Installing a trampoline on common property

Hi,

I am on the EC and been approached by a tenant asking to install  a trampoline on a strip of common property. I am not against the install, but am worried about (1) use of the trampoline by one tenant only (they will lock it when not using it), & (2) where does that leave the body corporate with regard to injuries or other insurance claims by users of the trampoline?

Many thanks for your thoughts

Terry