Analysis of spine motion variability using a computerized goniometer compared to physical examination. A prospective clinical study.

A prospective clinical study was carried out to determine whether the CA-6000 Spine Motion Analyzer was more reliable in measuring spine motion compared to previously described methods of physical examination. One-hundred-twenty age-controlled patients with a negative back history were tested with the CA-6000 to establish normal values. Interexaminer and intraexaminer correlation coefficients and coefficients of variation were determined for 30 patients by three different examiners, each testing the patients three times each. Each test consisted of examining flexion, extension, lateral flexion, and rotation. For flexion, the CA-6000 was compared to the double inclinometer and Schober methods. For extension and lateral flexion, the CA-6000 was compared to the double inclinometer and Moll methods. For rotation, the CA-6000 was compared to the double inclinometer method. The interexaminer and intraexaminer variability using the CA-6000 was significantly less (P < or = 0.025) than other methods for all motions except flexion. In flexion, the differences were not significantly different. The data from this experiment indicate that the CA-6000 has significantly less variability in measuring spine motion clinically than the other methods tested.