It certainly never hurts to have some plan so you have a structured approach to completing your task while avoid unnecessary work. However, I have never used this to compensate for my wrists getting sour. If you write your plans down instead of typing them up you may still have to do the typing later possibly resulting in having to do more work instead of less.
I guess the best advice would be to try lots of different things.
You could use a large gym ball instead of an office chair. Or you could plan your day so that maybe you can throw in a white board session half way through. Or play darts or foosball (table soccer) or other short games that get you moving.
Alternatively, try pair programming and take turns on the keyboard and mouse. As the "navigator" you would then still keep a piece of paper and a pencil within reach.
Yet another option would be trying to use refactoring and other tools that replace or even speed up typing.
For me practicing my piano playing strengthens my fingers, improves typing speed, accuracy and also provides distraction for both my fingers and my mind.
Maybe it would make sense to have an experienced person you trust to observe you and see whether they can give you some suggestions for how to work differently?