by Sid Barrett » Thu Oct 15, 2015 4:48 pm
My DD used a weighted ball for a few weeks, when she was around 10 or so, with the intention of strengthening her shoulder and gaining velocity on her pitches. After a few weeks, her speed went up a bit...but she also suffered from a constant aching in her shoulder. Miraculously, when she stopped working out with the weighted ball, the pain went away.
For whatever my opinion is worth, I would stay away from the weighted ball at any age. I would recommend focusing on long toss when they are older, maybe 13 or 14, and work on overall strength and fitness for high school aged kids, (calisthenics, body weight squats, rowing motions using bands etc.)