Occupational medicine is largely related to dealing with issues related to medical conditions experienced as a result of injuries on the job, and in many cases dealing with the fitness requirements for return to work.
Many people may not know that this is one of the largest areas of general medical practice in the world. It is also one of the most important, because workplace injuries and workplace medical issues are a continuous stream of cases. Millions of people around the world every year require therapy through occupational medicine.
Occupational medicine is a formal study in its own right, but it's also directly related to basic medical practice, and the early stages of occupational medicine training have a lot in common with the early stages of MD training. Anatomy, biology, physiology and related subjects are all part of occupational medicine training. At advanced levels, the psychological welfare and health of patients is also a primary area of practice.
Generally speaking occupational medicine is a clinical/private practice area of employment, although more complex types of employment, including areas related workers compensation and ongoing rehabilitation treatment may involve travel and on-site treatment for patients.
In a clinical environment, progression is naturally hierarchical. While some of these clinical practices do provide adequate career progression for some individuals, obviously there are only so many clinical positions available. Experienced occupational medicine physicians may decide to branch out outside the clinical system and open private practices.
Career progression in these cases, therefore, is very much based on development of one's own practice. Usually, occupational medicine physicians work in concert with local GPs to refer patients to them for treatment. In that sense of occupational medicine practices is very much a local medical practice, and career progression is pretty much defined by the requirements of that market. Many occupational medicine physicians in private practice are extremely successful, so much so that they actually have to employ other physicians and effectively start a clinic themselves.
If you're looking for a career in this field, qualification to entry level is comparatively easy, but you will need to research and explore career progression issues.