Method and apparatus for bi-directional exercise movements

DETAILED DESCRIPTION The present invention addresses the aforesaid object with improved exercise methods and apparatus.
In accordance with the present invention, herein are disclosed exercise devices affording bi-directional resistance movements of the legs for exercise of the gluteus muscle group.
It will be appreciated that the same methods may be employed in arm exercises for other muscle groups including the deltoids.
The invention relates to or employs some steps and apparatus well known in the arts and therefore, not the subject of detailed discussion herein.
A preferred embodiment of the present invention utilizes barbell plates to provide an incrementally adjustable resistance.
The apparatus has a conventional main-frame and a centrally mounted seat.
A plane of symmetry extends through the middle of the frame and seat so that the two sides are mirror images with respect to a vertical mid-plane.
A sub-frame pivots on a transverse horizontal axis at the upper ends of its "U" shape, where it is mounted to the main-frame.
The sub-frame also includes right and left pivot axes oriented more or less perpendicularly to the horizontal axis and set at the bottom of the "U" where they are axially displaced from the horizontal axis.
Right and left lever arms are mounted to pivot on these axes.
Offset linkage members connect each lever arm to the main-frame so that, as the sub-frame pivots through a given angle, the lever arms pivot through opposing angles of the same order as the given angle.
Each of the lever arms has an exercising force input location, oriented to effect pivotal movement of the sub-frame about the horizontal axis, and a second exercising force input location, oriented to effect pivotal movement of the lever arms about the right and left axes.
In the present invention, the right and left pivot axes are axially displaced from the horizontal axis, so that lever arm pivotal reaction forces normal to the right and left pivot axes have a significant moment arm about the horizontal axis