One of our early studies led by Philip Gardiner (Londonderry, UK) involved testing 40 patients with axSpA to find out if measurements of spinal mobility using the ViMove© sensor (DorsaVi) were reliable. The results confirmed that sensor measurements remain the same no matter which therapist was doing the test or if the test was repeated a week later. This is the first such study to demonstrate the reliability of spinal rotation tests, previously thought to be a weakness of older IMU technology. A composite score (IMU-ASMI) was developed, combining all of the planar movements in the cervical and lumbar spine to generate a new and reliable outcome score for spinal mobility.
The other core validation study led by Juan-Luis Garrido-Castro and Eduardo Collantes-Estevez (Cordoba, Spain) involved testing the sensor measurements against an accurate electronic motion detection system. Motion capture systems are widely regarded as the gold standard for measuring body movement accurately. This team had previously developed and validated the UCOTrack© motion capture system specifically to measure spinal mobility in axSpA. Their study established that ViMove© sensor tests have a high degree of accuracy, comparable to that of their motion capture system. A strong correlation was found between spinal mobility tests and structural damage scores based on x-rays. Their study also provided validation of a new sensor positioning protocol which includes the thoracic segment of the spine, particularly relevant for axSpA clinical studies.
The third study led by Fiona Wilson (Dublin, Ireland) recruited another group of 40 axSpA patients to test whether or not sensor tests of movement and function can be carried out accurately at home. In this study, patients carried out movement tests in clinic with and without supervision and then again at home using recorded video instructions. Patients then continued to wear them for up to 24 hours alongside completing some questionnaires and a symptom/activity diary. During this period they carried out several standardised functional tests. This study has demonstrated for the first time that unsupervised range of movement tests can be carried out accurately without supervision by following video instructions. These results open up new possibilities both for clinical research and for patient self-management.
The fourth pilot study in Cordoba tested the sensitivity to change of sensor tests against the UCOTrack system in 20 patients before and after starting biologic drugs. This study has shown that both the UCOTrack system and the IMU based spinal mobility score have significantly greater responsiveness to change compared to BASMI. This was part of a three-centre observational study using concurrent spinal mobility tests and MRI outcome scores led by Pedro Machado (London, UK) including Londonderry as a third study site. This MRI study is still underway, but we are confident that it will provide further information on the relationship between changes in MRI inflammation and changes in spinal mobility scores.