fig1 is a perspective view of an exerciser , generally indicated at 10 , according to one embodiment of the invention . the exerciser 10 is generally of the type shown in u . s . pat . des . 382 , 319 , which was incorporated by reference above . the exerciser 10 includes a frame assembly , generally indicated at 12 , a movable body support , generally indicated at 14 , disposed on the frame structure 12 in a position to support the seat and back of the user in a position which allows the body of the user while in supported relation to move with the movable body support 14 with the feet of the user free to be supported with respect to the movable body support 14 , and a movable foot assembly , generally indicated at 16 , constructed and arranged to be mounted on the frame structure 12 in a position to be engaged by the feet of the user while movably supported on the movable body support 14 . the frame assembly 12 includes a frame 18 , which is adapted to support the movable body support 14 , with the user supported thereon . the frame 18 also includes a stand 20 , which is adapted to connect to the frame 18 to hold the frame 18 in a generally horizontal plane above floor level . as is shown in fig1 , an exploded perspective view of the exerciser 10 , the stand 20 comprises a plurality of legs 22 connected at respective upper ends thereof by cross bars 24 , such that the stand portion 20 is comprised of generally rectangular or trapezoidal segments having legs 22 disposed at the corners of the segments . end caps 26 of a rubber or other non - skid material may be provided at floor - contacting ends of the legs 22 . upper receptacle sections 28 of the stand 20 are adapted to receive corresponding mating structures provided on the underside of the frame 18 ( not shown in the figures ), so as to operatively secure the frame 18 to the stand 20 . the legs 22 of the stand 20 may be of any length that provides a convenient user height for the frame portion 18 . depending on the embodiment , the frame 18 and stand 20 may be separable , so that the exerciser 10 can be stored easily . additionally , the stand 20 may be omitted or sold separately , particularly if the height provided by the stand 20 is not required for the exercises that are to be performed . moreover , it may be desirable to construct the stand 20 such that one end is wider than the other . a stand 20 with one wider end and one narrower end may be desirable if one end of the exerciser 10 requires a broader base of support to prevent lateral tipping , or if the exerciser 10 is constructed such that the stand 20 will only mate with the frame 18 if the frame 18 is in a particular orientation . the frame 18 is comprised of two generally parallel support tracks 30 , connected and braced by a number of cross members . each of the support tracks 30 has a generally c - shaped cross - section , such that each support track 30 defines an interior track 32 , in the shape of a channel , which is adapted to receive engaging portions of the movable body support 14 . the engaging portions of the movable body support 14 in this embodiment are rollers 33 ( shown in phantom in fig2 ) that rollingly engage interior tracks 32 . the rollers 33 are mounted to the underside of the movable body support 14 on appropriately - sized lateral projections , and allow the movable body support 14 to roll along the support tracks 30 between limiting portions of the support tracks 30 . the limiting portions of the support tracks 30 define the extent of travel for the movable body support 14 . in the exerciser 10 , one of the limiting portions is a crossbar 34 that extends between the two support tracks 30 ; the other limiting portion is defined by an endpiece 36 of the frame portion 18 . alternatively , the limiting portions may simply be the ends of the grooves 32 in the support tracks 30 . although rollers 33 are used in the illustrated embodiment , a number of bearings and other movement support structures are known in the art , and any one of these known types of bearings may be used in place of the rollers . for example , instead of rollers , blocks of low - friction material may be used , and the inside tracks 32 in the support tracks 30 may be lubricated in order to facilitate sliding movement with reduced friction . the support tracks 30 may be continuous bars that run the length of the exerciser , or they may be comprised of sets of shorter bars which are secured together by welds or fasteners . as shown in fig2 , each support track is comprised of two shorter support bars 38 , 40 . at one end , each shorter support bar 38 , 40 connects to an endpiece 36 , 37 to form an end of the frame 18 of the exerciser 10 . ( the endpieces 36 , 37 of the illustrated embodiments are bars covered with decorative plastic moldings , but they may be made in other configurations .) at the other ends of the shorter support bars 38 , 40 , cooperating hinge structure 42 is provided , such that the shorter support bars 38 , 40 may be hingedly connected together in a manner which allows the exerciser 10 to be folded when not in use . in alternative embodiments of the invention , the support tracks may have a substantially rectangular cross section , and a movable body support with rollers or other movement support structures may be configured so as to rest on top of the support tracks , rather than engaging inside tracks defined within them . the precise manner of engagement of the movable body support and the support tracks is not critical . several body - engaging components are mounted on the movable body support 14 so as to facilitate the body positioning of the user . two padded shoulder blocks 44 , one on each side of the body support 14 , extend vertically , and are positioned so as to engage the upper portion of the user &# 39 ; s torso ( i . e ., at the collarbone or shoulder region ) when the user is lying prone or supine on the movable body support 14 , so as to prevent the user from sliding relative to the movable body support 14 in a direction away from the foot support 16 . the shoulder blocks 44 may be removably attached to the movable body support 14 , for example , by a threaded connection . a padded head rest 46 is also mounted on the movable body support 14 . in the position illustrated in fig1 and 2 , the head rest 46 is positioned such that its user - contacting surface is generally horizontal and co - planar with those of the movable body support 14 . however , the head rest may be mounted on a multi - position bracket , such that its angular position may be adjusted relative to that of the movable body support so as to support the user &# 39 ; s head in an inclined position . in addition to the head rest 46 , torso pad 48 is mounted on the movable body support 14 so as to cover a substantial portion of the movable body support 14 to provide traction and comfort . when the user is lying on the movable body support 14 in a supine position with his or her head on the head rest , the user &# 39 ; s feet are free from the movable body support 14 , and extend in a direction toward the movable foot assembly 16 . as can be seen in fig1 - 3 , in one example , the movable foot assembly 16 includes a foot contact portion 404 connected to a vertically extending support 406 by compression springs 408 and a piston and cylinder damper unit 409 . the foot contact portion 404 extends horizontally forward from the vertically extending support 406 . several variations of this are possible : in the top plan view of fig4 , a movable foot assembly 402 has two foot contact portions 410 , each foot contact portion 410 being sized to accommodate one of the user &# 39 ; s feet , whereas in the top plan view of fig3 and in fig1 and 2 , the foot contact portion 404 is a unitary structure sized to accommodate both feet . in each case , the foot contact portions 404 and 410 would be provided with a layer of foam or other padding material 414 to provide comfort and traction for the user &# 39 ; s feet . those of skill in the art will note that the exercising motion enabled by the foot support 402 is similar to the exercising motion enabled by the foot support 16 . the movable foot assembly 16 and movable foot assembly 402 are both in a position to be engaged by the feet of an exercising person supported on the movable body support 14 . the body support 14 is mounted so as to absorb the energy of the movement of the movable body support 14 in a first direction away from the movable foot assembly 16 , 402 by the exercising person supported thereon and to convert the absorbed energy to a movement of the movable body support 14 with the exercising person supported thereon in a second direction toward the movable foot assembly 16 , 402 . the movable foot support 16 , 402 provides for the damped resiliently resisted movement of the movable foot assembly 16 , 402 caused by the engagement thereof by the feet of an exercising person moving with the movable body support 14 in the second direction and establishes as a result of the damped resiliently resisted movement of the movable foot assembly 16 , 402 in the second direction ; a damped resilient return movement by the movable foot assembly 16 , 402 in the first direction . the exercising person can translate this movement into a movement of the movable body support 14 in the first direction , enabling the exercising person to control the repetition and magnitude of the movements of the movable body support 14 by flexure of the legs at the knees . the movable foot assembly 16 is intended to be moved by both feet whereas the movable foot assembly 402 can be moved by either foot acting alone or both together . fig5 is a perspective view of an exerciser 500 embodying the principles of the present invention . the exerciser 500 includes a frame , generally indicated at 502 . the frame 502 comprises two generally parallel frame members 504 joined at respective ends by front and rear crossmembers 506 and 508 . the frame members 504 define interior tracks 510 in the form of channels that extend substantially the entirety of the length of the frame members 504 . a movable body support 512 is mounted for movement in the tracks 510 by means of rollers ( not shown in fig5 ). the movable body support 512 includes padded shoulder blocks 514 that extend perpendicular to the movable body support 512 and are contoured and arranged to contact the shoulder / clavicular region of the user during exercise motions . a lumbar support 513 is provided as a gently upwardly sloped portion of the movable body support 512 . an adjustable head rest 516 forms a segment of the movable body support 512 beyond the shoulder blocks 514 . in addition , the movable body support 512 provides two fixed l - shaped members 515 that are secured to its underside and extend outwardly and upwardly therefrom . upper portions of the l - shaped members 515 may be used as hand grips . toward the front crossmember 506 , an intermediate crossmember 518 extends between the two parallel frame members 504 and limits the motion of the movable body support 512 by acting as a motion stop . in accordance with the principles of the present invention , a movable foot assembly generally indicated at 520 , is mounted between the two parallel frame members 504 and includes a mounting member in the form of a bolt 522 extending through each of the tracks 510 and secured in place by a nut . the movable foot assembly 520 also includes left and right support posts 524 pivotally mounted on the bolt 522 so as to rotate about a pivotal axis extending in a transverse horizontal direction . typically , the support posts 524 would include apertures of sufficient size to allow the bolt 522 to pass through them such that the support posts 524 are mounted for rotation about the bolt 522 . each of the support posts 524 includes an upper transversely - extending portion 526 , which would typically be welded or otherwise fixedly secured to the rest of the support post 524 . pivotally mounted on the transversely - extending portions 526 are the individual left and right foot support pieces 528 , which rotate about pivotal axes defined by the transversely - extending portions 526 . the exerciser 500 is of the type that provides one foot support piece 528 for each foot , which would allow the user to exercise each one of his or her legs individually or in combination , in synchronized , alternating , or random fashion . a shift in weight or pressure from one leg to the other is possible during the exercising motions . because the individual support pieces 528 are pivotally mounted on the transversely - extending portions 526 , they can assume whatever angle is required to establish or maintain contact with the user &# 39 ; s feet . in accordance with the principles of the present invention , the movable foot assembly 520 provides for the movement of the foot support pieces 528 to be yieldingly resisted with a damping action capable of effecting a resiliently damped return movement when the moving pressure is released by the user . the resiliency is provided by two torsion coil springs 530 , each of which is mounted on the bolt 522 adjacent to one of the support posts 524 . as best shown in fig5 , a first arm 532 of each torsion spring 530 is received in a channel 534 on the support post 524 ; a second arm 536 of each torsion spring 530 is received in a receiving member 540 that is mounted on the front crossmember 506 . with this mounting arrangement , motion of the support posts 524 in a direction toward the front crossmember 506 is resiliently opposed by the torsion springs 530 . in the absence of any user - applied forces , the support posts 524 are resiliently biased toward the position shown in fig5 by the torsion springs 530 . the damping associated with each resiliently resisted user movement and resilient return movement is provided by left and right piston and cylinder damper units 541 . as best shown in fig6 and 7 , the damper units 541 are connected between lower free ends of the left and right posts 524 and undersides of a forward portion of the frame 502 . the exerciser 500 is supported on a horizontal surface such that it can be inclined at a plurality of angles . arcuate rocker feet 542 extend on the underside of the frame 502 between the front crossmember 506 and the intermediate crossmember 518 . each rocker foot 542 can provide good contact with a horizontal surface , such as the floor or a mat , at a plurality of angles . typically , the rocker feet 542 would be covered with a non - skid material , such as a rubber , to prevent the exerciser 500 from skidding or sliding along the horizontal surface while in use . two pivotable frame supports 544 support the frame 502 proximate to the rear crossmember 508 . each frame support 544 is essentially triangular with a rounded bottom portion 546 that is adapted to contact the horizontal surface . the frame supports 544 and rocker feet 542 can be seen more clearly in the side elevational view of fig6 . each frame support 544 can pivot about a horizontal pivotal axis defined by a hinge pin 548 supported in a bracket 550 on the underside of the frame 502 . however , in the position illustrated in fig5 and 6 , the frame supports 544 are fixed in their illustrated , relatively upright position by a threaded rod that passes through the rear crossmember 508 and releasably engages a crossbar 552 that extends between the two frame supports 544 and secures them relative to one another . a user - accessible knob 553 attached to the threaded rod allows the user to remove it from or insert it into the crossbar 552 , thereby securing or releasing the two frame supports 544 . once the two frame supports 544 have been released , they can be pivoted counterclockwise ( with respect to the coordinate position of fig5 and 6 ) to assume the position shown in fig7 , another side elevational view of the exerciser 500 . as shown in fig7 , the angle between the frame 502 and the horizontal surface on which it rests has decreased . additionally , the portions of the frame supports 544 and the rocker feet 542 that engage the horizontal surface have changed . the position of the exerciser 500 shown in fig7 is a stable position and a user may exercise in it . the exerciser 500 also includes a set of wheels 554 rotatably mounted on wheel extensions 556 that extend forwardly from the front crossmember 506 . in the positions illustrated in fig6 and 7 , the wheels 554 are not in contact with the horizontal surface and do not allow the exerciser 500 to be moved . however , if the user tilts the exerciser 500 so that the wheels 554 are in contact with the horizontal surface , the wheels 554 allow for easy movement of the exerciser 500 . the angle between the frame 502 and the horizontal surface on which it rests determines the degrees to which the energy of the user movement of the movable body support 512 in a direction away from the movable foot assembly 520 is absorbed and then converted into a movement of the movable body support 512 in the opposite direction toward the movable foot assembly 520 . the angle adjustment system described provides for two different absorption and conversion levels . other adjusting systems may be provided instead which provide for a multiplicity of adjusted positions within a range of positions . in the two level system described , the energy of user movement is absorbed and converted into a return movement by gravity acting on the users weight supported by the movable body support 512 . preferably , this gravitational action is supplemented by a resilient multiple removable bungee cord system of the type well known in pilates exercisers . such a system is shown in fig5 and 8 as embodying four bungee cords 558 of different resilient resistance removably connected to the frame cross member 518 and to the movable body support 512 . while both adjustments are preferred , it is within the contemplation of the present invention to utilize either without the other . as was noted above , the resiliency of the foot supports of exercisers according to the present invention may be created in a variety of ways . fig8 is a perspective view of an exerciser 600 according to another embodiment of the present invention . many of the components of the exerciser 600 are identical to those found in the exerciser 500 ; therefore , the description above will suffice for those components which are designated by the same reference numerals . the primary difference between the exerciser 500 and the exerciser 600 is in the resilient damping system connected to the support posts 624 . instead of torsion springs 530 and damper units 541 , the exerciser 600 uses two combination spring and damper units 630 mounted on the underside of the front crossmember 606 . fig9 is a perspective view of the underside of the exerciser 600 proximate to the front crossmember 606 , showing the units 630 and their attachment in more detail . as before , the piston rods 631 of the units 630 are pivotally connected to short lever arms 632 , forming lower free ends of the support posts 624 . with the units 630 connected to the lever arms 632 below the foot support mount member 520 ( about which the support posts 624 pivot ), the overall arrangement is such that a movement of the support posts 624 forward ( clockwise with respect to fig8 ) results in an extension of the piston rods 631 of the units 630 . the action of the units 630 is such that resilient restorative force is provided to retract the shaft 631 of the unit 630 and thereby to return the support post 624 to its original position ( i . e ., that illustrated in fig8 ) when the shaft 631 of the unit 630 is extended . as those of skill in the art will appreciate , spring and shock absorber units 630 could also be attached to points on the support posts 624 that are above the foot support mount member 520 , in which case the “ sense ” of the motion would be reversed and the shaft of the unit would need to retract upon forward motion of the support post 624 and resiliently extend to return the support post 624 to its original position . other types of connections between the support posts 624 and the units 630 may also necessitate motion of the “ sense ” opposite that illustrated in fig8 and 9 . the particular type and internal arrangement of the units 630 is not critical to the invention . many types of spring and shock absorber units are known in the art and may be used or adapted for use in exercisers according to the present invention . for example , u . s . pat . nos . 5 , 622 , 527 and 5 , 071 , 115 disclose exemplary types of hydraulic cylinders that may be used as shocks in exercisers according to the present invention , and the disclosure in those two references that pertains to hydraulic cylinders is hereby incorporated by reference . the units 630 of the exerciser 600 would generally comprise a damper ( i . e ., hydraulic or gas cylinder with restricted orifices to control the flow between chambers in the cylinder or across the piston ) in parallel with a conventional compression or tension spring . the spring may be placed inside or outside of the cylinder . if the spring is outside of the cylinder , it may be axially coextensive with the cylinder . fig1 is a longitudinal cross - sectional view of one suitable type of unit 630 that may be used in the exerciser 600 of the present invention . the unit 630 combines resistive structure and biasing structure in a single cylinder having a central axis 632 . the unit 630 holds a compressible coil spring 634 between the piston 636 and the cylinder end piece 638 of the cylinder 640 , which biases the shaft 631 to resiliently retract and return to the position shown in fig1 when extended . piston 636 is shown as having a peripheral shoulder 642 within which spring 634 is registered to maintain its alignment within cylinder 640 . the piston 636 includes a peripheral o - ring 644 for sealing the piston within the cylinder 640 . the piston 636 is shown fixed to a threaded 646 reduced diameter portion 648 of shaft 631 by a locknut 650 . a collar 652 is fitted on reduced diameter portion 652 , and retains a check valve spring 654 on the reduced end 656 . the spring 654 holds washer 656 against the piston 636 to overcover the orifices 658 , preventing oil flow through the orifices 658 when the pressure on the washer side 660 of the piston is higher than the pressure on the opposite side 662 . orifices 664 permit fluid flow in both directions . cylinder end piece 666 is attached to the cylinder 640 as by welding . the end piece 666 is shown with a circular slot 668 in its exterior face into which seal spring 670 fits . seal spring 670 maintains pressure on shaft seal 672 to prevent leakage from the outer chamber 674 . an orifice 676 in the end piece 638 permits pressure equalization across the end piece 638 so that seal 672 does not become overpressurized . an orifice 678 in cylinder 640 permits pressure equalization between the cylinder 640 and chamber 674 . the exercisers 500 , 600 illustrated in fig5 - 9 are of the sort that might be used primarily in the home , because they are relatively lightweight , simple in construction , and capable of being moved and stored . however , certain adaptations to the exercisers 500 , 600 are advantageous if the exercisers are to be used in a professional setting . for example , in a professional setting , it is advantageous if the damping / resistance provided by the units 630 can be user controlled so as to provide a more or less intense workout depending on the user &# 39 ; s fitness level . this may be accomplished , for example , using the type of unit shown in u . s . pat . no . 5 , 071 , 115 . in more “ advanced ” embodiments , the variable restriction valve or other control structure within the unit 630 could be placed under computer control and manipulated electrically ( e . g ., in the case of a solenoid valve ) or electromechanically / hydraulically ( e . g ., in the case of a traditional restricted orifice ). in either case , an interface would be provided , allowing the user to select the amount of resistance . additionally , instead of the two position frame supports 544 , the exercisers 500 , 600 could include supports that are hydraulically or electromechanically controllable to produce a user desired incline angle from a continuous range of possible incline angles . if the exerciser 500 , 600 includes both variably adjustable resistance levels and a variably adjustable incline , the controls and interface for the two features , as well as the control lines or hydraulic fluid lines may be integrated into one set of controls and conduits . the exercisers according to the present invention provide several advantages . first , the user can perform exercises in a supine or prone position , which is usually at least perceived to be more comfortable by the user . second , the type of exercises that can be performed on exercisers according to the invention may have cardiovascular , strength , and flexibility benefits . third , as was described above , certain known types of exercises , such as pilates exercises , may be performed on exercisers according to the invention , if desired by the user . although the invention has been described with respect to certain embodiments , those of ordinary skill in the art will realize that modifications may be made within the scope of the invention .
an exerciser including a movable body support mounted on an exerciser frame for movement along tracks provided by the frame . a movable foot support extends from the exerciser frame . the movable foot support is adapted to be engaged by the user &# 39 ; s feet to absorb the energy of movement in a first direction and to provide the user with a bouncing movement , which the user may translate into a movement of the movable body support in the opposite direction . the movable foot support may be provided as an attachment and retrofitted to existing exercisers , and , in some embodiments , may comprise independently movable foot supports for each foot . the exerciser may include a resilient resistance system coupled to the movable body support and a set of pull lines with user grips trained over pulleys carried by the exerciser frame . also disclosed are methods for enabling users to exercise .