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

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.

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. Measurements from the 2 techniques were compared with Pearson correlation coefficient and simple linear regression to determine R(2), the regression coefficient and the regression equation. Reliability was assessed using the intraclass correlation coefficient.

There were 40 participants with a mean age of 30.5 (SD, 9.1) years. Goniometer measurements had good to excellent correlation with both absolute and percentage change in tape measurement (correlation coefficients, 0.74-0.94 and 0.75-0.91, respectively). Correlation was highest for flexion and extension, lowest for rotation and lateral flexion. The amount of variability in the data explained by the linear regression models (R(2)) varied from 55% to 89%. Intraclass correlation coefficient ranged from 0.44 to 0.69 and 0.38 to 0.59 for intrarater and interrater reliability, respectively. Reliability was greatest for flexion and extension, lowest for rotation and lateral flexion.

This study demonstrated that tape measurements correlated well with a universal goniometer. The tape measure may be useful for measuring cervical spine range of motion where availability, simplicity, and low cost are important considerations such as with conduct of research or patient management.