To refresh the athletic trainer's knowledge of articular cartilage biomechanics, physiology, and structure and explore the role of glucosamine sulfate in treating articular cartilage pathologic conditions, including supplementation methods and clinical outcomes. We searched MEDLINE from 1989 through 2000 and SPORT Discus from 1975 through 2000 using the following key words: glucosamine sulfate, articular cartilage, osteoarthritis, and proteoglycans. Articular cartilage functions as a wear-resistant, smooth, nearly frictionless, load-bearing surface. Glucosamine sulfate can be thought of as a building block that helps restore the proteoglycan-rich extracellular matrix and thus balance articular cartilage catabolism and anabolism. Beneficial clinical effects of glucosamine sulfate in the osteoarthritic population have been documented. However, the use of glucosamine sulfate for athletic articular cartilage injuries is unproved. Clinical studies indicate that glucosamine sulfate has been shown to be a safe and relatively effective treatment for osteoarthritis. However, no evidence to date supports or refutes a carryover effect to the athletic population and the injuries that occur in sport.