[Epionics SPINE-use of an objective method to examine spinal mobility in patients with axial spondyloarthritis]

Axial spondylarthritis (axSpA) is a chronic inflammatory disease of the spine that can be associated with loss of physical function, mobility and upright postural impairment. Established tools for the assessment of function that are largely based on subjective perception are semiquantitatively recorded by standardized questionnaires (Bath ankylosing spondylitis functional index, BASFI), while measurement of spinal mobility of patients with axSpA is based on physical examination of various movement regions particularly the axial skeleton (Bath ankylosing spondylitis metrology index, BASMI). Recently, a performance test has been added to assess the range of motion and speed of certain tasks (AS performance-based improved test, ASPI); however, since these tests have limited reliability and reproducibility, more objective tests would be desirable. In this study the spinal mobility of patients with axSpA was quantified using the Epionics SPINE device (ES) and data were evaluated using the outcome measures in rheumatology (OMERACT) criteria. The ES automatically measures various patterns of spinal movements using electronic sensors, which also assess the range and speed of carrying out movements. Patients with back pain from other causes and persons without back pain served as controls. The measurement results obtained with ES differed between the groups and correlated with BASMI values (r = 0.53-0.82, all p = <0.03). Patients with radiographically detectable axSpA had more limited and slower mobility than those with non-radiographically detectable axSpA. Overall, the results presented here suggest that ES measurements represent a valid and objective measurement procedure of spinal mobility for axSpA patients.