Back step ?

[Comp]

10U travel ball, prior to our games, the ump confirmed the step-back is legal. A pitcher’s feet are set whenever her hands come together. Of course, most pitchers kept both feet on the rubber; however, a few used the step-back (quasi Superman pitch) without any problems.

I would have to double check the USA rule, but under NFHS, no the feet are not set once the hands come together. Under NFHS rules the pitcher can step back at anytime up until the start of the pitch, which is when the hands separate.