Dvorak solved this for me permanently.
Dvorak optimizes alternating hands (ever felt dumb typing "street" or "states" in Qwerty?), useful keys on the home row (aoeuidhtns VS asdfghjkl;), typing inwards (try tapping your fingers in rapid succession inwards on your desk. Now try outwards or in a random order...) and typing with the strong fingers (The farther from the pinky the better) and the right hand (usually the strongest one), among other things.
Those features reduce stress injury because they result in less finger movement and more natural dynamics.