David - I've never seen that ! That looks quite interesting. I can see how it would do wonders to shoulders and posture. Definitely something to look into on a side. (But as I watch it, its SO tempting to throw them! lol)
I had a flexibility problem with the right side of my neck and shoulder due to a high school wrestling injury for thirty six years. Doctors and physical therapy did not help. After two weeks of daily practice with the Indian clubs the problem was gone.
It also helps with my arthritis.