There are a lot of "what worked for me in here" and that's great, but I want to stress that people need to consider seeing a physician, and possibly an OTR/L several times. The anatomy of your arms are more complicated than you think and any number of issues can cause pain, weakness, tingling or numbness. These people work with these issues 40+ hours a week and are more equipped to target and fix the issue sooner than you are on your own.
Sometimes it's just one lifestyle choice you need to change to improve your health (e.g. posture), but for some people it's more complicated than that. Everyone's physiology is just a little bit different and responds differently to different treatments.
Primary care physicians are often switchboard operators - they hook you up with potential resources or referrals that may lead to a solution. The chances that any given PCP is going to know a lot about RSI is pretty small, they have literally the entire spectrum of human health to consider, not to mention the looming issues of obesity, heart disease, cancer, and other more damaging syndromes.
Personally, I found wrist pain to be of multifactorial origin: too much typing, driving, playing piano, not enough cardio, strength training, and relaxation vs. stress.
This is true, and I certainly don't blame PCPs for not being up to date on the specifics of low-frequency disorders like RSI.
But my frustration is that even the 'switchboard' component of PCPs seems to be broken on this topic - across several musculoskeletal issues, I've only ever gotten recommendations to surgeons (who then said "you're not sick enough yet"). PCPs didn't even know what kind of specialist to suggest for finding causes and reducing pain, and the internet wasn't much better.
At risk of saying "what worked for me", talking to a physical therapist was a huge help with each problem - they didn't have cures, but their education was much more relevant to saying "here are some common risk factors and pain reducers you could look into".
And yes - 'multifactorial' seems like the usual answer, so I'm not surprised everyone has a different fix.
I have the same experience. Doctors and physiotherapists were of no help to me - they had no experience with RSI. In the end I found my own solution that worked:
Absolutely, but in the complete opposite direction, don't give up looking for answers.
The quality of people you see, and their willingness to look for answers, will vary DRAMATICALLY. There is joke, what do you call the person who finished last in medicine? Doctor.
If no one is finding an answer to your problem, dedicated research yourself is liable to be a LOT more effective than ten minutes with a trained professional who is not that interested or willing to do any real research.
There are a whole range of issues where PCPs tend to be very poor support. In particular, disorders which are not life threatening, have no clearcut sign or single 'cure', and don't have an obvious class of specialists to handle them. As someone else said here, PCPs are 'switchboard operators' - but these issues are rare requests with no obvious person to forward you to. It's not especially their fault, this is how triage works, but it means "go ask your doctor" has an unusually low success rate.
Joint and chronic pain definitely count, as do lots of intestinal issues, unclear-cause headaches, and so on. Maybe you need a surgeon, or else a physical therapist; maybe a nutritionist, or else an allergist; maybe a neurologist, or else a psychiatrist. These sorts of problems seem to require a willingness to try many things, talk to a bunch of different people, and potentially push back on a doctor who's only recommending one path.
Sometimes it's just one lifestyle choice you need to change to improve your health (e.g. posture), but for some people it's more complicated than that. Everyone's physiology is just a little bit different and responds differently to different treatments.