Many physical therapists embrace ultrasound (US) imaging as a means to deliver precise and personalised rehabilitation. Since the first published use of US by physical therapists (1980),1–5 there have been three notable milestones in the evolution of US use by physical therapists; a series of commentaries6–8 and original research published after the first International Symposium on Rehabilitative Ultrasound Imaging (RUSI; hosted by the US Army-Baylor University Doctoral Programme in Physical Therapy, Fort Sam Houston, Texas, 2006),9 a networking session at the International Federation of Orthopaedic Manipulative Physical Therapists conference (Quebec City, Canada, 2012),10 and a second (although not affiliated) international symposium hosted by the Universidad Francisco de Vitoria and the Spanish Society of Ultrasound in Physiotherapy (Madrid, Spain, 2016).11 Despite these efforts, there remains considerable confusion and inconsistencies in terminology associated with physical therapist use of US due, in part, to the diversity of manners in which US is used across the profession. It is also clear that previously identified gaps related to scope of practice (a statement describing physical therapy within the context of the regulatory environment and the evidence base for practice within a jurisdiction. Scopes of practices are dynamic and evolving in accordance with changes in the evidence base, policy and needs of service users)12 and specialised training are growing.
At the time of the 2006 symposium, the majority of reported uses of US by physical therapists involved the evaluation of muscle structure (morphology) and function, or as a source of biofeedback to aid rehabilitation of neuromuscular control. The term RUSI was coined to encompass these applications, and along with a definition (see below) an accompanying visual representation (figure 1) of how the practice of RUSI fits into the larger field of medical US was developed.