It is impossible to pinpoint a mistake without seeing video of the attempt, but I can take a guess. You are likely passing the handle to your back arm, and allowing that arm to lock straight, which stops you from completing the spin within the rotation. Trampoline will help more than anything, but what you need to practice is keeping the handle close to your torso immediately after you pass the handle. The handle should come from around your back and travel close to your abs and back to your front hip for landing. The closer it stays, the better odds you have of taking it to a moby dick 540. Hope that makes sense.
|