Quantifying the individuality of knee kinematics during running gait.

The purpose of this study was to quantify the individuality of knee kinematics during running by examining the level of similarity between closely matched runners. Our results suggest that it becomes easier to identify similar runners as the size of a candidate pool increases; however, there is a limit to the similarity between closely matched runners, suggesting that running gait can be considered a unique trait which has implications for research design.