Theia is a markerless motion tracking software that uses artificial intelligence to identify skeletal landmarks on the body. This software works in conjunction with synchronized video cameras to film the individual and process the data. We recommend Qualisys for its synchronization and data post-processing capabilities. Furthermore, Theia offers the flexibility to collect data from multiple subjects in their usual environments, such as a workplace or a sporting event, allowing for a much more realistic and accurate quantification of athlete or employee performance.