As the application of dynamic systems theory to motor behavior became evident in the scientific literature in the 1980’s and 1990’s, therapists began to adapt their explanations of intervention methods to incorporate the new theory. One therapist, Ingrid Tscharnuter, PT, DPT, not only studied in detail works of authors applying dynamic systems theory but also examined chaos theory and perception-action theory. Her integrative study of works by Bernstein, Thelen, Schoner, Scholz, Kelso, Jeka and James and Eleanor Gibson led Tscharnuter beyond applying new theories to old methods of intervention. Instead, she took a further step by creating a novel intervention approach synchronous with the new theories.
Training of therapists and making connections between theory and its clinical application became the focus of Tscharnuter’s work until her retirement in 2007. Participants in courses she taught generally concluded that the new approach was a significant departure from methods they were using previously and produced better outcomes for children with movement disorders.
The approach proposed by Tscharnuter has been advanced in multiple ways. Its foundation has been strengthened to emphasize the Neuronal Group Selection Theory and integrate it with dynamic systems and perception-action theories. Contributions to the literature have been made by Rahlin and Harbourne. Harbourne has completed a clinical trial strongly suggesting benefits of this approach over the home program approach commonly used in Early Intervention. Concepts of movement variability, complexity, and adaptability are now better understood in relation to this patient population, especially in light of new research in the area of neuroplasticity. The International Classification of Function (ICF) model with its emphasis on activity and participation is used in planning intervention.
As science moves forward and provides therapists with new information, the history of Perception-Action Approach will continue to evolve.