I used to have debilitating RSI when typing. I tried everything and it just got worse over time. Stretches. Typing a certain way. Taking breaks etc. My wrist would become locked after 10 minutes of typing and stay that way for the rest of the day.
I then read a book claiming that all pain is just based on expectation, so if you think it'll be painful it'll be painful, and get worse overtime as the expectation reinforces.
Quite literally within the space of 5 minutes, it all went away. All gone. That was around 8 years ago and I've not had it since. Doesn't matter how long I type, in what position etc. Doesn't affect me at all.
As per Acceptance and Commitment therapy (not the book, something I discovered much later) this can be defined as "the solution is the problem". When you focus on the solution, it defines itself as the problem and it simply becomes worse (think for example, someone who's overweight so eats to make themselves feel better, thereby becoming more overweight and the cycle repeating itself etc.)
Interestingly, the only time my wrist gets sore is when I get really stressed. So I think there's some merit to it being a response from the brain.
I think a large part of it has to do with the eastern idea of letting go. The basic idea is that suffering is a result of holding on too tightly, as opposed to observing intently. Once you observe, the suffering goes away.