Novice runners have a high risk of running-related injury. Likewise, runners that change footwear or running technique may experience injury during their transition. With no consistent risk factors currently identified to predict injury, what may be more important is to understand the individual-specific characteristics that enable one runner to adapt successfully while another gets seriously injured. This project involves examining intra-individual variability patterns, which represent underlying gait strategies, in order to explain injury and performance blockers with respect to running.