Scott Caans arm

Interesting.

Apparently it is a real injury, but I can't get to the bottom of it.

I found an article that stated, "According to the show’s CBS publicist, Mr. Caan hurt his arm in real life while not working on the series so the injury was written into the show,” he wrote.

I saw fan speculation that it was injured due to a fall or that Scott had surgery on it, but nothing that was confirmed, only speculation by fans.

Looks like the kind of brace they give you when you have tendon or ligament surgery, like when pitchers rip their muscles off their bones from throwing too hard.