Abdominal Flexibility?

Mine is just terrible.

The only thing I can think of doing are bridges, but because of my shoulder, I can't get in to one. I can hold one with one arm, but I can't push up in to one.

Halp? I don't know any exercises or so.

What about cobra variations, Backwards bending, Rotational exercises? Think they work pretty well

The only one I know of those is the back bending o.o

I'm imagining that cobra thing is a chest roll? I don't really feel it even if I grab onto my legs and pull. :/ Unless you mean the thing that looks like a seal. Again, I don't feel that so well either.