Abstract:
A resistance chair with wheels assists users with performing correct abdominal crunches by guiding the user&#39;s effort. The resistance chair includes a seat connected to a hinged back with back support that extends to support the user&#39;s back and assist in the crunch recovery following the crunch extension.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/792,570, filed Jun. 2, 2010, which is a continuation of U.S. patent application Ser. No. 11/786,400, filed Apr. 10, 2007, now U.S. Pat. No. 7,740,572, which claims priority from U.S. Provisional patent application 60/791,470, filed Apr. 13, 2006, and U.S. Provisional patent application 60/796,650 filed Apr. 21, 2006. 
    
    
     FIELD 
     The following description relates generally to the field of exercise equipment and more specifically to the field of low impact abdominal exercisers. 
     BACKGROUND 
     In an age of exercise and fitness, the time-honored abdominal crunch is under attack as potentially damaging if done incorrectly especially if performed by someone in poor physical condition. What is needed is an exercise tool to enable anyone to perform a correct abdominal crunch, and provide varying levels of resistance or assistance to accommodate people unaccustomed to exercise. 
     SUMMARY 
     The following simplified summary is provided in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview, and is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
     A resistance chair with wheels assists users with performing correct abdominal crunches by guiding the user&#39;s effort and eliminating the initial jerking motion commonly experienced when doing an abdominal crunch. The resistance chair includes a seat connected to a hinged back with back support that extends to support the user&#39;s back and assist in the crunch recovery following the crunch extension. 
     In operation, a resistance chair provides support for a user&#39;s back, adjustable resistance moving from the start position to the extended position thus exercising muscles that ordinarily don&#39;t receive work in abdominal crunches. The back support and the adjustable resistance of the resistance chair also assist the user by overcoming a portion of gravity to help the user perform a correct crunch moving from the extended position to the start position. 
     By providing resistance to the backwards movement, the user engages the lower back muscles and thereby exercises the front and the back of the abdominal muscles. The backrest further permits core rotation providing the user the ability to do a sideways twist and engage the oblique muscles. 
     To the accomplishment of the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles of the claimed subject matter may be employed and the claimed subject matter is intended to include all such aspects and their equivalents. Other advantages and novel features may become apparent from the following detailed description when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a resistance chair in the starting position. 
         FIG. 2  is a perspective view of the resistance chair of FIG. I in the extended position. 
         FIG. 3  is an exploded view of the resistance chair of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1  and  FIG. 3 , resistance chair  10  includes seat  12  pivotally secured to first end  14  of first arm  15  which is pivotally secured to second end  17  of second arm  18 . First end  20  of the second arm engages axle  21  and any suitable wheels such as wheels  22  and  23  may be secured to axle  21  to enable extension of resistance chair  10  to extended position  30  as illustrated in  FIG. 2 . Any suitable back support elements such as rollers  24  and or shoulder support  25  may be secured to first arm  15 . Rollers  24  may be secured at any suitable position on first arm  15  and may be included in a backrest such as backrest  27  that may swivel at the point of attachment to first arm  15 . Seat  12  may be molded plastic, metal, foam or a combination of wood, steel and upholstery. Front edge  12 F may be higher relative to rear edge  12 R to place a user at a slight incline into the back support. This position ensures optimal comfort when performing an abdominal crunch. 
     One or more resistance bands such as bands  26  may be used to provide selectable resistance to a user moving from start  20  position  28  of  FIG. 1  to extended position  30  of  FIG. 2 . The resistance bands also assist the user to perform a correct crunch motion when moving from extended position  30  to start position  28 . Resistance bands  26  may be secured between axle  21  and axle  32  using any suitable technique such as band engagement elements  33  directly secured to axle  21  and seat  12  secured to axle  32 . 
     Optional shoulder straps  34  may be attached to hinge  35  between first arm  15  and second arm  18  or to an extension such as extension  15 B from first arm  15 . Straps  34  may provide additional resistance to a user seeking to extend the crunch position and continue to move their upper body forward past start position  28 . This extends the crunch, contracts the user&#39;s abdominal muscles farther than the start position and engages the user&#39;s arms in the exercise. 
     In use a user sits upon seat  12  with the user&#39;s back adjacent to back rollers  24  in start position  28  of  FIG. 1 . The user must lean back against the back rollers  24  and shoulder support  25  using the user&#39;s back muscles to push against the back rollers  24  and shoulder support  25 . Wheels  22  and  23  will begin to roll away from the user and permit first arm  15  and  10  second arm  18  to fold to a horizontal position parallel to the ground as in extended position  30  of  FIG. 2 . The transition from start position  28  of  FIG. 1  to extended position  30  of  FIG. 2  stretches resistance bands  26 . The energy stored in stretched resistance bands  26  counteracts a portion of the gravitational force on the user&#39;s upper body and assists the user to perform an abdominal crunch to return the user&#39;s upper body from the extended position  30  of  FIG. 2  to at least start position  28  of  FIG. 1 . By performing these movements the user is doing an abdominal crunch with back support and resistance that stretches the lower back muscles, forces the user to use more muscles when pushing backwards, and supporting the user when the user moves from the fully extended position to the upright start position, thereby creating a more comfortable, efficacious exercise. 
     While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. Other embodiments and configurations may be devised without departing from the spirit of the inventions and the scope of the appended claims.