Jay wrote: When you take off, you want the bottom arm to be straight correct?
Yes and no. The only reason you want it straight is so that your plant is as high as it can possibly be. AFTER your foot leaves the ground, there's no reason to keep your bottom arm straight.
Jay wrote: not pushing into the pole but rigid, right?
A rigid bottom arm isn't what's going to bend your pole. It's going to bend due to the force that you put into it thru your TOP arm (the force from your run and takeoff).
Jay wrote: Will it improve my vault a lot?
The higher your plant, the less angle the pole has to move thru to get to vertical. That will improve your vault ... a lot!
Jay wrote: it seems that my bottom arm is collapsing as soon as i take off.
That's OK. If you're straight-poling, that to be expected. Focus on getting a good JUMP off the ground, reaching as high as possible with BOTH hands as you jump (a high plant). At 10-0, you shouldn't be worrying too much about bending the pole ... or about your bottom arm collapsing becuz the pole isn't bending. Even if the pole IS bending, you shouldn't worry about your bottom arm collapsing.
You must learn to straight-pole correctly before you advance to flex-pole vaulting!
Jay wrote: If I'm a 10 foot vaulter how much higher do you think i can get purely on working on the bottom arm?
Just work on your run, pole drop, takeoff, and swing. Once these are done properly, the pole will start bending on its own without you applying any force with your bottom arm. This is especially true once you begin to raise your grip.
Jay wrote: sorry for the hard question
Not at all.
Kirk