Getting on the side of the ball

My son does this as well, but he's only 12 and doesn't throw high 80s! I can't figure it out - it's his natural throwing motion, so don't really want to mess with it. I'm also worried about future possibility for injury, however, as it just seems like the torque, pitch after pitch, cannot be healthy........will be curious to see what others chime in with.

Many times this is due to fingers/hands being too small to properly grip/throw the ball. After many repetitions, muscle memory sets in.

One good way to learn proper rotation is to throw a hockey puck (short distance and little velocity). You can even isolate the grip/release by holding the tricep parallel to the ground and "throwing" using only the forearm and releasing the hockey puck.

Great idea, redbird -- now I'm off to the basement to locate our couple of old pucks!

The problem you describe is identified with solutions

Throwing Clinic

Another drill I've read of is similar to the hockey puck. Simply paint/magic marker a strip on a baseball and you will get immediate feedback. Remember that the stripe will not necessarily be straight up and down depending on arm slot.