I did both parks in a leg cast but I was about 3 weeks post break so I was a little more hesitant in what I rode. There was nothing in Universal Studios that I did not ride. I did have to wait for a special car at the Mummy to ensure that it went back to the same side so that I would not have to do stairs, so if you can do stairs, this would not be an issue.
IoA, on the other hand was lacking in rides that I could do. I honestly only did Poseidon's, the Sinbad show, Spiderman, and the Cat in the Hat. The other rides were not acceptable for the cast or would get it wet and I couldn't put any weight on my leg, so it was too hard to get back up from the low rides