US3784194A

US3784194A - Bilateral reciprocal isokinetic exerciser

Info

Publication number: US3784194A
Application number: US00245742A
Authority: US
Inventors: J Perrine
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-04-20
Filing date: 1972-04-20
Publication date: 1974-01-08
Anticipated expiration: 1991-01-08

Abstract

An Isokinetic Exerciser for exercising the limbs of a person bilaterally reciprocally includes an actuator means with simultaneous reciprocal force receiving input members on opposite ends of the actuator. A limb supporting lever is attached to each of the force receiving members. The actuator is coupled to a valve which adjustably controls the limit speed of rotation of the levers effectively independent of the forces applied thereto by controlling the flow of fluid through the valve.

Description

tes atet 1 [11] 3,7843 Perrine Jan. 8, 1974 [54] BILATERAL RECHPROCAL ISOKHNETEC 3,465,592 9/1969 Pcrrinc 272/DlG. 6 EXERCHSER 3,495,824 2/1970 Cuinier .0 272/79 C X 3,702,188 11/1972 Phillips et a1. 272/79 C X [76] Inventor: James .B. Pcrrine, 8973 Kobe PL,

San Dlego Calif 92123 Primary Examiner-Richard C. Pinkham [22] Filed: Apr. 20, 1972 Assistant Examiner-William R. Browne [21] App]. No.: 245,742

[57] ABSTRACT 52 US. CH 272/79 C 272/5 0/545 R An Isokinetic Exerciser for exercising the limbs Of a 272/DIG 4, 272/DIG 1 272/DIG 6 272/79 person bilaterally reciprocally includes an actuator D means with simultaneous reciprocal force receiving 51 im. Cl. A63b 23/04, A63b 21/00 input members on Opposite ends of the actuatofl A [58] Field of Search 272/58 80, 54 79 G; limb supporting lever is attached to each of the force 60/545 91/186, 435 receiving members. The actuator is coupled to a valve which adjustably controls the limit speed of rotation of [56] References Cited the levers effectively independent of the forces applied thereto by controlling the flow of fluid through UNITED STATES PATENTS the valve- 2,903,263 9/1959 Ross 272/54 3,395,698 8/1968 Morehouse 272/73 UX 12 Claims, 11 Drawing Figures PAIE'NTEDJAN 819M :siemsm SHUT 1 BF 5 sum 2 or 5 PATENTED 8 4 PATENnmm 8I974 saw u. (If 5 I PATENTEIJ JAN 81974 SHEEI 5 BF 5 BIILATERAL RECIPIROCAL ISOKINETIC EXERCISER This invention is directed at an isokinetic exerciser and more specifically to a bilateral-reciprocal isokinetic exerciser.

My isokinetic exerciser disclosed in US. Pat. No. 3,465,592, describes an isokinetic apparatus of the type wherein a user moves one or both arms and legs together in the same direction against an accommodating resistance at a controlled speed. By contrast, the present invention is directed to an lsokinetic exerciser which provides for simultaneous bilateral-reciprocal movement of two limbs.

According to the invention there is provided an isokinetic bilateral reciprocal exercising device comprised of an actuator means with simultaneous reciprocal motion inputs on opposite sides of the actuator and a limb supporting lever is connected to each of the inputs. The actuator incorporates control means for controlling the speed of movement and providing an accommodating resistance to the limb supporting levers. In one embodiment the actuator may be a rotary hydraulic actuator in which a rotor is driven via a gear train and attached levers by the leg movements of a user.

It is therefore the principal object of the present invention to provide a bilateral-reciprocal isokinetic exerciser for exercising the upper or lower limbs in a simultaneously bilateral reciprocal movement pattern against isokinetic loading.

It is another object of the present invention to provide a bilateral-reciprocal isokinetic exerciser which will permit physically handicapped patients to practice the coordinated bilateral-reciprocal lower limb movements needed for efficient ambulation.

These and other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:

FIG. 1 is a perspective view of an exerciser device for exercising lower limbs of a seated patient, shown installed on a stand with a seat for the patient;

FIG. 2 is an enlarged partially exploded perspective view of the actuator;

FIG. 3 is a right side elevational view of the device illustrated in FIG. 2;

FIG. 4 is a left side elevational view of the device illustrated in FIG. 2;

FIG. 5 is an enlarged central vertical sectional view taken along line 55 of FIG. 2;

FIG. 6 is a cross-sectional view taken along line 66 of FIG. 5;

FIG. 7 is a fragmentary sectional view taken along line 77 of FIG. 3;

FIG. 8 is a longitudinal sectional view taken through a control valve along line 88 of FIG. 4;

FIG. 9 is a fragmentary vertical sectional view taken along line 9-9 of FIG. 8;

FIG. 10 is an exploded perspective view of the control valve and associated parts; and

FIG. 11 is a perspective view of another actuator used .with my exerciser device.

Referring, now to the drawings wherein like reference characters designated like or corresponding parts throughout, there is illustrated in FIGS. 1 through 4 an exerciser device generally designated as reference numeral 20 mounted on a platform 22. The exerciser device 20 includes an actuator housing 21 having two massive rectangular

vertical side plates

24, 26 each of which is provided with a threaded bottom hole 28 which receives a bolt 30 securing the exerciser 20 to the platform 22. A threaded hole 32 (FIG. 4) in each upper end of the

walls

24, 26 defines a bolt (not shown) for securing a seat frame 34 to the top of the exerciser device 20. A seat 36 is mounted on the frame 34 by any conventional well known fastener means. Secured to the frame 34 is a backrest 38 and a pair of lateral arms 40. A person using the exerciser may sit on the seat 36 and place each of his feet through a loop 41 of a pedal 42 secured to a forward end 44a of an L-shaped lever 44, located on each side of the exerciser 20. The levers 44 turn in a vertical plane parallel to the

plates

24, 26 and each of the levers have a short inwardly turned arm 46 which terminates at the hub or flange 48 (FIG. 2). In this embodiment, the hub or flange 48 is located at opposite sides of the exerciser 20, and each flange 48 provides a separate input to the actuator housing 21. The hub or flange 48 may be selectively bolted to gears (54, 56 and 58, 60) at opposite ends of the exerciser as will thereinafter be more fully described.

A plurality of bolts 50 secured by nuts 51 extend through the

plates

24, 26 and hold them in abutment with opposite ends ofa cylindrical fluid-filled rotary actuator tube 52. At the outer side of the plate 24 is a pair of

mating spur gears

54, 56 which rotate in opposite directions. At the outer side of the plate 26 is another pair of

mating spur gears

58, 60 which rotate in the same direction with respect to one another.

Two valve assemblies generally designated as

reference numberals

64 and 66 extend between the

plates

24, 26 and each has a control knob 68 secured on a rotatable valve control shaft 72 which extends axially from the valve casing 74.

A fitting 76 is secured in a

bore

80 and 82 with each fitting carrying a flexible tube 84 to provide communication between a pressure gauge 88 and the interior of the

valve assemblies

64 and 66. A fitting 92 in a bore 94 at the top of the plate 26 carries a flexible tube 95 which provides communication between the interiors of the value casings 74 and a pipe 96 which is closed at the upper end by a cap 97 and is partially filled with a fluid 98. The fluid 98 which may be a free flowing oil fills the tube 95, the tubes 84 and the interiors of the

valves

64 and 66 and the actuator tube 52. The tube 95 is attached to the lower end of the pipe 96 by a fitting 93.

The

lower gears

56 and 60 rotate on respective shafts 102 journaled in bearings in the

end plates

24, 26. The shafts 102 are axially aligned between the

end walls

24, 26 by shaft 100. The

upper gears

54 and 58 are secured to opposite ends of a horizontal shaft 103 extending axially of the actuator tube 52 (see FIG. 5). The

gears

54,56,58,60 are provided with threaded holes 104 which receive bolts 106 by means of which the mounting flanges 48 can be secured to selected gears at opposite ends of the exerciser device.

An idler gear 62 rotates on a fixed shaft bolted to the end wall 26, as best viewed in FIGS. 3 and 7. Supporting a shaft 108 inside the actuator tube 52 are bushings 110 and 111 (FIGS. 5, 6) which are sealed by O-rings 112 in respective grooves 114. The periphery of the bushings 110, 111 is enclosed by the actuator tube 52 and is sealed by O-rings 113 to keep the fluid 98 inside the actuator tube 52. Within the shaft 108 is a tie bolt 103 to which is attached the gear 58.

Mounted on the shaft 108 by a plurality of bolts 115 is a radially extending rotor 116 (FIG. 6) which is provided with seals 118 secured thereto at opposite faces of the rotor. The rotor seals 118 snugly fill the actuator bore radially between the shaft 108 and the actuator tube 52 and axially between the bushings 110 and 111. The rotor 116 can turn in either direction between opposite faces of a stator 120 which is secured by a plurality of bolts 122 to the inside of the actuator tube 52. The shaft 108 clears the inner concave side of stator 120 which is provided with seals 123 secured thereto at opposite faces thereof. The stator seals 123 fill a space radially between the shaft 108 and the actuator tube 52 and axially between the bushings 110-and 111. The rotor 116 and the stator 120 constitute movable and fixed partitions respectively which divide the interior of the actuator tube 52 into two chambers 125a and 1251) both of which are filled with the fluid 98. A pair of

ports

126, 128 in the bushing 110 open into the chambers 125a and 1251) respectively and communicate with the

bores

80, 82 respectively in the end plate 24.

Both

valve assemblies

64 and 66 are identical in con struction so a description of one valve assembly will suffice for both. Reference is now made to FIGS. 6, 8, 9 and wherein each

valve assembly

64 and 66 includes the cylindrical hollow stationary valve casing 74 in which is secured a cylindrical liner 149. The distal end of the casing 74 is closed by a plug 150 which is secured in a hole 152 in the end plate 26 by a plurality of bolts 153. The distal end of the valve casing 74 is seated in the hole 152 and is sealed by a gasket 155 and O-

rings

145, and 147. A plurality of holes 156 are formed in the cylindrical liner 149 of the valve casing 74 near its distal end (see FIGS. 8 and 10). A plurality of slots 159 are formed in the valve casing 74 to expose holes 156 which communicate with the vertical .bore 94 in the plate 26. The distal end of the valve casing 74 in hole 152 communicates with a pipe 96 via the bore 94 the fitting 92 and the tube 95. The pipe 96 serves as an accumulator for the fluid 98 in a manner explained further below.

The proximal end of each valve casing 74 is set in a hole 160 in the plate 24, which is closed by a plug 162 and sealed by a gasket 164 at an abutment 165. Control rods or shafts 72 extend axially of the respective valve casings. An O-ring 163 seals the end of the valve casing at the abutment 165 in the plate 24. The shaft 72 carries a diametral cross pin 166 at its inner end which is engaged in diametrically opposed slots 168 formed in a cylindrical valve member 170. The valve member 170 has an open proximal end and a wall 172 at the distal end of the valve member which is formed with a crescent shaped hole 174; see FIGS. 8, 9, 10. A coil spring 175 in the valve member 170 which is compressed between the pin 166 and the end wall 172 urges the valve member 170 into contact with an apertured end wall 176 of another cylindrical valve member 180. The valve member 170 is freely rotatable whereas, the value member 180 is movable axially but is held nonrotatably in the value casing. A pair of diametrically opposed slots 182 are formed in valve member 180. A fixed pin 184 extends diametrally 0f the valve casing through the slots 182 and is seated in holes 185 in the cylindrical liner 149 of the valve casing. The pin 184 prevents rotation of valve member 180 but permits axial movement of valve member 180, so that it can move under fluid pressure to the right as viewed in FIG. 8 for closing holes 156 and closing off the interior of the valve casing from bore 94. A compressed coil spring 186 in the valve member 180 is located between the pin 184 and the end wall 176. This spring keeps valve member 180 retracted from holes 156. End wall 176 has a crescent shaped hole 188 which can register with the hole 174 in the end wall 172 of the valve member 170 in one position of the valve member 170. By rotation of the valve member 170

holes

174 and 188 can be overlapped or misaligned for partially or completely closing the passage for flow of fluid 98 between the interiors of the two

valve members

170 and 180. It will thus be apparent that rotation of knob 68 and valve control shafts 72 can adjust the size of passage defined by the intersecting holes 174, 188 in the

walls

172, 176 for determining the rate of pressure compensates oil flow through the casings. The proximal ends of the valve casings are provided with projections 190 by means of which the end of the valve casing is spaced from the annular abutment 165 extending across the hole 160 in the plate 24. There is thus defined a passage between the interior ofeach valve casing at its proximal end in the plate 24 and the bore or 82 communicating with the nipple 76. In addition, the bore 80 communicates with the hole 126 and the bore 82 communicates with the hole 128 in the bushing as hereinbefore mentioned.

It will now be apparent from an inspection of the drawings, that the

gears

54, 58 and 60 rotate in one direction and that the

gears

56 and 62 rotate in a direction opposite thereto. By this arrangement, four different movements of the

levers

44, 45 are possible as follows:

l. Coaxial, reciprocal movements in opposite directions-obtained by attaching the flange 48 to the axially aligned gears 56 and 60 at opposite ends of the exerciser device.

2. Coaxial, simultaneous in-line movements-obtained by attaching the flange 48 to the axially aligned gears 54 and 58.

3. Reciprocal movements in opposite directions on vertically spaced horizontal axes-obtained by attaching the flange 48 to the axially spaced gears 56 and 58, or 56 and 54.

4. Simultaneous in-line movements on vertically spaced horizontal axes-obtained by attaching the flange 48 to the axially spaced gears 54 and 60.

The operation of the exerciser device will now be explained. Suppose first for purposes of illustration, that flange 48 is attached to the

gear

56 and 60 for reciprocal movements in opposite directions as indicated in arrangement No. 1 above. The person operating the device sits on the seat 36 with his feet engaged in the loops 41 of the pedals 42. The knob 68 is turned to overlap the

holes

172, 188 in the valve member 170, to any desired extent. The positions of the arrows on the knobs indicate the valve settings. The arrows might be set parallel to each other so that both of the valve assemblies have substantially the same setting. Now the person alternately extends one leg forcefully while the other leg rises automatically due to reciprocal movements of the levers. The speed with which the

levers

44, 45 reciprocate is automatically controlled by the apparatus. The control speed can only be changed by turning the control shaft 72 to adjust the

valve assemblies

64, 66. The manner in which these automatic controls are effected will now be explained.

Suppose the gear 56 moves clockwise as viewed in FIG. 6 to raise the attached lever 44 while the opposed gear 60 moves counterclockwise with the shaft 108, and the rotor 116. This will cause a reduction of volume in the chamber 125a and an increase in the volume of the chamber 125b. The fluid 98 will be forced out of the chamber 125a through the hole 126 in the bushing 110, and through the bore 80 to the proximal end of the upper valve casing 74 where the fluid 98 enters the casing 74 and passes through the

valve members

170, and 180. At this point it will be understood that if the valve holes 174 and 188 are not at least partially overlapping, the passage for fluid will be closed and no rotational movement of the gears and levers will be possible. The rate of fluid flow is determined by the size of the passage defined by the overlapped holes 174, 188. From the valve member 180 in the upper casing 74 the fluid flows through the holes 156 to the bore 94 and to the lower valve casing 74. The fluid passes through the

lower valve members

180 and 170 in turn to the bore 82 and enters the chamber 125 through the hole 128 in the bearing plate 110. Varying the force applied to the pedals 42 cannot have any material effect in varying the speed of movement since this is primarily limited by the compensating action of the valve member 180. When a leg movement reaches the control speed, the resulting pressure drop across the orifice defined by overlapping

holes

174, 188 will cause the valve member 180 to move to the right as viewed in FIG. 8, to close a portion of the holes 156 and increase the fluid pressure thereby resisting acceleration of the gears and levers. The restraining force acting on the pedals thus accommodates to effectively match the force applied by the leg at the control speed.

When the rotor 116 reaches the stator 120, angular turning motion of the levers is stopped. The lever 45 attached to the gear 60 is now raised and reverse motion of the levers can not be effected. Now the rotor 116 will turn clockwise as viewed in FIG. 6 to increase the volume of chamber 125a and reduce the volume of chamber 125b.

It will be apparent that by setting the valve members in both valve assemblies to defined passages of equal size, the

levers

44 and 45 will turn with substantially equal speed in both directions of movement. If the passage in the upper valve assembly 64 is set larger than the passage in the lower valve assembly, the lever 44 will move at a faster speed than the lever 45. In order to compensate for temperature changes and resulting expansion or contraction the fluid passes via the bore 94 to the reservoir pipe 96 and the air chamber 99 alternately contracts and expands accordingly.

The same speed controls are effective when the flanges 48 are attached to any other pair of gears listed above. When up and down simultaneous movement of both the

lever

44 and 45 is desired the flanges 48 will be attached to

gears

54, 58 or 54, 60 as mentioned above. Then the patient or user may force both legs up and down simultaneously with the speed controlled by the valve settings as previously described. If desired, an attendant may manually raise the

levers

44, 45 after they have been fully lowered by the patient.

Referring now to FIG. 11 there is shown another actuator 200 supported by the

side walls

24, 26. Actuator 200 is a conventional cylinder 201 having end plates 206 and a reciprocal piston 210 which divides the cylinder into two chambers. The piston 210 is connected via couplings 209 to a plastic coated cable 202 which exits through each chamber from the cylinder 201 at each input end of the actuator 200. The cable 202 travels around a

pulley

204 and 205 where it is anchored by conventional means (not illustrated). Each hub or flange 48 of the respective L-shaped

levers

44, 45 is rigidly fixed to the side of one of the pulleys 205. The pulley 204 is journaled between the arms of a bracket 203 and the pulley 205 is journaled on a shaft 207 which is fixed in the

respective side wall

24, 26. The

valve assemblies

64 and 66 extend between the

side walls

24, 26 and communicate the fluid between the opposite chambers of the cylinder 201 internally within the

assemblies

64 and 66 and via external tubes (not shown) which are connected to the assemblies and the respective chambers. The

valve assemblies

64 and 66 function in the same fashion as previously described with respect to the actuator 21 and thus control the speed with which the

levers

44, 45 reciprocate.

While only two embodiments of the inventions have been illustrated and described especially adapted for lower limb therapy it will be apparent that many modifications and variations are possible. For example, the device may be mounted on other suitable housings. Moreover other types of lsokinetic control actuators, i.e., hydraulic, electro-mecha'nical, centrifugal compensating brake, etc. may be used.

It should thus be understood that the foregoing relates to preferred embodiments of the invention and that they are intended to cover all changes and modifications of the examples of the invention herein chosen for the purposes of the disclosure, which do not consti tute departures from the spirit and scope of the invention.

The invention claimed is:

1. An isokinetic bilateral reciprocal exerciser comprising an actuator means for transmission of forces exerted by a user, said actuator means having two force receiving means, said actuator means having one of said force receiving means mounted at one end of said actuator means for applying a users force so that when said latter mentioned force receiving means is moved in one direction a user's force will be transmitted to the opposite end of the actuator means to simultaneously move the other force receiving means mounted at the opposite end of the actuator means in an opposite direction, each of said force receiving means being movable through planes that are substantially parallel to each other, and means for supporting both of said force receiving means in spaced relationship to each other so that a user may position, respectively, each of his limbs simultaneously on both of said force receiving means during an exercise program,

a limb supporting lever means coupled to each of said force receiving means, means for receiving a force exerted by a user and an isokinetic speed controlling means connected to said actuator means for controlling the speed of motion of said force receiving means effectively independent of the force applied to said limb supporting lever means once the speed of motion of said force receiving means has reached a predetermined value.

2. An isokinetic bilateral reciprocal exerciser as defined in claim 1, further including means for adjustably setting said speed controlling means to obtain different selected control speeds of rotation of each of said force receiving means.

3. An isokinetic bilateral reciprocal exerciser as defined in claim 1, wherein said actuator means include a first gear and a second gear axially spaced from each other and meshed with each other at one end of said actuator means, and a third gear, a fourth gear and a fifth gear each axially spaced from each other at the other end of said actuator means, said fifth gear being an idler gear meshed with said third gear and said fourth gear; and a rotatable shaft coupled to said first and third gears in coaxial array at opposite ends of said actuator means, said second and said fourth gears being disposed in coaxial alignment, whereby said first and said second gears rotate in opposite directions, said second and said fourth gears rotate in opposite directions, and said first, said third, and said fourth gears rotate in the same direction when a connection of said lever means between said second and said third gears effects coaxially rotation in opposite directions of said spaced apart lever means and a connection of said lever means to said second and said fourth gears effects coaxial rotation of each of said lever means in an opposite direction.

4. An isokinetic bilateral reciprocal exerciser as defined in claim 3, further including adjustment means for adjustably setting said speed controlling means to obtain different selected maximum speeds of rotation of said gears and said lever means.

5. An isokinetic bilateral reciprocal exerciser as defined in claim 3 wherein said lever means comprises a pair of levers;

a pair of apertured flanges, each of said levers, re-

spectively, secured to one of said apertured flanges for attachment to one of said gears at opposite ends of said actuator means; and

limb engaging means on said levers to keep a persons limbs engaged on said levers during movements thereof.

6. An isokinetic bilateral reciprocal exerciser as defined in claim 4, wherein said actuator means further includes a pair of spaced plates;

a cylinder secured between said plates;

said shaft extending axially through said cylinder;

a rotor secured to said shaft;

a stator secured to said cylinder end bushings closing opposite ends of said cylinder; said rotor, said stator, said cylinder and said bushings defining two fluid filled chambers in said cylinder,

said plates being formed with ports communicating with said two chambers for passing fluid out of one chamber and into the other chamber when said rotor rotates, and the speed of rotation of said gears being controlled by the rate of flow of fluid passing between said chambers.

7. An isokinetic bilateral reciprocal exerciser as defined in claim 6, wherein said speed controlling means comprises a pair of fluid filled valve assemblies having respectively, a casing communicating with said ports; said controlling means comprising an adjustment means for rotating a rotatable valve member adjacent a non-rotatable valve member in each of said valve casings, said valve members having abutting walls with adjustably overlapping holes defining a passage for fluid, and the rate of flow of fluid and speed of rotation of said gears being determined by the size of said passage.

8. An isokinetic bilateral reciprocal exerciser as defined in claim 7 wherein said non-rotatable valve member is axially slidable against a spring bias, each of said valve casings having lateral holes closable by said nonrotatable axially slidable valve to limit flow of fluid and resist acceleration of rotation of said gears and said respective levers.

9. An isokinetic bilateral reciprocal exerciser as defined in claim 6, further comprising pressure indicating means operatively connected to said valve assemblies for indicating pressure of said fluid in said valve casings.

10. An isokinetic bilateral reciprocating exerciser as defined in claim 8, further including an accumulator means partially filled with fluid and connected to said valve assemblies for relieving excess pressure due to thermal expansion.

11. An isokinetic bilateral reciprocating exerciser as defined in claim 1 wherein said actuator means comprises a cylinder;

a piston axially movable in said cylinder, and

a coupling means for connecting each side of said piston, respectively to each one of said limb supporting lever means.

12. An isokinetic bilateral reciprocating exerciser as defined in claim 11 wherein said coupling means comprises a plastic coated cable.

Claims

1. An isokinetic bilateral reciprocal exerciser comprising an actuator means for transmission of forces exerted by a user, said actuator means having two force receiving means, said actuator means having one of said force receiving means mounted at one end of said actuator means for applying a user''s force so that when said latter mentioned force receiving means is moved in one direction a user''s force will be transmitted to the opposite end of the actuator means to simultaneously move the other force receiving means mounted at the opposite end of the actuator means in an opposite direction, each of said force receiving means being movable through planes that are substantially parallel to each other, and means for supporting both of said force receiving means in spaced relationship to each other so that a user may position, respectively, each of his limbs simultaneously on both of said force receiving means during an exercise program, a limb supporting lever means coupled to each of said force receiving means, means for receiving a force exerted by a user and an isokinetic speed controlling means connected to said actuator means for controlling the speed of motion of said force receiving means effectively independent of the force applied to said limb supporting lever means once the speed of motion of said force receiving means has reached a predetermined value.

5. An isokinetic bilateral reciprocal exerciser as defined in claim 3 wherein said lever means comprises a pair of levers; a pair of apertured flanges, each of said levers, respectively, secured to one of said apertured flanges for attachment to one of said gears at opposite ends of said actuator means; and limb engaging means on said levers to keep a person''s limbs engaged on said levers during movements thereof.

6. An isokinetic bilateral reciprocal exerciser as defined in claim 4, wherein said actuator means further includes a pair of spaced plates; a cylinder secured between said plates; said shaft extending axially through said cylinder; a rotor secured to said shaft; a stator secured to said cylinder end bushings closing opposite ends of said cylinder; said rotor, said stator, said cylinder and said bushings defining two fluid filled chambers in said cylinder, said plates being formed with ports communicating with said two chambers for passing fluid out of one chamber and into the other chamber when said rotor rotates, and the speed of rotation of said gears being controlled by the rate of flow of fluid passing between said chambers.

8. An isokinetic bilateral reciprocal exerciser as defined in claim 7 wherein said non-rotatable valve member is axially slidable against a spring bias, each of said valve casings having lateral holes closable by said non-rotatable axially slidable valve to limit flow of fluid and resist acceleration of rotation of said gears and said respective levers.

11. An isokinetic bilateral reciprocating exerciser as defined in claim 1 wherein said actuator means comprises a cylinder; a piston axially movable in said cylinder, and a coupling means for connecting each side of said piston, respectively to each one of said limb supporting lever means.