Abstract:
A reciprocating rehabilitation device that can be used as a stand alone unit or incorporated within a stationary bicycle. The device utilizes independently operating pedals together with range of motion limiters. Patients and therapists alike can rehab each limb independently through any necessary progressive range of motion on the way to recovery.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     None. 
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present disclosure relates generally to rehabilitation devices and equipment with pedals that help people recover from joint injuries, surgeries or the like. More particularly, it relates to reciprocating pedals, which are used by therapists, to repeatedly take an injured appendage through a limited, but adjustable, range of motion. 
     II. Description of the Prior Art 
     After an injury or surgery to the knee, for example, one of the first priorities is to begin to restore the range of motion to the affected joint. Typical range of motion of the knee can be measured in knee flexion and knee extension by a device called a goniometer. A goniometer has two pieces that are connected by a central hinge. By lining up each of the pieces along a specific joint area and having the individual move that joint, a value in degrees (measure of an angle where one degree (°) is one 360 th  part of a full circle) can be observed and recorded. Knee flexion can be measured when an individual lies on their back and draws their heel to the back of their leg. Typical values for knee flexion are approximately 130-150°. Knee extension is the amount to which a person can straighten their leg. Typical values for knee extension are 0-10°. 
     Bicycles are human-powered modes of transportation typically consisting of a frame, two wheels, seat, handlebars, pedals, gears, and a chain. By using the pedals, one can propel the bicycle forward and can control the speed at which they move by varying their pedal speed along with changing an associated gearing system, if installed, of the bicycle. 
     Stationary bicycles allow an individual to remain in place as they pedal. Stationary bicycles are typically used in gyms or homes by individuals when the weather is not conducive for riding outside or for training/workout purposes. Stationary bicycles are also used by physical therapist/rehabilitation technicians for rehabilitation purposes. They allow an individual rehabbing to workout various muscles and joints without risking a fall. Additionally, an individual can rehab in such a way as to remove the weight from specific load bearing joints and muscles that may not be ready for full weight bearing exercises. 
     While stationary bicycles have been used for rehabilitation for many years, almost two-thirds of the 360° circular motion associated with conventional stationary bicycles is non-productive, especially with respect to rehabilitation, since the range of motion that effectively produces resistance is only 130°. Also, the full circular pedal motion of these bicycles requires 115° of knee flexion which is much more flexion than is required in normal walking or jogging motion. Thus, conventional stationary bicycles are unable to produce leg motion which uses the same body muscles as walking or jogging, and are unable to promote early rehabilitation after knee, hip, or ankle surgeries which require less than 115° of knee flexion. In fact, many rehabilitation efforts using the full cycling motion irritate the injured joint of patients with range of motion limitations. 
     Accordingly, there have been a plethora of attempts to design both new rehabilitation stationary bicycles as well as new stand alone and/or retro-fit rehabilitation devices that do not use, or perhaps limit, the full cycling motion. Such devices range, for example, from relatively simplistic adjustable pedal throw (radius) systems to fully automated systems that evaluate the condition of the patient, design a therapy program for the patient and then monitor the progress of the patient. 
     However, there still remains a need for a rehabilitation device that can be utilized by a patient with no or very little therapist aide. Indeed, even with all of the prior art designs, professional therapists still desire to stand next to a conventional stationary bicycle and help the patient position and reposition their limbs with every crank of the pedals. In particular, the therapist helps the patient onto the conventional stationary bicycle and positions the foot near the top of the cranking radius; the patient then provides the force to move the pedal to their maximum; the therapist then needs to reposition the foot back near the top; and the patient pushes again, and so on. 
     It is therefore a general object of this disclosure to provide a device for addressing the deficiencies of the current practices regarding issues associated with rehabilitation devices used after knee and other joint injuries or surgeries. 
     It is another general object of this disclosure to provide a rehabilitation device incorporated within a stationary bicycle. 
     It is another general object of the present disclosure to provide a standalone and/or retro-fit rehabilitation device. 
     It is more specific object of this disclosure to provide a rehabilitation device that takes an injured appendage through a limited, but adjustable, range of motion. 
     These and other objects, features and advantages of this disclosure will be clearly understood through a consideration of the following detailed description. 
     SUMMARY OF THE INVENTION 
     According to an embodiment of the present disclosure, there is provided a reciprocating rehabilitation device having a crank axle supported by a frame with a foot pedal coupled to the axle through a crank arm where the pedal has a circular range of motion about the axle. A resistance element resists a direction of pedal motion by the user while a force element urges pedal motion in the opposite direction. The range of motions of these pedal directions are adjustable. 
     There is also provided a reciprocating foot pedal assembly having a crank axle supported by a frame with left and right foot pedals coupled to opposite ends of the axle through respective crank arms wherein the pedals have circular range of motion about the axle. A resistance element resists a direction of pedal motion by the user while a force element urges pedal motion in the opposite direction. The range of motions of these pedal directions are adjustable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will be more fully understood by reference to the following detailed description of one or more preferred embodiments when read in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout the views and in which: 
         FIG. 1  is a perspective view of a reciprocating rehabilitation device according to the principles of an embodiment of the present invention as incorporated within a stationary bicycle. 
         FIG. 2  is a simplified diagram of the basic motion of the pedals of the device of  FIG. 1 . 
         FIG. 3  is a simplified diagram of the reciprocating motion of user engaged pedals of the device of  FIG. 1 . 
         FIGS. 4 a -4 c    are a series of simplified diagrams of various positions within the basic motions of the pedals of the device of  FIG. 1 . 
         FIG. 5 a -5 b    are simplified range of motion diagrams of various positions within the basic motions of the pedals of the device of  FIG. 1 . 
         FIG. 6  is a perspective view of a finite adjustability embodiment of the range of motion of the device of  FIG. 1 . 
         FIGS. 7 a -7 d    are perspective views illustrating an infinite adjustability embodiment of the range of motion of the device according to the principles of the present invention. 
         FIGS. 8 a -8 b    are perspective views illustrating the independently moving pedals of the device of  FIG. 1 . 
         FIG. 9  is a perspective view illustrating both pedals of the device of  FIG. 1  moving simultaneously. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the disclosure, its application or use. These exemplars are merely used to better describe the true spirit and scope of the present disclosure. 
     Turning now to the Figures, and in particular  FIG. 1 , a pedal assembly, which may also be referred to as a reciprocating rehabilitation device,  10  is shown incorporated within a conventional stationary bicycle  12 . It will be appreciated that the device may be a stand alone device with or without connection to or being incorporated with a stationary bicycle. The conventional stationary bicycle  12  may include a frame  14 , including front and rear supports ( 16 ,  18 ), and a flywheel  20  having a resistance adjustment mechanism  22  including a brake pad  24  biased against the flywheel  20  via a screw type crank  26 . As is well known in the art, when the user sits on the seat  28 , he can either use the left and right handles ( 30 ,  32 ) and/or the left and right pedals ( 34 ,  36 ) to engage the flywheel  20  through their respective associated linkages. 
     Rather than the pedals traversing a full 360° circle, as they would in a conventional stationary bicycle, the pedals of the reciprocating device  10  are moved down  38  by the user and then are forced up  40  and back to a starting position. This basic pedal motion is illustrated in the abstract drawing of  FIG. 2 . In particular, the pedal  42  moves  44  around a central point  46  and then a force mechanism  48  returns the pedal  42  to a starting position  50  from a reference point  52 . The reciprocating motion, e.g. user forcing the pedal down  44  and the force mechanism  48  (for example a spring  54 ) urging the pedal back up  56 , is better shown in  FIG. 3 . The pedal, via its crank, is coupled to a gear shaft or crank axle  58  via a one-way clutch, for example, which may then be connected to a flywheel (or other resistance element) through a chain  60 , while the spring  54  is secured to a frame  62  through a fastener  64 . 
     The positions of the reciprocating motion of  FIG. 3  are further illustrated in  FIGS. 4 a -4 c   . In particular,  FIG. 4 a    shows the pedal in the starting or upper position wherein the user would be engaged with a bent knee.  FIG. 4 b    shows an intermediate position wherein the user would be pressing down on the pedal and extending their knee.  FIG. 4 c    shows the end or lowest position wherein the user would be restricted from rotating the pedal any father due to a built in stop (supra). The pedal would then return to the starting position of  FIG. 4   a.    
     The pedals of the reciprocating device  10  move around a point, but cannot move past a set stop position. Using an analog clock as a visual exemplar, and turning now to  FIG. 5 a   , the pedal  66  is shown rotating about the center  68  of the analog clock  70 . In an ordinary bicycle (stationary or otherwise), the pedals would have a full 360° range of motion. In other words, the pedal  66  would make a complete circle about the center  68  in a counterclockwise direction from 12:00 ( 72 ) to 6:00 ( 74 ) and back up to 12:00 ( 72 ). By contrast, the range of motion of the pedals of the present disclosure are adjustably limited. For example, the starting position is shown at 12:00 ( 72 ) and the stopping position is shown at 6:00 ( 74 ). The total amount of rotation can be restricted as the range of motion of the patient progresses. As a further example, the limited extension is illustrated by  FIG. 5 b    wherein the pedal stops can be adjusted to accommodate the range of motion of each user, starting  76  and/or stopping  78  anywhere within the full 12:00-6:00 range, for example. 
     The adjustability of the start and stop positions of the reciprocating rehabilitation device  10  can be finite or infinite. An example of a finite adjustability is illustrated in  FIG. 6 . More particularly, the pedal  80  of  FIG. 6  is rotatably mounted to the crank or lever arm  82  such that the downward force moves the pedal and the crank downward  84  conjointly. The force mechanism (infra) then urges the pedal and crank back upward  86  conjointly. This reciprocating movement is limited by utilizing one or more limiters or stops  88  along the path of the crank  82 . For example, a downward stop  88   a , in the form of a thumbscrew or the like, positioned within one of a plurality of apertures  90  (within a plate, the frame, or otherwise) along the path of travel of a crank extension arm  92  will limit the downward travel  84  of the crank arm  82  and thus the pedal  80 . Similarly, an upward stop  88   b , positioned within an aperture  90  will limit the upward travel  86  of the crank arm  82  and thus the pedal  80 . 
     An example of an infinite adjustability range is illustrated in  FIGS. 7 a -7 d   . In particular, the pedal  80  is rotatably mounted to the crank  82  such that the downward force of a user moves the pedal and crank downward  84  conjointly, while the force mechanism urges the pedal and crank back upward  86  conjointly. Again, this reciprocating movement is limited by utilizing one or more limiters or stops  88  along the path of the crank  82 . However, instead of a finite number of positions ( 90 ) to set the limiters, as shown in  FIG. 6 ,  FIG. 7  shows the stops capable of being positioned anywhere along the positioning slots  94 , for example. Accordingly, downward stop  88   a  and upward stop  88   b  can be positioned to start and/or stop the movement of the pedals anywhere along the reciprocating path of travel. 
     Another advantageous feature of the design of the present disclosure that is not possible with common bicycles, stationary machines, etc. is the ability of the left and right pedals to move independently and/or together. Typical pedals move 180° with respect to one another, or in other words, when one pedal is on the top of the rotation the other pedal is on the bottom of the rotation. The reciprocating rehabilitation device of the present disclosure allows the patient to better use one pedal (limb) at a time and or both pedals (limbs) at the same time. 
     An example of the independent movement of the pedals is illustrated in  FIGS. 8 a  and 8 b   .  FIG. 8 a    shows the right pedal  96  moving downward  98  via the user and upward  100  due to the force mechanism as the left pedal  102  remains stationary. By contrast, and as shown in  FIG. 8 b   , the left pedal  102  moves downward  98  and back upward  100  while the right pedal  96  remains stationary. 
     On the other hand, an example of both pedals moving together is illustrated in  FIG. 9 . Both the right pedal  96  and the left pedal  102  can move down  98  (and up) together or at the same time. Accordingly, as each pedal is independent, the patient (and therapist) can utilize one or both depending on the needs of the rehabilitation process. 
     It will be understood that the pedal assembly of the present disclosure need not be incorporated within a stationary bicycle. Indeed, the device could merely consist of a frame, pedals and their respective cranks, a downward resistance element, an upward biasing element and one or more range of motion stops. Such an embodiment could be utilized by a patient in a wheelchair (or other chair) or someone in a standing position. 
     The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom. Accordingly, while one or more particular embodiments of the disclosure have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the invention if its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the present disclosure.