Assessment of thoracolumbar rotation in ankylosing spondylitis: a simple tape method.

Results of a 'new' method for thoracolumbar rotation by tape (TRPav), simple instrumental rotation (TRi), the modified Schober test and thoracolumbar flexion (ThFL) were correlated with radiological changes in patients with ankylosing spondylitis (AS). TRPav showed a significant radiological correlation (Ls-r: 0.38; Th-r: 0.31), while the instrument method (TRi) did not; both the Schober test and ThFL, again, correlated fairly highly (Ls-r: 0.71, 0.62; Th-r: 0.49, 0.42). Both inter- and intratester reliability of the tests was good (Bland and Altman plots). Thoracolumbar rotation is one of the three principal levels of spinal motion and seems to be less affected by age. TRPav proved a valid and reliable method for measuring thoracolumbar rotation and clinically is a non-invasive, quick and easy complement to AS measurement methodologies.