The purposes of this study were to determine the intertester reliability of the posterior-anterior (PA) examination in assessing intersegmental lumbar spine motion and to evaluate the validity of this procedure in vivo with dynamic magnetic resonance imaging (MRI). Twenty-nine subjects with central lumbar pain participated in this study. Two physical therapists independently identified each subject's most and least mobile lumbar segments using the PA procedure. Midsagittal lumbar images were obtained simultaneously during one examiner's assessment. The intertester reliability for identifying the least mobile segment was good, but it was poor for identifying the most mobile segment. The level of agreement between the PA assessments and intervertebral motion measured by MRI was poor.
Despite good intertester reliability for identifying the least mobile segment, PA assessments of lumbar segmental mobility did not agree with sagittal-plane motion measured by dynamic MRI. This finding calls into question the validity of the PA procedure for assessing intervertebral lumbar spine motion.
Physical Therapy, 2008, 8(1), 43-49