I don't know if they ever tried that but I play with a yoyo, looping style (2A) and it is a wonderful exercise for the shoulder area. I broke my collarbone two

I don't know if they ever tried that but I play with a yoyo, looping style (2A) and it is a wonderful exercise for the shoulder area. I broke my collarbone two years ago and couldn't use my right arm for almost two months. After that I picked up yoyo and I'm certain that it helped me recover my strength and flexibility.