I was playing rhythm games on a keyboard, so basically button mashing. The real killer was that I was pushing myself beyond what I was actually able to play. There's a certain technique to button-based rhythm games, and once you aren't able to read what is happening on the screen any more you tend to naturally transition to just brute force button mashing with high force, which tends to be very straining. I believe this was the problem for me.

If I had been a bit more intelligent at how I was learning, and focused on improving reading skill instead of simply wanting to play whatever music I liked, I would have probably never had problems. Rhythm games in general boil down to training your brain to read moving patterns and convert them to scheduled movements in your body (but mostly your hands). Once you get to an intermediate level you get these "flow states" where you realize you were basically unconscious for most of the song, not a single thought, just internally observing your body's reactions to the screen. Almost a type of meditation.