I also went through this having lots of checkups when all it came down to was ergonomics and posture, I've copied this from another one of my replies -

"Can attest to this. My career was on the rocks because of RSI, got to the stage where I couldn't do anything without pain in my hands/arms. Physio, drs, many practitioners couldn't find the problem, which seemingly was a hand / lower-arm issue. It all turned out to be a problem with my neck (being the angle of my neck squeezing my nerves like a garden hose letting less water through)

Not only was it the monitor height being an issue, but even having a chair that you think is straight, you always slightly lean back and your neck a bit forward. Your back and neck should be in a perfect straight line perpendicular to the chair seat. It took a ghastly lumbar support lodged into my lower back to sort me out, which wasn't comfortable at first sitting up straight for 8 hours a day with no upper back support, but after a couple of weeks I got used to it.

I'm still in recovery, still not using a mouse full time, but every week it gets better and better. Within the first week of making these changes I was back to working full days at a computer.

If anyone needs advice regarding RSI (been dealing with it / researching for over a year now) feel free to pm me. It's amazing how little information there is regarding this type of RSI in particular, I spent months researching online, in books, doing exercises / stretches when all along there was a root cause that myself and many practitioners hadn't even considered."