Yep - that's what I imagined. You might try adding a *lot* of litter to the floor to cushion the landing, or it it was me I'd block off the rafters with plastic netting so they can't get up there (if you don't have too many chickens to comfortably roost on the lower bar to the left).
It looks from the picture that they can't fly down to easily due to limited space, so they might just be kinda jumping down from a pretty big height which is hurting their legs. Also looks like a concrete floor with very little litter...hard landing there too.
In our old coop they'd roost about 4 feet up but there was *very* limited space to get down...they would have to hop on two other bars to get to the ground, otherwise they'd hit the nest boxes. I watched them several times and they had a lot of trouble hitting the other bars coming down...sometimes slipping, sometimes just going for it and hitting the nest boxes. One of my buff orpingtons got fed up with the whole process and would wait on the top bar for me each morning...would walk over to me when I opened the door, and let me put her down by hand...pretty funny.
