Dr Muir has been qualified as a doctor since 1983. His specialist anaesthesia training was completed in 1994 and included work in the Anaesthesia Departments of Leicester, Oxford, St. Vincent's Hospital Melbourne and Royal Childrens and Woman's hospitals. In 1998 Dr Muir returned to Melbourne to establish the Barbara Walker Center for Pain Management, a multidisciplinary pain clinic based at St. Vincents's Hospital. He remained Director of the unit until 2008. Later in 1998 he was appointed Clinical Director of the Geelong Hospital Pain Clinic.Dr Muir is in full time Pain Management practice both in private and in the public hospital system. His interests are in the use of interventional techniques in the control of chronic noncancer pain as well as the role of multidisciplinary program based techniques. Dr Muir's practice also includes a medicolegal component through his involvement with the Melbourne Pain Group. He has continuing responsibility for Registrar teaching through his involvement with the ANZCA teaching program for Anaesthetists preparing for Primary and Final Fellowship examinations between 1998 and 2009, and as Supervisor of Training at the Barbara Walker Centre for Pain Management.