TRAK ontology: defining standard care for the rehabilitation of knee conditions

J Biomed Inform. 2013 Aug;46(4):615-25. doi: 10.1016/j.jbi.2013.04.009. Epub 2013 May 7.


In this paper we discuss the design and development of TRAK (Taxonomy for RehAbilitation of Knee conditions), an ontology that formally models information relevant for the rehabilitation of knee conditions. TRAK provides the framework that can be used to collect coded data in sufficient detail to support epidemiologic studies so that the most effective treatment components can be identified, new interventions developed and the quality of future randomized control trials improved to incorporate a control intervention that is well defined and reflects clinical practice. TRAK follows design principles recommended by the Open Biomedical Ontologies (OBO) Foundry. TRAK uses the Basic Formal Ontology (BFO) as the upper-level ontology and refers to other relevant ontologies such as Information Artifact Ontology (IAO), Ontology for General Medical Science (OGMS) and Phenotype And Trait Ontology (PATO). TRAK is orthogonal to other bio-ontologies and represents domain-specific knowledge about treatments and modalities used in rehabilitation of knee conditions. Definitions of typical exercises used as treatment modalities are supported with appropriate illustrations, which can be viewed in the OBO-Edit ontology editor. The vast majority of other classes in TRAK are cross-referenced to the Unified Medical Language System (UMLS) to facilitate future integration with other terminological sources. TRAK is implemented in OBO, a format widely used by the OBO community. TRAK is available for download from In addition, its public release can be accessed through BioPortal, where it can be browsed, searched and visualized.

Keywords: Knee; Ontology; Physiotherapy; Rehabilitation; Taxonomy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Knee Injuries / rehabilitation*
  • Vocabulary, Controlled*