Don't use the motion tab unless you need an exact value or scale.  I never do, I only use the two tools, "rotate" primarily and "move" secondary (I find the "universal manipulator" to be a little cramped and too easy to misclick).  First, I select the body part from the tree, so it and all its children are highlighted, the I slip off to the other side of the screen to find the right tool.  Once that is done, you should see either a sphere of red, blue, and green circles, or the move arrows of the same colors.  Each color refers to a direction and if you click on the colored line, you only manipulate the object along that axis.

I have used poser since Poser 4 and those silly dials for movement are what is keeping me from using it seriously now.