horse pulling back

["spencer" <spencer@inu.net>]

First of all thanks to all of those who sent me some great suggestions.
Update:  it appears the the trigger mechanism is pressure on the noseband!!
 The trainer last year discovered she was difficult to bridle when tied but
not when loose.  So he just had her loose for the bridling.  She is over
that and I can bridle her with the halter around her neck with almost never
a pull back now.  Have tried some of the suggestions from ridecamp.  FYI
inner tubes from bicycles are not strong enough but do have the elastic,
which didn't yet have any effect.  She will put her head down with poll
pressure and I can get her to trot out by pulling on the halter.  But if
there is pressure across the nose where the nose band for halter or english
bridle go, she pulls back.  Not as violently as a few months ago.  Maybe
some sheepskin on the nose band will help.  Asked my dressage instructor
about it.  She thinks some horses get 'high' (ie adrenaline rush) from the
'excitement of the pulling back!  Interesting.....Also, at her barn there
is older Thoroghbred gelding who cannot be tied AT ALL.  When he goes to
shows he HAS to have a stall!!   It appears there are many causes for the
pulling back and the specific cause needs to be figured out.  Then good
fashioned conditioning must be used with positive reinforcement.  Happy
trails, Mary Ann, Tx