A trial is a single motion capture recording, typically lasting from three to twenty seconds, during which the subject may perform an action or stand in a static pose while the motion measurement system generates 3D coordinates from specific locations on, or associated with, the subject.  During the 3D data collection additional analog sensors such as force plates, electromyography systems, and accelerometers, generate detailed information related to the subject that must be synchronized temporally with the 3D data samples that record the sampled 3D locations.  A typical motion collection session consists of multiple trials recorded under identical conditions.