Scapular movement in Dinos

[NANNOTYRAN@aol.com]

  Is there any decent argument against scapular rotation in quadrepedal
dinosaurs?  GSP illustrates his dinosaur skeletons showing a fore-and -aft
motion of the scapula, presumably to give the animal extra push in it's back
stride.  He mentions that the corocoid would "slide" up and down a
cartilaginous sternum that would make this theory possible.  As an animator,
this is a wonderful thing to work with, but with the upmost respect for
dinosaur science, I don't want to accept this explanation without some other
viewpoints to ponder.  I see plenty of arguments for a moving scapula, the
muscles all appear to attach that would indicate such a motion, but I'm a
little hard up for evidence against it.  A number of computer animation tests
that show a 10-15 degree of movement work wonderfully with the limb
proportions and trackway evidence.
 Do the books say scapulas move to sell copies, or is it a valid argument?