Next time you're out for a rip make a mental note and take notice how hard you "are" hanging on. You'll be surprise how many of us hang on way to tight. Your hands should almost float on the grips.
Mostly true.
I guarantee when your in what you subconsciencly feel is "tough stuff" you've gone into the mode of gripping the bars tightly and your whole upper body is tensed up. IMO, it's no coincidence that "get offs" happen when your riding in just this mode.... well, not always. But after a "get off" and remounting, I often feel I was riding tensed up and not letting the bike work under my upper body.
Think of the connection between the bike and you ... your upper half, via your hands and your lower half, thru your legs ( 'cause your feet can't grip). The easier the riding ... the more your input into the bike is thru your hands. ( I fact you can just "sit" there and hand steer).But quickly, the more technical the terrain becomes, the more lower body input becomes important. Gripping the bike at times .... and just as importantly, a times releasing the leg grip and weight biasing one peg or the other.
Might
sound dumb but it's true. And I think good riders simply have a built-in instinct to do this and us lessers have to constantly remind ourselves of it.
When I raced, the times when I didn't "feel right"... was riding crappy .... and it was me, not a bike issue, I'd tell myself, "Relax, loosen up, reset your brain". Things improved.
Sometime a section just gets so gnarly or when something happens and you were on the "hairy edge", you cannot avoid tensing up. It happens, so just ASAP, get over it and "reset" yourself.
Tension causes pain and not necessarily limited to the wrists. I'm way out of shape now and even so, I recently did an adventure ride in the desert for three consecutive days, about 100 miles each, with no resulting wrist pain. The pace was often spirited but never race speeds, so no real tension and so no pain.
Ooops, last thing occurred to me. You are standing up while you ride the hairy stuff right?

Dave