First thing first: for many children with complex medical diagnosis, medical stability should be established before developmental therapies can be used effectively. This often means that the child needs to have the best possible physiological state such as good seizure control, sufficient airway/respiratory support, adequate nutritional status, and finally least side-effects possible from medical management such as medications.

When optimal physiological stability is not possible, developmental therapies may take on the role of either prevention, such as positioning and handling so poor postures can be reduced to a minimum, or for maintenance of current functions for quality of life.