Abstract:
Methods and apparatus are provided for monitoring plasma parameters in plasma doping systems. A plasma doping system includes a plasma doping chamber, a platen located in the plasma doping chamber for supporting a workpiece, an anode spaced from the platen in the plasma doping chamber, a process gas source coupled to the plasma doping chamber, a pulse source for applying pulses between the platen and the anode, and a plasma monitor. A plasma containing ions of the process gas is produced in a plasma discharge region between the anode and the platen. The pulses accelerate ions from the plasma into the workpiece. The plasma monitor may include a sensing device which senses a spatial distribution of a plasma parameter, such as plasma density, that is indicative of dose distribution of ions implanted into the workpiece.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to resistance training exercise apparatus mounted to walking exercise equipment such as treadmills. 
       BACKGROUND 
       [0002]    Home exercise machines are widespread. Some machines provide aerobic exercise, such as treadmills and other “cardio machines.” Some machines provide strength training such as weight machines and resistance machines using elastic straps or resistance gears. Examples include such suppliers as BOWFLEX™ and NAUTILUS™. These machines have drawbacks, however. These machines are essentially single purpose—they provide either a cardio workout or a strength workout, but can&#39;t provide for both in the same footprint. Most people have limited space in their home or office to store and use exercise equipment and don&#39;t have room for both a cardio machine and a strength machine. These machines can also be quite expensive. The cost of purchasing a stand-alone cardio machine and a stand-alone strength machine can be prohibitive for many. 
         [0003]    Adding strength exercises to aerobic exercise machines such as treadmills substantially increases the intensity of the cardiovascular workout when both are used simultaneously. During tests, the inventors have found that adding strength exercises may increase cardiovascular activity and calories burned by up to a third compared to the same treadmill speed and inclination without strength exercises. However, current machines providing some measure of upper body work with a treadmill lack flexibility. They are unable to adjust for users of different heights and widths. They are unable to adjust to work both upper and lower torso muscle groups during treadmill use, and they are unable to adjust to provide a pure strength workout without the treadmill motion—such as bench press and squat lifts. Additionally, existing machines which use rigid arm extensions create a constrained range of motion which can lead to a less effective workout, reduced flexibility or even injury over time. Rigid arm extensions cause the user to shift from side to side when operating them while walking on a treadmill. Providing offset handles with some rotational range of motion greatly alleviates this problem because the handle will follow the hand and arm&#39;s natural path rather than forcing the hand and arm to track a straight path back and forth. 
         [0004]    Additionally, existing combination machines do not provide the ability to rotate the strength training mechanisms completely out of the way to provide unfettered use of the treadmill treadway or to allow folding treadmills to fold up completely for stowage. Again, this lack of flexibility creates significant footprint problems that discourage people from purchasing and/or use exercise equipment. Nor do existing machines provide simple means to adjust resistance levels. 
         [0005]    Thus, there is a need for an apparatus combining the benefits of simultaneous strength training and cardio workouts within a compact footprint, and providing simple means to achieve full natural ranges of motion and adjustable resistance levels. Such a machine should also be able to accommodate basic strength training exercises separately from the treadmill cardio work as well. 
       SUMMARY AND ADVANTAGES 
       [0006]    A treadmill resistance training apparatus including left side and right side units, each having a vertical support with adjustable base connector and upper connector to couple to a treadmill, a riser to receive a rotational coupling and resistance arm, one or more resistance elements coupled between movable connectors on the resistance arm and an anchor point; an adjustable handle coupled to the resistance arm by an articulation joint, wherein the adjustable handle is selectively adjustable rotationally and lengthwise at a plurality of selectable fixed or dynamic positions. The apparatus may include a locking hinge mechanism to rotate the resistance arms between deployed and stowed position for unhindered access to the treadmill. The apparatus may include power actuated adjustment mechanisms to adjust resistance levels by adjusting the movable resistance element connectors. The apparatus includes a treadmill with left and right side units coupled to the treadmill. 
         [0007]    A treadmill resistance training apparatus as described herein presents numerous advantages: (1) it may be provided installed on a treadmill or augmented to an existing treadmill; (2) it supports a wide variety of strength and cardio exercises on a single machine without significant added footprint; (3) it provides a higher intensity workout than achievable on a treadmill alone; (4) it provides the ability to rotate the resistance arms out of the way of the treadmill for unencumbered access to the treadway or to fold a folding treadmill; (5) it provides means to easily adjust resistance levels without the need to reconfigure resistance elements; (6) it provides a more balanced torque load on moving parts by mounting resistance elements on opposing sides of a resistance arm; (7) an articulation joint provides a much wider range of motion to accommodate different size persons and different muscle groups; (8) an adjustable handle provides easy adjustment of both width and length; (9) an adjustable handle provides for limited rotation during use to allow more natural movements; (10) height adjustment accommodates different size persons and different muscle groups; (11) adaptable upper and lower connectors permit mounting to virtually any treadmill. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present invention and, together with the detailed description, serve to explain the principles and implementations of the invention. 
           [0009]      FIG. 1  shows a rear perspective view of a first embodiment of the invention being used for combined cardio and strength training. 
           [0010]      FIG. 2  shows a side perspective view of a first embodiment of the invention being used for strength training from a supine position. 
           [0011]      FIG. 3  shows a side perspective view of a first embodiment of the invention being used for strength training from a supine position. 
           [0012]      FIG. 4  shows close up overhead perspective view of a first embodiment of the invention. 
           [0013]      FIG. 5  shows a close up view of an adjustable handle of a first embodiment locked in a fixed position. 
           [0014]      FIG. 6  shows a close up view of an adjustable handle of a first embodiment locked in a dynamic position. 
           [0015]      FIG. 7  shows a front perspective view of a second embodiment of the invention in the deployed position. 
           [0016]      FIG. 8  shows a front perspective view of a second embodiment of the invention with one side in a partially rotated position. 
           [0017]      FIG. 9  shows a front perspective view of a second embodiment of the invention with one side in a stowed position. 
           [0018]      FIG. 10  shows a front perspective view of a second embodiment of the invention with both sides in a stowed position and the treadmill treadway folding up to stowed position. 
           [0019]      FIG. 11  shows a close up view of a left side of a second embodiment of the invention. 
           [0020]      FIG. 12  shows a close up view of a left side of a second embodiment of the invention. 
           [0021]      FIG. 13  shows a close up view of a vertical support upper adjustable connector of a second embodiment of the invention. 
           [0022]      FIG. 14  shows a cutaway side view of third embodiment of the invention. 
       
    
    
     REFERENCE NUMBERS FOR DRAWINGS 
       [0023]    The following list of reference numbers used in the Detailed Description and Drawings is provided for convenience:
     10  Left Unit     12  Right Unit     100  First Embodiment     102  Vertical Support     110  Adjustable Base Connector     112  First Base Connector Leg     114  Second Base Connector Leg     116  First Compression Member     118  Lower Slot     120  Second Compression Member     122  Third Compression Member     124  Upper Slot     126  Adjustable Base Unit Sleeve     128  Adjustable Base Unit Index Holes     130  Riser Portion     132  Adjustable Upper Connector     134  Clamp Portion     136  Clamp First Member     138  Clamp Second Member     140  Clamp Compression Member     142  First Clamp Member Adjustment Slot     144  Threaded Fastener     146  Second Clamp Member Adjustment Slot     148  Rotational Coupling Connector     150  Rotational Coupling     152  Rotational Axis     154  Resistance Arm     156  Resistance Arm First End     158  Resistance Arm Second End     160  First Resistance Element Connector     162  First Resistance Element Connector Locking Mechanism     164  First Resistance Element First Connection Point     166  Finger Clamp     168  Second Resistance Element Second Connection Point     170  Finger Clamp     172  Resistance Arm Index Holes     174  Resistance Element     176  Resistance Element First Connection End     178  Resistance Element Second Connection End     180  Resistance Element Anchor     182  Finger Clamp     184  Resistance Element     186  Resistance Element     188  Second Resistance Element First Connection Point     190  Finger Clamp     192  Second Resistance Element Second Connection Point     194  Finger Clamp     196  Resistance Arm Stop     198  Flexible Strap First End     200  Flexible Strap Second End     202  Second Resistance Element Connector     206  Articulation Joint     208  Index Plate     210  Indexing Holes     212  Indexing Hole Pin     214  Compression Member     216  Adjustable Handle     218  Handle First Part     220  Handle Second Part     222  Offset Grip Portion     224  Interface Region     226  Handle Locking Mechanism     228  Handle Locking Mechanism Pin     230  Rotational Coupling Connector Bolts     232  Rotational Coupling Connector Spacers     234  Riser Upper End     236  Riser Portion Receiving Holes     238  Rotational Coupling Connector Anchor Plate   240 Riser Locking Pin     242  Handle Locking Mechanism Close Apertures     244  Handle Locking Mechanism Slotted Apertures     246  Index Plate Receiving Hole     248  Handle First Part First End     250  Receiving Channel     252  First Side Arm     254  Second Side Arm     256  First Side Arm Receiving Hole     258  Second Side Arm Receiving Hole     260  First Side Arm Index Pin Receiving Hole     262  Second Side Arm Index Pin Receiving Hole     264  Riser Portion Lower End     1000  Second Embodiment     1110  Adjustable Base Connector     1112  First Base Plate     1114  Second Base Plate     1116  Threaded Compression Member     1120  Threaded Compression Member     1122  Threaded Compression Member     1124  Slot     1126  Base Connector Sleeve Portion     1130  Riser Portion     1132  Upper Connector     1134  Clamp Portion     1136  Clamp First Member     1138  Clamp Second Member     1140  Clamp Compression Member     1142  Clamp Adjustment Slot     1144  Clamp Threaded Fasteners     1148  Rotational Coupling Connector     1150  Rotational Coupling     1152  Fulcrum Point     1154  Resistance Arm     1156  Resistance Arm First End     1158  Resistance Arm Second End     1160  First Resistance Element Connector     1162  First Resistance Element Connector Locking Mechanism     1164  First Resistance Element First Connection Point     1166  Finger Clamp     1168  Second Resistance Element Second Connection Point     1170  Finger Clamp     1174  Resistance Element     1180  Resistance Element Anchor     1184  Resistance Element     1186  Resistance Element     1188  Second Resistance Element First Connection Point     1190  Finger Clamp     1192  Second Resistance Element Second Connection Point     1194  Finger Clamp     1196  Resistance Arm Stop     1198  Flexible Strap First End     1200  Flexible Strap Second End     1202  Second Resistance Element Connector     1204  Second Resistance Element Connector Locking Mechanism     1206  Articulation Joint     1216  Adjustable Handle     1218  Handle First Part     1220  Handle Second Part     1222  Offset Grip Portion     1224  Handle Interface Region     1226  Handle Locking Mechanism     1228  Locking Pin     1230  Handle Index Holes     1234  Riser portion upper end     1236  Riser Portion Index Holes     1266  Hinge Connector     1268  Hinge Safety Pin     1270  Hinge Mounting Bracket     1272  Mounting Bracket Holes     1274  Threaded Compression Members     1276  Upper Hinge Plate     1278  Lower Hinge Plate     1280  Mounting Bracket Spine     1282  Hinge Axle     1284  Hinge axle First End     1286  Hinge axle Second End     1288  Hinge Post     1290  Hinge Arm     1292  Hinge Arm Distal End     1294  Hinge Post First End     1296  Hinge Post Second End     1298  Hinge Post Locking Pin Receiving Hole     1300  Hinge Post Top Flange     1302  Hinge Index Holes     1304  Hinge Index Pin     1306  Hinge Locking Pin Receiving Hole     1310  Upper Connector Articulation Joint     1312  Index Plate     1314  Center Receiving Hole     1316  Index Holes     1318  Coupling Member First End     1320  Retaining Bolt     1322  Coupling Member Second End     1324  Coupling Member Index Hole     1326  Index locking pin     1328  Coupling Member     1330  Gripping Protrusions     2000  Third Embodiment     2106  Articulated Joint     2130  Riser Portion     2132  Upper Connector     2150  Rotational Coupler     2154  Resistance Arm     2156  Resistance Arm First End     2158  Resistance Arm Second End     2160  First Movable Resistance Element Connector     2174  Resistance Element     2180  Resistance Element Anchor     2184  Resistance Element     2202  Second Movable Resistance Element Connector     2266  Hinge Connector     2270  Hinge Mounting Bracket     2304  Hinge Indexing Pin     2402  First Power Actuated Resistance Adjustment Mechanism     2404  Second Power Actuated Resistance Adjustment Mechanism     2406  Controller and Power Supply     2408  Power and Control Cable     2410  Air Compressor     2412  Pneumatic Tubing     2414  Pneumatic Tubing     2416  First Electro-pneumatically Actuated Piston     2418  Pneumatic Tubing     2420  Pneumatic Tubing     2422  Second Electro-pneumatically Actuated Piston     2424  First Piston Rod     2426  First Universal Joint     2428  Second Piston Rod     2430  Second Universal Joint   
 
       DETAILED DESCRIPTION 
       [0221]    Before beginning a detailed description of the subject invention, mention of the following is in order. When appropriate, like reference materials and characters are used to designate identical, corresponding, or similar components in differing figure drawings. The figure drawings associated with this disclosure typically are not drawn with dimensional accuracy to scale, i.e., such drawings have been drafted with a focus on clarity of viewing and understanding rather than dimensional accuracy. 
         [0222]    In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer&#39;s specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure. 
         [0223]    For ease of reference a common identification system is used herein for describing the disclosed embodiments. An exercise treadmill as used in this Specification is defined to include a treadway, which the exerciser walks upon during use, a front end, which is the end the exerciser faces when walking forward, and a back end, which is open for the exerciser to enter the treadmill. A treadmill generally includes left and right support columns or a centrally mounted support column. A treadmill generally includes a base or frame which rests on the floor through leveling feet and supports the rest of the treadmill apparatus. 
         [0224]    The invention disclosed includes mirror image left-side and right-side units for an exercise treadmill. “Mirror-image” includes where the components of the left and right-side units are actually identical and interchangeable. For clarity, in this Specification, description is provided referring to a single unit, with the understanding that the opposite side-unit is the same. 
         [0225]    Referring to  FIGS. 1-6 , a first embodiment is shown. A treadmill resistance training apparatus  100  having mirror image left and right units  10  and  12 , respectively, is coupled to a treadmill T having a treadway, a forward end F, an aft end A, a frame support F coupling treadmill T to the ground, and an upper portion U providing user interface controls and railing supports. Each of units  10  and  12  includes a vertical support  102  having an adjustable base connector  110  to couple vertical support  102  to treadmill frame F, a riser portion  130  coupled to and extending upward from the base connector  110 , and an adjustable upper connector  132  to couple the vertical support  102  to the treadmill upper portion U; a rotational coupling connector  148  connecting a rotational coupling  150  to the riser portion  130 ; a rotational coupling  150  mounted to the rotational coupling connector  148  such that the rotational axis  152  of the rotational coupling  150  is approximately horizontal; a resistance element anchor  180  coupled to the riser portion  130 ; an elongated resistance arm  154  having opposing first and second ends  156  and  158 , respectively, the resistance arm  154  coupled to the rotational coupling  150  at a fulcrum point  152  between the resistance arm first and second ends  156 ,  158 ; a first resistance element connector  160  movably coupled to the resistance arm  154  between the rotational coupling  150  connection and the first end  156  of the resistance arm  154  and including a resistance element connector locking mechanism  162  to lock the first resistance element connector  160  at user selectable positions along the resistance arm  154 ; one or more resistance elements  174 ,  184  and  186 , connectable between the resistance element anchor  180  and the first resistance element connector  160 ; an adjustable handle  216 ; and, an articulation joint  206  coupling the handle  216  to the resistance arm first end  156  at a plurality of user selected angles. 
         [0226]    In the embodiment, the height of the rotational coupling connector  148  along the riser portion  130  is user adjustable. Rotational coupling connector  148  includes a pair of connector bolts  230  bolted into receiving holes  236  along riser portion  130  through spacers  232 , which anchor plate  238 . The height of coupling connector  148 , and therefore fulcrum point  152 , can be adjusted without affecting the installation of the unit  10  to the treadmill by simply selecting different receiving holes  236  for attachment. Riser portion  130  is coupled to adjustable base connector  110  at an adjustable height. Riser portion  130  fits slidably into sleeve portion  126  of adjustable base connector  110 , so a user can move it up or down and lock it in place by inserting pin  240  into index holes  128  and through a corresponding riser receiving hole  236 . In the embodiment, resistance element anchor  180  is coupled to riser portion  130  separately from rotational coupling connector  148  and so must be moved independently. 
         [0227]    In the embodiment, adjustable base connector  110  includes first and second parallel base legs  112  and  114  which straddle a part of frame F to compress the part and couple base connector  110  to frame F and to the floor. First compression member  116  passes under frame F and is adjusted within lower slot  118  (and a corresponding slot in leg  114 , not visible) to abut upwardly against frame F to carry at least some of the weight of treadmill T, so that base connector  110  is more firmly coupled to the ground. First compression member  116 , with second and third compression members  120  and  122  passing above frame F, firmly compress frame F between connector legs  112  and  114 , and pass through receiving holes in sleeve portion  126 , to firmly engage adjustable base connector  110  to frame F. In the embodiment, compression members  116 ,  120  and  122  are threaded connectors. Upper slot  124  (and a corresponding slot in leg  114 , not visible) provides adjustment to provide height adjustment for base connector  110  and to displace compression member  122  for greater resistance to twisting. 
         [0228]    In the embodiment, adjustable upper connector  132  includes a clamp portion  134  to clamp against a part of the treadmill upper portion U. Clamp portion  134  includes first and second opposing L-shaped clamp members  136  and  138 , which are nested so that member  136  slides within member  138  when compression member  140  is tightened, and retained in alignment by threaded fastener  144  extending through a riser portion receiving hole  236  and adjustment slots  142  in first member  136  and  146  in second member  138 . Fastener  144  connecting through receiving hole  236  and clamp member slots  142  and  146  allows a user to extend the length of and select the optimum for upper connector  132  to couple vertical support  110  to treadmill upper portion U. This articulation joint, allowing rotation in a selected plane, provides great flexibility to integrate a standard unit to virtually any treadmill design, including those with only a horizontal rail extending around without left and right vertical posts. 
         [0229]    In the embodiment, first resistance element connector  160  is a short sleeve fitting slidably over resistance arm  154 , with a spring loaded locking pin  162  engagable with index holes  172  along at least a portion of the length of resistance arm  154 . Moving the resistance element connection point linearly along resistance arm  154  varies the resistance experienced by the user by changing the moment arm imposed by the resistance elements created by the distance between the connection point on connector  160  and fulcrum point  152 . The moment arm imposed by the user remains essentially constant if the user grips handle  216  at the same location. 
         [0230]    A second resistance element connector  202  is coupled to resistance arm  154  between rotational coupling  150  and second end  158  of the resistance arm  154 , in this case actually mounted over second end  158 , but is not movable. One or more resistance elements  174 ,  184  and  186  are connectable between resistance element anchor  180  and the second resistance element connector  202 . 
         [0231]    In the embodiment, first and second resistance element connectors  160  and  202  include opposing first and second resistance element connection points  164 ,  168  and  188 ,  192 , respectively, disposed on left and right sides of resistance arm  154 . In the embodiment connection points  164 ,  168 ,  188  and  192  are projections, with finger clamps  166 ,  170 , and  190 ,  194 , respectively, preventing resistance elements from slipping off. Providing connection points on opposing sides of arm  154  reduces twisting torque on arm  154 , handle  216 , and rotational coupling  150 . 
         [0232]    In the embodiment, resistance arm stop  196  is provided, consisting of a flexible strap coupling at a first end  198  to second resistance element connector  188  and at a second end  200  to anchor  180  on riser portion  130 , so as to prevent resistance arm  154  from rotating beyond a selected point in one direction. Stop  196  may be shifted to first resistance element connector  160  to prevent resistance arm  154  from over rotating in the opposite direction. 
         [0233]    In the embodiment, resistance elements  174 ,  184  and  186  are identical, so only element  174  is described in detail. Resistance element  174  is symmetrical and includes a first connection end  176  and a second connection end  178  which engage either anchor  180  or a connection point such as  164 . In the embodiment, resistance elements  174 ,  184 , and  186  are bands or straps of elastomeric materials, but other resistance elements could be used, such as springs, pneumatic pistons or similar mechanisms. 
         [0234]    Referring again to  FIGS. 1-6 , and especially to  FIGS. 5 and 6 , an adjustable handle  216  coupled to resistance arm  154  by articulation joint  206  is shown. In the embodiment, handle  216  includes a first part  218  coupled to articulated joint  206  and a second part  220  including an offset grip portion  222 . Handle second part  220  slidably and rotatably connects to handle first part  218  along an interface region  224 , the interface region being the region in which the handle parts overlap or intersect each other. Handle locking mechanism  226  allows a user to selectively lock handle second portion  220  at a selected fixed or selected dynamic position relative to the handle first part  218 . In the embodiment handle locking mechanism  226  includes a spring loaded pin  228  mounted to handle first part  218  within interface region  224 ; and, an alternating pattern of close fitting apertures  242  and transverse slotted apertures  244  disposed along the length and circumference of second handle part  220  within interface region  224  to receive pin  228 . Pin and apertures could be swapped between handle first and second parts as well. When pin  228  is received in a selected close fitting aperture  242  the handle first and second parts  218  and  220  are locked relative to each other, both rotationally and lengthwise, providing a “fixed” locking position as shown in  FIG. 5 . When pin  228  is received in a selected transverse slotted aperture  244  the handle first and second parts  218  and  220  are prevented from sliding longitudinally or lengthwise relative to each other but have limited coaxial rotational movement relative to each other, thereby providing a “dynamic” locked position as shown in  FIG. 6 . Providing both lengthwise and rotation adjustment, combined with the offset grip portion  222 , accommodates users of any size, from skinny to wide, and allows users to isolate different muscle groups by widening or narrowing their grip. Selecting a dynamic locked position provides limited rotational movement for the offset grip portion  222  to orbit around the main longitudinal axis of handle  216 , allowing freer movement of the arms to building strength in supporting muscles and tendons for a better overall workout. Reference to offset grip portion  222  does not imply that this is the only area where a user can grip handle  216 . Rather, a user may grip handle  216  anywhere that is convenient. 
         [0235]    In the embodiment, articulation joint  206  couples handle  216  to resistance arm  154 . Articulation joint  206  includes an index plate  208  rigidly coupled to resistance arm first end  156  and having a receiving hole  246  to receive threaded compression member  214  there through and a plurality of angle indexing holes  210  distributed around receiving hole  246  at selected angular offsets. Handle first part  218  includes a first end  248  with a channel  250  forming opposing side arms  252  and  254  to receive index plat  208 , with receiving holes  256  and  258  to align with receiving hole  246  and index pin receiving holes  260 ,  262  to align with indexing holes  210 . Handle first part  218  extends to a second end  264  which engages with handle second part  220 . Threaded compression member  214  is loosened to permit rotation to a selected angle, then tightened to compress opposing side arms  252  and  254  against index plate  208  and index pin  212  inserted through index pin receiving holes  260  and  262  aligned with indexing holes  210  to lock handle  216  at the desired angle relative to resistance arm  254 . 
         [0236]    Referring to  FIGS. 8-13 , a second embodiment  1000  is shown which is similar in many ways to the first described embodiment  100 , and so described in less detail. In a second embodiment, left and right side units  1002  and  1004 , respectively, are provided which are mirror images of each other and so a single description is provided. 
         [0237]    Each of units  1010  and  1012  includes a vertical support  1102  having an adjustable base connector  1110  to couple vertical support  1102  to treadmill frame F, a riser portion  1130  coupled to and extending upward from the base connector  1110 , and an adjustable upper connector  1132  to couple the vertical support  1102  to the treadmill upper portion U; a rotational coupling connector  1148  connecting a rotational coupling  1150  to the riser portion  1130 ; a rotational coupling  1150  mounted to the rotational coupling connector  1148  such that the rotational axis  1152  of the rotational coupling  1150  is approximately horizontal; a resistance element anchor  1180  coupled to the riser portion  1130 ; an elongated resistance arm  1154  having opposing first and second ends  1156  and  1158 , respectively, the resistance arm  1154  coupled to the rotational coupling  1150  at a fulcrum point  1152  between the resistance arm first and second ends  1156 ,  1158 ; a first resistance element connector  1160  movably coupled to the resistance arm  1154  between the rotational coupling  1150  connection and the first end  1156  of the resistance arm  1154  and including a resistance element connector locking mechanism  1162  to lock the first resistance element connector  1160  at user selectable positions along the resistance arm  1154 ; one or more resistance elements  1174 ,  1184  and  1186 , connectable between the resistance element anchor  1180  and the first resistance element connector  1160 ; an adjustable handle  1216 ; and, an articulation joint  1206  coupling the handle  1216  to the resistance arm first end  1156  at a plurality of user selected angles. 
         [0238]    In the embodiment, rotational coupling connector  1148  includes a hinge connector  1266  mounted to riser portion  1130 , with hinge connector  1266  selectively lockable in a deployed position, as shown in  FIG. 7 , and a stowed position, as shown in  FIG. 9 , using hinge safety pin  1268 . Hinge connector  1266  includes a u-shaped mounting bracket  1270  with mounting holes  1272  to align with riser portion index holes  1236  and receive threaded compression members  1274 , to firmly couple hinge connector  1266  to riser portion  1130  at a selected height. Upper and lower hinge plates  1276  and  1278 , respectively, extend from mounting bracket spine  1280  to retain hinge post  1288  between them, which receives internal hinge axle  1282  there through, with hinge axle  1282  secured at first and second ends  1284  and  1286  by the respective hinge plates,  1276 ,  1278 , leaving hinge post  1288  free to rotate about hinge axle  1282 . Hinge arm  1290  is rigidly coupled to and extends out from hinge channel  1288  to receive rotational coupling  1150  at its distal end  1292 . Hinge post  1288  is a hollow tube with opposing first and second ends  1294  and  1296 , respectively, and a locking pin receiving hole  1298  extending transversely through at approximately its midpoint. Hinge post  1288  includes a top flange  1300  rigidly connected to first end  1294 , proximal to upper hinge plate  1276 , and including hinge index holes  1302  to receive spring loaded hinge index pin  1304  there in. Hinge axle  1282  is secured at its ends  1284  and  1286  to prevent rotation, and includes hinge locking pin receiving hole  1306  transversely through its midsection so that it is aligned with receiving hole  1298  when unit  1002  is fully deployed for use, as shown in  FIG. 7 , and when unit  1002  is rotated 180 degrees around hinge axle  1282  to the fully stowed position, as shown in  FIG. 9 . An operator may disengage hinge locking pin  1304 , pull up spring loaded hinge index pin  1304  to clear hinge index holes  1302 , rotate unit  1002  to a desired position, and then reengage index pin  1304  into the selected hinge index hole  1302 . 
         [0239]    In the embodiment, resistance element anchor  1180  projects from hinge post  1288  so that the height of anchor  1180  adjusts with the rotational coupling connector  1150  to remain constant, and resistance elements  1174 ,  1184  and  1186  rotate with resistance arm  1154 . 
         [0240]    Base connector  1110  includes opposing first and second base plates  1112  and  1114  engage a part of frame F tightening threaded compression members  1116 . Base connector sleeve portion  1126  extends upward from second base plate  1114  to receive riser portion lower end  1108 . Threaded compression members  1120  and  1122  insert through riser portion receiving holes  1236  within slot  1124  to permit adjustment of the height of riser portion  1130 . 
         [0241]    In the embodiment, adjustable upper connector  1132  includes a clamp portion  1134  to clamp against a part of the treadmill upper portion U. Clamp portion  1134  includes first and second opposing L-shaped clamp members  1136  and  1138 , which are nested so that member  1136  slides within member  1138  when compression member  1140  is tightened, and retained in alignment by threaded fasteners  1144  extending through adjustment slot  1142 . Clamp portion  1134  includes a plurality of gripping protrusions  1330  disposed on at least a portion of the contact area between the clamp  1134  and the treadmill upper portion U. 
         [0242]    In the embodiment, upper connector  1132  includes an articulation joint  1310  to accommodate a wider range of angular adjustments. Articulation joint  1310  includes an index plate  1312  rigidly coupled proximal to riser upper end  1234 . Index plate  1312  includes a center receiving hole  1314  to receive retaining bolt  1320  and a plurality of index holes  1316  distributed around center receiving hole  1314  at selected angular offsets. Coupling member  1328  couples at a first end  1318  to index plate  1312  by retaining bolt  1320  and at a second end  1322  to clamp portion  1134  by threaded fasteners  1144  through adjustment slot  1142 , which allows extension or retraction. Coupling member  1328  includes an index hole  1324  to align with index holes  1316  and receive index locking pin  1326 . 
         [0243]    In the embodiment, a second resistance element connector movably coupled to the resistance arm between the rotational coupling and the second end of the resistance arm and including a locking portion to lock the second resistance element connector at user selectable positions along the resistance arm; and, one or more resistance elements connectable between the resistance element anchor and the second resistance element connector. 
         [0244]    In the embodiment, first resistance element connector  1160  is a short sleeve fitting slidably over resistance arm  1154 , with a threaded locking bolt  1162  engagable with index holes along at least a portion of the length of resistance arm  1154 . Moving the resistance element connection point linearly along resistance arm  1154  varies the resistance experienced by the user by changing the moment arm imposed by the resistance elements created by the distance between the connection point on connector  1160  and fulcrum point  1152 . The moment arm imposed by the user remains essentially constant if the user grips handle  1216  at the same location. 
         [0245]    A second resistance element connector  1202  is coupled to resistance arm  1154  between rotational coupling  1150  and second end  1158  of the resistance arm  1154 , and essentially identical in operation to first resistance element connector  1160 , including threaded locking bolt  1204  to engage index holes along resistance arm  1154 . One or more resistance elements  1174 ,  1184  and  1186  are connectable between resistance element anchor  1180  and the second resistance element connector  1202 . 
         [0246]    In the embodiment, first and second resistance element connectors  1160  and  1202  include opposing first and second resistance element connection points  1164 ,  1168  and  1188 ,  1192 , respectively, disposed on left and right sides of resistance arm  1154 . In the embodiment connection points  1164 ,  1168 ,  1188  and  1192  are projections, with finger clamps  1166 ,  1170 , and  1190 ,  1194 , respectively, preventing resistance elements from slipping off. Providing connection points on opposing sides of arm  1154  reduces twisting torque on arm  1154 , handle  1216 , and rotational coupling  1150 . 
         [0247]    In the embodiment, adjustable handle  1216  is coupled to resistance arm  154  by articulation joint  1206 . Handle  1216  includes a first part  1218  coupled to articulated joint  1206  and a second part  1220  including an offset grip portion  1222 . Handle second part  1220  slidably and rotatably connects to handle first part  1218  along an interface region  1224 , the interface region being the region in which the handle parts overlap or intersect each other. Handle locking mechanism  1226  allows a user to selectively lock handle second portion  1220  at a selected fixed position relative to the handle first part  1218 . In the embodiment handle locking mechanism  1226  includes an locking pin  1228  insertable through index holes  1230  in handle first part  1218  and second part  1220  within interface region  1224 . 
         [0248]    The apparatus of claim  1 , further comprising: a power actuated resistance adjustment mechanism coupled to the resistance arm and the first resistance element connector to move the first resistance element connector to user selectable positions along the resistance arm; and, a power actuated resistance element connector locking mechanism. 
         [0249]    Referring to  FIG. 14 , a third embodiment  2000  is shown having power actuated resistance adjustment mechanisms  2402  and  2404  mounted at resistance arm  2154  first and second ends  2156  and  2158 , respectively, to adjust resistance. The third embodiment is generally similar to the second embodiment, having a riser  2130 , upper connection  2132 , first and second movable resistance element connectors  2160  and  2202  on resistance arm  2154 , with resistance arm  2154  connected at a fulcrum point to hinged connector  2266  by rotational coupler  2150 . Hinge connector  2266  couples to riser portion  2130  by hinge bracket  2270 , and hinge indexing pin  2304  locks hinge connector  2266  at user selected angles. Resistance elements  2174  and  2186  couple between movable connectors  2160  and  2202  and resistance element anchor  2180  projecting from hinge post  2288  to rotate therewith. A handle (not shown) couples to resistance arm  2154  by articulated joint  2106 . Power and control are provided by controller  2406  through flexible cable  2408  to air compressor  2410 . Air compressor  2410  supplies pressurized air to first and second bi-directional pistons  2416  and  2422  by flexible tubing  2412 ,  2414  and  2418 ,  2420 , respectively. Pistons  2416  and  2420  are mounted rigidly to resistance arm  2154 . First piston  2416  couples to first resistance connector  2160  by first piston rod  2424  via universal joint  2426 . Second piston  2422  couples to second resistance connector  2202  by second piston rod  2428  via universal joint  2430 . Air compressor  2410  includes built in solenoid valves in fluid communication with each of the opposing piston sides in first and second pistons  2416  and  2422  to provide a controlled locking mechanism. Alternatively, the pistons and associated couplings could be replaced by electromagnetically actuated linear motors, or by electrically powered lead screws, either of which could provide powered adjustment capability to move resistance element connectors  2160  and  2202  along resistance arm  2154  to a user-selected resistance level. Controller  2406  may be integrated into a treadmill controller, or could be installed separately onto a treadmill at a convenient location. 
         [0250]    Those skilled in the art will recognize that numerous modifications and changes may be made to the preferred embodiment without departing from the scope of the claimed invention. It will, of course, be understood that modifications of the invention, in its various aspects, will be apparent to those skilled in the art, some being apparent only after study, others being matters of routine mechanical, chemical and electronic design. No single feature, function or property of the preferred embodiment is essential. Other embodiments are possible, their specific designs depending upon the particular application. As such, the scope of the invention should not be limited by the particular embodiments herein described but should be defined only by the appended claims and equivalents thereof.