I notice you're not talking about back pain, so this really is about the angle of your wrists, which means the position, height and inclination of the grips.
Have you thought of North Road Bars, which give you at once elevation, setback of the handlebar grips (often a desirable solution in itself), and a true ergonomic angle of grip. It is true that you lose the multiple handle holds of drop bars or trekking bars, but how important that is depends on how successful the overall solution is: I've never missed multiple handholds since I went to North Road Bars, and now view multiple handholds as a kiudge for incompetently designed or implemented handlebars. The main thing about the right North Road bars, set up right, is that your hands fall naturally on them, zero contortions, zero opportunity to stress the joints. I'm a writer, a sort of handworker -- I operate a keyboard all day long -- and very sensitive to any stress in my hands and wrists, but it's been years since I noticed the handlebars on my bike except when someone else mentions handlebars, because I haven't felt any pain, nor discomfort even, since I switched from more overtly sporting bars to North Road bars.
