One of the few Full-Time Specialists in Sport and Exercise Medicine in the UK, Dr Crosby took his first Degree in Human Physiology at University College, Oxford and then read Clinical Medicine at St Mary's Hospital, Medical School, London. He trained in Orthopaedic Surgery and set up several Sports Injury Clinics in London and the South East before moving into Full-Time Sports Medicine in 1989.
He was the Founder of the Eastern Region of the British Association of Sport and Exercise Medicine (BASEM) and one of the original Founders of the United Kingdom Association of Doctors in Sport (UKADIS). He is a Fellow of The Royal Society of Medicine and Past President of the Section of Sport and Exercise Medicine there.
He was elected to a Foundation Fellowship of the new Faculties of Sport and Exercise Medicine in both the UK and Ireland and he was a Specialist Appraiser for the UK Faculty.
He has been a Director on the Executive Board of The Institute of Sport and Exercise Medicine (ISEM) for over ten years and is currently its Treasurer. He is Visiting Lecturer in Sports Medicine at The Postgraduate Medical School of the University of Hertfordshire and lectures extensively in the field to Medical. Paramedical, Student, Coaching and Athletic/Sporting Bodies in the UK and abroad.
He has been Staff Tutor for The National Coaching Foundation (NCF) and a Lecturer in Anatomy of Motion and Exercise Physiology for the Physical Exercise Association of Great Britain (PEA).
He was the first Medically Qualified Independent Sampling Officer for the Doping Control Unit of the then Sports Council of Great Britain (SCGB) and was Sports Medicine Consultant for the Central Council for Physical Recreation (CCPR) where he drafted the medical aspects for their seminal Report "A Charter for School Sport" which was so influential in shaping Government thinking about the place of Physical Activity in the National Curriculum.
He is, or has been, Sports Medicine Advisor to several companies, Gyms, Clubs and other bodies including London Weekend Television (where he oversaw the medical aspects of the popular "Gladiators" series.), Hertfordshire Fire and Rescue Service, Luton Marathon, Middlesex RFC, Belsize Park RFC, Relaxion PLC, Munich Re Insurance, The Beazley Group and Talbot PLC. He was also appointed by the Football Association (FA) to supervise the Sports Medicine Insurance Services for the England Squad during the 2010 World Cup.
Publications include the Sports Medicine Chapter in the Royal College of Physicians' " Current Themes in Rheumatology Care", the Project Manual for the General Practice Exercise Referral Scheme and he is a contributing author to the "BMA Guide to Sports Injuries".
He has a long-standing interest in Spa Medicine and was Co-Founder and Secretary of the British Association of Thermal Therapy (BATH) and was a Member of the Medical Advisory Board of the International Spa Association (ISPA) and for the Bath Spa Millennium Project. He was Medical l Director of the prestigious Champneys Group for over 20 years and is currently a Member of the Medical Advisory Board at Grayshott Spa in Surrey.