When I was 12 I ended up in a full leg cast. Finally one day when the parents were in town I couldn't take it anymore so I got on my motorcycle and went for a ride. It really wasn't going too bad until I clipped the neighbor's 4x4 mailbox post with the cast. Busted it good. Worse, I dislodged the two pins in my knee so I had blood seeping out around the foot area. I raced back to the house and tried to clean it off and wrap it with trainer's tape. But I couldn't get the blood out of the soft rolled part on my foot...so I knew I was busted. Strange thing was when the doctor removed the cast he noticed the holes were the pins were put in were infected and the skin becoming necrotic. Probably would have turned into a real problem if I hadn't busted the cast and they got a look at it.
I only mention it because riding with a cast can turn out to be a good thing. Just saying.
On the other hand, your picture sort of reminds me of therapy they do for people in the looney bin.