It's going to cause temporary discomfort/strain that will heal fairly quickly, not a pain syndrome.
Running or weight lifting for hours and hours - far more stressful and repetitive than typing can ever be - doesn't cause injury, so why should typing? And what does "wrong muscles" mean?
I'm jumping in :biggrin:.
Now, lets consider this, if your knee hurts after running for a few hours, and you run anyways. Is this bad?
Let's then consider typing. Many people, need to type, in order to work (e.g. Programmer, typist, etc.). Now if there hands start hurting a little bit, they will notice.
Unfortunately, the work still needs to get done (or they'll get fired...). So the usual reaction is to just keep working.
Repeat for a few years.
Eventually, the small pain becomes manageable, and not really noticeable.
Unfortunately the pain is there for a reason, your body does not like something that you are doing (pinching nerves, wearing out cartilage, etc.).
The RSI occurs, once all the "safety" in your body wears out, and even a small amount of movement will cause agony (grinding of bones, cutting off of nerves). Something like this takes years of proper recovery to heal (often impossible to bring back to 100%).
Now lets jump to ergonomic keyboards.
Yes, some keyboards that are "ergonomic" are a steaming pile of dog crap. But that doesn't mean all of the are.
The general purpose of an ergonomic keyboard is to lead your body into a good typing position, without having to think about it too much.
For example, split keyboards angling your hands (you don't necessarily need to do this on a generic keyboard).
Another example, switch weight (ricercar prefers MX Browns for this reason, if I remember correctly). This has to do with the force required to actuate, and making sure not to bottom out the switch (tactility and/or sound is a very good mental queue for this).
Sure you can train yourself (as I do), to not bottom out on heavy and light linear switches, but that takes a lot of effort (months/years, not really worth it, unless you like life hacks).
Myself, I change the way I type so that I can type comfortably on the keyboard I am using. This can be switching to a standing desk style, to angle of my elbows, to the chair I'm using, to raising my wrists.
Yes this is a completely viable solution, but it takes conscious effort (mental cycles), that not everyone is willing to (or can) give to fixing their comfort while typing.
