This low single rail drill helps gymnasts to understand how to cast to a handstand with straddled legs.  Beginning from a hollow prone support the gymnast moves down to a tight arch, and from there quickly snaps the hips up, aiming to bring the body weight on top of the arm support without letting the legs come down too much.  The straddle cast handstand action somehow mimics the regular straddle press handstand on the floor, but the feet and legs should not come dramatically down when the hips move up or the whole action becomes neutral and does not go up to a handstand.  The goal is to bring the piking hips on top of the support with the straddle legs also moving up.