More than 40 years ago, the Bobaths introduced a treatment concept for individuals with central nervous system impairment. The concept was developed from a therapist's clinical observations. A theoretical framework for the approach was based on the common belief in the 1940s that the nervous system functions in a hierarchy. Clinical aspects of the NDT approach have grown and changed during the past 40 years. This article details the original NDT concepts, notes common misconceptions, and looks at the concept with regard to newer theoretical frameworks of nervous system functioning.