The purpose of this study is to determine the validity of using a 2D marker-based video tracking system and a markerless 3D system, based on the fundamentals of geometry and stereoscopic images, when compared with the gold standard, 3D motion capture. Several measures will be calculated using the 3D motion capture system. Results from the two other tracking methods will be compared to those of the gold standard to determine the validity of the new systems. This method could allow for more widely and clinically accessible data collection methods to be used to gather kinematic movement data. These techniques could then be used during rehabilitation, gait and injury risk assessments, and preventative care efforts driven by movement evaluation.