Validation of a method to assess range of motion of the cervical spine using a tape measure.

Objective: The purposes of this study were to validate a tape measure method for measuring cervical spine range of motion compared with a universal goniometer in all planes of motion and to derive equations to convert a linear measurement to an angular distance.

Methods: Participants were healthy volunteers. Measurements of flexion/extension, rotation, and lateral flexion were made with the universal goniometer and tape measure, in the neutral position, extreme of motion, and 2 positions between.