Arm only stroke, go ahead and lock the ankles, hips, or whatever to keep the lower body steady. Shoulder only stroke, allow some flexibility. Mr. Kelley did not want us golfers to lose the radius of the circle. He didn't want us to be moving low point around. That is where his genious on the putting green comes out. He is advocating a very simple stroke.
Imagine a radius (either from the left shoulder for the arm only or from the spine for the shoulder only) and your job is to keep that radius constant. Don't move the head or sway the body. Don't rotate the hips or roll the feet. Just keep it simple and TRACE THE BASE LINE, KNOW THE HINGE ACTION YOU ARE USING, and KNOW YOUR GRIP.
After you get good on the greens. It is time to get great! Now get precise with things. Go back over your stroke components and create precision.
