with a torn ACL you dont need to walk with crutches....but that is about all the leneancy you get. Anything else and you risk putting more strain on your PCL....which is the other one in the middle of your knee. That one pops too.....you are gonna be stuck wherever it happened until someone carries you back....Even if you try to hop on one foot...just the bouncing of a disconnected knee is gonna hurt like you wouldn't believe.