The actuator for the exercise machine is mounted to the seat to pivot about a
vertically extending axis to permit the user to rotate her/his upper torso and
vary the muscle groups being exercised to enhance the beneficial effects. A rotational
connection between a shoulder harness element and the actuator arm facilitates
this side crunching motion. A second feature which may be used separately or in
conjunction with the rotational actuator, is an actuator arm with both a shoulder
socket and an elbow joint that pivot, the elbow joint requires additional force
to break over. This dual-pivot actuator arm permits the user to perform abdominal
crunches with a predetermined resistance.
