In the Emacs world, while remapping Caps Lock to Ctrl helps in reducing strain for many people, it also causes strain for some people. Every time, this discussion comes up in the Freenode #emacs channel, I have always noticed someone mentioning that remapping Caps Lock to behave like Ctrl caused them RSI.
Surprisingly, I did suffer from pain due to repetitive strain under the base of my forefinger once which seemed to be linked to overuse of mouse. The repetitive clicking, dragging and dropping in the Windows world nearly 10 years ago had taken a toll on my right hand forefinger. Taking inspiration from how we use keyboard with both hands, I then taught myself to use mouse with both hands (alternating between left hand and right hand every hour or so) and the pain gradually disappeared.
I also avoid using hjkl all the time and use the arrow keys to counter RSI.