Recovering from Injury, Recommended Upper Body Workouts

I injured myself almost three weeks ago during an extended walk. I had a patellar subluxation. I have been unable to walk as I have wanted to as I have been in a knee brace. I start rehab soon ( terrified to death as I do not handle pain well but that would be a whole other post !). I am currently doing alot of upper body work but I am terribly weak here. Are there any specific beginner programs that you would recommend to help me get the upper body into shape that I can do now? Just another question as well, if anyone had a patellar sublaxtion, how long were you immobilized so to speak and was rehab difficult? Thanks in advance!