Lately, I have taken a particular interest in a "ball" too. In fact, what I want to talk about is a 70 to 80 centimeters wide ball full of air an chemical resin used for physical exercise. I've been told that making it bounce while sitting or jumping while holding it in the hands straightens up the spine and pelvis. By instinct, I didn't understand how such faint movements could do that; so, being naturally suspicious, I had to watch professional athletes using it to convince myself of that method's effectiveness, which is also said to firm up internal organs.