Basketball is a sport that involves multiple impacts with the ground through a variety of moves such as running Jumping, and cutting. Repetitive impacts have been associated with stress-related injuries in other sports such as running. The purpose of this investigation was to gain an understanding of the typical stresses the body experiences during common basketball moves. To this end, the ground reaction forces from 24 players from five professional basketball teams were studied. In addition, a game analysis was performed to determine the frequency of selected moves. These data indicated that certain common movements, such as jump landings and shuffling, resulted in absolute and relative forces much greater than many of those reported previously in studies of other sports. These movements were also identified in a companion paper as being associated with large angular excursions and velocities. Findings are discussed with respect to injury risks, and suggestions for future study are made.