for purposes of the description hereinafter , spatial orientation terms , if used , shall relate to the referenced embodiment as it is oriented in the accompanying drawing figures , or otherwise described in the following detailed description . however , it is to be understood that the embodiments described hereinafter may assume many alternative variations and embodiments and that the specific embodiments illustrated in the accompanying drawing figures and described herein are simply exemplary and should not be considered as limiting . referring first to fig1 - 4 , an exercise machine 10 may generally include a frame 20 , a body support assembly 30 , and a counter balance assembly 40 . the body support assembly 30 and counter balance assembly 40 may be pivotable with respect to the frame 20 at a pivot point 35 . as shown , the counter balance assembly 40 may include a reaction arm 42 , which extends from the rear portion of the body support assembly 30 . the reaction arm 42 , being part of counter balance assembly 40 , is also pivotable about the frame 20 and may include a weight bearing end 44 , which is opposite the body support assembly 30 . as illustrated in fig1 - 4 , the weight bearing end 44 is adapted to receive weights directly thereon . the weight bearing end 44 may , for example , include tubing 46 , which can receive weights 48 , such as olympic - style weights . tubing 46 can be metal tubing , such as two inch round aluminum tubes . referring now to fig6 a and 6b , the weight bearing end 44 of reaction arm 42 may optionally be pivotable with respect to the reaction arm 42 by , for example , a hinge 45 . in this embodiment , the weight bearing end 44 may be angularly adjustable with respect to the reaction arm 42 between a plurality of angular positions from a position extending completely outward from and parallel to reaction arm 42 , indicated in fig6 a , to any position along broken line a , such as that indicated in fig6 b . the hinge 45 of adjustable weight bearing end 44 may be lockable , such that weight bearing end 44 does not pivot about hinge 45 while in use , thereby maintaining a constant angular position with respect to reaction arm 42 . referring now to fig8 , the counter balance assembly 40 may alternatively include a cable and pulley system 144 . counter balance assembly 40 includes reaction arm 142 , which is connected to a cable 145 , which runs over a pulley 146 , which is capable of lifting weights from weight stack 148 via a lifting rod . the weights in the weight stack 148 may be a plurality of ten pound plates . in use , when a user is in a downward position , the reaction arm 42 will rotate with the body support assembly 30 , thereby pulling weights from weight stack 148 upward with the weight stack 148 counter balancing the user &# 39 ; s body weight . in this embodiment , reaction arm 42 may be welded to chest pad frame 32 , at an angle as shown , so that chest pad frame 32 and reaction arm 42 are fixedly secured to each other . referring now again to fig1 - 4 , the exercise machine frame 20 may include a base frame 22 , two side frames 24 , which may extend in an upward direction from the base frame 22 , and a knee pad mounting bar 26 . the knee pad mounting bar 26 may be connected to an elevated platform 28 . as best illustrated in fig3 - 5 , the frame 20 may include two knee pad mounting bars 26 . the knee pad mounting bar 26 may be positioned on a front edge of the platform 28 , with the platform being supported by two vertical bars 27 extending downwardly to a base cross bar 29 , which attaches to and extends between the base frame 22 . the frame may also include a ladder 25 attached to a rear portion of platform 28 . attached to the knee pad mounting bar 26 is a knee pad assembly 50 . the knee pad assembly 50 may include a knee pad 55 attached to a knee pad frame 52 , which includes rear extensions 54 , which are attached to knee pad mounting bar 26 . the knee pad assembly 50 may also include adjustable toe and heel pads 58 between which a user &# 39 ; s feet are secured during use . a steel bar 56 may extend through extensions 54 and knee pad mounting bar 26 , thereby connecting the knee pad frame 52 to knee pad mounting bar 26 . the knee pad assembly 50 may be positioned at any angular position , for example , a 75 ° angle to a horizontal plane , and the knee pad assembly 50 may permanently secured in that angular position . however , alternatively , referring to fig4 and 5 , the knee pad assembly 50 may also be adjustable between a plurality of angular positions between , for example , between 90 ° and 45 ° or between 90 ° and 0 ° to a horizontal plane , wherein at 0 ° the knee pad assembly 50 would be parallel to the ground . as shown in fig5 , the angle of the knee pad assembly 50 is less than the angle shown in fig4 . the knee pad mounting bar 26 may permit the knee pad assembly 50 to be angularly adjustable with respect to the frame 20 and / or platform 28 , such that knee pad assembly 50 pivots about mounting bar 26 . the knee pad assembly 50 may then be fixedly secured in any of the plurality of angular positions by way of a removable pin and adjustment bar connected under a front part of the knee pad assembly 50 . the adjustment bar may be a curved piece of 1½ inch metal tubing which is mounted to a bottom portion of the knee pad frame 52 which extends between vertical bars 27 , wherein a the pin extends through apertures defined through the adjustment bar and vertical bars 27 to fixedly secure the knee pad assembly 50 in place . such an arrangement will allow the knee pad assembly 50 to be fixedly secured during use between any number of positions . the body support assembly 30 , shown in fig1 - 4 , may be , for example , a chest pad assembly having a chest pad frame 32 to which a chest pad 34 is attached . the body support assembly 30 may also include a pivot bar 36 , as best shown in fig2 , extending through a rear portion of the body support assembly 30 and a bottom portion of knee pad assembly 50 , thereby defining an axis of rotation between body support assembly 30 and knee pad assembly 50 . the pivot bar 36 may extend through chest pad frame 32 and knee pad frame 52 via cylinder fittings positioned therethrough . the pivot bar 36 allows the body support assembly 30 to pivot about knee pad assembly 50 during operation of exercise machine 10 , and corresponds to pivot point 35 on body support assembly 30 . as shown , the reaction arm 42 of counter balance assembly 40 may be an extension of chest pad frame 32 , which extends from pivot point 35 in a rearward direction . also , the chest pad frame 32 may be vertically adjustable to account for variations in a user &# 39 ; s height . for example , chest pad frame 32 may be adjustable to various vertical positions indicated by adjustment holes 38 on chest pad frame 32 . the chest pad frame 32 may be in slidable engagement with reaction arm 42 , such that chest pad frame 32 may be slidably adjusted to any of the positions indicated by adjustment holes 38 . as best shown in fig1 - 3 , the frame 20 may also include a stopper pad 37 which provides a limit on the amount of angular / pivotable displacement of chest pad assembly 30 and reaction arm 42 . for example , in an unused state , reaction arm 42 will pivot to a downward position and chest pad assembly 30 will pivot to an opposite upward position until reaction arm 42 contacts stopper pad 37 . in an opposite position , when the exercise machine 10 is being used and the chest pad assembly 30 is in a downward position , with reaction arm 42 in an upward position , the chest pad frame 32 will contact stopper pad 37 at its lowest point , thereby preventing chest pad assembly 30 and reaction 42 from pivoting any further . the stopper pad 37 may be constructed of any material suitable to withstand the repeated contact of reaction arm 42 and chest pad assembly 30 . also , referring to fig1 , 4 , and 5 , stopper pad 37 may be vertically adjustable via a removable pin or bolt 39 a and adjustment holes 39 b , wherein the bolt 39 a would extend through side frame 24 , stopper pad 37 , and a vertical bar 27 . the lower stopper pad 37 is positioned , the greater the amount of allowed angular displacement of chest pad assembly 30 and reaction arm 42 . for example , in an unused state with chest pad assembly 30 in the upward position , chest pad assembly 30 will be closer to vertical , the lower stopper pad 37 is positioned . referring now to fig7 , in an alternative embodiment , the chest pad frame 32 may include an adjustment member 31 , which is attached to a rear portion of the chest pad 34 . the chest pad frame 32 may optionally be attached to a wood plate , which may , for example , be twenty inches , which , in turn , may be attached to 3 / 16 or ¼ inch plate aluminum . the adjustment member 31 may then be attached to a rear portion of the plate aluminum . the adjustment member 31 is in slidable engagement with the chest pad frame 32 and may be adjustable to various positions via an adjustable spring loaded pin or plunger pin 33 . the chest pad frame 32 may include , for example , two inch square metal tubing whereas adjustment member 31 may include 1¾ inch square tubing so as to be able to be in slidable engagement with chest pad frame 32 . in general , the construction of exercise machine 10 , including frame 20 , body support assembly 30 , and counter balance assembly 40 may include metal tubing sections , such as two by two or two by four metal tubing . the tubing sections could then be welded and / or bolted together . referring now to fig9 and 10 , in use , a user would secure their feet between toe and heel pad 58 with their knees and shins being positioned against knee pad 55 , thereby maintaining the lower legs and knees of the user in a stationary position . the user would then orient his or her body prone against the body support assembly 30 . the user &# 39 ; s body weight will force the body support assembly 30 to pivot to a downward position with the counter balance assembly 40 pivoting to an opposite upward position , as shown in fig1 . the user will then pivot his or her body and body support assembly 30 by pulling the top two - thirds of the body , including the torso , up at the user &# 39 ; s knees toward the lower portion of the user &# 39 ; s legs positioned against the knee pad assembly 50 , the counter balance assembly 40 will offset the user &# 39 ; s body weight because with weight bearing end 44 of counter balance assembly 40 being in an upward position , gravity will act to pull the weight downward , thereby assisting the user to complete the motion . upon completion of the motion , the user &# 39 ; s head will be pointed toward the ceiling . this motion will provide tension in the user &# 39 ; s hamstring and gluteus muscles , which upon release of that tension , the user &# 39 ; s body weight will again force the body support assembly 30 downward and the counter balance assembly 40 upward . when using the embodiment of weight bearing assembly 44 , including a hinge 45 , as noted above , the weight bearing assembly 44 is pivotable between a completely outward position wherein the weight bearing assembly 44 is parallel to reaction arm 42 and a plurality of other angular positions along broken line a . in use , the hinge 45 may be locked in any of such plurality of angular positions , or may be unlocked so that weight bearing assembly 44 may pivot about hinge 45 when in use as reaction arm 42 raises and lowers . when the weight bearing assembly 44 is completely outward parallel to reaction arm 42 , less weight will be needed to offset the user &# 39 ; s body weight . this is because , generally , the longer the reaction arm 42 is in comparison to the rest of the exercise machine 10 , the greater the ability of counter balance assembly 40 is to offset the weight of a user when in use . while specific embodiments of the above - described exercise machine have been described in detail , it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the present disclosure . the presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention , which is to be given the full breadth of the appended claims and any and all equivalents thereof .
an exercise machine includes a frame , a body support assembly in pivotable engagement with the frame , and a counter balance assembly connected to the body support assembly , wherein , in operation , the body support assembly is pivotable from a downward position to a top position . the counter balance assembly partially balances a body weight of a user in a prone position against the body support assembly as the body support assembly is pivoted from the downward position to the top position . the counter balance assembly may include a reaction arm extending from a rear portion of the body support assembly and pivotable about the frame , and may include a weight bearing end opposite the body support assembly . a method of using an exercise machine includes positioning a user body prone against a body support assembly , wherein the body support assembly is pivotally engaged with an exercise machine frame and counterbalancing the user &# 39 ; s bodyweight .