The straighter you can keep your wrist, the better. Repetitive motion disorders (carpal tunnel syndrome is one) are caused by...um, repetitive motion. And even if you don't move your wrist a lot, keeping it bent under stress for long periods can cause it. So keep your wrist straight. If you're rotating it so your pinkie-finger side is closer to the fingerboard, and you think that's the problem, try moving the head end out to the side a little more. Those wrist braces do little more than remind you to pay attention to movement. If people rely on them, they can do more harm than good, because they give a false sense of security and in the long run, can lead to other problems.