Patent ID: 7070545

Claim:
An exercise machine comprising: a frame; a means for transferring an incident force from the legs of a user; a first four bar linkage system operably mounted to the frame and operably connecting the transferring means to the frame, the first four bar linkage system for allowing back and forth movement of the transferring means along a path of travel about an instantaneously changing axis of rotation and for changing the angle of inclination of the transferring means to maintain the transferring means in a position normal to the length of the lower legs of the user during a corresponding leg extension movement of the user; a second four bar linkage system operably engaging the first four bar linkage system; a resistance means; and a means for operatively connecting at least one of the first four bar linkage system and the second four bar linkage system to the resistance means; and wherein the second four bar linkage system operates in conjunction with the first four bar linkage system and the resistance means to create a mechanical disadvantage to the user; a first arm member connected to the frame; a second arm member pivotally mounted to the first arm member; and a handlebar operably connected to the second arm member; and a means for operably connecting the handlebar to the resistance means; and wherein the handlebar is positioned above the head of the user for grasping by the hands of the user; the handlebar is movable along an arcuate path together with the user while the user performs an abdominal crunch exercise; and the handlebar resists a pulling force exerted by the user when the user performs an abdominal crunch exercise while grasping the handlebar, the handlebar operated on by the constant force of the resistance means in opposition to the pulling force.