no... moving the 'body' does not add translations to the hip...everything in the figure remains the same as before, you are just moving the entire animation in world space... .bvh animations arent fully compatable with poser because in poser the 'root' of the figure is the 'body' actor whereas with .bvh files the root is the 'hip' actor ...

 there are all kinds of bugaboos to using .bvh files in poser(even  those exported from poser) because of the root issue, once the hip leaves the 'body' circle, hip joint rotations dont behave as they did before and making adjustments can be difficult to say the least, this is because the hip rotational centers are left behind in the body circle ,so the further you get from the center the more erratic these rotations become.... im not saying its impossible to mix motion files files in poser, just that its no simple task ,it takes lots of patience and practice...

:O)

Y'all have a great day.