Although functionality and disease classifications are available thanks to initiatives such as the "international classification of functioning, disability and health", the "systematized nomenclature of medicine - clinical terms" and the "international classification of diseases", a formal model of rehabilitation interventions has not been defined yet. This model can have a fundamental role in the design of computer-based decision support in rehabilitation. Some initiatives such as the "international classification of health interventions" are in development, but their scope is overly general to cope with the specificities that characterize rehabilitation. The aim of this work is to represent knowledge in order to carry out diagnosis and personalization of activities in cases of people with functional diversity. To define the diagnosis and activity personalization, a methodology has been developed to extract standardized concepts from clinical scales and the literature.