Inter- and intratester reliability of measuring neck motions with tape measure and Myrin® gravity-reference goniometer

This study was designed to evaluate the reliability of measuring neck motions with tape measure (TM) and the Myrin® gravity-reference goniometer (MG). Three physical therapists measured six neck motions of 21 healthy subjects across several (19.8 ± 24.3) days. The neck motions measured were extension, flexion, right and left side bending, and right and left rotation. With the exception of the flexion motion, the intratherapist reliability coefficients (r) for both the TM and MG methods were moderately high. The r-value for the TM method ranged from 0.26 (p > 0.05) to 0.88 (p < 0.001) while the MG method ranged from 0.31 (p > 0.05) to 0.86 (p < 0.001). The intertherapist reliability coefficients across both testing sessions for the TM method ranged from 0.30 (p > 0.05) to 0.92 (p < 0.001) while the MG method ranged from 0.26 (p > 0.05) to 0.84 (p < 0.001). The present results were compared to those in the other studies, and the findings were discussed.