It's like Sam said, but I'd like to flesh it out a bit.

As a universal fix that should work in any situation, you can load a primitive, place it where you want the axis of rotation to be, hide it,  parent the figure to it (from the menu bar; Figure > Set Figure Parent), then rotate the primitive.

The other way is to impilment the rotation in the BODY, but this requires a particular method of working. Here is what I do. When I translate the figure in X or Z I always translate the BODY, not the hip. When I translate the figure in Y I use the hip. When I want to spin the whole figure around a vertical axis I use the BODY's yRotate, for any other rotations I use rotations of the hip.

When you use this method you will always be able to spin the figure around the vertical axis of the BODY (world up). If you were to translate the figure in X and Z by translating the hip, when you came to yRotate the BODY the figure would orbit rather than spin. I know this sounds very complicated, and I'm probably not explaining it very well, but with practice it becomes second nature.

One problem is that the BODY actor is invisible, and this makes it hard to visualise what is happening. As an exercise, load a Poser Box primitive, load another Box, place it on top of the first and parent it to the box below. You can think of box_1 as the BODY and box_2 as the hip (that has been y translated 0.100 Poser Units). Experiment with diffrent ways of translating and rotating the "BODY" and "hip" substitutes.

The most important point to note is that the hip can be moved away from the BODY, but when the BODY moves the hip always follows. Also note that poser does not save pose data for the body when you save a pose.