if you will throw your back out when you fall
Why? thats bullshit.
Its like when your little and you play with legos and come up with your dream house with a sick ass fort and trapdoors. When I'm older and have a house I'm going to have an olympic trampoline sunk into the ground surrounded by mats and I'm going to have some jibs and and bomb drops off my roof. Its gonna be sicknasty.
Never even bulid them when you die