This paper describes the use of diagrammatic exploration to facilitate the transition from observational to interventional stages of a PhD study, and its potential to support collaborative work between design researchers and healthcare staff. The translation of ethnographic notes into diagrams of people, place, process and relationships enhanced the researcher’s understanding of the healthcare context, made their assumptions explicit and highlighted the emergent research questions. The discussion and development of these diagrams with healthcare staff enabled a co-critique of the current rehabilitation model and gave staff experience in participatory methods in anticipation of future design interventions. The origination, presentation and co-development of these diagrams is discussed, with examples given.