I'm currently in college, and I live real close to a couple good mountains, but my younger brothers are practicing at home on a backyard setup. They recently just picked up a pre-drilled and already tuned/sharpened head oblivion 177 for like $100 to use in the backyard. One of them fell off the rail and the ski hit his wrist, he didn't think anything of it.
20 minutes later he could see the ligament of his wrist. Park season is practically ruined for him, if he lands on his wrist, he's fucked.
Get your skis detuned and don't catch edges, plus, they won't slice through your skin.