Dr. Blomberg proposes that one of the reasons RMT works so well is that it provides the stimulation the brain missed in infancy and helps develop new neural connections for proper brain maturity. You can see from the study here that "brain connectivity" is often underdeveloped in children with Autism.
Dr. Blomberg has also done primary research on Rhythmic Movement in Sweden, though his current book is not translated to English yet. Interestingly, Dr. Blomberg first used RMT with his psychiatric patients, many of whom got well even from severe psychosis and protracted schizophrenia.
As we talked about on the phone RMT is also excellent for developing balance and posture. The article here shows the link between anxiety and balance challenges which are present in many children with Autism.