The project started in April 2017. Results from the criterion validity & reliability studies patients were presented in 2019. These studies demonstrated both the accuracy and the reliability of IMU sensor based measurements of spinal mobility in axSpA (including rotation). We demonstrated that spinal mobility correlates with BASMI, BASFI and mSASSS. The ambulatory study has shown that unsupervised testing of spinal mobility is also a reliable alternative to supervised testing in the clinic. The completion of the responsiveness study will be delayed because of the covid19 crisis. A smartphone app has been developed to display the spinal mobility scores (see below).