings, and the surfaces which the bearings contact are hard and smooth.  
         [0047]    In this preferred embodiment, the resistance mechanism  50  (shown in FIG. 10) is located on the opposite side of the frame  20  from the mechanical linkage  25  and is comprised of a pulley system with hydraulic cylinder resistance. The shaft of joint  30  extends through the hole with pillow block bearings  31  in the frame  20  and out the other side to interact with the resistance mechanism  50 . The upper pulley wheel  51  is rigidly attached at its center to the shaft of joint  30 , such that it rotates in unison with the shaft of joint  30 . The upper pulley wheel  51  is a sprocket with teeth. The lower pulley wheel  53  is also a sprocket with teeth. The lower pulley wheel  53  is rotatably mounted to the frame  20  (i.e. the axis of rotation of the lower pulley wheel  53  is rigidly attached to the frame  20  such that lower pulley wheel  53  rotates about the axis) some distance below the upper pulley wheel  51 . A chain  52 , which is formed into an elliptical loop, connects the upper pulley wheel  51  to the lower pulley wheel  53 , with the teeth of the upper pulley wheel  51  and the lower pulley wheel  53  catching the links of the chain  52  so that motion is transmitted between the upper pulley wheel  51  and the lower pulley wheel  53  (and vice versa) via the chain  52 . A sprocket  56  is rotatably attached to the frame  20  between the upper pulley wheel  51  and the lower pulley wheel  53 , and its position may be altered incrementally and then fixed. The sprocket  56  has teeth and is to be positioned so that it meshes with the chain  52 . The sprocket is used to maintain a tight fit of the chain  52  between the upper pulley wheel  51  and the lower pulley wheel  53 . If the chain  52  begins to loosen over time, the user may extend the sprocket  56  to take up the slack.  
         [0048]    Typically, the lower pulley wheel  53  is significantly larger in size (diameter) than the upper pulley wheel  51 , so that a large rotation of the arm  35  and thereby the upper pulley wheel  51  via the shaft of joint  30  results in only a slight rotation of the lower pulley wheel  53 . This is particularly important in this type of embodiment since a full swing range should not rotate the lower pulley wheel  53  more than 180 degrees in order to effectively translate the rotational motion into linear motion of the pistons in the hydraulic cylinders  54   a  and  54   b . Typically, the ratio of size between lower pulley wheel  53  and upper pulley wheel  51  is between 1.75-2.5 to 1; in the preferred embodiment, the ratio is approximately 2 to 1. The top of the pistons of both one-way hydraulic cylinders  54   a  and  54   b  are rotatably attached to a face of lower pulley wheel  53  equidistantly spaced about the axis of rotation in resting mode, with one on each side, while the exterior of the hydraulic cylinders  54   a  and  54   b  are rotatably mounted upon the frame  20  directly below the connection of the pistons to the lower pulley wheel  53  when the GSC  10  is at rest. In this initial rest position, both pistons of both hydraulic cylinders  54   a  and  54   b  extend up approximately half of their stroke length. The hydraulic cylinders are mounted a distance below the lower pulley wheel  53  relative to the length of the piston stroke, and the piston stroke must be sufficiently long to span the maximum up/down displacement caused by rotation of the lower pulley wheel  53  during a full swing (i.e. approximately based on the diameter of the lower pulley wheel  53 ). These rotatable connections allow the hydraulic cylinders  54  to orient themselves as the lower pulley wheel  53  rotates.  
         [0049]    Thus, when the lower pulley wheel  53  rotates, one of the pistons of the hydraulic cylinders  54  is pushed down in compression (experiencing resistance), while the other piston of the other hydraulic cylinder  54  is pulled up (with no resistance). If the lower pulley wheel  53  rotates the other way, the opposite effect occurs. Thus, the two hydraulic cylinder  54   a  and  54   b  provide resistance to the rotation of the lower pulley wheel  53  no matter which way it rotates, and this resistance is passed up through the chain  52  to the upper pulley wheel  51  and through the shaft of joint  30  to the arm  35 . The amount of resistance is typically adjustable by altering the opening size of a valve in the hydraulic cylinders  54   a  and  54   b  via a knob, for example, with a larger opening reducing the resistance while a smaller opening increases resistance.  
         [0050]    The frame  20  and the base platform  24  should be made of a strong and durable material so that they can effectively support the weight of the entire GSC  10 . In the preferred embodiment, the frame  20  is made of steel and base platform  24  is made of steel framing with a plywood top coated with a rubber gripping surface. The arm  35  should be made of a strong, durable, and lightweight material, and the lower rod  35   b  of the arm  35  should also have a hard, smooth surface for the bearing contact of the bushed housing of connector  40 , so that the bearings may slide and rotate smoothly along the surface without catching. In the preferred embodiment, the upper rod  35   a  of the arm  35  is made of steel tubing, while the lower rod  35   b  is made of steel, with a hard chrome surface finish. Similarly, the bearing surface on the inside of the outer sleeve cover  45   c  and the bearing surface on the outside of the inner rod  45   b  of the handle  45  should both be hard and smooth. Finally, the bearing surface on the shaft of joint  30  should also be hard and smooth. Preferably, there will be little or no resistance in the mechanical linkage  25  itself, such that all resistance is evenly and smoothly applied by the resistance mechanism  50 . This allows for a smooth, fluid swinging motion, without any jerking or catching that could cause injury, and reduces wear to improve durability. In the preferred embodiment all bearings/bushings are self-lubricating, hard, and tough. This ensures that they are durable enough to work effectively over the life of the GSC. In the preferred embodiment, garlock bushings are used throughout. But, even with the self-lubricating bearings/bushings, additional lubrication is advisable.  
         [0051]    There are additional preferred embodiments of the resistance mechanism  50  (to be used in conjunction with a frame  20  and a mechanical linkage  25  as described in either of the above preferred embodiments) which would also effectively translate the rotational input of the shaft of joint  30  into a linear motion for the hydraulic cylinders. FIG. 9 illustrates a lever-connecting-rod-rocker bar resistance mechanism  50 . One end of a lever  51  is rigidly attached to the end of the shaft of joint  30  so that the lever  51  extends out from the shaft and rotates in unison with the shaft. Rigidly attached to the frame some distance below the lever  51  is a pivot point  53 . A rocker bar  54  is rotatably attached to the pivot point  53 , such that the rocker bar  54  may rotate about the pivot point  53 . The rocker bar  54  extends out in both horizontal directions from the pivot point  53  (when GSC  10  is at rest), with one side of the rocker bar  54  extending out farther from the pivot point  53  than the other side of the rocker bar  54 . This longer, extended end of the rocker bar  54  extends out farther from the pivot point  53  than the lever  51  does from the shaft of joint  30 . Thus, the rocker bar  54  is eccentrically located about the pivot point  53 . Typically, the ratio between the rocker bar  54  and the lever  51  is between 1.75-2.5 to 1; in the preferred embodiment, the ratio is approximately 2 to 1.  
         [0052]    The hydraulic cylinders  55   a  and  55   b  are located beneath the rocker bar  54  and the pivot point  53 , one on each side of the pivot point  53  equidistantly spaced, and the exterior of both hydraulic cylinders  55  are rotatably attached to the frame  20 . The pistons of each of the hydraulic cylinders  55   a  and  55   b  extend up to rotatably attach to a face of the rocker bar  54 , with the piston of the hydraulic cylinder  55  on each side of the pivot point  53  attaching to the rocker bar at a point directly above its hydraulic cylinder  55  (in resting position, i.e. when the rocker bar is horizontal) on the same side of the pivot point  53 . In this initial rest position, both pistons of both hydraulic cylinders  54   a  and  54   b  extend up approximately half of their stroke length. The hydraulic cylinders are mounted a distance below the rocker bar  54  relative to the length of the piston stroke, and the piston stroke must be sufficiently long to span the maximum up/down displacement caused by rotation of the rocker bar  54  during a full swing (i.e. approximately based on the rotational diameter of the rocker bar  54 ).  
         [0053]    Finally, a connecting rod  52  links the lever  51  to the rocker bar  54 . One end of the connecting rod  52  is rotatably attached to the outer face of the lever  51  near the free end of the lever  51  away from the shaft of joint  30 , while the other end of the connecting rod  52  is rotatably attached to the inner face of the rocker bar  54  near the end of the rocker bar  54  which extends beyond the rotatable attachment of the piston of the hydraulic cylinder  55  and is eccentrically extended. Both the free end of the lever  51  and the longer, extended end of the rocker bar  54  should be located on the same side of the frame  20  (and the pivot point  53  and the shaft of joint  30 ) in the initial, resting position, with both the lever  51  and the rocker bar  54  approximately horizontal, and with the free end of the lever  51  extending out in the same horizontal direction as the longer, extended end of the rocker bar  54 .  
         [0054]    [0054]FIGS. 11, 12, and  13  illustrate another preferred embodiment of the resistance mechanism  50 , the offset lever mechanism. An L-shaped bracket  51  is rigidly attached to the end of the shaft of joint  30 . In resting position, the bracket extends up above the shaft of joint  30  and then extends outward away from the frame  20 . A lever  52  is rigidly attached to the bracket  51 , such that the center of the lever  52  is rigidly attached to the bottom of the extended portion of the bracket  51 , and the lever  52  extends out horizontally (in resting position) equidistant on each side. Two hydraulic cylinders  54   a  and  54   b  are rotatably attached to the frame  20  some distance below the lever  52  at points directly below the two ends of the lever  52  in horizontal, resting position. The pistons of the two hydraulic cylinders  54   a  and  54   b  extend upward and connect rotatably to the faces of the lever  52  on the respective ends of the lever  52  (when the lever  52  is horizontal), such that the pistons of the hydraulic cylinders  54   a  and  54   b  are approximately vertical when the lever  52  is in horizontal mode. In this initial rest position, the pistons of both hydraulic cylinders  54   a  and  54   b  extend up approximately half of their stroke length. The hydraulic cylinders are mounted a distance below the lever  52  relative to the length of the piston stroke, and the piston stroke must be sufficiently long to span the maximum up/down displacement caused by rotation of the lever  52  during a full swing.  
         [0055]    More specifically, one of the pistons of the hydraulic cylinders  54  attaches rotatably to the inner face of the lever  52  on one end of the lever  52 , while the other piston attaches to the outer face of the lever  52  on the other end of the lever  52  (i.e. they attach on opposite ends of the lever  52  and on opposite faces of the lever  52 ). Thus, the rotary connections between the pistons of the two cylinders  54   a  and  54   b  and the lever  52  (on the opposite ends—one on the left end and one on the right end—of the lever  52  when it is horizontal) are offset by the thickness of the lever  52 , such that one of the rotatable connections is on the inside surface of the lever  51  (towards the frame  20 ) and the other rotatable connection is on the outside surface of the lever  51  (away from the frame  20 ). The bracket  51  must extend away from the shaft of joint  30  a sufficient distance to provide clearance for the pistons of the hydraulic cylinders  54 . The resistance provided by the hydraulic cylinders will vary depending in part upon the length of the lever  52 .  
         [0056]    To employ the GSC  10  to condition the muscles used during a swing, the user will stand on the base platform  24  facing the mechanical linkage  25  and the frame  20  at approximately a right angle to the handle  45  of the mechanical linkage  25 . The user addresses the handle  45  of the mechanical linkage  25  as if it were the handle of the club actually used in the sport, golf for example, and holds the handle  45  in the appropriate manner. The user may then swing the handle  45  as if it were the club, employing a natural swing as used in the particular sport. The mechanical linkage  25  will pivot about joint  30  to provide a natural swinging motion. If the GSC  10  being used is of the type in the second preferred embodiment, it will automatically adjust to the user. If, however, the GSC  10  being used is of the type in the first preferred embodiment, then the user will have to pre-set the height of the frame  20  and the arm  35  (all other adjustments will be automatic). And, if the GSC  10  being used has an adjustable resistance mechanism  50 , then the user may want to adjust the level of resistance to fit their needs.