Codman Circumduction Exercises

In a post titled "Home Exercises" I attempted to describe one of the exercises I have to do at home and did not do a great job at it so here is a better description.  The exercise is called the Codman Circumduction Exercise, or Pendulum Exercise.  And what is consists of is the following:  I bend forward 90 degrees at the waist, using a table for support then rock body in a circular pattern to move arm clockwise 20 times, then counterclockwise 20 times.
Here is an example of the exercise: