As I'm currently recovering from rotator cuff surgery, yes, I do know. Fortunately, my recovery has progressed (3 months) to the point where I can do most things except lift heavy things; still not sure about hand propping the plane, though.
I spent a good part of today practicing welding so I can build my new landing gear. It's frustrating; I'll run several inches of beautiful bead and think I'm finally getting it, then it all goes to hell and I have a great big ugly mess or snot or blow a hole in the piece. But the welds are holding when I beat them with a hammer, so there's that.