The mechanics of running have been studied for hundreds of years. With the increase in interest in running as a recreational activity in recent years, running-related injuries have become common. Hundreds of studies on the mechanics of running have been conducted over the past few decades. However, the relationship between the mechanics of running and injury is still not well understood. This article describes the evolution of the study of the mechanics of running, with a focus on their relationship to injury. A brief historical review is presented, followed by a summary of the era of descriptive research and, finally, an overview of the more recent generation of hypothesis-driven research. The article concludes with suggestions for future research that may lead to greater insight into the relationship between lower-extremity biomechanics and injury.