Abstract:
An exercise device and method of use is provided. The exercise device includes an elongated elastic element having a first end and a second end. The elongated elastic element is stretchable along its length. The exercise device further includes a pulley system comprising a pulley having a channel along its outer circumference through which the elongated elastic element runs. An engagement mechanism removably anchors the pulley to a fixed point while allowing the pulley to rotate as the elongated elastic element passes through the channel.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an exercise device and method of use and, more particularly, to an exercise device for knee strengthening. 
     BACKGROUND OF THE INVENTION 
     Within the fields of medical care and devices, there exists an important unmet medical need for a simple yet effective knee muscle strengthening device. Such strengthening may act to prevent surgery for those who have injured their knee. The universally accepted method for strengthening the knee involves the strengthening of the vastus medialis muscle, whose weakness is responsible for 99% of all chronic knee injuries. See, for example, A. A. Halpern, “The Runner&#39;s World Knee Book, What Every Athlete Needs to Know about the Prevention and Treatment of Knee Problems,” New York, Collier Books, 1984. Unfortunately, most people suffering from knee pain do not understand how to properly strengthen their knee and often wait too long to treat their injury. This combined with inconvenient, painful, useless or expensive treatment options may lead to situations in which those with injured knees view invasive surgery as their only option. 
     Knee strengthening methods require proper performance of the knee extension or leg extension exercise from an eccentric or stretched position to a concentric or contracted position of the muscles surrounding the knee, mainly the vastus medialis muscle. The main touchstone by which any strengthening program must be judged and which is universally accepted is specificity, overload, progression and regularity (SOPR). 
     The resistance must be specifically applied by selecting the proper movement. In the case of knee strengthening, it is the leg extension exercise targeting the vastus medialis and surrounding muscles. Overload stimulus must be applied in order to get a training effect or strengthening of the muscles and surrounding knee structures over time. This time may range from six weeks to three months, with results being achieved sooner if the trainee is diligent in performing their exercise. Overload is accomplished by slow but steady continual application of resistance each time the knee extension exercise is performed on a regular basis. Resistance should be easily controlled in the smallest increment possible by the user in order to gently but surely micro-load the muscles and surrounding knee structures over time. This micro-loading technique is highly respected and used to guarantee the quickest desired training effect without injury, as well as to motivate and safely train athletes. 
     Existing products range from leg extension machines to simple elastic tubing or ankle weights with vague instructions. Leg extension tables are large and expensive and, aside from the most costly commercial units, lack the gentle yet effective variable resistance and proper bio-mechanics. Thus, devices and techniques are needed that secure variable resistance in such a way as to make the knee-extension exercise bio-mechanically correct. It is also desirable to have a device with a resistance that is adjustable by the user at all times, and that is inexpensive and convenient enough that all those in need of help may benefit. 
     SUMMARY OF THE INVENTION 
     The present invention, in illustrative embodiments thereof, provides a system and method for strengthening the muscles around the knee through a leg extension exercise with an exercise device having an elongated elastic element and a pulley system. 
     In accordance with one aspect of the present invention, an exercise device is provided. The exercise device includes an elongated elastic element having a first end and a second end. The elongated elastic element is stretchable along its length. The exercise device further includes a pulley system comprising a pulley having a channel along its outer circumference through which the elongated elastic element runs. An engagement mechanism removably anchors the pulley to a fixed point while allowing the pulley to rotate as the elongated elastic element passes through the channel. 
     In additional embodiments of the present invention, the first and second ends of the elongated elastic element may have body engaging members. Further, the engagement mechanism may include at least a first element removably connected to a housing of a pulley. At least a portion of the first element is wider than a defined width, such that the first element is prohibited from passing through a specified aperture. 
     In another aspect of the present invention, a method of performing a knee extension exercise is provided. A foot of a user is inserted through a body engaging member at a first end of an elongated elastic element stretchable along its length. The user is in a seated position with the foot elevated above a floor. A second end of the elongated elastic element is held in a hand of the user. The leg of the user is extended at the knee of the user so that the elongated elastic element passes through a pulley system as a pulley rotates. The pulley system is anchored on a surface beneath the foot of the user. 
     In an additional embodiment, a resistance of the elongated elastic element may be adjusted by moving a grip of the hand of the user further along the length of the elongated elastic element from the second end. 
     Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a leg extension exercise device, according to an embodiment of the present invention; 
         FIG. 2  is a diagram illustrating a first alternative of a rotating body, according to an embodiment of the present invention; 
         FIG. 3  is a diagram illustrating a second alternative of a rotating body, according to an embodiment of the present invention; 
         FIG. 4  is a diagram illustrating a pulley system of the leg extension exercise device of  FIG. 1 , according to an embodiment of the present invention; 
         FIG. 5  is a diagram illustrating a pulley system of the leg extension exercise device of  FIG. 1 , according to an embodiment of the present invention; 
         FIG. 6  is a diagram illustrating a leg extension device in connection with a weighted element, according to an embodiment of the present invention; and 
         FIG. 7  is a flow diagram illustrating a leg extension exercise methodology, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the present invention provide methods and apparatus for strengthening and developing the muscles of the thigh responsible for knee stability and resistance to injury. Such methods and apparatus are effective, inexpensive, portable, easily adjustable, safe and bio-mechanically correct. 
     Referring initially to  FIG. 1  a diagram illustrates a leg extension exercise device, according to an embodiment of the present invention. An elongated elastic element  102  is shown having a first end and a second end. Elongated elastic element can be substantially stretched beyond its at-rest configuration. In a preferred embodiment shown in  FIG. 1 , elongated elastic element  102  is shown as a single length of stretchable rubber tubing. In additional embodiments of the present invention, elongated elastic element  102  may take on different forms and may be composed of different materials, such as, for example, an elastic rubber cord, an elastic fabric cord, and an elastic strap. 
     At the first end of elongated elastic element  102  is a first body engaging member  104  for a foot of a user. Any mechanism that may securely hold the foot of the user may be utilized, such as, for example, a loop, an adjustable strap, or a stirrup. At the second end of elongated elastic element  102  is a second body engaging member  106  for a hand of the user. Any strap or handle may be utilized at the second end of elongated elastic element  102 . Further, second body engaging member  106  may also be slidable and lockable along the length of elongated elastic element  102 , so that the user may increase the resistance of elongated elastic element  102  between the hand of the user and the foot of the user. It is also possible for the user to grab elongated elastic element  102  without the assistance of a strap or a handle. 
     Elongated elastic element  102  is run through a pulley system  108 . Pulley system  108  includes a pulley  110  and an engagement mechanism  112 . In a preferred embodiment shown in  FIG. 1 , pulley  110  is wheel-shaped, however any other type of rotating body through which elongated elastic element may be run may also be utilized. Two of many such examples of rotating bodies that may be utilized in pulley system  108  are shown in  FIGS. 2 and 3 . 
     Referring now to  FIG. 4 , a diagram illustrates a pulley system of the leg extension exercise device of  FIG. 1 , according to an embodiment of the present invention. Pulley system  408  includes a pulley  410  having a wheel  414  with a groove  416  through which elongated elastic element  102 , of  FIG. 1  runs. Pulley  410  further includes a pin  418  that runs through a central aperture of wheel  414 . A housing  420  engages both sides of pin  418 , allowing wheel  414  of pulley  410  to turn as elongated elastic element  102  runs through groove  416 . 
     An engagement mechanism  412  of pulley system  408  includes a first element  422  that is removably connected to housing  420  of pulley  410 . First element  422  may take the form of any clip or clasping element, such as a carabiner. First element  422  is also connected to a second element  424  of engagement mechanism  412 . Second element  424  has a specified width that allows the engagement mechanism  412  to be anchored to a weighted or fixed element. More specifically, in a preferred embodiment, first element  422  may be detached from either housing  420  or second element  424  so that it may pass through an aperture of a weighted element. When engagement mechanism  412  is reattached fully, with second element  424  on an opposing side of the weighted element, the specified width of second element  424  prevents it from passing through the aperture of the weighted or fixed element, thereby anchoring the engagement mechanism to the weighted or fixed element. Further, in a preferred embodiment, engagement mechanism  412  is anchored below the foot of the user when the user is in a seated position, as described in further detail in  FIG. 6 . 
     Referring now to  FIG. 5 , a diagram illustrates a pulley system of the leg extension exercise device of  FIG. 1 , according to another embodiment of the present invention. Pulley system  508  includes a pulley  510  having a wheel  514  with a groove  516  through which elongated elastic element  502  of  FIG. 1  runs. Pulley  510  further includes a pin  518  that runs through a central aperture of wheel  514 . A housing  520  engages both sides of pin  518 , allowing wheel  514  of pulley  510  to turn as elongated elastic element  502  runs through it. 
     An engagement mechanism  512  of pulley system  508  includes a first element  522  that is removably connected to housing  520  of pulley  510 . First element  522  has a specified width that allows the engagement mechanism  512  to anchor to a weighted or fixed element. More specifically, in a preferred embodiment, first element  522  may be detached from housing  520  so that it may pass through an aperture of a weighted or fixed element. When engagement mechanism  512  is reattached fully from an opposing side of the aperture, the specified width of first element  522  prevents it from passing through the aperture of the weighted or fixed element, thereby anchoring engagement mechanism  512  to the weighted or fixed element. 
     Referring now to  FIG. 6 , a diagram illustrates a leg extension exercise device in use with a weighted or fixed element, according to an embodiment of the present invention. A user  626  is seated on an elevated platform  628  such as a desk or a higher chair, so that the user&#39;s feet do not reach the floor. A foot of user  626  is inserted in a first body engaging member  604 , while a hand of user  626  holds elongated elastic element  602  or a second body engaging member  606 , connected to elongated elastic element  602 . Elongated elastic element  602  runs through a pulley system  608 , which is anchored to a weighted or fixed object  630  on the surface beneath user  626 . As elongated elastic element  602  is stretched, it smoothly runs through pulley system  608  to decrease friction. Elongated elastic element  602  allows for gentle yet effective variable resistance. For example, elongated elastic element  602  offers the least resistance when muscles are brought from at the eccentric position, where they are weakest and the knee joint is subject to further injury. As the muscles are contracted and the knee is flexed, the resistance increases as the muscles reach their strongest or contracted position, where the knee is flexed and the leg is straightened. Pulley system  608  also protects elongated elastic element  602  from friction and breakdown over the lifetime of the device. Finally, pulley system  608  allows for smoother contractile performance of the exercise since it allows for substantially frictionless motion. 
     Examples of a weighted or fixed object  630  may include a weight plate. The device is anchored to a point that may be moved by a user to an exact position that will specifically target the vastus medialis muscle of the knee, and to apply the correct source position for resistance. For example, the weight plate allows for correct bio-mechanical positioning for targeting of a knee strengthening process. The weight plate further conforms to the standard height of tables, bureaus or desks in using the device. The weight plate is also readily accessible in most households and provides a secure anchor without any attachments to the floor itself. As user  626  extends their leg and elongated elastic element is pulled through pulley system  608 , pulley system  608  stays stationary and anchored on the surface beneath user  626 . Resistance may be adjusted in accordance with where user  626  holds elongated elastic element  602 . 
     Referring now to  FIG. 7 , a flow diagram illustrates a leg extension exercise methodology, according to an embodiment of the present invention. The methodology begins in block  702  where a user inserts a foot through a body engaging member at a first end of an elongated elastic element stretchable along its length. The user is in an elevated seated position so that the user&#39;s feet do not reach the floor. For example, the user may be seated on a table, bureau or desk. In block  704 , the user holds a second end of the elongated elastic element. In block  706 , the user&#39;s leg is extended at the knee so that the elongated elastic element passes through a pulley system anchored to a point on the floor beneath the foot of the user. More specifically, target muscles are contracted that are to be stimulated and progressively overloaded. In block  708 , it is determined if it desirable to adjust the resistance of the elongated elastic element. If it is desirable to adjust the resistance of the elongated elastic element, the user&#39;s grip may be moved further along the length of the elongated elastic element, in block  710 . If the user&#39;s grip is moved closer to the second end of the elongated elastic element, resistance will decrease, and if the user&#39;s grip is moved further from the second end of the elongated elastic element, resistance will increase. The methodology then returns to block  706 , to repeat the exercise. If it is not desirable to adjust the resistance of the elongated elastic element, the methodology returns to block  706  to repeat the exercise. Any desired number of repetitions and sets may be performed depending on the strengthening or rehabilitation program. 
     Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the invention.