So if all you got is some bumps or bruises, don't report it. They will use that against you.
Yep. Also, if they write you up, fuck the open door. Go to OSHA. Reporting an injury is a right protected under the Occupational Safety and Health Act, and disciplining you for doing so is considered illegal discrimination/retaliation by OSHA - unless they consistently write people up for the same rule in the absence of an injury.
A couple of years ago, I sustained a minor head injury w/ heavy bleeding and was told I'd receive a Step 1 for it. A day or two earlier, another associate got a splinter during a safety walk, and got written up. He complained to OSHA. I didn't get that Step 1, and I assume that he didn't get his either, because I can't see any other reason than his complaint that I didn't get written up because, even though I had a complaint ready, I never submitted it because my understanding is that the write-up has to actually happen before you can file a complaint about it.
OSHA Factsheet: Your rights as a whistleblower - PDF file
Filing a Complaint If you believe that your employer retaliated against you because you exercised your legal rights as an employee, contact OSHA as soon as possible because you must file your complaint within the legal time limits.