I had RSI issues early in my career (not Emacs related), and learned some tricks that come handy with Emacs.

Your keyboard has two control keys. Use both of them. In particular, use the "opposite" one. If you want to press C-c, use the right Control key with your right hand. If you want to press C-l, use the left control key with your left hand. This way you're distributing the work with both hands and are not twisting your hands into weird shapes trying to get both buttons with one hand.

And also: Once you do this, no reason to insist on using your pinky to hit Control. I often use my thumb as well.

I never got the Emacs pinky.