The dual flat-panel Walk-Through PET (WT-PET), recently proposed by the MEDISIP group at Ghent University, offers high throughput, simplified setup, reduced personnel workload, and higher spatial resolution compared to conventional cylindrical PET scanners. In the WT-PET, patients stand upright between two detector panels, which may lead to increased motion. Understanding motion patterns during WT-PET imaging is essential for improving image quality and diagnostic accuracy. This motion can be broadly divided into rigid motion that is characterized by rotations or translations such as head motion, and non-rigid motion that involves more complex movements such as twisting or bending such as respiratory and cardiac motion.