Pat,
I too have the book on Feeding and swallowing disorders in infancy.
Tongue thrusting may not be the correct word, but how else do you
describe a baby whose tongue is correctly positioned then back and up
then positioned well again and so on?  Tongue thrusting seemed to me
to be what it was doing?  I do get your point though.
Val, Busselton, Western Australia
RN RM IBCLC