Problems with staying back is very commom with youth pitchers. Let’s talk about what staying back actually means because staying back can be interpreted in different ways. Staying back does NOT mean staying over the rubber and not moving down the mound. What it means is that the pitchers upper body must stay over the back leg/hip as he strides down the mound. If the pitchers weight is not over the back leg then the back leg cannot be used fully.
If your having problems with your pitchers staying back then try this: Instruct the pitcher to, right about at hand break, to take his front hip and glove arm out and up towards the sky or out and up over the catchers head. This will create a slight tilt with the hips and the shoulders so that the front hip and shoulder are slightly higher than the rear hip and shoulder. You can also instruct the pitcher to show the bottom of his spikes or cleats to the catcher which will create some tilt as well. This will automatically shift the upper body back over the back leg. Once the pitcher is ready to rotate into landing, then the rear hip and shoulder will start to level out and then begin titling forward in an angle aligned with the slope of the mound. The back foot is responsible for getting the rear hip elevated above the front hip as the front foot touches down and the glove arm elbow and shoulder pull down and to the side of the front hip to create forward tilt with the upper body.
Ryan