Participation in athletics at both the recreational and competitive levels has grown enormously over the last decade, and now involves a substantial segment of the population of many countries, particularly those in Europe and North America. This change in the life-style of many individuals has been accompanied by the desire and necessity on the part of physicians to define the consequences of chronic athletic training and competition to the participant. Coincident with the of public interest in sporting competition has been the evolution and growth development of new non-invasive...