Physical medicine rehabilitation interventions for post-acute traumatic brain injury (TBI) are heterogeneous and subject to differences based on multi-disciplinary treatment plans . There is no universal knowledge representation (KR) model for TBI rehabilitation which impedes data collection, aggregation, computation, and sharing. This paper describes results of an analysis of the National Institute for Neurological Disorders and Stroke (NINDS) TBI 'Common Data Elements' (CDE) clinical data standardization set. We conducted this to understand current TBI rehabilitation KR and as a foundational step toward the creation of a domain ontology. A content coverage study was performed on the 'Treatment/Intervention' sub-set of CDEs. Results show that coverage of the CDEs is broad but lacks depth to represent the context of data collection in the TBI rehabilitation process. Next steps will be development of a KR model and identification and validation of domain concepts for a foundational ontology.