You can give a thumbs up both ways...
Put your arms out at your sides and do it both ways and tell me which way will give you carpal tunnel syndrome.
But which way is more comfortable if you hold your hands closer to your face?
It just depends on how far your hands are from your face.
Closer to your face would be more comfortable with straight wrists. See now you've made it all complicated.
We have to take into consideration arm angle, wrist position, face position, height and width apart as well as thumb angle.
bd
db
d
b
b
d
Oh well, potato, potatoe, tomato, tomatoe and all that. Since it's Feechy's invention, he should be responsible for writing a usage guideline so everyone knows the difference between a Hillary Clinton, a Borat, a Super Dave Osborne and a John McCain.