STEPHEN DORFF

The Backbeat star shot scenes in a working prison and the tense atmosphere onset led to over-enthusiastic fight scenes.

He explains, "I got hit a couple of times. The fights we had were so real and so frenetic and they weren't choreographed, so it was a melee of mixed martial arts and grappling, strength and power.

"We were all just basically knocking the c**p out of people. In doing that, I bumped heads a few times. I got a concussion a couple of times. My face swelled up a little bit and I had a big knot on my head.

"But I've got hurt in movies where I hadn't done anything, silly things like you're jumping off a car as it's moving at slow speed and you tweak your back."

Source: WENN