Biomechanical analysis of functional movement tests, such the drop jump, which requires certain level of neuromuscular and motor control, are currently used in sports to assess technique performance and prevent injuries. Concretely, a biomechanical evaluation of a drop jump test is widely used to prevent non-contact anterior cruciate ligament injuries (ACL) in sports. Mainly, the analysis consists on evaluating different biomechanical factors that have been reported to be related to the injury, such as dynamic knee valgus, and detect if this athlete is prone to have an injury or not. Three-dimensional kinematic measurements of human motion provide useful data for clinical practice and biomechanical research. Gait Analysis Laboratories determine the position of a set of reflective markers attached to the human body and use this information to obtain kinematic and dynamic information such as joint positions and velocities, joint angles, or joint torques and power. A large set of markers can be used in laboratory conditions. However, nowadays, new plug&play marker tracking solutions are available. These systems are easily transportable and allow obtaining data out of the laboratory setting; therefore, they are useful for clinical or sport environments. Since these devices are compact (the cameras are self-contained in a bar), the standard marker protocols cannot be used; i.e., some of the markers could not be detected since they can be covered by the subject itself. Moreover, in order to facilitate the work out of the laboratory environment, a reduced number of markers has to be used (and the kinematic and dynamic information obtained from them has to be as maxim as possible). The proposed work has two main objectives: the first one is to create a new marker protocol for studying the drop-jump motion, the second one is to quantify the influence of this protocol on the kinematic and dynamic results of the simulation compared with the results obtained using the standard one.
