If by "hinge" you mean some
hard material like a metal door hinge, then absolutely not.
If by "hinge" you mean a piece of bumper fabric or other
soft material attached to your bumper so that it will be in the corner area, then it is approved as the rules are written the way I understand it being on a team which has used Bumpers in many of the years past to FIRST Standard Bumper Specs..
See this post:
http://www.chiefdelphi.com/forums/sh...8&postcount=19
Ignore the other stuff in that post, or read it if you want, but focus on the quotes from image shown in the manual.