Hop-hop.

At first, my back hurt terribly after using the machines, and I even skipped some sessions. Now, either I've gotten used to it, or my posture has actually improved a bit.
But yes, I have a lot of contraindications, but I don't move much, I eat a lot, and I'm very weak, so I still think going to the gym is a good idea, and I also feel better when I stretch or jump around.