Patent Publication Number: US-6217488-B1

Title: Lower extremity rehabilitation and toning exercise apparatus method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 08/509,206, filed Jul. 31, 1995, U.S. Pat. No. 5,851,166 and incorporates the subject matter of Disclosure Document No. U.S. PTO-jc586 filed Apr. 5, 1998 in the Patent and Trademark Office. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to physical conditioning and medical rehabilitation, general exercise and the toning of the lower extremities of the body. More particularly the invention provides an apparatus and method for maintaining circulation and muscle tone in the feet and lower legs of individuals, which is useful while they are seated or confined to a chair. 
     2. Prior Art 
     Vigorous athletes, such as runners and the like, frequently injure their lower legs and/or feet necessitating relatively severe restriction of movement during healing. For example, runners are frequently subject to hairline stress fractures of the bones of the lower leg, also known as “shin splints”. Cramps of the calf muscles are also quite common among runners. These types of injuries can often pull or tear muscle tissue, requiring long term enforced inactivity to allow healing to occur. During such enforced inactivity, much of which may be passed resting or reclining in a chair, athletes who are normally quite physically active become uncomfortable or even nervous from lack of exercise. Enforced inactivity also tends to delay healing of the injured muscle tissue. Often, the enforced inactivity will require the injured athlete to spend an inordinate amount of time reclining or sitting in a chair, even while undertaking other activities. While sitting, circulation is often seriously decreased to the lower extremities (legs, ankles, feet, etc.) tending to induce additional injury. These same problems are often encountered by non-athletes, and can be particularly troublesome for older persons, whose level of physical activity may already be diminished and whose physical health may be declining with age. 
     Physical inactivity often causes the muscular tissue of the heart to lose tone and become weaker. This loss of heart muscle may take place at the same time as extra strain is placed on the heart due to illness or age. Such extra strain can also be due to lack of movement of the muscles. Movement of the muscles of the lower extremities in particular, where many of the major muscles and blood vessels of the body are located, serves normally to significantly aid in pumping blood through the body due, in part, to kneading, or continuing variable pressure, of the moving muscles against adjacent blood vessels. It is frequently estimated that in active walking or running, a significant percentage of the actual pumping of blood in the body, up to as much as twenty to twenty-five percent or more, is due to the pumping effects of blood moving through the vessels of the legs under the impetus of muscles squeezing against blood vessels. Thus, a certain amount of movement of the lower extremities can be very important in maintaining health even in fairly vigorous persons. Consequently, there is a need for a practical exercise apparatus to enable movement in the lower extremities to be continued, at least on a reduced scale, by those persons subjected to long periods of inactivity, particularly in a seated position. 
     In recent years there have been numerous attempts to provide ergonomically designed office machines and office furniture for improving circulation. These efforts have been directed more toward developing office machines that are less tiring to operate, than providing ways to actually relax the body and maintain circulation by mild exercise. A number of large and small scale exercise machines are known for exercising the legs, such as treadmills, bicycling machines and so-called stepping machines. These and other known exercise apparatus often rely upon a stepping or placing of the weight alternately upon first one leg and then the other while in a standing position, or, at a minimum, while being in a cycling position such as in the use of a stationary bicycle. These types of known exercise machines are normally not devised for use by persons who are seated in a conventional chair, e.g., a desk chair or easy chair. Some examples of known, small scale exercise machines are set forth below. 
     U.S. Pat. No. 5,256,118—Chen discloses a small scale so-called “stepper” device car pedal exerciser in which two adjacent pedals are pivoted at one end and act against a pair of air bellows between the pedals and a base. The bellows allow the pedals to rise and fall resiliently as the user transfers his or her weight alternatively from one to the other pedal. The device does not appear to be suitable for operation or use from a sitting position. 
     U.S. Pat. No. 5,267,923—Piaget et al. discloses a stepper-type exercise machine involving the use of bellows at the opposite end of pedals in a small scale, easily portable and storable exercise machine. While the arrangement of the pedals of the Piaget machine is such that it could possibly be used from a seated position, such use would be quite awkward unless the seating was in a position similar to that assumed on a bicycle. 
     U.S. Pat. No. 5,290,204—Lee discloses a small and compact pedaling machine in which the pedals are pivoted at one end and movement is resisted by a fluid cylinder means of a suitable type and including a coordinating arm to allow only one pedal to be depressed at a time. 
     U.S. Pat. No. 5,304,105—Hsieh discloses a small scale stepping-type exerciser in which the pedals are pivoted at one end, and are rendered resiliently movable by the use of interconnected inflatable balls positioned under the pedals. As with Piaget et al., the Hsieh device may possibly be used, with some difficulty, from a seated position, but it is not conveniently designed for such use. 
     U.S. Pat. No. 5,299,995—Ko discloses a relatively small scale foot or leg exercising device in which a pair of conventionally pivoted bicycle pedals are mounted on flexible members that provide for a reciprocable movement in an adjustably pivoting tower arrangement which allows the user to, in effect, obtain a bicycling exercise motion from a seated position. The essential movement of the pedals is up and down on the apparatus. 
     There is a need for a small, easily portable and readily usable apparatus for mildly exercising the lower extremities, and particularly the feet and calves, from a sitting position such as is customarily assumed when watching television, operating a computer, traveling in a car or plane which will keep the legs and feet moving, but will not injure already injured muscles or ligaments. There is also a need for a method for use of this and similar apparatus to exercise the lower extremities. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide an apparatus in which a foot support or pedal pivots from a central or near central area of the support so that the support is conveniently and easily operated with a rocking motion from a conventional seated position. 
     It is a further object of the invention to provide an exercise apparatus that provides a gentle rocking motion to the feet from a seated position causing movement in the muscles of the lower extremities without excessive movement tending to distract the exerciser or overextend injured tissues. 
     It is a still further object of the invention to provide a mild exercise and movement of the feet of the user that will be effective to relieve tension in the lower portion of the lower extremities and keep the blood circulating in the tissues involved. 
     It is a still further object of the invention to provide a rocking motion foot exerciser that can be used from a seated position to move and mildly exercise the feet either with or without resilient resistance to such rocking motion. 
     It is another object of the invention to provide a rocking-type foot exerciser that can be used from a seated position in which the rocking motion can be inactivated and the apparatus used as a simple foot rest. 
     It is a further object of the invention to provide a rocking-type foot exerciser having two centrally pivoted pedals which can operate independently or coordinated so that the pedals act as a single pedal coordinated to rock in alternating fashion or alternatively together in unison. 
     It is a still further object of the invention to provide a rocking-type foot exerciser in which a motor, solenoid, actuator or similar means is provided to generate the rocking motion of a centrally pivoted pedal. 
     These and other objects are accomplished in the lower extremity exercising device according to the invention. The lower extremity exercising device has a base upon which is preferably mounted a single pedal having sufficient width to accommodate a pair of feet. The pedal is pivotally connected at a centrally located portion thereof to the base to allow a rocking-type movement of the pedal about a transverse pivotal axis. A motor, solenoid, actuator or other electrical, hydraulic or pneumatic means or any combination thereof may be used for generating the rocking-type pedal movement. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a basic embodiment of the invention. 
     FIG. 2 is a side elevation, partially broken-away, of the embodiment of the invention shown in FIG.  1 . 
     FIG. 2A is a partially broken-away side elevation, similar to FIG. 2, except that two pedals are shown inclined oppositely. 
     FIGS. 2B and 2C are diagrammatic figures illustrating the exercise movement attained with the invention. 
     FIG. 3 is an end elevation of the embodiment of the invention shown in FIGS. 1 and 2, with the pedals inclined oppositely as shown in FIG.  2 A. 
     FIG. 4 is a side elevation of an alternate embodiment of the invention in which the rocking pedals are provided with a resilient means positioned at the far end of the pedal to provide additional resistance to movement of the pedal, the resistance being, in the instance shown, provided by a coil spring-type resistance. 
     FIG. 5 is a side elevation of a still further embodiment of the invention in which the pedals are provided at both ends with additional resistance to movement of the pedal, in this instance fluid cylinder-type resistance. 
     FIG. 6 is an end elevation of an embodiment of the invention in which the two pedals are provided with separate flat coil spring means to resist rocking and the pedals may, if desired, be secured together to provide coordinated movement. 
     FIG. 6A is a partial side view of one of the flat coil spring arrangements arranged about the axle of the pedals to provide resistance against rocking. 
     FIGS. 7 and 7A are an end view and a partial axle view of an embodiment of the invention constructed to provide or allow the rocking pedal exercise machine to be used as a simple footrest upon the election of the user. 
     FIG. 8 is an end elevation of an embodiment of the invention in which the two pedals are coordinated together by a lever-type connection so that they rock alternatively, one pedal being depressed as the other pedal rises. 
     FIG. 9 is an isometric view of a portable version of the invention in which a cover is provided that may be folded or pivoted upwardly to enclose the apparatus for carrying on an airplane or train. 
     FIG. 10 is an isometric view of an alternative embodiment of the invention particularly adapted for construction of a plastic resin material in which the pivot point of the pedals has been moved farther from the surface of the pedal, in the case shown, essentially to the surface, or just below the surface, of the base. 
     FIG. 11 is an enlarged side elevation of the embodiment of the invention shown in FIG.  10 . 
     FIG. 12 is an end view of the embodiment of the invention shown in FIGS. 10 and 11 which alternative embodiment may also be formed from a plastic resin material. 
     FIG. 13 is an enlarged side elevation of an alternative version or embodiment of the displaced pivot version of the invention shown in FIGS. 10 through 12, which alternative embodiment may also be formed from a plastic resin material. 
     FIG. 14 is an end view of the alternative embodiment of the invention shown in FIG.  13 . 
     FIG. 15 is an enlarged side elevation of a still further embodiment of the invention in which the pivot point of the pedals is within the structure of the pedals themselves, which embodiment may also be readily formed of a plastic resin material. 
     FIG. 16 is an end view of a single pedal embodiment of the invention with an alternative arrangement for providing resilience to movement of the pedal. 
     FIG. 17 is a partially broken away side elevation of the embodiment shown in FIG.  16 . 
     FIG. 18 is an end view of a still further alternative embodiment of the invention. 
     FIG. 19 is a partially broken-away, side elevation, of the embodiment shown in FIG.  18 . 
     FIG. 20 is an end view of a still further embodiment of the invention with an alternative arrangement for providing resilience to the pedals. 
     FIG. 21 is a partially broken-away, side elevation, of the embodiment of FIG.  20 . 
     FIG. 21A is an enlarged detail of the mechanical arrangement of the spring assembly of the embodiment of the invention shown in FIGS. 20 and 21. 
     FIG. 22 is a partially broken-away, side elevation, of an alternative arrangement for providing resilience to the pedals of the exercising apparatus of the invention. 
     FIG. 23 is an enlarged detail of an alternative arrangement for locking together and coordinating the movement of two pedals of an exercising machine in accordance with the invention. 
     FIG. 24 is a plan view of two typical pedals in accordance with the invention showing the arrangement of the feet of a user upon the pedal and the preferred placement of the pivot point with respect to the feet and the pedal. 
     FIG. 25 a  is a side elevation view of another embodiment of the invention showing an alternative arrangement for a single pedal embodiment wherein a driving wheel, pulley and resilient means are used to generate a rocking motion of the pedal and the resilient means is in an extended position. 
     FIG. 25 b  is a side elevation view of the embodiment of the invention shown in FIG. 25 a  with the resilient means in a contracted position. 
     FIG. 26 a  is a side elevation view of another embodiment of the invention showing an alternative arrangement for a single pedal embodiment wherein an actuator and sliding wheel, and resilient means are used to generate a rocking motion of the pedal and the resilient means is in a contracted position. 
     FIG. 26 b  is a side elevation view of the embodiment shown in FIG. 26 a  with the resilient means shown in an extended position. 
     FIG. 27 a  is a side elevation view of another embodiment of the invention wherein a solenoid is used to generate a rocking motion of the pedal and the solenoid is in a contracted position. 
     FIG. 27 b  is a side elevation view of the embodiment shown in FIG. 27 a  with the solenoid shown in an extended position. 
     FIG. 28 is a perspective view of another embodiment of the invention showing a motor/actuator positioned beside the platform used to generate a rocking motion of the pedal. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Active persons or even relatively inactive persons, may be injured so that they cannot safely continue to effectively exercise their lower legs, in particular their feet and calves. Cessation of exercise causes loss of tone and strength in the muscles and ligaments involved. Continued exercise would be very beneficial both to maintain conditioning and promote healing by encouraging blood supply to the affected parts. In these cases, it may not be desirable to provide really vigorous exercise. Yet, mild exercise is desirable to prevent a general stasis of the blood, as well as to soothe the patient and make him more comfortable. In addition, persons having a relatively sedentary work environment, including computer programmers, word processor operators and the like, often have difficulty in keeping adequate circulation in their lower limbs. Travelers in cars and airplanes also are exposed to long periods of sitting in relatively restricted positions that interfere with adequate circulation. 
     It has been found by the inventor that mild and soothing exercise can be attained by the use of a novel rocking exercise apparatus for the feet which allows the user to be comfortably seated in a chair or the like while they rock their feet upon rocking pedals on a portable exercise device, thus encouraging circulation in the lower legs and feet and soothing the user. By periodically rocking the feet from front to back or vice versa, from time to time or continuously over a period of time, the user keeps the feet from becoming stiff and maintains a range of movement in the ankles. In addition, and very importantly, the user maintains a continuous or periodic kneading or massaging of the muscles, particularly of the calves, as well as the muscles toward the front of the lower legs upon maintaining circulation and combatting stasis or pooling of the blood in the tissues. Maintenance of circulation plus periodic movement not only increases physical fitness and health, but also has a desirable cosmetic effect of maintaining shapely calves. Periodic movement also contributes to comfort and general well being of the user. 
     FIG. 1 is an isometric view of a basic embodiment of the exercise device of the invention in which reference numeral  10  indicates the device broadly. Exercise device  10  is comprised of a base  11  that is adapted for placement on the floor of a room or other surface upon which one may place their feet. There are provided upon base  11  a left side wall  13  and a right side wall  15  that are secured to base  11  in any suitable manner. For example, side walls  13  and  15  may be integral continuations of base  11 . Attached to, or extending through side walls  13  and  15  is a pivot rod  17 , which, as shown, passes through orifices or openings  18 . Fasteners  23  are disposed on the ends of pivot rod  17  so as to maintain pivot rod  17  in position within openings  18  of side walls  13  and  15 . Pivot rod  17  supports pedals  19  and  21  upon which the feet of the user are placed during use of exercise device  10 . Left pedal  19  and right pedal  21  are journaled upon pivot rod  17 , and secured by pivot rod fittings  25 , as shown more particularly in FIGS. 2 and 3. Pivot rod fittings  25  are secured to pedals  19  and  21  via fasteners  27 . It should be understood that pedals  19  and  20  are loosely journaled on pivot rod  17  so that the two pedals may be independently rocked upon pivot rod  17 . 
     FIG. 2 is a partially broken-away diagrammatic side elevation of the exercise device shown in FIG. 1 with the side wall  15  partially broken-away to show, in particular, pivot rod fitting  25  and fitting fasteners  27  which together secure pedal  19  and pedal  21  to the pivot rod  17 . FIG. 2A is a diagrammatic view of the arrangements shown in FIGS. 1 and 2, but in which an additional portion of the side wall  15  has been partially cut away and the pedal  19   a  is turned downwardly with its farther end near the base  11 , while the pedal  21  remains in the same position as shown in FIG. 2 with the rear or nearest end of the pedal near to the user and rocked downwardly so as to be adjacent to the base  11 . FIG. 3 is an end elevation of FIG. 2A showing the pedals  19  and  21  positioned in the same arrangement as in FIG.  2 A. The pivot rod fittings  25  and their fitting fastenings  27  are also clearly visible on the lower side of the pedal  19  in FIG.  3 . 
     Pedals  19  and  21  constitute convenient foot contact and support means upon which the left and right feet of the user may be placed so that either the sole of the user&#39;s foot or the sole of any footwear which the user happens to be wearing are substantially completely supported against the support surface of the contact and support means or members. The heel of a user&#39;s foot is placed upon the “near” end (relative to the user) of the upper surface  19 A,  21 A of each pedal  19  and  21 , and the toe of the user&#39;s foot is placed upon the “far” end (relative to the user) of upper surfaces  19 A,  21 A of each pedal so that each of the user&#39;s feet are disposed in a comfortable position against the upper surface of each pedal. Depending upon the height of pivot rod  17  above base  11 , and the length of pedals  19  and  21 , the normal resting position of the feet of the user upon the upper surfaces  19 A and  21 A will be either with the lower ends  19 B and  21 B of pedals  19  and  21  contacting the upper surface of base  11  or with lower ends  19 B and  211 B of pedals  19  and  21  held a certain distance above the upper surface of the base  11 . It will be understood that if the lower ends  19 B and  21 B of pedals  19  and  21  are maintained above the upper surface of the base  11  when the feet of the user are securely placed upon upper surfaces  19 A and  21 A, an opportunity for the user to rock their toes upwardly or forwardly, and their heels downwardly, is provided so as to desirably flex the ankles of the user and to stretch the calf muscles. 
     Referring to FIGS. 1,  2  and  2 A, the pivot point or position of pivot rod  17 , with respect to the base  11 , is displaced somewhat toward the near or rear portion of exercise device  10  to create a steep angle of pedals  19  and  21 , relative to base  11 , when the foot of the user is rocked rearwardly. This arrangement allows the users foot to be pivoted about the ankle joint, toward the shin bone to a position where the angle between the user&#39;s foot and the user&#39;s shin is less than or equal to ninety degrees. The user&#39;s foot may then be rocked forwardly to a substantially extended position. Exercise device  10  is normally placed on the ground at a comfortable distance from the user so that the user may place its foot lightly upon pedals  19  and  21 . Exercise device  10  has a height which will tend to lift the outer end of the leg of the user higher than it might normally be when placed directly upon the ground surface. 
     In the preferred embodiment of the invention, pedals  19  and  21  are freely rotatable on pivot rod  17 , so that exercise device  10  will normally be pushed, by the user, out to a position farther away from the user than his foot would normally be placed without the exercise apparatus. This will automatically tend to extend the entire leg of the user so that the foot is normally in a position somewhat extended, with respect to the leg, as if the foot were being placed upon a foot rest or hassock in front of the user. In this position, the foot is already extended in its normal position upon the pedals  19  and  21 , so that the major movement available is to the rear, tending to pivot the rear surface or rear end  21   b  of pedals  19  and  21  downwardly toward base  11 . When the user&#39;s foot is extended forwardly, to its maximum extension, it will tend to rotate less. In fact, if the device is pushed out to a point where the leg of the user is more or less completely extended, the relative rotation of the foot of the user will be much less toward the front and will tend to bring the foot almost parallel to the upper surface of base  11 , rather than be rotated downwardly against base  11 . Rearward rocking of the foot will tend to bring each pedal  19 ,  21  to an angle that is greater than perpendicular, as measured from an axis directed longitudinally along an extended leg. This relationship is shown in FIGS. 2B and 2C. FIG. 2B shows, diagrammatically, the normal leg and foot position of a human body  30  seated in a chair, such as, an office chair  32 . The feet of the user are placed upon the ground  34  upon which the chair  32  also rests. FIG. 2C shows, diagrammatically, the same position of human body  30  with feet  38  placed on pedals  19  and  21  of exercise device  10 . The exercise range of the foot is normally from about parallel with the extended leg of the user to about 10 to 25 degrees beyond a point perpendicular to a line that is parallel to the lower leg of the user. 
     More particularly, and referring to FIG. 2B, the lower leg  36  of human body  30  extends downwardly to foot  38  which is disposed in parallel relation to ground  34 . This is the normal position of a person sitting in a typical chair  32 . FIG. 2C diagrammatically shows human body  30  seated in chair  32  with foot  38  placed upon the upper surface of pedal  42  of an exercise device  10 , such as is shown in FIGS. 1 through 3. Base  11  of exercise device  10  is shown placed upon ground  34 . Since exercise device  10  has a certain height above ground  34 , it will be seen that lower leg  36  of human body  30  will normally be positioned at a more acute angle with respect to ground  34 , and foot  38  will be more nearly parallel to ground  34 . See views I of I-IV of FIG.  2 C. This is actually a more relaxed position, since it more closely approaches the position which the leg and foot would assume if they were being supported upon a conventional footrest or hassock. 
     To exercise the muscles in the foot and the calf as well as other muscles in the lower leg, foot  38  is rocked rearwardly to an angle as shown in view II of FIG.  2 C. Here, foot  38  and pedal  42  are rocked backwardly or rearwardly, i.e., toward human body  30 , until foot  38  is slightly more than perpendicular to a line  44  drawn parallel to the longitudinal axis of leg  36  or, approximately 10 to 25 degrees upwardly from, or beyond perpendicular to, the longitudinal axis of leg  36 . In view III of FIG. 2C, foot  38  is shown rocked forwardly or downwardly to the front, i.e., away from human body  30 , until the angle of pedal  42  and foot  38  are nearly parallel to line  44 . In other words, foot  38  is essentially parallel to the longitudinal axis of the lower portion of leg  36 . The angle between the maximum rocked backward position of foot  38  on pedal  42  is, as shown diagrammatically in view IV of FIG. 2C, essentially the angle  46  which, if measured, would be found to be approximately 110 to 115 degrees for the average person, or in exceptional persons, up to 125 degrees. 
     The length of foot contact and pedals of the exercise device  10  should preferably not be much greater than the length of the foot of the person using the apparatus. In this way the range of movement or pivoting of the pedal is not limited any more than is necessary. However, as a practical matter, the length of the foot contact and support means will be made to be approximately as long as the foot of the largest average dimensioned person who is likely to use the device. Pedals for men or women may be supplied, and each pedal includes a heel and ball of the foot contact portions, which in some cases will actually be delineated upon the pedal. 
     Referring now to FIG. 4, a resistance means (broadly designated by reference numeral  29 ) is shown positioned on the far end of pedal  21 . Resistance means  29  may comprise a coil spring type resistance having a series of interconnected coils  31  which, when pressed together, towards each other, allow far end  21   c  of pedal  21  to be forced downwardly toward base  11  and in that manner provides resistance against the movement of foot  38  of the user. In this way additional exercise, particularly to the calf muscles, is provided by rotating the foot downwardly against the resistance of coils  31  of the resistance  29 . 
     Referring now to FIG. 5, in an alternative embodiment of the present invention, two resistance means  33   a  and  33   b  may be positioned in contact with the lower side of the pedal  21  and the upper surface of base  11 . In this position, resistance  33   a , which is shown in the form of a fluid pressure cylinder, will resist rocking of pedal  21  downwardly toward the rear or near end of exercise device  10 , while pressure cylinder  33   b  will resist movement of the opposite end of pedal  21  toward the base  11 . The two resistance means  33   a  and  33   b  act together to provide resistance to the movement of the pedal at all times. Such fluid resistance cylinders may be either single acting or double acting and are shown diagrammatically merely to illustrate that various resistance means or resilient resistance means may be used to resist movement of the pedals and therefore provide additional resistance against movement of the muscles of the user&#39;s body to provide additional exercise. 
     Referring to FIG. 6, there is shown an end view of a diagrammatic representation of an exercise apparatus in accordance with the invention in which pedals  19  and  21  are journaled on separate concentric sections of a single pivot rod mounting  35 . Pivot rod  35  is formed from an inner pivot rod  35 A, upon which the pedal  19  is secured, and an outer pivot rod  35 B to which pedal  21  is attached. In this case, the two pivot rod sections  35 A and  35 B are journaled in side walls  13  and  15  so that pivot rod  35  rotates as a unit when pedals  19  and  21  are rotated in unison, and the two sections  35 A and  35 B when operated independently rotate independently with respect to each other. Pedals  19  and  21  are attached rigidly to the two pivot rod sections  35 A and  35 B so that the entire assembly, including the pedal and the portion of pivot rod upon which it is mounted, rotate or rock back and forth as a unit. Pivot rod  35  may be journaled in end walls  13  and  15  in any suitable bearing arrangement, e.g., a lubricated orifice or bearings or roller bearings or other suitable bearing arrangement, not shown. At the ends of the two concentric pivot rod sections  35   a  and  35   b , there are shown coil spring assemblies  37  which are attached to the pivot rods  35   a  or  35   b  and to the adjacent side walls  13  or  15 . In this way, when pivot rod sections  35   a  or  35   b  rotate, the spring elements  37  will be either tightened or loosened, depending on the particular rotation of pivot rod sections  35   a  or  35   b . As a result, the rotation of the pivot rod sections is resisted and through such resistance, the resistance of foot pedals  19  and  21  to movement of the feet of the user is provided. The embodiments shown in FIGS. 6 and 6A provide a convenient and efficient arrangement for securing independent resistance against rocking or rotational movement of the two pedals, independently, to provide additional exercise to the lower portions of the legs and the feet of the user. 
     There is also shown in FIGS. 6 and 6A, two latching means for securing the two independently-acting foot pedals together in case it is desired to operate in a single foot pedal mode. In this case, a single foot pedal acts in unison with respect to the two feet of the user and, the user obtains twice the resistance to movement of the two pedals as would be obtained with one pedal. More particularly, straight securing means, or pins  39 , are shown mounted on the lower portions of pedals  19  and  21  in loops or pin fittings  41  in which pins  39  slide and align with similar loops or pin fittings  43  on the underside of the adjacent pedal, in this case pedal  19 . The end of pins  39  are slid to lock pedals  19  and  21  together for coordinated movement rather than independent movement. As viewed in FIG. 6, upper pin  39  on the nearer portion of the pedal  21  is shown retracted from the loops  43  so that this portion of the pedals  19  and  21  are not secured together, while lower pin  39  is shown pushed through loops  41  and  43  on both pedals  19  and  21  so that the farther or outward portions of the pedals  19  and  21  are temporarily locked together. It will be understood that the foregoing arrangement for locking the two pedals together is merely a simple illustrative arrangement. There are, of course, many other means of interlocking the pedals. 
     Referring to FIGS. 7 and 7A a somewhat similar arrangement of pedals  19  and  21  upon concentric pivot rods  35   a  and  35   b  includes a spring resistance arrangement at the two ends, which have attached thereto concentric pivot rods to which pedals  19  and  21  are permanently secured to independent locking members  45 A. Locking member  45 A may be welded or soldered to the pivot rods so that locking members  45  are, in effect, integral with pivot rods  35   a  and  35   b . Locking members  45  have a series of locking orifices  47  which extend through the locking members and provide openings for receiving locking pins  49 , which may extend through orifices (not shown) in side walls  13  and  15  at both sides of pivot rods  35   a  and  35   b . Locking pins  49  act to immobilize locking members  45  by extending through the locking orifices  47 . Since pedals  19  and  21  are secured directly to pivot rods  35   a  and  35   b  in this embodiment, pivot rods  35   a  and  35   b  may be effectively immobilized in any position desired by the user to form a foot rest. 
     Referring to FIG. 8, a coordinating arm  51  is shown pivoted at  53  and extending into contact with the lower portion of each pedal  19  and  21 . A pair of rollers  52  are journaled on the ends of arm  51  to allow the ends to move easily in contact with the bottom of each pedal  19 ,  21 . It will be understood that when pedal  19  is pushed downwardly (as is shown for the nearer portion in FIG. 8) the coordinating arm  51  will be raised on the right side under pedal  21  and will cause a portion of pedal  21  to pivotally rise while another portion of pedal  21  will be pressed downwardly. In this way, the movement of the two pedals is coordinated in a very simple mechanical manner so that one will necessarily rock in one direction while the other is rocking in a second direction. This may be convenient to some users who lack coordination in movements of their feet. However, it also enables the user to place varying degrees of pressure upon one pedal that is dependent on the resistance placed on the other pedal. This arrangement sets up a form of dynamic tension in which one portion of the body is arranged to act against another portion of the body so that the body of the user is providing the tension or pressure on the exercise device to exercise different parts of the body. These dynamic tension arrangements are often a simple way to provide additional tension in an exercise arrangement. 
     Referring to FIG. 9, the entire exercise device  10  is provided with a cover  55 . Cover  55  may be swung up to enclose the apparatus when not in use to make it portable. For example, with this embodiment it is possible to exercise the legs while riding in an automobile, bus, or airplane during long trips when circulation in the legs may become stagnant. A latch  57  is provided to interact with another latch, not shown, at the opposite end of the apparatus to hold the cover  55  over the apparatus during transportation. Pivot pins  59  are provided for pivotally attaching cover  55  to side walls  13  and  15 . 
     Referring to FIG. 10, a pivot point for the pedals, in this case enumerated as pedals  59  and  61 , is provided with a unitary pivoting arrangement in which there is no separate pivot rod. Instead, an extension  63  on the lower portion of pedals  59  and  61  include a cylindrical pivot support  65  which mates with a cylindrical pivot groove or channel  67 . Pivot groove  67  is semicircular so that it partially encompasses pivot support  65  to prevent pivot support  65  from slipping out of pivot groove  67  in base  69 . Base  69  may have a series of short, outward extensions  71  on the lower surface which provide roughness to such lower surface which will tend to interact with a heavy carpet or the like, and prevent base  69  from sliding along ground. 
     FIG. 11 is an enlarged side elevation of the arrangement shown in FIG. 10 in which pivot support  65  may be contained within pivot groove  67  in base  69 . It will be noted that the upper portion or opening  73  along the top of pivot groove  67  is narrower than the extreme diameter of the pivot support  65  so that once the pivot support  65  is inserted into pivot groove  67 , from the side of base  69 , pivot support  65  cannot be withdrawn from pivot groove  67  except from the side of base  69 . Pivot support  65  is held upon the end of extension  63 , and the width of the extension along the top of pivot support  65  is such that a significant clearance is provided between the side of opening  73  and extension  63  so that extension  63  may be rocked from side to side without contacting the edges of opening  73 . This allows pedal  61 , which is mounted upon the upper portion of extension  63 , to rock from side to side in accordance with pressure placed upon its surface by the feet of the user. Flexible spring strips  75  are secured to pedal  61  by fastening loop  77  to the top of base  69  by a similar fastening loop  79 . The flexible strips hold the underside of pedal  61  away from the upper side of base  69 . Flexible strips  75  may be formed from any of the well known spring materials. Flexible strips  75  serve as an effective rocking resistance medium for exercise device  10 . 
     Exercise device  10  is structurally arranged such that a force must be applied to the surface of pedals  59  and  61  to cause them to rock so that first one and then the other end approaches the surface of base  69 . As noted before, the bottom of base  69  is provided with light extensions of the surface which serve to roughen the surface and provide additional gripping with whatever surface the bottom of base  69  is set upon. A square or even circular pattern of slight extensions may also be very effective when placed upon a pile rug to prevent slippage of base  69 . If base  11  is to be placed upon a wooden floor, it is desirable to provide rubber extensions or even metal extensions having points upon the ends to obtain a better grip. Since the feet of the user are actually placed on top of the pedals and then the feet rocked to obtain the exercise inherent in operation of the device, there is less tendency for base  11  to slide upon the ground. 
     Referring to FIG. 12 extension  63  on the bottoms of both pedals  59  and  61 , along with the spring strips  75 , serve to provide resilient resistance against rocking of pedals  59  and  61 . The apparatus shown in FIGS. 10-13 is particularly adaptable for molding from a plastic resin composition, while the apparatus shown in FIGS. 1 through 9 is particularly adaptable for construction from metal, wood, hardboard and the like. 
     Referring to FIG. 13, a similar rocking arrangement is provided as in FIGS. 10 through 12, with pivot support  65  journaled within a pivot groove  67 . In this case, rather than being an actual groove in the base, pivot groove  67 A comprises overlapping portions  67   b  which together form enclosed groove  67   a  in which pivot support  65  is journaled. As may be seen in FIG. 13, pivot support  65  may be slid into the pivot groove  67 A from the side of base  11 . However, in this embodiment, groove  67  is partially embedded in base  69  and partially secured upon the surface of base  69 . In this way, the pivot point of pedal  61  is moved closer to the pedal. The resilient means which tend to keep the pedal from approaching the surface of base  69  comprise resilient elastic members such as rubber sections  81  which are held at both ends in mounting rings  83  and  85 , respectively, on the surface of the pedal and the surface of the base. Such resilient members  81  may, for example, be in the form of somewhat egg-shaped sections of natural or synthetic rubber or may be inflated egg-shaped sections or may take several other forms of polymeric substance serving as a resistance means to discourage close approach between the lower surface of the pedal and the upper surface of the base. 
     Referring to FIG. 14, extension  63  will be seen to extend upwardly to the bottom of pedals  59  and  61  only in the center of these pedals and the enclosing members  67   b  only extend over pivot supports  65  at the ends of the pivot supports, away from the extensions, so that the enclosing members  67   b  can fit more closely about the top of pivot support  65  without preventing pivoting of pedals  59  or  61 . In such an arrangement, the pedals  59  and  61  will still pivot, since upon pivoting to either side, the extensions  63 , which are spaced between the enclosing members  67   a , pass downwardly about the members at a different point and there is no interference between the rocking of the pedals  59  and  61  and contact of the extensions  63  with the top of the enclosing members  67   b.    
     Referring to FIG. 15, an alternative embodiment is disclosed in which pivot support  65  is supported on extension  63  and embedded within the pedal structure  61  rather than within the structure of base  69 . In other words, pivot support  65  is supported directly upon base  69  by extension  63  and pedal  61  is fitted over pivot support  65  in a pivot groove  67 . The same arrangement of resilient members which resist pivoting of pedal  61  with respect to base  69  is shown in FIG. 15 is as shown in FIGS. 13 and 14. It will be noted that the pivot support which defines the pivot point of each pedal is mounted near the rear of the central portion of the pedal. In one embodiment, the pivot point is positioned at about ¼ to ½ the length of the pedal, as measured from an end. If such position of the pivot point of the pedal is used, the user will obtain the gentle, soothing rocking motion desired in the apparatus. Moving the pivot point well beyond the central portions will tend to unbalance the entire apparatus and to prevent the soothing rocking motion which has been found to be particularly appropriate for the treatment of injuries to the lower extremities. 
     Referring to FIGS. 16 and 17, a further version of the invention is disclosed in which there is only a single pedal  91  having a width sufficient to accommodate a pair of feet. At least one resilient spring  93  provides tension to pedal  91 . In such an arrangement, springs  93  and  95  are attached by bar extensions  97  and  99  to the outer lower portions of pedal  91  as well as to short posts or bollards  101  mounted upon base  103  near the center of exercise device  10 . As pedal  91  is rocked on its pivot rod  105 , one or the other of springs  93  or  95  are extended. In this particular embodiment the pivot rod  105  passes either directly through the center of pedal  91  or via a joint (bearing) attached to the bottom of the pedal. The arrangement and size of the springs  93  and  95  shown in FIG. 17 has the advantage of providing a fairly soft rocking movement of the pedal due to the longer tension springs. 
     Referring to FIGS. 18 and 19, a two pedal version of the apparatus of the invention is disclosed, in which two fluid cylinders  107  and  109  are substituted, on two separate pedals  91   a  and  91   b , for the springs  93  and  95 . One end of fluid cylinders  107  and  109  is also attached, via extension bars  97   a  and  97   b , to transverse attachment bar  111  which extends between elevated support pedestals  113  and  115 , into which pivot rod  105  is also journaled. The remainder of the reference numerals in FIGS. 18 and 19 refer to similar structures as shown in FIGS. 16 and 17 when referring to similar structures. The use of the support pedestals  113  and  115  rather than side walls  13  and  15  shown in previous figures has the advantage of providing a more open structure, but requires a sturdier construction to securely support pivot rod  105 . The advantage of the arrangement of the fluid cylinders shown in FIGS. 18 and 19 is that a larger travel of the piston in the cylinder is available and the general feel of the resistance will consequently be somewhat different from the analogous use or arrangement of fluid cylinders shown in FIG.  5 . 
     Referring to FIGS. 20 and 21, a further embodiment of the invention is disclosed in which two pedals are shown mounted upon a pivot rod  17 , as shown in FIGS. 1 through 4. Pivot rod  17  is mounted upon the underside of two pedals  19 A and  19 B. The remainder of the arrangement is essentially the same as is shown in FIGS. 1 through 4, except that pivot rod  17  is mounted in pedestals  113  and  115 . A different arrangement of spring biasing means is used in this embodiment, in the form of coil springs  113  and  113   a  which are coiled about pivot rod  17 , and caught behind support structures  115  and  115   a . When pedals  19  and  21  are depressed either forwardly or rearwardly, springs  113  and  113   a  will either be compressed or allowed to extend, thus providing resistance against depression of the pedal on either end. An enlarged and simplified detail of the spring arrangement is shown in FIG. 21 A with nonessential elements of the resilience impacting device deleted. Pivot rod  17  is mounted on the bottom of pedals  19  and  21  to provide a convenient spring mounting for this type of resistance spring arrangement. 
     FIG. 22 shows a still further embodiment of the invention in which a pedal  19  having an internal pivot rod  105  (as in FIGS. 16 through 19) is used, but in which corrugated air or balloon-type spring resistance elements  117  and  119  are shown arranged to provide resistance to depression of one or the other end of the pedal  91 . 
     FIG. 23 is an enlarged view showing an improved internal latch arrangement in which a slide bolt  121  is slidingly mounted in a groove or cut out section of one pedal  91 B opposite an orifice  123  in an adjacent pedal  91 A. A handle  125  extends from a groove  127  over the bolt and allows bolt  121  to be slid either to connect the two pedals or to disconnect them. 
     FIG. 24 is a diagrammatic plan view of the foot exerciser of the invention in which an actual outline of the feet of the user is shown on top of the pedals as a guide to the placement of the feet with a scale indication on the side of the relative distance of the pivot point from the defining point or heel of the arrangement as a guide. One of the outlines is shown as the sole of a shoe and one represents the sole of a barefoot. As indicated, the placement of the pivot of the pedals may be from {fraction (3/16)} of the distance from the rear of the heel position of the pedal, to the front toe position on the pedal to {fraction (9/16)} of the distance from the rear of the heel position to the front toe position on the pedal. More preferably, the pivot will be located between ¼ and ½ of the same distance, and most preferably the pivot will be located between {fraction (5/16)} and {fraction (7/16)} of the same distance. These three ranges are shown at the side of Figure or the bottom of the figure by side by side brackets marked “A” for the widest or broadest range, “B” for the still more preferable range and “C” for the most preferable range. It will be noted that the actual pivot point in FIG. 24 is within each of these ranges. The heel of both foot patterns  131 A and  131 B in FIG. 24 are designated as  133 A and  133 B, and the front of the foot patterns are designated as  135 A and  135 B. 
     Normally the user of exercise device  10  will place its feet upon the pedal, after a little practice or experience, in the most comfortable position with respect to the pivot point to obtain a comfortable rocking position. This will be found to conform with the range of positions enumerated hereinabove. If the pedal is longer than the foot and the pivot position is measured with an equal amount of pedal extension on both ends of the foot the proper placement of the pivot point will be maintained. In other words, if a foot of any reasonable length is imagined placed centrally upon the pedal and the pivot point is determined as set forth above, approximately the correct position will be attained. Furthermore, if the pedal is approximately the same length as the foot the distances can be measured from the rear of the pedal. Of course, a custom positioning can also be made for any particular user by finding the length of their foot, laying out such length on the surface of the pedal and then arranging the pivot point within the ranges specified. 
     It will be understood that the apparatus of the invention may be formed of various materials, depending on the particular design. For example, as indicated above, the embodiments of the invention shown in FIGS. 1 through 9 may be readily made of metal, or in some cases, even of wood and various grades of plastic. Those embodiments shown, however, in FIGS. 10 through 15, will generally be more adaptable to formation out of various types of structural-type plastic material. Combinations of materials may also be used. 
     In general, in the use of the apparatus shown in the foregoing drawings and figures, the feet of the exerciser are placed upon or against a contact and rocking surface which is arranged to be pivotable upon some form of pivot support or other apparatus or arrangement providing a comparable movement when pressed upon by the feet of the user. The user then alternately depresses, or presses downwardly, with the rear or heel portion of his or her feet and downwardly with the forward or toe portion of their feet. Pressing downwardly with the heels while raising the toes, if persisted in until the feet and ankles feel stretched or mildly stressed, will be found to be relaxing to the lower legs not only to one whose normal movement has been restricted by injury, but also to those merely spending a large amount of time in a seated position such as on the job or watching television or the like. When the forward or toe portion of the foot is pressed downwardly, on the other hand, the relatively large calf muscles as well as other muscles in the leg and feet participate in moving the foot aiding in particular, as explained above, in the movement of blood through and away from the legs thus avoiding stasis or pooling of the blood as well as contributing to both the tone of the muscles and a feeling of well being of the one making the movement. The more resistance offered particularly to depressing of the forward position of the exercising apparatus, normally the forward portion of a pedal of the exercise apparatus, the more exercise will be had by the participant. The advantage, in particular, of being able to rock the feet backward as well as merely forward as is more usual in other already available apparatus, is that rearward movement or rocking movement of the foot actively stretches and relaxes the muscles and ligaments in the leg before again stressing them in moving the foot in the opposite direction to contract the calf muscles. In addition, of course, there is also active exercising of the relatively small muscles in the lower legs which actively raise the forward portion of the foot relative to the leg, which muscles are seldom exercised or toned, except by some rather specialized weight-type exercise apparatus found usually only in certain commercial health-type exercise centers. 
     In practicing the method of the invention, therefore, the user of the apparatus of the invention or any other apparatus providing or allowing a similar movement will alternatively rock their foot against the apparatus, first raising the toe and pressing down the heel, and then raising the heel and pressing down the toes, or vice versa, in usually any rhythm that is comfortable to the exerciser. While it is true that anyone can do the same thing by extending their leg and alternately rocking the feet up and down even without an apparatus against which to rest or press the feet, the effect is completely different. In the first place, movements accomplished without any coordinating apparatus tends to become uncoordinated. In the second place, to properly make the movement, the feet will usually have to be raised from the floor, which position cannot be held for more than a short time by the usual individual. In the third placed, the foot usually operates while in contact with a surface, except while changing feet or stepping when either walking or running. As a result, the feet simply feel better when exercising, if they are placed in contact with a surface. Furthermore, without a suitable apparatus it is not possible to conveniently apply any contra or reverse pressure against the movement of the foot, particularly when seated. Thus it is only with a suitable apparatus that any real contra resistance to the movements of the foot can be obtained. However, as indicated, there are a number of possible variations of apparatus of which the Applicant&#39;s claimed apparatus is particularly suitable. 
     FIGS. 25 a  and  25   b  show a further embodiment of the invention in which there is only a single pedal  142  having a width sufficient to accommodate a pair of feet. The pedal  142  is pivotally connected to a base  144 . A means for generating pivotal movement of the pedal is further provided and includes a drive wheel  146  mounted to the output shaft of an electric motor (not shown). A pulling line  148  is connected between the drive wheel  146  and the pedal  142  whereby each rotation of the drive wheel  146  produces a reciprocating motion of the pulling line  148 . In the embodiment shown, the pulling line  148  rides on a pulley wheel  150  which is journaled to base  144 . The pulley wheel redirects the orientation and force generated through the pulling line to provide for a full range of motion of the pivoting pedal for each revolution of driving wheel while maintaining a compact design of the apparatus. A resilient member  152  such as a coil spring, for example, is connected between the pedal  142  and the base  144  and provides an opposing force to the reciprocating pulling line to maintain tension in the pulling line and return the pedal to its starting position as the driving wheel completes each revolution. 
     FIGS. 26 a  and  26   b  show a further embodiment of the invention incorporating a single pedal design in which a means for generating pivotal motion of the pedal  142  comprises a pivot arm  154  which is mounted at one end to an actuator (not shown). It is contemplated that numerous known actuator devices including electrical, hydraulic and pneumatic actuators may be used in accordance with the present invention. A sliding wheel  112  is journaled to the opposite end of the pivot arm  154  and has a circumferential edge  158  which rides on the surface of pedal  142 . Operation of the actuator imparts an oscillating motion to the pivot arm  154  causing the sliding wheel  156  to roll across the surface of the pedal  142 , vertically displacing the contacted end of the pedal  142  and pivoting the pedal about its pivotal axis. A resilient member  160  such as a coil spring, for example, is connected between the pedal  142  and the base  144  and provides an opposing force to the force of sliding wheel  156  against pedal  142  such that when the direction of the pivot arm  154  and sliding wheel  156  reverses through each cycle, the opposing spring force returns the pedal  142  to its starting position. 
     FIGS. 27 a  and  27   b  show a further embodiment of the invention having a single pedal design wherein a solenoid is used to generate pivotal motion of the pedal  142 . The solenoid  162  is connected between the pedal  142  and base  144  and may be selectively positioned on either side of the pivotal axis of pedal  142 , to alternately push or pull, to generate a rocking-type motion of the pedal  142 . 
     While the aforementioned embodiments of the invention are particularly adapted to providing a compact design wherein the various mechanisms for facilitating rocking-type motion are disposed beneath the foot pedals, it is also contemplated that a mechanism for producing a rocking-type motion of a foot pedal may be positioned alongside or above the foot pedals. FIG. 28 shows a further embodiment of the invention wherein a motor/actuator  164  is positioned beside a pedal  142 . A connecting arm  166  extends between the motor/actuator and pedal whereby activation of the motor/actuator causes a reciprocating motion of the connecting arm  166 , which in turn generates a rocking-type motion of the pedal  142 . 
     While the present invention has been described at some length and with some particularity with respect to several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or the particular embodiment, but is to be construed broadly with reference to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention.