Apparatus for isolated, closed chain exercise of a person's quadriceps muscles

An exercise machine includes a frame designed to rest upon a floor surface; a back rest mounted on the frame; and a foot platform mounted on the frame. At least one of the foot platform and the back rest is pivotally mounted on the frame in such a manner that a person may rest his back against the back rest and exercise his quadriceps muscles in isolated, closed chain fashion. A resistance device is preferably provided to resist movement of the back rest and/or the foot platform in a manner that opposes the user's efforts to straighten his legs at the knees.

BRIEF DESCRIPTION OF THE FIGURE OF THE DRAWING

With reference to the Figures of the Drawing, wherein like numerals designate like parts and assemblies throughout the several views,

FIG. 1 is a perspective view of a preferred embodiment exercise machine constructed according to the principles of the present invention;

FIG. 2 is a side view of the exercise machine of FIG. 1, showing a user in a start position;

FIG. 3 is a side view of the exercise machine of FIG. 1, showing the user's legs in an extended position;

FIG. 4 is an enlarged and fragmented side view of an optional foot platform adjustment arrangement (shown on the exercise machine of FIG.

1);

FIG. 5

a is an enlarged and fragmented side view of an optional arrangement (not shown on the exercise machine of FIG. 1) for latching the seat relative to the frame and/or limiting forward pivoting of the seat relative to the frame, showing the seat latched to the frame;

FIG. 5

b is an enlarged and fragmented side view of the optional arrangement of FIG. 5

a, showing a limit imposed on forward pivoting of the seat;

FIG. 6 is a side view of a prior art leg extension machine, showing a user in a start position;

FIG. 7 is a side view of the prior art leg extension machine of FIG. 6, showing the user's legs in an extended position;

FIG. 8 is a side view of a prior art leg press machine, showing a user in a start position; and

FIG. 9 is a side view of the prior art leg press machine of FIG. 8, showing the user's legs in an extended position.

1. A closed chain quadriceps exercise apparatus, comprising:

2. The A closed chain quadriceps exercise apparatus, comprising:

3. The closed chain quadriceps exercise apparatus of claim 1, further comprising an adjusting means for selectively adjusting the foot platform fore and aft relative to the frame.

4. The closed chain quadriceps exercise apparatus of claim 1, further comprising an adjusting means for selectively adjusting an angle defined between the foot platform and the frame.

5. The closed chain quadriceps exercise apparatus of claim 1, wherein a back engaging surface on the back rest extends generally perpendicular to a foot engaging surface on the foot platform in the rest position.

6. A closed chain quadriceps exercise apparatus, comprising:

7. The closed chain quadriceps exercise apparatus of claim 1, wherein when the person occupies the rest position, the back rest faces upward and forward at an angle of approximately fifty degrees relative to the floor surface, and the foot platform faces upward and rearward at an angle of approximately forty degrees relative to the floor surface.

8. A closed chain quadriceps exercise apparatus, comprising:

9. The closed chain quadriceps exercise apparatus of claim 8, wherein the back rest and the foot platform cooperate to support the person with his hips at a pivot radius of between twelve and twenty-four inches from the axis.

10. The closed chain quadriceps exercise apparatus of claim 9, wherein the pivot radius is eighteen inches.

11. The closed chain quadriceps exercise apparatus of claim 10, wherein the back rest rotates through a range of forty degrees to accommodate a change in distance of twelve inches between a user's hips and ankles.

12. The closed chain quadriceps exercise apparatus of claim 8, further comprising a locking means for selectively locking the back rest relative to the frame.

13. The closed chain quadriceps exercise apparatus of claim 8, further comprising a limiting means for selectively limiting the back rest to a desired extent of rotation relative to the frame.

14. The closed chain quadriceps exercise apparatus of claim 1, wherein a seat is rigidly secured to a lower end of the back rest.

15. The closed chain quadriceps exercise apparatus of claim 14, further comprising left and right handles rigidly secured to opposite sides of the seat.

16. A closed chain quadriceps exercise apparatus, comprising:

17. A closed chain quadriceps exercise apparatus, comprising: