Actually, a friend of mine messed up his shoulder from a similar repetitive motion. Tbh, he fixed it by switching which hand he used for lighter parts of the job.

You mentioned regional passes and flexible dates cutting costs in half. What was the biggest sign you were looking at the wrong passes before? Like, were you only seeing the big cross-country tickets and missing the local networks, or was it more about not knowing how to book the flexible days? I've seen some passes that look cheap but then lock you into specific trains.