Test–retest reliability and validity of cervical range of motion measurement using a smartphone clinometer and compass application among individuals with and without neck pain

Cervical disorders are major health problems in our society and an important source of disability. Assessing range of motion is a significant part of the physical therapist’s role when evaluating a patient presenting with cervical disorders. The purpose of this study was to evaluate the intrarater relibility as well as the criterion validity of two phone applications (clinometer and compass) when assessing the cervical range of motion among individuals with and without neck pain. In total, 80 participants were included in this study and split into two groups. Group A comprised 40 participants (18 women and 22 men) without neck pain. Group B included 40 participants (26 women and 14 men) with neck pain (mean pain rating on visual analogue scale 3.76 ± 0.93). Cervical range of motion was measured with the clinometer application (flexion, extension, right and left lateral flexion) and compass application (right and left rotation). The readings were compared with a universal goniometer. Estimates of reliability and validity were then established using the intraclass correlation coefficient, standard error of measurement and minimum detectable change. The smartphone applications had good intrarater reliability when compared to a universal goniometer, showing good to excellent validity (intraclass correlation coefficient >0.65) for all six cervical ranges of motion in participants with and without neck pain. The smartphone clinometer application was found to be valid and reliable in measuring frontal and sagittal cervical ranges of motion in participants with and without neck pain. The compass application was found to be valid and reliable when assessing the horizontal cervical range of motion in a seated position. The applications will benefit physiotherapists when assessing cervical range of motion.