Mr Crocker is a consultant neurosurgeon with a large NHS practice at St George's Hospital, London. He has a full general neurosurgery practice and subspecialist interests in spinal surgery and vascular neurosurgery. He is the chair of the regional spine MDT and holds clinical lead positions for metastatic spinal cord compression, undergraduate teaching and neurotrauma. He is the clinical lead for the regional neurosurgery unit. He trained in London in neurosurgery 2005-2012 and undertook a two year period of research into cerebral bloodflow and brain tumours 2008-2010 as the McKissock Lecturer at St George's University London. In 2011 he was awarded the Norman Dott Medal for the most outstanding performance in the FRCS (Neurosurgery) exams. He visited the Barrow Neurological Institute in 2012 as the Marjorie Newsome Travelling Fellow. He was appointed as a consultant to The Atkinson Morley Wing at St George's in 2012 and also has a private practice based at The Parkside Hospital, Wimbledon.