My kid (now 18) broke his right radius and ulna wrestling Jan 3 last year and was able to keep in shape enough to ride at the Desert 100 (first of April) last year and the doc had already cleared him to start freestyle wrestling 3 weeks earlier. It was only the poker ride portion but he and his friend kept me from passing them the whole time (doesn't say anything about my ability though
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His doc told us after it was plated he could start rehabbing the muscles as soon as he fealt ready because the bones weren't going to move because of the plates and screws, just not to get too crazy.
My non-professional opinion would be to work on regaining flexibility. (I did the same thing with my tibia and fibula). Use the hand exercisers to work on keeping your hand clenched. Also clench your hand (with the hand exersizer) and rotate your wrist up and down. Sorry I have a mental block as to "hand exerciser" you know, the hand-grip things with the spring that helps keep them open? I bought a nice one cheap that had a dial to adjust the tension at the local variety store.
You can do this, just don't damage the plates/bones/screws as they heal together. The big part is to keep the muscles that will protect your forearm in shape.
To make you feel better here's a picture of his (4 brakes in all)....
by the way, sorry to hear of the accident