Abdominal organ motion provides challenges for radiotherapy treatments, leading to inhomogeneous dose distributions with over- and underdosage regions in the target volume. Repeated 4D-MRI acquisitions, allow to analyze inter- and intrafractional spatial motion. The aim of this study was to investigate the impact of abdominal corsets for motion reduction purposes, based on repeated 4D-MRI data sets. We found pronounced reductions in cranio-caudal and anterior-posterior direction using corsets, which additionally lead to more reproducible motion amplitudes. Lower amplitudes and better reproducibility are beneficial for radiotherapy and could lead to smaller irradiation margins and dose reductions to healthy tissue.