Normally-designed operation of the Cybex Torso Rotation machine has the
exerciser planting both feet on slightly toe-out platforms and sitting
on an adjustable height seat pan.
Advanced users can easily perform reps with weight resistance in the
150-190 LB maximum range. However, at higher resistance it often feels
like the opposite side (from direction toward concentric action of torso
rotation) is doing most of the work — ‘pushing’ the rotation as
opposite external oblique abdominal muscles are the primary movers.
But what if you say “I want to really focus on my internal oblique
abdominal muscles?” Advanced users with conditioned muscles, ligaments
and tendons might be ready to try a progressive modification of the
Cybex Torso Rotation machine.
The position described below may put more stress on the lower back, hip
joints, and sacroiliac joints; so proceed with caution and closely
monitor the stress you feel on these musculoskeletal regions. You might
start with a lighter resistance than the normal exercise. Also, the seat mount on the Cybex Torso Rotation machine occasionally fails either by broken parts or by slippage of the sawteeth that mount the seat to the machine. The modified position described below makes the user more vulnerable to a fall if the seat fails because it is more difficult to react with your feet and put your body in a stable position to prevent or attenuate a fall. Take extra care to make sure the seat is secure and stay ready to bail safely if the seat fails.
Now for the exercise action description:
Place both feet on the outermost foot platform of the Cybex Torso
Rotation machine. Feet can be placed parallel, but if your feet are
wide, you may want to place your feet in a tandem position.
Rotate toward the center the same way you would rotate the foot platorms
in the normal exercise. You will feel much more concentric action coming
from the same-side internal oblique muscles. You will also feel more
same-side action due to forces transmitted in force grounding action
along the gluteus medius, tensor fascia latae and possibly the vastus
lateralis.
Remember that it is always best to rotate the exercise only roughly to
the center position during each repetition for a set, and then readjust
the machine to rotate in the opposite direction for another set.