Great movie, but why the horrible limp?

I was wondering that too. I think it may have been put in to confuse the audience, so they don't realise Jarrod is the killer until Sue discovers it. It also adds more suspense when he walks after Sue. If he was limping, she'd be able to get away easily. But he walks with great ease and would have no struggle chasing her.

I also think maybe Jarrod was trying to protect his identity, just in case somebody saw him (as Sue did). If the police were ever searching for the killer, they'd be looking for a man with facial burns and a noticeable limp. Jarrod doesn't match that description as he supposedly has no burns on his face, and he presumably can't even walk, let alone with a limp.

Or maybe it's to show how much time has passed since the events early on in the film? His legs have had time to properly heal. I don't know, I'm just coming up with theories. ^_^

It is possible that part of it is a matter of upper/lower body strength. Most of us don't think about our own weight when we walk but if we try to carry something/someone of any weight any distance we feel weighed down. So it's possible that though he had recovered from the accident at the start of the movie that the character of Jarod isn't quite as strong as he looks so the weight of another person does weigh him down a bit. And perhaps he's also supposed to have some residual breathing problems as well. Either the heated air searing his lungs or fumes from the melting wax or both so that he is weakened by prolonged exercise.

That made me wonder too. Either he faked the limp, and if so, why, you'd think when chasing the girl he'd have run as well as he could, or he had a real limp and made a quick and complete recovery. It was a confusing detail.