What is the correct way to perform cuban rotation with a single dumbbell?
I am experimenting with cuban rotation as an assistance exercise for olympic lifting and gymnastic arm balances. My current exercise plan is 3x per week olympic lifting plus handstand skill work every other day (not really structured) plus some light yoga in the mornings. I have no shoulder injuries or mobility problems, I want to use this exercise primarily to increase strength.
I have seen cuban rotations performed in a number of ways:
Standing, with barbell: the bar goes from the stomach to behind the head in 180 degree angle.
With dummbell, elbow unsupported: the same as above, with either 1 or 2 dumbbells, standing or sitting, 180 degrees motion
With dumbbell, elbow supported: with 1 dumbbell, the elbow supported on the knee, but only 90 degrees of rotation (lowering the dumbbell from vertical to horizontal, and back)
What are the advantages/disadvantages of each version? Currently I prefer the single dumbbell version, because even an unloaded barbell seems too heavy for this exercise, and I only have a single dumbbell at home.
With a single dumbbell, should I have my elbows supported or not? Should the range of motion be 90 degrees or 180?
The supported version with a ROM of more than 90 degrees feels awkward and sometimes very slightly painful in my shoulder. Should I reduce the weight and try to perform in full range of motion, or is 90 degrees ok in the long term?