Julie's post really got me thinking!  I think it's good for all of us to challenge what we think is "correct" or "right" from time to time. 

The clearest feeling I've ever gotten for using "balanced" posture while riding comes from an exercise that Donna Snyder-Smith and Peggy Cummings use in their clinics.  One person, "the horse" gets down on all fours.  Another person, "the rider" sits lightly on their back, with a balanced head/shoulder/hip/ankle position, and then the horse is asked to go forward.  Peggy or Donna will ask "the horse" how easy it feels to move forward.  Then, the rider is asked to go behind the vertical, sitting on their pockets, in a "chair seat".  Again, the horse is asked to go forward.  Usually there are groans from "the horse".  When asked why, "the horse" will say there the rider's weight has shifted to their forehand, and they are almost unable to move.  (I know Bruce Weary will have a field day with this!)  Try this exercise, and see what you think.  There are lots of other things you can experiment with, too, like having the rider arch their back, tighten their back, slump forward, grip with their knees, the list goes on and on.  It's amazing what you will feel being "the horse".  
 

Naomi Preston

www.TTeamforendurance.com