A 3D kinematic method for evaluating voluntary movements of the cervical spine in humans.

The purpose of this study was to assess the reliability of a 3D kinematic method of evaluating movements of the cervical spine. Range of motion (ROM) of the cervical spine was evaluated in 8 control subjects during flexion-extension, rotation and lateral bending movements. The test was repeated on two separate occasions. The ROM test-retest difference ranged from 1.42 degrees for right axial rotation to 9.11 degrees for left axial rotation. The test showed good reliability, with an intraclass correlation coefficient which was higher than 0.74 in extension movement and excellent in flexion, axial rotation and lateral bending. In conclusion, the method proposed for the 3D kinematic analysis of neck movement proved to be useful and non-invasive and to show good-excellent reproducibility. Furthermore the method is easily applicable in clinical practice to evaluate neck function in cervical spine disorders.