I just did 3 pull-ups. I COULDN'T HELP IT!!! Walking underneath that pull-up bar dozens of times a day, without using it, was driving me crazy!!
I've been afraid of hurting my underarm incision by doing pull-ups, but also afraid of my muscles weakening if I DON'T do pull-ups...
So I figured just doing one third of my usual amount was a good compromise. (Uh, does that actually make any logical sense??) And my incision doesn't hurt at all. My shoulders hurt a bit, though, and my upper abs, which is odd - usually I don't feel anything in my abs while doing pull-ups.
Pull-ups are a poor substitute for trapeze, but it's better than nothing.