Epidemiology originates from the Greek words "epi" meaning upon and "demos" meaning people. Hence, epidemiology is the study of what is "upon the people" or the analysis of the patterns of disease in a defined population. Epidemiological studies are important in defining "at-risk" patient populations so research can be directed toward these groups. It is important to understand that epidemiology does not determine causation. However, it is reasonable for clinicians (me) to opine on the reasons for these epidemiological trends. I believe that the major factors responsible for the changing incidence in shoulder stabilization are the use of the arthroscope and the surgical management of the first time dislocator.