BackgroundDiagnostic imaging for low back pain (LBP) without any indication of a serious underlying cause does not improve patient outcomes. However, there is still overuse of imaging, especially at emergency departments (EDs). Although evidence-based guidelines for LBP and radicular pain management exist, a protocol for use at the ED in the Belgian University Hospitals Leuven was not available, resulting in high practice variation. The present paper aims to describe the process from protocol development to the iterative implementation approach and explore how it has influenced practice.MethodsIn accordance with a modified ‘knowledge-to-action’ framework, five steps took place within the iterative bottom-up implementation process: (1) identification of the situation that requires the implementation of evidence based recommendations, (2) context analysis, (3) development of an implementation plan, (4) evaluation and (5) sustainability of the implemented practice recommendations. Two potential barriers were identified: the high turnover of attending specialists at the ED and patients’ and general practicioners’ expectations that might overrule the protocol. These were tackled by educational sessions for staff, patient brochures, an information campaign and symposium for general practitioners.ResultsThe rate of imaging of the lumbar spine decreased from over 25% of patients to 15.0%–16.4% for CT scans and 19.0%–21.8% for X-rays after implementation, but started to fluctuate again after 3 years. After introducing a compulsory e-learning before rotation and catchy posters in the ED staff rooms, rates decreased to 14.0%–14.6% for CT scan use and 12.7–13.5% for X-ray use.ConclusionsImplementation of a new protocol in a tertiary hospital ED with high turn over of rotating trainees is a challenge and requires ongoing efforts to ensure sustainability. Rates of imaging represent an indirect though useful indicator. We have demonstrated that it is possible to implement a protocol that includes demedicalisation in an ED environment and to observe changes in indicator results.