Devices are known in the art which may be used to exercise muscles. These devices, however, have limitations, such as, by way of example only, lack of portability, heavy weight, large size, inconvenient storage, incompatibility, lack of adaptability to different users and/or restriction on muscle groups exercised.
One such apparatus is described in U.S. Pat. No. 5,766,118 issued Jun. 16, 1998 to Conner. The Conner apparatus is used for developing the abdominal muscle group. The Conner apparatus attaches to a vertical surface such as a door or wall using a clamp and includes an elastic resistance band which is formed into a closed loop and a harness which is pulled to exercise the muscles.
U.S. Pat. No. 5,601,518 issued Feb. 11, 1997 to Weintraub discloses a portable exercise device that comprises two bases. Each of these bases attaches to the top and bottom of a door respectively. A bar is pivotally mounted to the bottom base. The bar is attached to a strap on one end and a longitudinally extending biasing means on the other. By pulling on a rod attached to the strap, the user can exercise his or her muscles.
U.S. Pat. No. 5,571,064 issued Nov. 5, 1996 to Holm discloses an exercise device which includes a loop for attachment to an anchoring structure, such as a door, which loop receives an elastic cord, which elastic cord is connected to a handle assembly.
U.S. Pat. No. 5,254,065 issued on Oct. 19, 1993 to Pollock discloses a fastening strap configured as a loop securable between a door and its associated frame. The strap is used for support of exercise.
U.S. Pat. No. 4,830,365 issued on May 16, 1989 to March discloses an exercise device for home use for attachment to a suitable surface, such as a door, having a vertical tubular housing with spring mechanism and molded piston assembly inside, to which is attached a rope with various handle means for exercise.
U.S. Pat. No. 5, 662,563 issued on Sep. 2, 1997 to Maerzke discloses a portable exercise device comprising a flexible elastic material strap gripped by three rods held together by removable caps at each end.
It is apparent that an exercise apparatus that overcomes one or more of the limitations of the exercise apparatus described above would be advantageous.