Originally Posted by canada

Oh and good point with the rotator cuff. I have advanced tendonitis in my right shoulder, and this excersise hurts sometimes if I weight it too much and go too far down.

As a general rule of thumb I try and go no further then making a 90 degree bend at my elbow, so my forearms and upper arms are bent at a 90 degree. That puts my hands exactly above my hip bones. You can feel when you've gone too far.