Structural family therapy was developed by Salvador Minuchin at the Philadelphia Child Guidance Clinic. It is based on systems theory and focuses on structural change as the main goal of therapy. The therapist takes an active role in restructuring the family. Structural family therapy addresses problematic patterns of interaction within families. It uses techniques like joining, reframing, and enactment to restructure the family system and make interactions more flexible. The goal is to establish clear boundaries between subsystems like parents and children.