Objective - Physiotherapy extended scope practitioner (ESP) roles are widely utilized in the management of musculoskeletal conditions. The present article reviews the current literature, with particular emphasis on the decision-making process, patient/clinician interaction and clinical outcomes. Methods - A systematic review of musculoskeletal extended scope practice was carried out. The review focused on the outcome of interventions, and the interactions and decision-making processes between ESPs and their patients. A wide search strategy was employed, through multiple databases, grey literature and experts in the field. Qualitative and quantitative studies alike were included and a mixed-methods synthesis approach was undertaken in analysing the findings of included studies. Results - A total of 476 articles were identified for inclusion, 25 of which (22 quantitative and three qualitative) meeting the criteria for full quality appraisal and synthesis. It was not possible to conduct a meta-analysis owing to data heterogeneity. The results showed high patient satisfaction with the ESP role, support for ESP staff listing patients for orthopaedic surgery, a high positive correlation of decision making between ESPs and orthopaedic surgeons and evidence of a positive impact on patient outcomes. Qualitative themes reflected the importance of ESP clinical decision making and interpersonal skills and their role in patient education. Conclusions - There is broad support for the physiotherapy ESP role and evidence of favourable outcomes from ESP intervention. Clinical decisions made by ESPs correlate well with those of medical colleagues, although there is a lack of detail explaining the ESP decision-making process itself and the influences and mechanisms by which this occurs.