For what it’s worth, I switched from a mouse to a Logitech M570 Trackball, the not-so-popular device that is guided with the thumb, not the fingers like the Trackman.  Anyway, that was about ten years ago and haven’t had any issues since.  This product has never taken off in the market so I keep a spare in case they drop it.

That, and the Microsoft split keyboard, (the 4000).

The Herman Miller chair with the “waterfall design” seat which improves leg circulation by sloping forward under the thighs … solved the problem of my legs cramping or going to sleep.

Three monitors helps too.  Less switching between apps.

Sam