yeah, we have two bones in our forearms so we can twist ~180
the thinner one, the radius, is more prone to breaks than the thicker, "outer" one (that would be closest to your body when your arms are by your side palms forward)
similar things are present in the leg too, there is two bones there

the leg can't twist as much, and the bones in the foot and ankle give the lateral range of motion mostly
anyway, part of what causes problems with pain from computer use comes from the fact that you operate a computer with your forearm bones in a twist
