Although video-photogrammetry is the gold standard for human movement analysis, its complexity and high cost arouse interest in simpler and cheaper alternatives. One of them is videoanalysis, which allows analyzing movements in a plane. An alternative that allows the study of movements in 3D is the uaugmented reality markers (AR markers), widely used in the field of robotics. These systems allow to analyze, in real time and with a single video camera, the position and orientation of objects with sufficient precision for use in many biomechanical applications. This article analyzes the accuracy of ArUco markers in the measurement of angles and displacements, comparing the movements measured with the system with two precision techniques: encoders of linear and angular displacements and a standar equipment of videophotogrammetry . The results show that markers can measure displacements with errors lower than those associated with human variability, so it would be possible to use this type of markers in a wide variety of biomechanical applications.