Current methods for cervical spine movement evaluation: a review.

Cervical spine mobility is difficult to investigate accurately because of its anatomic structure and the compensatory movements. Different methods have been conceived in order to obtain a reliable measurement of cervical range of movement (ROM). We reviewed different instruments described in the literature: x-rays, CT and MRI, goniometer, inclinometer, cybex and related devices, and opto-electronic scanners. Cybex and 3D kinematic analysis by means of opto-electronic scanners (Elite system) seemed to be the most reliable and reproducible methods. Cybex equipment is relatively inexpensive and easy to use in a clinical setting, while the Elite system is expensive and requires special training of the personnel. However, the choice of method depends primarily on whether the physician's goal is a clinical screening or a thorough investigation of neck function (e.g., post-traumatic cervical spine disorders). For the first purpose, certain types of goniometers (gravity goniometer, ad modum Myrin), as well as the cybex, show good reproducibility and reliability in evaluating maximal cervical ROM (flexion-extension, rotation, lateral bending), while x-rays and, above all, 3D kinematic analysis (using opto-electronic scanners) are more suitable for diagnostic and follow-up evaluation of neck disorders.