How to perform it

Stand side-on to a solid wall, about an arm's length plus the ball away.
Hold the ball at chest height, arms relaxed, weight slightly on the back foot.
Turn the back hip through first, then let the trunk and arms follow — the ball is the last thing to move.
Throw as hard as you can, catch or pick up the rebound, and reset before the next rep.

Common mistakes

Skip or adapt this movement if any of these apply — and check with a professional when in doubt.