How to pole vault<br>Select the height of the bar for your vault. For your first few vaults, you should remove the bar completely to give you the most space to learn the movements of vaulting. For your next few jumps, try using a bungee cord to approximate the feeling of a pole.
It's ok to use a trampoline in this exercise
The context does not mention a trampoline, so we can not be certain that a trampoline can or can't be used, at least not based on this context, alone. The system may have gotten thought this incorrect, because there was no mention of a trampoline. 
( z1 okay :ARG1 ( z2 use :ARG1 ( z3 trampoline ) :ARG2 ( z4 exercise :mod ( z5 this ) ) ) )