I think the best thing you can do is resistance training exercise. Also going from a wide keyboard (full size Apple keyboard with number pad) to a narrow keyboard (narrow Apple Keyboard no number pad) worked for me. For a while I was doing the exercise in the video below and it helped me but I think just regular weight training can do wonders. I mostly just do shoulder, back, arms, and chest exercises and still haven’t had the pain I used to have. Hope you find something that works for you!